Added a new widgets project.

03_sdl_basics/17_sdl_widgets/.clang-format

@@ -0,0 +1,128 @@
+# Commented out parameters are those with the same value as base LLVM style
+# We can uncomment them if we want to change their value, or enforce the
+# chosen value in case the base style changes (last sync: Clang 6.0.1).
+---
+### General config, applies to all languages ###
+BasedOnStyle:  LLVM
+AccessModifierOffset: -4
+AlignAfterOpenBracket: DontAlign
+# AlignConsecutiveAssignments: false
+# AlignConsecutiveDeclarations: false
+# AlignEscapedNewlines: Right
+# AlignOperands:   true
+AlignTrailingComments: false
+AllowAllParametersOfDeclarationOnNextLine: false
+# AllowShortBlocksOnASingleLine: false
+AllowShortCaseLabelsOnASingleLine: true
+AllowShortFunctionsOnASingleLine: Inline
+AllowShortIfStatementsOnASingleLine: true
+# AllowShortLoopsOnASingleLine: false
+# AlwaysBreakAfterDefinitionReturnType: None
+# AlwaysBreakAfterReturnType: None
+# AlwaysBreakBeforeMultilineStrings: false
+# AlwaysBreakTemplateDeclarations: false
+# BinPackArguments: true
+# BinPackParameters: true
+# BraceWrapping:
+#   AfterClass:      false
+#   AfterControlStatement: false
+#   AfterEnum:       false
+#   AfterFunction:   false
+#   AfterNamespace:  false
+#   AfterObjCDeclaration: false
+#   AfterStruct:     false
+#   AfterUnion:      false
+#   AfterExternBlock: false
+#   BeforeCatch:     false
+#   BeforeElse:      false
+#   IndentBraces:    false
+#   SplitEmptyFunction: true
+#   SplitEmptyRecord: true
+#   SplitEmptyNamespace: true
+# BreakBeforeBinaryOperators: None
+# BreakBeforeBraces: Attach
+# BreakBeforeInheritanceComma: false
+BreakBeforeTernaryOperators: false
+# BreakConstructorInitializersBeforeComma: false
+BreakConstructorInitializers: AfterColon
+# BreakStringLiterals: true
+ColumnLimit:     0
+# CommentPragmas:  '^ IWYU pragma:'
+# CompactNamespaces: false
+ConstructorInitializerAllOnOneLineOrOnePerLine: true
+ConstructorInitializerIndentWidth: 8
+ContinuationIndentWidth: 8
+Cpp11BracedListStyle: false
+# DerivePointerAlignment: false
+# DisableFormat:   false
+# ExperimentalAutoDetectBinPacking: false
+# FixNamespaceComments: true
+# ForEachMacros:
+#   - foreach
+#   - Q_FOREACH
+#   - BOOST_FOREACH
+# IncludeBlocks:   Preserve
+IncludeCategories:
+  - Regex:           '".*"'
+    Priority:        1
+  - Regex:           '^<.*\.h>'
+    Priority:        2
+  - Regex:           '^<.*'
+    Priority:        3
+# IncludeIsMainRegex: '(Test)?$'
+IndentCaseLabels: true
+# IndentPPDirectives: None
+IndentWidth:     4
+# IndentWrappedFunctionNames: false
+# JavaScriptQuotes: Leave
+# JavaScriptWrapImports: true
+# KeepEmptyLinesAtTheStartOfBlocks: true
+# MacroBlockBegin: ''
+# MacroBlockEnd:   ''
+# MaxEmptyLinesToKeep: 1
+# NamespaceIndentation: None
+# PenaltyBreakAssignment: 2
+# PenaltyBreakBeforeFirstCallParameter: 19
+# PenaltyBreakComment: 300
+# PenaltyBreakFirstLessLess: 120
+# PenaltyBreakString: 1000
+# PenaltyExcessCharacter: 1000000
+# PenaltyReturnTypeOnItsOwnLine: 60
+# PointerAlignment: Right
+# RawStringFormats:
+#   - Delimiter:       pb
+#     Language:        TextProto
+#     BasedOnStyle:    google
+# ReflowComments:  true
+# SortIncludes:    true
+# SortUsingDeclarations: true
+# SpaceAfterCStyleCast: false
+# SpaceAfterTemplateKeyword: true
+# SpaceBeforeAssignmentOperators: true
+# SpaceBeforeParens: ControlStatements
+# SpaceInEmptyParentheses: false
+# SpacesBeforeTrailingComments: 1
+# SpacesInAngles:  false
+# SpacesInContainerLiterals: true
+# SpacesInCStyleCastParentheses: false
+# SpacesInParentheses: false
+# SpacesInSquareBrackets: false
+TabWidth:        4
+UseTab:          Always
+---
+### C++ specific config ###
+Language:        Cpp
+Standard:        Cpp03
+---
+### ObjC specific config ###
+Language:        ObjC
+Standard:        Cpp03
+ObjCBlockIndentWidth: 4
+# ObjCSpaceAfterProperty: false
+# ObjCSpaceBeforeProtocolList: true
+---
+### Java specific config ###
+Language:        Java
+# BreakAfterJavaFieldAnnotations: false
+JavaImportGroups: ['org.godotengine', 'android', 'androidx', 'com.android', 'com.google', 'java', 'javax']
+...

03_sdl_basics/17_sdl_widgets/application.cpp

@@ -0,0 +1,72 @@
+#include "application.h"
+
+#include "renderer.h"
+
+Application* Application::_instance = nullptr;
+
+#include <chrono>
+
+void Application::event(const SDL_Event &current_event) {
+	switch (current_event.type) {
+		case SDL_QUIT:
+			running = false;
+			break;
+	}
+    
+    scene->event(current_event);
+}
+
+void Application::update(float delta) {
+    scene->update(delta);
+}
+void Application::render() {
+    scene->render();
+
+	Renderer::get_singleton()->present();
+}
+
+void Application::main_loop() {
+	std::chrono::high_resolution_clock::time_point start = std::chrono::high_resolution_clock::now();
+
+	//handle input
+	SDL_Event current_event;
+	while (SDL_PollEvent(&current_event)) {
+		event(current_event);
+	}
+
+	update(frame_delta);
+	render();
+
+	std::chrono::high_resolution_clock::time_point end = std::chrono::high_resolution_clock::now();
+	std::chrono::duration<double> elapsed_seconds = end - start;
+	double t = elapsed_seconds.count();
+
+	double tfps = 1.0 / static_cast<double>(target_fps);
+
+	double remaining = tfps - t;
+
+	if (remaining > 0) {
+		Uint32 fms = static_cast<Uint32>(remaining * 1000.0);
+
+		frame_delta = tfps;
+
+		SDL_Delay(fms);
+	} else {
+		frame_delta = t;
+	}
+}
+
+Application::Application() {
+    running = true;
+    target_fps = 60;
+
+    scene = nullptr;
+    _instance = this;
+}
+Application::~Application() {
+    _instance = nullptr;
+}
+
+Application* Application::get_singleton() {
+    return _instance;
+}

03_sdl_basics/17_sdl_widgets/application.h

@@ -0,0 +1,32 @@
+#ifndef APPLICATION_H
+#define APPLICATION_H
+
+#include <SDL.h>
+
+#include "scene.h"
+
+class Application {
+public:
+    bool running;
+    int target_fps;
+
+    virtual void event(const SDL_Event &current_event);
+    virtual void update(float delta);
+    virtual void render();
+
+    void main_loop();
+
+    Application();
+    virtual ~Application();
+
+    Scene *scene;
+
+    static Application* get_singleton();
+
+    double frame_delta = 0;
+
+protected:
+    static Application* _instance;
+};
+
+#endif

03_sdl_basics/17_sdl_widgets/button.cpp

@@ -0,0 +1,93 @@
+#include "button.h"
+
+#include "math.h"
+
+void Button::event(const SDL_Event &ev) {
+	if (state == BUTTON_STATE_OFF) {
+		return;
+	}
+
+	switch (ev.type) {
+		case SDL_MOUSEMOTION: {
+			int x = ev.motion.x;
+			int y = ev.motion.y;
+
+			if (transform.x < x && transform.x + transform.w > x && transform.y < y && transform.y + transform.w > y) {
+				state = BUTTON_STATE_HOVER;
+			} else {
+				state = BUTTON_STATE_UP;
+			}
+
+			break;
+		}
+		case SDL_MOUSEBUTTONDOWN: {
+			int x = ev.motion.x;
+			int y = ev.motion.y;
+
+			if (transform.x < x && transform.x + transform.w > x && transform.y < y && transform.y + transform.w > y) {
+				state = BUTTON_STATE_DOWN;
+			}
+
+			break;
+		}
+		case SDL_MOUSEBUTTONUP: {
+			int x = ev.motion.x;
+			int y = ev.motion.y;
+
+			if (transform.x < x && transform.x + transform.w > x && transform.y < y && transform.y + transform.w > y) {
+				state = BUTTON_STATE_HOVER;
+
+				if (on_click) {
+					on_click();
+				}
+
+				if (on_click_member) {
+					on_click_member(cls);
+				}
+			} else {
+				state = BUTTON_STATE_UP;
+			}
+
+			break;
+		}
+	}
+}
+
+void Button::update(float delta) {
+}
+
+void Button::render() {
+	if (state == BUTTON_STATE_UP) {
+		if (up) {
+			up->set_transform(transform);
+			up->draw();
+		}
+	} else if (state == BUTTON_STATE_HOVER) {
+		if (hover) {
+			hover->set_transform(transform);
+			hover->draw();
+		}
+	} else if (state == BUTTON_STATE_DOWN) {
+		if (down) {
+			down->set_transform(transform);
+			down->draw();
+		}
+	} else if (state == BUTTON_STATE_OFF) {
+		if (off) {
+			off->set_transform(transform);
+			off->draw();
+		}
+	}
+}
+
+Button::Button() {
+	state = BUTTON_STATE_UP;
+
+	up = nullptr;
+	down = nullptr;
+	hover = nullptr;
+	off = nullptr;
+}
+
+Button::~Button() {
+}

03_sdl_basics/17_sdl_widgets/button.h

@@ -0,0 +1,47 @@
+
+#ifndef BUTTON_H
+#define BUTTON_H
+
+#include <SDL.h>
+
+#include "rect2.h"
+#include "sprite.h"
+
+#include <functional>
+
+class Button {
+public:
+    enum ButtonState {
+        BUTTON_STATE_UP,
+        BUTTON_STATE_HOVER,
+        BUTTON_STATE_DOWN,
+        BUTTON_STATE_OFF,
+    };
+
+	void event(const SDL_Event &ev);
+	void update(float delta);
+	void render();
+
+    //ver a: (Csak statikus fv állítható be rá)
+    std::function<void(void)> on_click;
+
+    //ver b: (Képes osztályok függvényeit is meghívni)
+    //Meg lehet oldani sokféleképp, egyik sem annyira szép sajnos
+    //mindneképp érdemes lenne setter mögé rejteni ezeket
+    void* cls;
+    std::function<void(void*)> on_click_member;
+
+    Button();
+    virtual ~Button();
+
+    ButtonState state;
+
+	Rect2 transform;
+
+    Sprite *up;
+    Sprite *down;
+    Sprite *hover;
+    Sprite *off;
+};
+
+#endif

03_sdl_basics/17_sdl_widgets/camera.cpp

@@ -0,0 +1,24 @@
+#include "camera.h"
+
+#include "renderer.h"
+
+void Camera::bind() {
+    Renderer::get_singleton()->set_integer_scaling(integer_scaling);
+
+    Renderer::get_singleton()->set_scale(scale_w, scale_h);
+
+    Renderer::get_singleton()->set_viewport(viewport);
+    Renderer::get_singleton()->set_clip_rect(&clip_rect);
+}
+
+Camera::Camera() {
+    integer_scaling = false;
+
+    scale_w = 1;
+    scale_h = 1;
+
+    viewport = Renderer::get_singleton()->get_viewport();
+    clip_rect = Renderer::get_singleton()->get_clip_rect();
+}
+Camera::~Camera() {
+}

03_sdl_basics/17_sdl_widgets/camera.h

@@ -0,0 +1,22 @@
+#ifndef CAMERA_H
+#define CAMERA_H
+
+#include <SDL.h>
+
+#include "rect2.h"
+
+class Camera {
+public:
+    void bind();
+
+    Camera();
+    virtual ~Camera();
+
+    bool integer_scaling;
+    float scale_w;
+    float scale_h;
+    Rect2 viewport;
+    Rect2 clip_rect;
+};
+
+#endif

03_sdl_basics/17_sdl_widgets/color.cpp

@@ -0,0 +1,100 @@
+#include "color.h"
+
+uint32_t Color::to_key() const {
+	uint32_t val = 0;
+
+	//<< = left shift int típusoknál -> azaz az intek bitjeit eltolja eggyel balra:
+	//pl.: 001010101 ből lesz: 010101010, aztán 101010100, aztán 010101000 etc
+
+	//az r az uint8_t, azaz egy 8 bites int (unsigned byte típus pl java/c#-ban)
+	//tehát alakítsuk át 32 bites uint-é: static_cast<uint32_t>(r)
+	//Ez az új c++-os castolás, lehetne így is: (uint32_t) r
+	//De, nem ajánlják már, mert ez 4-5 ilyen static_cast, dynamic_cast etc függvényt
+	//próbál végig, megadott sorrendben, és csak kiírtam a megfelelőt expliciten.
+
+	//static_cast<uint32_t>(r) << 24: (8db 0) (8db 0) (8db 0) (r száma) Ez lessz: (r száma) (8db 0) (8db 0) (8db 0)
+	//static_cast<uint32_t>(g) << 24: (8db 0) (8db 0) (8db 0) (g száma) Ez lessz: (8db 0) (g száma) (8db 0) (8db 0)
+	//static_cast<uint32_t>(b) << 24: (8db 0) (8db 0) (8db 0) (b száma) Ez lessz: (8db 0) (8db 0) (b száma) (8db 0)
+	//static_cast<uint32_t>(a) << 24: (8db 0) (8db 0) (8db 0) (a száma) Ez lessz: (8db 0) (8db 0) (8db 0) (a száma)
+
+	//| a bináris vagy -> a számok birtjeit össze bináris vagyolja -> azaz ahol valaho 1 van, ott az eredmény be egy lesz: 00100 | 00010 -> 00110
+	//|= -> bináris vagy egyenlő
+
+	val |= static_cast<uint32_t>(r) << 24;
+	val |= static_cast<uint32_t>(g) << 16;
+	val |= static_cast<uint32_t>(b) << 8;
+	val |= static_cast<uint32_t>(a) << 0;
+
+	//azaz a végeredmény:
+	//1 uint32t, aminek a bitjei: (r száma) (g száma) (b száma) (a száma)
+
+	return val;
+}
+
+void Color::from_key(const uint32_t key) {
+	//A to_key függvény megfordítása.
+
+	//& itt a bináris és.
+	//azok a bitek lesznek 1ek, amik mindkét operandusba 1-ek: 001010 & 111110 -> 001010
+
+	//A 16-os számrendszerbeli számokat 0x<valami> formában lehet megadni.
+
+	//Azért használtam 16os számrendszerbeli számokat, mert itt sokkal szemléletesebbek.
+	//Ugyanis-> 0xF = 1111
+	//Azaz minden F 4db 1es bitet jelöl.
+	//Így már biztosan látszik, hogy mit csinálunk
+
+	//key & 0xFF000000 kiszedjük a legelől levő 8 bitet (Minden más bit biztosan 0 lesz.), etc
+
+	r = (key & 0xFF000000) >> 24;
+	g = (key & 0x00FF0000) >> 16;
+	b = (key & 0x0000FF00) >> 8;
+	a = (key & 0x000000FF) >> 0;
+
+	//>> az itt a right shift, ugyan az mint a left shift, csak itt a biteket jobbra mozgatjuk
+
+	//Nyilván, egyéb módon is meg lehet csinálni ezt a függvényt.
+	//pl csak right shiftelgetni, és castolni uint8_t-vé az eredményt, etc.
+
+	//Azért cisnáltam így, mert szerintem ezt a módszert a leghasznosabb látni hosszú távon.
+	//Pl. ugyan így lehet hálózati csomagokat méretre optimalizálni.
+}
+
+SDL_Color Color::to_sdl_color() const {
+    SDL_Color c;
+
+    c.r = r;
+    c.g = g;
+    c.b = b;
+    c.a = a;
+
+    return c;
+}
+
+void Color::from_sdl_color(const SDL_Color &key) {
+    r = key.r;
+    g = key.g;
+    b = key.b;
+    a = key.a;
+}
+
+Color::Color() {
+	r = 0;
+	g = 0;
+	b = 0;
+	a = 255;
+}
+
+Color::Color(uint8_t p_r, uint8_t p_g, uint8_t p_b, uint8_t p_a) {
+	r = p_r;
+	g = p_g;
+	b = p_b;
+	a = p_a;
+}
+
+Color::Color(const uint32_t key) {
+	from_key(key);
+}
+
+Color::~Color() {
+}

03_sdl_basics/17_sdl_widgets/color.h

@@ -0,0 +1,26 @@
+#ifndef COLOR_H
+#define COLOR_H
+
+#include <inttypes.h>
+#include <SDL.h>
+
+class Color {
+public:
+	uint32_t to_key() const;
+	void from_key(const uint32_t key);
+
+	SDL_Color to_sdl_color() const;
+	void from_sdl_color(const SDL_Color &key);
+
+	Color();
+	Color(uint8_t p_r, uint8_t p_g, uint8_t p_b, uint8_t p_a = 255);
+	Color(const uint32_t key);
+	virtual ~Color();
+
+	uint8_t r;
+	uint8_t g;
+	uint8_t b;
+	uint8_t a;
+};
+
+#endif

03_sdl_basics/17_sdl_widgets/compile.bat

@@ -0,0 +1,55 @@
+@echo off
+
+if not exist "obj" (
+    mkdir obj
+)
+
+if not exist "bin" (
+    mkdir bin
+)
+
+rem debug
+set VER=-g
+
+if "%~1"=="r" (
+    set VER=-o3
+)
+
+set GPP=g++
+
+for %%X in (g++.exe) do (set FOUND=%%~$PATH:X)
+
+if not defined FOUND (
+    set GPP="C:\Program Files\CodeBlocks\MinGW\bin\g++"
+)
+
+set SDL2_CFLAGS=-I..\..\lib\SDL2\include\SDL2
+set SDL2_LIBS=-L..\..\lib\SDL2\lib -lmingw32 -lSDL2main -lSDL2.dll -luser32 -lgdi32 -lwinmm -ldxguid
+XCOPY ..\..\lib\SDL2\bin\*.dll bin /D /Y
+
+
+%GPP% -Wall %VER% -c math.cpp -o obj/math.o
+%GPP% -Wall %VER% %SDL2_CFLAGS% -c rect2.cpp -o obj/rect2.o
+%GPP% -Wall %VER% %SDL2_CFLAGS% -c color.cpp -o obj/color.o
+%GPP% -Wall %VER% %SDL2_CFLAGS% -c vector2.cpp -o obj/vector2.o
+%GPP% -Wall %VER% %SDL2_CFLAGS% -c vector3.cpp -o obj/vector3.o
+%GPP% -Wall %VER% -c string.cpp -o obj/string.o
+
+%GPP% -Wall %VER% %SDL2_CFLAGS% -c renderer.cpp -o obj/renderer.o 
+%GPP% -Wall %VER% %SDL2_CFLAGS% -c image.cpp -o obj/image.o 
+%GPP% -Wall %VER% %SDL2_CFLAGS% -c texture.cpp -o obj/texture.o 
+%GPP% -Wall %VER% %SDL2_CFLAGS% -c sprite.cpp -o obj/sprite.o 
+%GPP% -Wall %VER% %SDL2_CFLAGS% -c camera.cpp -o obj/camera.o 
+%GPP% -Wall %VER% %SDL2_CFLAGS% -c true_type_font.cpp -o obj/true_type_font.o 
+%GPP% -Wall %VER% %SDL2_CFLAGS% -c text_image.cpp -o obj/text_image.o 
+%GPP% -Wall %VER% %SDL2_CFLAGS% -c text_sprite.cpp -o obj/text_sprite.o 
+
+%GPP% -Wall %VER% %SDL2_CFLAGS% -c button.cpp -o obj/button.o 
+
+%GPP% -Wall %VER% %SDL2_CFLAGS% -c scene.cpp -o obj/scene.o 
+%GPP% -Wall %VER% %SDL2_CFLAGS% -c application.cpp -o obj/application.o 
+%GPP% -Wall %VER% %SDL2_CFLAGS% -c main_scene.cpp -o obj/main_scene.o 
+
+%GPP% -Wall %VER% %SDL2_CFLAGS% -c main.cpp -o obj/main.o
+
+%GPP% -o bin/program obj/math.o obj/rect2.o obj/color.o obj/vector2.o obj/vector3.o obj/string.o obj/renderer.o obj/image.o obj/texture.o obj/sprite.o obj/true_type_font.o obj/text_image.o obj/text_sprite.o obj/camera.o obj/button.o obj/scene.o obj/application.o obj/main_scene.o   obj/main.o %SDL2_LIBS%

03_sdl_basics/17_sdl_widgets/compile.sh

@@ -0,0 +1,42 @@
+
+if [ ! -d "obj" ]; then
+    mkdir obj
+fi
+
+if [ ! -d "bin" ]; then
+    mkdir bin
+fi
+
+#-Iinclude
+
+#g++ -Wall -g -c vector2.cpp -o obj/vector2.o
+#g++ -Wall -g -c vector3.cpp -o obj/vector3.o
+#g++ -Wall -g -c int_vector.cpp -o obj/int_vector.o
+
+g++ -Wall -g -c math.cpp -o obj/math.o
+g++ -Wall -g $(sdl2-config --cflags) -c rect2.cpp -o obj/rect2.o
+g++ -Wall -g $(sdl2-config --cflags) -c color.cpp -o obj/color.o
+g++ -Wall -g $(sdl2-config --cflags) -c vector2.cpp -o obj/vector2.o
+g++ -Wall -g $(sdl2-config --cflags) -c vector3.cpp -o obj/vector3.o
+g++ -Wall -g -c string.cpp -o obj/string.o
+
+g++ -Wall -g $(sdl2-config --cflags) -c renderer.cpp -o obj/renderer.o 
+g++ -Wall -g $(sdl2-config --cflags) -c image.cpp -o obj/image.o 
+g++ -Wall -g $(sdl2-config --cflags) -c texture.cpp -o obj/texture.o 
+g++ -Wall -g $(sdl2-config --cflags) -c sprite.cpp -o obj/sprite.o 
+g++ -Wall -g $(sdl2-config --cflags) -c camera.cpp -o obj/camera.o 
+g++ -Wall -g $(sdl2-config --cflags) -c text_image.cpp -o obj/text_image.o 
+g++ -Wall -g $(sdl2-config --cflags) -c text_sprite.cpp -o obj/text_sprite.o 
+
+g++ -Wall -g $(sdl2-config --cflags) -c true_type_font.cpp -o obj/true_type_font.o
+
+g++ -Wall -g $(sdl2-config --cflags) -c button.cpp -o obj/button.o 
+
+g++ -Wall -g $(sdl2-config --cflags) -c scene.cpp -o obj/scene.o 
+g++ -Wall -g $(sdl2-config --cflags) -c application.cpp -o obj/application.o 
+g++ -Wall -g $(sdl2-config --cflags) -c main_scene.cpp -o obj/main_scene.o 
+
+g++ -Wall -g $(sdl2-config --cflags) -c main.cpp -o obj/main.o
+
+g++ -o bin/program obj/math.o obj/rect2.o obj/color.o obj/vector2.o obj/vector3.o obj/string.o obj/renderer.o obj/image.o obj/texture.o obj/sprite.o obj/camera.o obj/text_image.o obj/text_sprite.o  obj/true_type_font.o obj/button.o obj/scene.o obj/application.o obj/main_scene.o   obj/main.o $(sdl2-config --libs) -lSDL2_ttf 
+

03_sdl_basics/17_sdl_widgets/image.cpp

@@ -0,0 +1,260 @@
+#include "image.h"
+
+#include <stdio.h>
+
+void Image::create(const Uint32 flags, const int width, const int height) {
+	if (_surface) {
+		free();
+	}
+
+	//SDL_PIXELFORMAT_RGBA8888 SDL_pixels.h ból
+	SDL_CreateRGBSurfaceWithFormat(flags, width, height, 32, SDL_PIXELFORMAT_RGBA8888);
+}
+
+void Image::enable_transparent_color(const Color &color) {
+	if (!SDL_SetColorKey(_surface, 1, color.to_key())) {
+		printf("enable_transparent_color error.\n");
+	}
+}
+
+void Image::disable_transparent_color() {
+	if (!SDL_SetColorKey(_surface, 0, 0)) {
+		printf("disable_transparent_color error.\n");
+	}
+}
+
+bool Image::has_transparent_color() {
+	return SDL_HasColorKey(_surface);
+}
+Color Image::get_transparent_color() {
+	uint32_t key;
+
+	SDL_GetColorKey(_surface, &key);
+
+	return Color(key);
+}
+
+Color Image::get_color_mod() {
+	Uint8 r;
+	Uint8 g;
+	Uint8 b;
+
+	SDL_GetSurfaceColorMod(_surface, &r, &g, &b);
+
+	return Color(r, g, b);
+}
+void Image::set_color_mod(const Color &color) {
+	SDL_SetSurfaceColorMod(_surface, color.r, color.g, color.b);
+}
+
+Color Image::get_alpha_mod() {
+	Uint8 a;
+
+	SDL_GetSurfaceAlphaMod(_surface, &a);
+
+	return a;
+}
+void Image::set_alpha_mod(const Uint8 alpha) {
+	SDL_SetSurfaceAlphaMod(_surface, alpha);
+}
+
+SDL_BlendMode Image::get_blend_mode() {
+	SDL_BlendMode mode;
+
+	SDL_GetSurfaceBlendMode(_surface, &mode);
+
+	return mode;
+}
+void Image::set_blend_mode(const SDL_BlendMode mode) {
+	SDL_SetSurfaceBlendMode(_surface, mode);
+}
+
+Rect2 Image::get_clip_rect() {
+	SDL_Rect r;
+
+	SDL_GetClipRect(_surface, &r);
+
+	Rect2 rect;
+
+	rect.x = r.x;
+	rect.y = r.y;
+	rect.w = r.w;
+	rect.h = r.h;
+
+	return rect;
+}
+void Image::set_clip_rect(const Rect2 &rect) {
+	SDL_Rect r;
+
+	r.x = rect.x;
+	r.y = rect.y;
+	r.w = rect.w;
+	r.h = rect.h;
+
+	SDL_SetClipRect(_surface, &r);
+}
+
+void Image::duplicate(Image *into) {
+	if (into == nullptr) {
+		return;
+	}
+
+	into->_surface = SDL_DuplicateSurface(_surface);
+}
+
+void Image::fill_rect(const Rect2 &rect, const Color &color) {
+	SDL_Rect r;
+
+	r.x = rect.x;
+	r.y = rect.y;
+	r.w = rect.w;
+	r.h = rect.h;
+
+	SDL_FillRect(_surface, &r, color.to_key());
+}
+
+void Image::fill_rects(const Vector<Rect2> &rects, const Color &color) {
+	SDL_Rect *r = new SDL_Rect[rects.size()];
+
+	for (int i = 0; i < rects.size(); ++i) {
+		r[i].x = rects[i].x;
+		r[i].y = rects[i].y;
+		r[i].w = rects[i].w;
+		r[i].h = rects[i].h;
+	}
+
+	SDL_FillRects(_surface, r, rects.size(), color.to_key());
+
+	delete[] r;
+}
+
+void Image::set_pixel(const int x, const int y, const Color &color) {
+	if (_surface == nullptr) {
+		return;
+	}
+
+	Uint32 *p = reinterpret_cast<Uint32 *>(_surface->pixels);
+
+	p[x * _surface->w + y] = color.to_key();
+}
+
+Color Image::get_pixel(const int x, const int y) {
+	if (_surface == nullptr) {
+		return Color();
+	}
+
+	Uint32 *p = reinterpret_cast<Uint32 *>(_surface->pixels);
+
+	return Color(p[x * _surface->w + y]);
+}
+
+void Image::blit_surface(const Image &source, const Rect2 &srcrect, const Rect2 &dstrect) {
+	SDL_Rect sr;
+
+	sr.x = srcrect.x;
+	sr.y = srcrect.y;
+	sr.w = srcrect.w;
+	sr.h = srcrect.h;
+
+	SDL_Rect dr;
+
+	dr.x = dstrect.x;
+	dr.y = dstrect.y;
+	dr.w = dstrect.w;
+	dr.h = dstrect.h;
+
+	SDL_BlitSurface(source._surface, &sr, _surface, &dr);
+}
+
+void Image::lock() {
+	SDL_LockSurface(_surface);
+}
+void Image::unlock() {
+	SDL_UnlockSurface(_surface);
+}
+
+void Image::free() {
+	SDL_FreeSurface(_surface);
+
+	_surface = nullptr;
+}
+
+void Image::load_bmp(const String &file_name) {
+	if (_surface != nullptr) {
+		free();
+	}
+
+	_surface = SDL_LoadBMP(file_name.c_str());
+
+	if (_surface != nullptr && _surface->format->format != SDL_PIXELFORMAT_RGBA8888) {
+		//Nem ARGB8888 as formátum, konvertáljuk át
+		SDL_Surface *n = SDL_ConvertSurfaceFormat(_surface, SDL_PIXELFORMAT_RGBA8888, 0);
+
+		free();
+
+		_surface = n;
+	}
+}
+
+void Image::save_bmp(const String &file_name) {
+	SDL_SaveBMP(_surface, file_name.c_str());
+}
+
+Uint32 Image::get_width() const {
+	if (_surface == nullptr) {
+		return 0;
+	}
+
+	return _surface->w;
+}
+Uint32 Image::get_height() const {
+	if (_surface == nullptr) {
+		return 0;
+	}
+
+	return _surface->h;
+}
+
+SDL_Surface *Image::get_surface() {
+	return _surface;
+}
+
+void Image::set_surface(SDL_Surface *surface) {
+	_surface = surface;
+
+	if (_surface != nullptr && _surface->format->format != SDL_PIXELFORMAT_RGBA8888) {
+		//Nem ARGB8888 as formátum, konvertáljuk át
+		SDL_Surface *n = SDL_ConvertSurfaceFormat(_surface, SDL_PIXELFORMAT_RGBA8888, 0);
+
+		free();
+
+		_surface = n;
+	}
+}
+
+Image::Image() {
+	_surface = nullptr;
+}
+
+Image::Image(const String &file_name) {
+	_surface = nullptr;
+
+	load_bmp(file_name);
+}
+
+Image::Image(SDL_Surface *surface) {
+	_surface = surface;
+
+	if (_surface != nullptr && _surface->format->format != SDL_PIXELFORMAT_RGBA8888) {
+		//Nem ARGB8888 as formátum, konvertáljuk át
+		SDL_Surface *n = SDL_ConvertSurfaceFormat(_surface, SDL_PIXELFORMAT_RGBA8888, 0);
+
+		free();
+
+		_surface = n;
+	}
+}
+
+Image::~Image() {
+	free();
+}

03_sdl_basics/17_sdl_widgets/image.h

@@ -0,0 +1,63 @@
+#ifndef IMAGE_H
+#define IMAGE_H
+
+#include "color.h"
+#include "rect2.h"
+#include "string.h"
+#include "vector.h"
+#include <SDL.h>
+
+class Image {
+public:
+	void create(const Uint32 flags, const int width, const int height);
+
+	void enable_transparent_color(const Color &color);
+	void disable_transparent_color();
+	bool has_transparent_color();
+	Color get_transparent_color();
+
+	Color get_color_mod();
+	void set_color_mod(const Color &color);
+
+	Color get_alpha_mod();
+	void set_alpha_mod(const Uint8 alpha);
+
+	SDL_BlendMode get_blend_mode();
+	void set_blend_mode(const SDL_BlendMode mode);
+
+	Rect2 get_clip_rect();
+	void set_clip_rect(const Rect2 &rect);
+
+	void duplicate(Image *into);
+
+	void fill_rect(const Rect2 &rect, const Color &color);
+	void fill_rects(const Vector<Rect2> &rects, const Color &color);
+	void set_pixel(const int x, const int y, const Color &color);
+	Color get_pixel(const int x, const int y);
+
+	void blit_surface(const Image &source, const Rect2 &srcrect, const Rect2 &dstrect);
+
+	void lock();
+	void unlock();
+
+	void free();
+
+	void load_bmp(const String &file_name);
+	void save_bmp(const String &file_name);
+
+	Uint32 get_width() const;
+	Uint32 get_height() const;
+
+	SDL_Surface *get_surface();
+	void set_surface(SDL_Surface *surface);
+
+	Image();
+	Image(const String &file_name);
+	Image(SDL_Surface *surface);
+	virtual ~Image();
+
+private:
+	SDL_Surface *_surface;
+};
+
+#endif

03_sdl_basics/17_sdl_widgets/impl_application.h

@@ -0,0 +1,18 @@
+#ifndef IMPL_APPLICATION_H
+#define IMPL_APPLICATION_H
+
+#include "application.h"
+
+#include "main_scene.h"
+
+class ImplApplication : public Application {
+public:
+    ImplApplication() : Application() {
+        scene = new MainScene();
+    }
+    ~ImplApplication() {
+        delete scene;
+    }
+};
+
+#endif

03_sdl_basics/17_sdl_widgets/main.cpp

@@ -0,0 +1,40 @@
+#ifdef __EMSCRIPTEN__
+#include <emscripten.h>
+#endif
+
+#include <SDL_ttf.h>
+
+#include "application.h"
+#include "renderer.h"
+
+#include "impl_application.h"
+#define APPLICATION_CLASS ImplApplication
+
+Renderer *renderer = nullptr;
+Application *application = nullptr;
+
+void handle_frame() {
+	application->main_loop();
+}
+
+int main(int argc, char *argv[]) {
+	TTF_Init();
+
+	renderer = new Renderer();
+	application = new APPLICATION_CLASS();
+
+#ifdef __EMSCRIPTEN__
+	emscripten_set_main_loop(handle_frame, 0, 1);
+#else
+	while (application->running) {
+		application->main_loop();
+	}
+#endif
+
+	delete application;
+	delete renderer;
+
+	TTF_Quit();
+
+	return 0;
+}

03_sdl_basics/17_sdl_widgets/main_scene.cpp

@@ -0,0 +1,118 @@
+#include "main_scene.h"
+
+#include "rect2.h"
+#include "renderer.h"
+
+#include <SDL.h>
+
+#include <stdio.h>
+
+void MainScene::event(const SDL_Event &ev) {
+	b1->event(ev);
+	b2->event(ev);
+	b3->event(ev);
+}
+
+void MainScene::update(float delta) {
+}
+
+void MainScene::render() {
+	Renderer::get_singleton()->clear();
+
+	_camera->bind();
+
+	b1->render();
+	b2->render();
+	b3->render();
+
+	//_s->draw();
+	//_s2->draw();
+	_ts->draw();
+}
+
+void MainScene::on_first_button_clicked() {
+	printf("Click!\n");
+}
+
+void MainScene::on_first_button_clicked_member(void* cls) {
+	if (cls) {
+		reinterpret_cast<MainScene*>(cls)->member_print();
+	}
+}
+void MainScene::member_print() {
+	printf("Click Member!\n");
+}
+
+MainScene::MainScene() {
+	_camera = new Camera();
+	_image = new Image("ti.bmp");
+	_texture = new Texture(_image);
+	_font = new TrueTypeFont("./DejaVuSans.ttf", 36);
+	_ii = _font->render_text_blended("Adsdsda", Color(255, 0, 0, 255));
+	_iit = new Texture(_ii);
+	_s = new Sprite(_iit);
+
+	_teximg = new TextImage(_font, "daDAdadad");
+	_iit2 = new Texture(_teximg->get_image());
+	_s2 = new Sprite(_iit2);
+
+	_ts = new TextSprite(_font, "Aqqqqqqq", Color(255, 0, 0));
+	_ts->set_y(50);
+
+	b1 = new Button();
+	b1->transform = Rect2(0, 0, 100, 100);
+	b1->up = new Sprite(_texture);
+	b1->down = new Sprite(_texture, Color(100, 100, 100));
+	b1->hover = new Sprite(_texture, Color(200, 200, 200));
+	
+	//b1->on_click = MainScene::on_first_button_clicked;
+
+	//a verzió lambda 1 (this-nélkül):
+	//b1->on_click = []() -> void { printf("Click lambda!"); };
+
+	//a verzió lambda 2 (this-el):
+	b1->on_click = [this]() -> void { this->member_print(); };
+
+	b2 = new Button();
+	b2->transform = Rect2(0, 110, 100, 100);
+	b2->off = new Sprite(_texture, Color(50, 50, 50));
+	b2->state = Button::BUTTON_STATE_OFF;
+
+	b3 = new Button();
+	b3->transform = Rect2(0, 220, 100, 100);
+	b3->up = new Sprite(_texture);
+	b3->down = new Sprite(_texture, Color(100, 100, 100));
+	b3->hover = new Sprite(_texture, Color(200, 200, 200));
+	b3->cls = this;
+	b3->on_click_member = MainScene::on_first_button_clicked_member;
+}
+
+MainScene::~MainScene() {
+	delete b1->up;
+	delete b1->down;
+	delete b1->hover;
+	delete b1;
+
+	delete b2->off;
+	delete b2;
+
+	delete b3->up;
+	delete b3->down;
+	delete b3->hover;
+	delete b3;
+
+	delete _s;
+	delete _iit;
+	delete _ii;
+
+	delete _teximg;
+	delete _s2;
+	delete _iit2;
+
+	delete _ts;
+
+	delete _font;
+	delete _texture;
+	delete _image;
+	delete _camera;
+}

03_sdl_basics/17_sdl_widgets/main_scene.h

@@ -0,0 +1,49 @@
+#ifndef MAIN_SCENE_H
+#define MAIN_SCENE_H
+
+#include "scene.h"
+
+#include "image.h"
+#include "texture.h"
+#include "sprite.h"
+#include "camera.h"
+#include "button.h"
+#include "true_type_font.h"
+#include "text_image.h"
+#include "text_sprite.h"
+
+class MainScene : public Scene {
+public:
+	void event(const SDL_Event &ev);
+	void update(float delta);
+	void render();
+
+	//ver a
+	static void on_first_button_clicked();
+
+	//ver b
+	static void on_first_button_clicked_member(void* cls);
+	void member_print();
+
+	MainScene();
+	~MainScene();
+
+	Camera *_camera;
+	Image *_image;
+	Texture *_texture;
+	TrueTypeFont *_font;
+	Image *_ii;
+	Texture *_iit;
+	Texture *_iit2;
+	Sprite *_s;
+	Sprite *_s2;
+	TextImage *_teximg;
+	
+	TextSprite *_ts;
+
+	Button *b1;
+	Button *b2;
+	Button *b3;
+};
+
+#endif

03_sdl_basics/17_sdl_widgets/math.cpp

@@ -0,0 +1,72 @@
+#include "math.h"
+
+float Math::inv_sqrt(const float x) {
+	return (float)(1.0 / ::sqrtf(x));
+}
+
+float Math::fast_inv_sqrt(const float number) {
+	long i;
+	float x2, y;
+	const float threehalfs = 1.5F;
+
+	x2 = number * 0.5F;
+	y = number;
+	i = *(long *)&y;
+	i = 0x5f3759df - (i >> 1);
+	y = *(float *)&i;
+	y = y * (threehalfs - (x2 * y * y));
+
+	return y;
+}
+
+float Math::is_equal_approx(const float a, const float b) {
+    if (a + EPSILON < b && a - EPSILON > b) {
+		return true;
+	}
+
+	return false;
+}
+
+float Math::is_zero_approx(const float a) {
+    if (a + EPSILON < 0 && a - EPSILON > 0) {
+		return true;
+	}
+
+	return false;
+}
+
+void Math::seed(const unsigned int s) {
+	srand(s);
+}
+
+void Math::randomize() {
+	srand(time(NULL));
+}
+
+int Math::rand() {
+	return ::rand();
+}
+
+float Math::randf() {
+	return ::rand() / static_cast<float>(RANDOM_32BIT_MAX);
+}
+
+double Math::randd() {
+	return ::rand() / static_cast<double>(RANDOM_32BIT_MAX);
+}
+
+int Math::rand(const int m) {
+    return rand() % m;
+}
+
+int Math::rand(const int from, const int to) {
+    return (rand() % (to - from)) + from;
+}
+
+float Math::rand(const float from, const float to) {
+	return randf() * (to - from) + from;
+}
+
+float Math::rand(const double from, const double to) {
+	return randd() * (to - from) + from;
+}

03_sdl_basics/17_sdl_widgets/math.h

@@ -0,0 +1,89 @@
+#ifndef MATH_H
+#define MATH_H
+
+#include <math.h>
+#include <stdlib.h>
+#include <time.h>
+#include <cstdint>
+
+#define MATH_PI 3.1415926535897932384626433833
+#define EPSILON 0.00001
+
+class Math {
+public:
+
+    static const uint64_t RANDOM_32BIT_MAX = 0xFFFFFFFF;
+
+    inline static float sin(const float x) { return ::sinf(x); }
+    inline static double sin(const double x) { return ::sin(x); }
+
+    inline static float cos(const float x) { return ::cosf(x); }
+    inline static double cos(const double x) { return ::cos(x); }
+
+    inline static float tan(const float x) { return ::tanf(x); }
+    inline static double tan(const double x) { return ::tan(x); }
+
+    inline static float asin(const float x) { return ::asinf(x); }
+    inline static double asin(const double x) { return ::asin(x); }
+
+    inline static float acos(const float x) { return ::acosf(x); }
+    inline static double acos(const double x) { return ::acos(x); }
+
+    inline static float atan(const float x) { return ::atanf(x); }
+    inline static double atan(const double x) { return ::atan(x); }
+
+    inline static float atan2(const float x, const float y) { return ::atan2f(x, y); }
+    inline static double atan2(const double x, const float y) { return ::atan2(x, y); }
+
+    inline static float sqrt(const float x) { return ::sqrtf(x); }
+    inline static double sqrt(const double x) { return ::sqrt(x); }
+
+    inline static float fmod(const float x, const float y) { return ::fmodf(x, y); }
+    inline static double fmod(const double x, const float y) { return ::fmod(x, y); }
+
+    inline static float floor(const float x) { return ::floorf(x); }
+    inline static double floor(const double x) { return ::floor(x); }
+
+    inline static float ceil(const float x) { return ::ceilf(x); }
+    inline static double ceil(const double x) { return ::ceil(x); }
+
+    inline static float pow(const float x, const float y) { return ::powf(x, y); }
+    inline static double pow(const double x, const float y) { return ::pow(x, y); }
+
+    inline static float log(const float x) { return ::logf(x); }
+    inline static double log(const double x) { return ::log(x); }
+
+    static float inv_sqrt(const float x);
+    static float fast_inv_sqrt(const float x);
+
+    inline static float abs(const float x) { return x > 0 ? x : -x; }
+    inline static double abs(const double x) { return x > 0 ? x : -x; }
+    inline static int abs(const int x) { return x > 0 ? x : -x; }
+
+    inline static float deg2rad(const float x) { return x * MATH_PI / 180.0; }
+    inline static double deg2rad(const double x) { return x * MATH_PI / 180.0; }
+    inline static int deg2rad(const int x) { return x * MATH_PI / 180.0; }
+
+    inline static float rad2deg(const float x) { return x * 180.0 / MATH_PI; }
+    inline static double rad2deg(const double x) { return x * 180.0 / MATH_PI; }
+    inline static int rad2deg(const int x) { return x * 180.0 / MATH_PI; }
+
+    static float is_equal_approx(const float a, const float b);
+    static float is_zero_approx(const float a);
+
+    static void seed(const unsigned int s);
+    static void randomize();
+
+    static int rand();
+    static float randf();
+    static double randd();
+
+    static int rand(const int m);
+
+    static int rand(const int from, const int to);
+    static float rand(const float from, const float to);
+    static float rand(const double from, const double to);
+
+};
+
+#endif

03_sdl_basics/17_sdl_widgets/rect2.cpp

@@ -0,0 +1,178 @@
+#include "rect2.h"
+
+#include "math.h"
+
+float Rect2::get_area() const {
+	return w * h;
+}
+
+bool Rect2::intersects(const Rect2 &b) const {
+	if (x >= (b.x + b.w))
+		return false;
+
+	if ((x + w) <= b.x)
+		return false;
+
+	if (y >= (b.y + b.h))
+		return false;
+
+	if ((y + h) <= b.y)
+		return false;
+
+	return true;
+}
+
+bool Rect2::intersects_include_borders(const Rect2 &b) const {
+	if (x > (b.x + b.w))
+		return false;
+
+	if ((x + w) < b.x)
+		return false;
+
+	if (y > (b.y + b.h))
+		return false;
+
+	if ((y + h) < b.y)
+		return false;
+
+	return true;
+}
+
+bool Rect2::encloses(const Rect2 &b) const {
+	return (b.x >= x) && (b.y >= y) &&
+		   ((b.x + b.w) <= (x + w)) &&
+		   ((b.y + b.h) <= (y + h));
+}
+
+bool Rect2::has_no_area() const {
+	if (w == 0 && h == 0) {
+		return true;
+	}
+
+	return false;
+}
+
+bool Rect2::has_point(const float px, const float py) const {
+	if (px > x && px < x + w && py > y && py < py + h) {
+		return true;
+	}
+
+	return false;
+}
+
+bool Rect2::is_equal_approx(const Rect2 &b) const {
+	if (x + EPSILON < b.x && x - EPSILON > b.x && y + EPSILON < b.y && y - EPSILON > b.y &&
+			w + EPSILON < b.w && w - EPSILON > b.w && h + EPSILON < b.h && h - EPSILON > b.h) {
+		return true;
+	}
+
+	return false;
+}
+
+void Rect2::grow(const float by) {
+	x -= by;
+	y -= by;
+	h += by;
+	w += by;
+}
+
+void Rect2::shrink(const float by) {
+	x += by;
+	y += by;
+	h -= by;
+	w -= by;
+}
+
+SDL_Rect Rect2::as_rect() const {
+	SDL_Rect r;
+
+	r.x = x;
+	r.y = y;
+	r.w = w;
+	r.h = h;
+
+	return r;
+}
+
+SDL_FRect Rect2::as_frect() const {
+	SDL_FRect r;
+
+	r.x = x;
+	r.y = y;
+	r.w = w;
+	r.h = h;
+
+	return r;
+}
+
+Rect2 &Rect2::operator+=(const Rect2 &b) {
+    x += b.x;
+	y += b.y;
+	w += b.w;
+	h += b.h;
+
+    return *this;
+}
+
+Rect2 &Rect2::operator-=(const Rect2 &b) {
+    x -= b.x;
+	y -= b.y;
+	w -= b.w;
+	h -= b.h;
+
+    return *this;
+}
+
+Rect2 operator+(Rect2 lhs, const Rect2 &rhs) {
+    lhs.x += rhs.x;
+	lhs.y += rhs.y;
+	lhs.w += rhs.w;
+	lhs.h += rhs.h;
+
+    return lhs;
+}
+
+Rect2 operator-(Rect2 lhs, const Rect2 &rhs) {
+    lhs.x -= rhs.x;
+	lhs.y -= rhs.y;
+	lhs.w -= rhs.w;
+	lhs.h -= rhs.h;
+
+    return lhs;
+}
+
+bool operator==(const Rect2 &a, const Rect2 &b) {
+    return a.is_equal_approx(b);
+}
+
+bool operator!=(const Rect2 &a, const Rect2 &b) {
+    return !a.is_equal_approx(b);
+}
+
+Rect2::Rect2() {
+	x = 0;
+	y = 0;
+	w = 0;
+	h = 0;
+}
+
+Rect2::Rect2(const Rect2 &b) {
+	x = b.x;
+	y = b.y;
+	w = b.w;
+	h = b.h;
+}
+
+Rect2::Rect2(const float rx, const float ry) {
+	x = rx;
+	y = ry;
+	w = 0;
+	h = 0;
+}
+
+Rect2::Rect2(const float rx, const float ry, const float rw, const float rh) {
+	x = rx;
+	y = ry;
+	w = rw;
+	h = rh;
+}

03_sdl_basics/17_sdl_widgets/rect2.h

@@ -0,0 +1,42 @@
+#ifndef RECT2_H
+#define RECT2_H
+
+#include <SDL.h>
+
+class Rect2 {
+public:
+	float get_area() const;
+	bool intersects(const Rect2 &b) const;
+	bool intersects_include_borders(const Rect2 &b) const;
+	bool encloses(const Rect2 &b) const;
+	bool has_no_area() const;
+	bool has_point(const float px, const float py) const;
+	bool is_equal_approx(const Rect2 &b) const;
+
+	void grow(const float by);
+	void shrink(const float by);
+
+	SDL_Rect as_rect() const;
+	SDL_FRect as_frect() const;
+
+	Rect2 &operator+=(const Rect2 &b);
+	Rect2 &operator-=(const Rect2 &b);
+
+	friend Rect2 operator+(Rect2 lhs, const Rect2 &rhs);
+	friend Rect2 operator-(Rect2 lhs, const Rect2 &rhs);
+
+	friend bool operator==(const Rect2 &a, const Rect2 &b);
+	friend bool operator!=(const Rect2 &a, const Rect2 &b);
+
+	Rect2();
+	Rect2(const Rect2 &b);
+	Rect2(const float rx, const float ry);
+	Rect2(const float rx, const float ry, const float rw, const float rh);
+
+	float x;
+	float y;
+	float w;
+	float h;
+};
+
+#endif

03_sdl_basics/17_sdl_widgets/renderer.cpp

@@ -0,0 +1,369 @@
+#include "renderer.h"
+
+#include <cstdio>
+
+#include "math.h"
+
+void Renderer::present() {
+	SDL_RenderPresent(_renderer);
+}
+
+void Renderer::set_draw_color(const Uint8 r, const Uint8 g, const Uint8 b, const Uint8 a) {
+	SDL_SetRenderDrawColor(_renderer, r, g, b, a);
+}
+
+void Renderer::set_draw_color(const Color &color) {
+	SDL_SetRenderDrawColor(_renderer, color.r, color.g, color.b, color.a);
+}
+
+void Renderer::clear() {
+	SDL_RenderClear(_renderer);
+}
+
+SDL_BlendMode Renderer::get_blend_mode() const {
+	SDL_BlendMode mode;
+	SDL_GetRenderDrawBlendMode(_renderer, &mode);
+
+	return mode;
+}
+void Renderer::set_blend_mode(const SDL_BlendMode mode) {
+	SDL_SetRenderDrawBlendMode(_renderer, mode);
+}
+
+void Renderer::draw_point(const int x, const int y) {
+	SDL_RenderDrawPoint(_renderer, x, y);
+}
+void Renderer::draw_point(const float x, const float y) {
+	SDL_RenderDrawPointF(_renderer, x, y);
+}
+
+void Renderer::draw_line(const int x1, const int x2, const int y1, const int y2) {
+	SDL_RenderDrawLine(_renderer, x1, x2, y1, y2);
+}
+void Renderer::draw_line(const float x1, const float x2, const float y1, const float y2) {
+	SDL_RenderDrawLineF(_renderer, x1, x2, y1, y2);
+}
+
+void Renderer::draw_rect(const Rect2 &rect) {
+	SDL_Rect r = rect.as_rect();
+
+	SDL_RenderDrawRect(_renderer, &r);
+}
+
+void Renderer::draw_fill_rect(const Rect2 &rect) {
+	SDL_Rect r = rect.as_rect();
+
+	SDL_RenderFillRect(_renderer, &r);
+}
+
+void Renderer::draw_texture(const Texture &texture, const Rect2 &dst_rect) {
+	SDL_Rect sr;
+
+	sr.x = 0;
+	sr.y = 0;
+	sr.w = texture.get_width();
+	sr.h = texture.get_height();
+
+	SDL_Rect dr = dst_rect.as_rect();
+
+	SDL_RenderCopy(_renderer, texture.get_texture(), &sr, &dr);
+}
+void Renderer::draw_texture(const Texture &texture, const Rect2 &src_rect, const Rect2 &dst_rect) {
+	SDL_Rect sr = src_rect.as_rect();
+	SDL_Rect dr = dst_rect.as_rect();
+
+	SDL_RenderCopy(_renderer, texture.get_texture(), &sr, &dr);
+}
+void Renderer::draw_texture(const Texture &texture, const Rect2 &src_rect, const Rect2 &dst_rect, const double angle, const float cx, const float cy, const SDL_RendererFlip flip) {
+	SDL_Rect sr = src_rect.as_rect();
+	SDL_FRect dr = dst_rect.as_frect();
+
+	SDL_FPoint p;
+
+	p.x = cx;
+	p.y = cy;
+
+	SDL_RenderCopyExF(_renderer, texture.get_texture(), &sr, &dr, angle, &p, flip);
+}
+
+void Renderer::draw_sprite(const Sprite &sprite) {
+	Texture *t = sprite.get_texture();
+
+	if (!t) {
+		return;
+	}
+
+	t->set_color_mod(sprite.get_color_mod());
+
+	double angle = sprite.get_angle();
+
+	if (Math::is_zero_approx(angle)) {
+		SDL_Rect sr = sprite.get_texture_clip_rect().as_rect();
+		SDL_Rect dr = sprite.get_transform().as_rect();
+
+		SDL_RenderCopy(_renderer, t->get_texture(), &sr, &dr);
+	} else {
+		SDL_Rect sr = sprite.get_texture_clip_rect().as_rect();
+		SDL_FRect dr = sprite.get_transform().as_frect();
+
+		SDL_FPoint p;
+
+		p.x = sprite.get_anchor_x();
+		p.y = sprite.get_anchor_y();
+
+		SDL_RenderCopyExF(_renderer, t->get_texture(), &sr, &dr, angle, &p, sprite.get_flip());
+	}
+}
+
+void Renderer::draw_sprite(const Sprite *sprite) {
+	if (!sprite)
+		return;
+
+	Texture *t = sprite->get_texture();
+
+	if (!t) {
+		return;
+	}
+
+	t->set_color_mod(sprite->get_color_mod());
+
+	double angle = sprite->get_angle();
+
+	if (Math::is_zero_approx(angle)) {
+		SDL_Rect sr = sprite->get_texture_clip_rect().as_rect();
+		SDL_Rect dr = sprite->get_transform().as_rect();
+
+		SDL_RenderCopy(_renderer, t->get_texture(), &sr, &dr);
+	} else {
+		SDL_Rect sr = sprite->get_texture_clip_rect().as_rect();
+		SDL_FRect dr = sprite->get_transform().as_frect();
+
+		SDL_FPoint p;
+
+		p.x = sprite->get_anchor_x();
+		p.y = sprite->get_anchor_y();
+
+		SDL_RenderCopyExF(_renderer, t->get_texture(), &sr, &dr, angle, &p, sprite->get_flip());
+	}
+}
+
+int Renderer::get_dpi() const {
+	float ddpi;
+	float hdpi;
+	float vdpi;
+
+	if (SDL_GetDisplayDPI(_window_display_index, &ddpi, &hdpi, &vdpi)) {
+		return ddpi;
+	}
+
+	//fallback
+	return 1;
+}
+
+int Renderer::get_window_size_w() const {
+	int w;
+	int h;
+
+	SDL_GetWindowSize(_window, &w, &h);
+
+	return w;
+}
+
+int Renderer::get_window_size_h() const {
+	int w;
+	int h;
+
+	SDL_GetWindowSize(_window, &w, &h);
+
+	return h;
+}
+
+int Renderer::get_size_w() const {
+	int w;
+	int h;
+
+	SDL_RenderGetLogicalSize(_renderer, &w, &h);
+
+	return w;
+}
+
+int Renderer::get_size_h() const {
+	int w;
+	int h;
+
+	SDL_RenderGetLogicalSize(_renderer, &w, &h);
+
+	return h;
+}
+
+void Renderer::get_size(int *w, int *h) const {
+	SDL_RenderGetLogicalSize(_renderer, w, h);
+}
+
+void Renderer::set_size(const int w, const int h) const {
+	SDL_RenderSetLogicalSize(_renderer, w, h);
+}
+
+float Renderer::get_scale_w() const {
+	float w;
+	float h;
+
+	SDL_RenderGetScale(_renderer, &w, &h);
+
+	return w;
+}
+float Renderer::get_scale_h() const {
+	float w;
+	float h;
+
+	SDL_RenderGetScale(_renderer, &w, &h);
+
+	return h;
+}
+void Renderer::set_scale(const float w, const float h) const {
+	SDL_RenderSetScale(_renderer, w, h);
+}
+void Renderer::get_scale(float *w, float *h) const {
+	SDL_RenderGetScale(_renderer, w, h);
+}
+
+bool Renderer::get_integer_scaling() const {
+	return SDL_RenderGetIntegerScale(_renderer);
+}
+void Renderer::set_integer_scaling(const bool enable) {
+	if (enable)
+		SDL_RenderSetIntegerScale(_renderer, SDL_TRUE);
+	else
+		SDL_RenderSetIntegerScale(_renderer, SDL_FALSE);
+}
+
+Rect2 Renderer::get_viewport() const {
+	SDL_Rect r;
+
+	SDL_RenderGetViewport(_renderer, &r);
+
+	return Rect2(r.x, r.y, r.w, r.h);
+}
+void Renderer::set_viewport(const Rect2 &rect) const {
+	SDL_Rect r = rect.as_rect();
+
+	SDL_RenderSetViewport(_renderer, &r);
+}
+
+Rect2 Renderer::get_clip_rect() const {
+	SDL_Rect r;
+
+	SDL_RenderGetClipRect(_renderer, &r);
+
+	return Rect2(r.x, r.y, r.w, r.h);
+}
+void Renderer::set_clip_rect(Rect2 *rect) const {
+	if (rect) {
+		SDL_Rect r = rect->as_rect();
+
+		SDL_RenderSetClipRect(_renderer, &r);
+	} else {
+		SDL_RenderSetClipRect(_renderer, nullptr);
+	}
+}
+bool Renderer::clip_rect_enabled() const {
+	return SDL_RenderIsClipEnabled(_renderer);
+}
+
+bool Renderer::render_target_supported() {
+	return SDL_RenderTargetSupported(_renderer);
+}
+
+SDL_Texture *Renderer::get_render_target() {
+	return SDL_GetRenderTarget(_renderer);
+}
+void Renderer::set_render_target(Texture *texture) {
+	if (texture) {
+		SDL_SetRenderTarget(_renderer, texture->get_texture());
+	} else {
+		SDL_SetRenderTarget(_renderer, nullptr);
+	}
+}
+
+void Renderer::initialize() {
+	if (SDL_Init(_flags) != 0) {
+		printf("SDL_Init() hiba!\n");
+
+		return;
+	}
+
+	if (SDL_CreateWindowAndRenderer(_initial_window_width, _initial_window_height, _window_flags, &_window, &_renderer) != 0) {
+		printf("SDL_CreateWindowAndRenderer() hiba!\n");
+
+		return;
+	}
+
+	_window_display_index = SDL_GetWindowDisplayIndex(_window);
+}
+
+void Renderer::destroy() {
+	if (_window)
+		SDL_DestroyWindow(_window);
+
+	if (_renderer)
+		SDL_DestroyRenderer(_renderer);
+
+	_window = nullptr;
+	_renderer = nullptr;
+}
+
+SDL_Window *Renderer::get_window() {
+	return _window;
+}
+
+SDL_Renderer *Renderer::get_renderer() {
+	return _renderer;
+}
+
+Renderer::Renderer() {
+	if (_singleton) {
+		printf("Renderer::Renderer(): _singleton is not null!\n");
+	}
+
+	_initial_window_width = 640;
+	_initial_window_height = 480;
+
+	_singleton = this;
+
+	_flags = SDL_INIT_VIDEO | SDL_INIT_TIMER;
+	_window_flags = SDL_WINDOW_SHOWN;
+
+	initialize();
+}
+
+Renderer::Renderer(unsigned int flags, unsigned int window_flags, int initial_window_width, int initial_window_height) {
+	if (_singleton) {
+		printf("Renderer::Renderer(flags): _singleton is not null!\n");
+	}
+
+	_initial_window_width = initial_window_width;
+	_initial_window_height = initial_window_height;
+
+	_singleton = this;
+
+	_flags = flags;
+	_window_flags = window_flags;
+
+	initialize();
+}
+
+Renderer::~Renderer() {
+	if (_singleton != this) {
+		printf("Renderer::~Renderer(): _singleton is not this!\n");
+	}
+
+	_singleton = nullptr;
+
+	destroy();
+}
+
+Renderer *Renderer::get_singleton() {
+	return _singleton;
+}
+
+Renderer *Renderer::_singleton = nullptr;

03_sdl_basics/17_sdl_widgets/renderer.h

@@ -0,0 +1,93 @@
+#ifndef RENDERER_H
+#define RENDERER_H
+
+#include "color.h"
+#include "rect2.h"
+#include "sprite.h"
+#include "texture.h"
+
+#include <SDL.h>
+
+class Renderer {
+public:
+	void present();
+	void set_draw_color(const Uint8 r, const Uint8 g, const Uint8 b, const Uint8 a);
+	void set_draw_color(const Color &color);
+	void clear();
+
+	SDL_BlendMode get_blend_mode() const;
+	void set_blend_mode(const SDL_BlendMode mode);
+
+	void draw_point(const int x, const int y);
+	void draw_point(const float x, const float y);
+
+	void draw_line(const int x1, const int x2, const int y1, const int y2);
+	void draw_line(const float x1, const float x2, const float y1, const float y2);
+
+	void draw_rect(const Rect2 &rect);
+
+	void draw_fill_rect(const Rect2 &rect);
+
+	void draw_texture(const Texture &texture, const Rect2 &dst_rect);
+	void draw_texture(const Texture &texture, const Rect2 &src_rect, const Rect2 &dst_rect);
+	void draw_texture(const Texture &texture, const Rect2 &src_rect, const Rect2 &dst_rect, const double angle, const float cx = 0, const float cy = 0, const SDL_RendererFlip flip = SDL_FLIP_NONE);
+
+	void draw_sprite(const Sprite &sprite);
+	void draw_sprite(const Sprite *sprite);
+
+	int get_dpi() const;
+	int get_window_size_w() const;
+	int get_window_size_h() const;
+	int get_size_w() const;
+	int get_size_h() const;
+	void set_size(const int w, const int h) const;
+	void get_size(int *w, int *h) const;
+
+	float get_scale_w() const;
+	float get_scale_h() const;
+	void set_scale(const float w, const float h) const;
+	void get_scale(float *w, float *h) const;
+
+	bool get_integer_scaling() const;
+	void set_integer_scaling(const bool enable);
+
+	Rect2 get_viewport() const;
+	void set_viewport(const Rect2 &rect) const;
+
+	Rect2 get_clip_rect() const;
+	void set_clip_rect(Rect2 *rect) const;
+	bool clip_rect_enabled() const;
+
+	bool render_target_supported();
+
+	SDL_Texture *get_render_target();
+	void set_render_target(Texture *texture);
+
+	void initialize();
+	void destroy();
+
+	SDL_Window *get_window();
+	SDL_Renderer *get_renderer();
+
+	Renderer();
+	Renderer(unsigned int flags, unsigned int window_flags, int window_width = 640, int window_height = 480);
+	virtual ~Renderer();
+
+	static Renderer *get_singleton();
+
+private:
+	int _initial_window_width;
+	int _initial_window_height;
+
+	unsigned int _flags;
+	unsigned int _window_flags;
+
+	SDL_Window *_window;
+	SDL_Renderer *_renderer;
+
+	int _window_display_index;
+
+	static Renderer *_singleton;
+};
+
+#endif

03_sdl_basics/17_sdl_widgets/scene.cpp

@@ -0,0 +1,9 @@
+#include "scene.h"
+
+Scene::Scene() {
+
+}
+
+Scene::~Scene() {
+    
+}

03_sdl_basics/17_sdl_widgets/scene.h

@@ -0,0 +1,16 @@
+#ifndef SCENE_H
+#define SCENE_H
+
+#include <SDL.h>
+
+class Scene {
+public:
+    virtual void event(const SDL_Event &ev) = 0;
+    virtual void update(float delta) = 0;
+    virtual void render() = 0;
+
+    Scene();
+    virtual ~Scene();
+};
+
+#endif

03_sdl_basics/17_sdl_widgets/sprite.cpp

@@ -0,0 +1,238 @@
+#include "sprite.h"
+
+#include "renderer.h"
+
+Rect2 Sprite::get_texture_clip_rect() const {
+	return _texture_clip_rect;
+}
+void Sprite::set_texture_clip_rect(const Rect2 &rect) {
+	_texture_clip_rect = rect;
+}
+
+Rect2 Sprite::get_transform() const {
+	return _transform;
+}
+void Sprite::set_transform(const Rect2 &rect) {
+	_transform = rect;
+}
+
+float Sprite::get_x() const {
+	return _transform.x;
+}
+void Sprite::set_x(const float val) {
+	_transform.x = val;
+}
+
+float Sprite::get_y() const {
+	return _transform.y;
+}
+void Sprite::set_y(const float val) {
+	_transform.y = val;
+}
+
+float Sprite::get_w() const {
+	return _transform.w;
+}
+void Sprite::set_w(const float val) {
+	_transform.w = val;
+}
+
+float Sprite::get_h() const {
+	return _transform.h;
+}
+void Sprite::set_h(const float val) {
+	_transform.h = val;
+}
+
+double Sprite::get_angle() const {
+	return _angle;
+}
+void Sprite::set_angle(const double val) {
+	_angle = val;
+}
+
+float Sprite::get_anchor_x() const {
+	return _anchor_x;
+}
+void Sprite::set_anchor_x(const float val) {
+	_anchor_x = val;
+}
+
+float Sprite::get_anchor_y() const {
+	return _anchor_y;
+}
+void Sprite::set_anchor_y(const float val) {
+	_anchor_y = val;
+}
+
+void Sprite::set_anchor(const float x, const float y) {
+	_anchor_x = x;
+	_anchor_y = y;
+}
+
+SDL_RendererFlip Sprite::get_flip() const {
+	return _flip;
+}
+void Sprite::set_flip(const SDL_RendererFlip val) {
+	_flip = val;
+}
+
+Color Sprite::get_color_mod() const {
+	return _color_mod;
+}
+void Sprite::set_color_mod(const Color &color) {
+	_color_mod = color;
+}
+
+Texture *Sprite::get_texture() {
+	return _texture;
+}
+Texture *Sprite::get_texture() const {
+	return _texture;
+}
+void Sprite::set_texture(Texture *texture) {
+	_texture = texture;
+}
+
+void Sprite::draw() {
+	Renderer::get_singleton()->draw_sprite(this);
+}
+
+Sprite::Sprite() {
+	_angle = 0;
+
+	_anchor_x = 0;
+	_anchor_y = 0;
+
+	_flip = SDL_FLIP_NONE;
+
+	_texture = nullptr;
+
+	_color_mod = Color(255, 255, 255, 255);
+}
+Sprite::Sprite(Texture *texture) {
+	_angle = 0;
+
+	_anchor_x = 0;
+	_anchor_y = 0;
+
+	_flip = SDL_FLIP_NONE;
+
+	_texture = texture;
+
+	if (_texture != nullptr) {
+		_texture_clip_rect.w = texture->get_width();
+		_texture_clip_rect.h = texture->get_height();
+
+		_transform.w = texture->get_width();
+		_transform.h = texture->get_height();
+	}
+
+	_color_mod = Color(255, 255, 255, 255);
+}
+
+Sprite::Sprite(Texture *texture, const Color &color_mod) {
+		_angle = 0;
+
+	_anchor_x = 0;
+	_anchor_y = 0;
+
+	_flip = SDL_FLIP_NONE;
+
+	_texture = texture;
+
+	if (_texture != nullptr) {
+		_texture_clip_rect.w = texture->get_width();
+		_texture_clip_rect.h = texture->get_height();
+
+		_transform.w = texture->get_width();
+		_transform.h = texture->get_height();
+	}
+
+	_color_mod = color_mod;
+}
+
+Sprite::Sprite(Texture *texture, const float x, const float y, const double angle) {
+	_angle = angle;
+
+	_anchor_x = 0;
+	_anchor_y = 0;
+
+	_flip = SDL_FLIP_NONE;
+
+	_texture = texture;
+
+	_transform.x = x;
+	_transform.y = y;
+
+	if (_texture != nullptr) {
+		_texture_clip_rect.w = texture->get_width();
+		_texture_clip_rect.h = texture->get_height();
+
+		_transform.w = texture->get_width();
+		_transform.h = texture->get_height();
+	}
+
+	_color_mod = Color(255, 255, 255, 255);
+}
+Sprite::Sprite(Texture *texture, const float x, const float y, const Rect2 &texture_clip_rect, const double angle) {
+	_angle = angle;
+
+	_anchor_x = 0;
+	_anchor_y = 0;
+
+	_flip = SDL_FLIP_NONE;
+
+	_texture = texture;
+
+	_transform.x = x;
+	_transform.y = y;
+
+	if (_texture != nullptr) {
+		_transform.w = texture->get_width();
+		_transform.h = texture->get_height();
+	}
+
+	_texture_clip_rect = texture_clip_rect;
+
+	_color_mod = Color(255, 255, 255, 255);
+}
+Sprite::Sprite(Texture *texture, const Rect2 &transform, const Rect2 &texture_clip_rect, const double angle) {
+	_angle = angle;
+
+	_anchor_x = 0;
+	_anchor_y = 0;
+
+	_flip = SDL_FLIP_NONE;
+
+	_texture = texture;
+
+	_transform = transform;
+	_texture_clip_rect = texture_clip_rect;
+
+	_color_mod = Color(255, 255, 255, 255);
+}
+Sprite::Sprite(Texture *texture, const float x, const float y, const float w, const float h, const double angle) {
+	_angle = angle;
+
+	_anchor_x = 0;
+	_anchor_y = 0;
+
+	_flip = SDL_FLIP_NONE;
+
+	_texture = texture;
+
+	_transform.x = x;
+	_transform.y = y;
+	_transform.w = w;
+	_transform.h = h;
+
+	if (_texture != nullptr) {
+		_texture_clip_rect.w = texture->get_width();
+		_texture_clip_rect.h = texture->get_height();
+	}
+
+	_color_mod = Color(255, 255, 255, 255);
+}
+Sprite::~Sprite() {
+}

03_sdl_basics/17_sdl_widgets/sprite.h

@@ -0,0 +1,77 @@
+#ifndef SPRITE_H
+#define SPRITE_H
+
+#include <SDL.h>
+
+#include "rect2.h"
+#include "texture.h"
+#include "color.h"
+
+class Sprite {
+public:
+	Rect2 get_texture_clip_rect() const;
+	void set_texture_clip_rect(const Rect2 &rect);
+
+	Rect2 get_transform() const;
+	void set_transform(const Rect2 &rect);
+
+	float get_x() const;
+	void set_x(const float val);
+
+	float get_y() const;
+	void set_y(const float val);
+
+	float get_w() const;
+	void set_w(const float val);
+
+	float get_h() const;
+	void set_h(const float val);
+
+	double get_angle() const;
+	void set_angle(const double val);
+
+	float get_anchor_x() const;
+	void set_anchor_x(const float val);
+
+	float get_anchor_y() const;
+	void set_anchor_y(const float val);
+
+	void set_anchor(const float x, const float y);
+
+	SDL_RendererFlip get_flip() const;
+	void set_flip(const SDL_RendererFlip val);
+
+	Color get_color_mod() const;
+	void set_color_mod(const Color &color);
+
+	Texture *get_texture();
+	Texture *get_texture() const;
+	void set_texture(Texture *texture);
+
+	void draw();
+
+	Sprite();
+	Sprite(Texture *texture);
+	Sprite(Texture *texture, const Color &color_mod);
+	Sprite(Texture *texture, const float x, const float y, const double angle = 0);
+	Sprite(Texture *texture, const float x, const float y, const Rect2 &texture_clip_rect, const double angle = 0);
+	Sprite(Texture *texture, const Rect2 &transform, const Rect2 &texture_clip_rect, const double angle = 0);
+	Sprite(Texture *texture, const float x, const float y, const float w, const float h, const double angle = 0);
+	virtual ~Sprite();
+
+private:
+	Rect2 _texture_clip_rect;
+	Rect2 _transform;
+	double _angle;
+
+	float _anchor_x;
+	float _anchor_y;
+
+	SDL_RendererFlip _flip;
+
+	Color _color_mod;
+
+	Texture *_texture;
+};
+
+#endif

03_sdl_basics/17_sdl_widgets/string.cpp

@@ -0,0 +1,333 @@
+#include "string.h"
+
+#include <stdlib.h>
+
+void String::push_back(const char element) {
+	ensure_capacity(_size + 1);
+
+	_data[_size++] = element;
+	_data[_size] = '\0';
+}
+
+void String::pop_back() {
+	if (_size == 0) {
+		return;
+	}
+
+	--_size;
+
+	_data[_size] = '\0';
+}
+
+void String::remove(const int index) {
+	_data[index] = _data[_size - 1];
+
+	--_size;
+
+	_data[_size] = '\0';
+}
+
+void String::erase(const char element) {
+	int index = find(element);
+
+	if (index != -1) {
+		remove(index);
+	}
+}
+
+void String::clear() {
+	_size = 0;
+}
+
+bool String::empty() const {
+	return _size == 0;
+}
+
+char String::get(const int index) {
+	return _data[index];
+}
+
+const char String::get(const int index) const {
+	return _data[index];
+}
+
+void String::set(const int index, const char value) {
+	_data[index] = value;
+}
+
+int String::size() const {
+	return _size;
+}
+
+int String::capacity() const {
+	return _actual_size;
+}
+
+void String::ensure_capacity(const int capacity) {
+	if (capacity <= _actual_size) {
+		return;
+	}
+
+	int tsize = capacity + _grow_by;
+
+	char *nd = new char[tsize];
+
+	for (int i = 0; i < _size; ++i) {
+		nd[i] = _data[i];
+	}
+
+	delete[] _data;
+
+	_data = nd;
+}
+
+void String::resize(const int s) {
+	ensure_capacity(s + 1); // +1 for the null terminator
+
+	_size = s;
+
+	_data[_size] = '\0';
+}
+
+void String::append_array(const String &other) {
+	ensure_capacity(_size + other._size + 1); // +1 for the null terminator
+
+	for (int i = 0; i < other._size; ++i) {
+		_data[_size++] = other._data[i];
+	}
+
+	_data[_size] = '\0';
+}
+
+int String::find(const char val) const {
+	for (int i = 0; i < _size; ++i) {
+		if (_data[i] == val) {
+			return i;
+		}
+	}
+
+	return -1;
+}
+
+float String::to_float() {
+	return atof(c_str());
+}
+
+double String::to_double() {
+	return atof(c_str());
+}
+
+int String::to_int() {
+	return atoi(c_str());
+}
+
+uint32_t String::to_uint() {
+	return static_cast<uint32_t>(atoll(c_str()));
+}
+
+char *String::c_str() {
+	return _data;
+}
+
+const char *String::c_str() const {
+	return _data;
+}
+
+char *String::dataw() {
+	return _data;
+}
+
+const char *String::data() const {
+	return _data;
+}
+
+const char String::operator[](const int index) const {
+	return _data[index];
+}
+
+char String::operator[](const int index) {
+	return _data[index];
+}
+
+String &String::operator+=(const String &b) {
+	ensure_capacity(_size + b._size + 1); // +1 for the null terminator
+
+	for (int i = 0; i < b._size; ++i) {
+		_data[_size++] = b._data[i];
+	}
+
+	return *this;
+}
+
+String &String::operator+=(const char chr) {
+	push_back(chr);
+
+	return *this;
+}
+
+String &String::operator+=(const char *p_c_str) {
+	int i = 0;
+	while (p_c_str[i] != '\0') {
+		push_back(p_c_str[i]);
+		++i;
+	}
+
+	return *this;
+}
+
+String operator+(String lhs, const String &rhs) {
+	lhs += rhs;
+
+	return lhs;
+}
+
+String operator+(String lhs, const char *rhs) {
+	lhs += rhs;
+
+	return lhs;
+}
+
+String operator+(String lhs, const char rhs) {
+	lhs += rhs;
+
+	return lhs;
+}
+
+bool operator==(const String &a, const String &b) {
+	if (a._size != b._size) {
+		return false;
+	}
+
+	for (int i = 0; i < a._size; ++i) {
+		if (a[i] != b[i]) {
+			return false;
+		}
+	}
+
+	return true;
+}
+
+bool operator!=(const String &a, const String &b) {
+	return !(a == b);
+}
+
+bool operator==(const String &a, const char *b) {
+	int i = 0;
+	while (b[i] != '\0' && i < a._size) {
+		if (a[i] != b[i]) {
+			return false;
+		}
+
+		++i;
+	}
+
+	if (i != a._size) {
+		return false;
+	}
+
+	return true;
+}
+
+bool operator!=(const String &a, const char *b) {
+	return !(a == b);
+}
+
+bool operator==(const char *b, const String &a) {
+	int i = 0;
+	while (b[i] != '\0' && i < a._size) {
+		if (a[i] != b[i]) {
+			return false;
+		}
+
+		++i;
+	}
+
+	if (i != a._size) {
+		return false;
+	}
+
+	return true;
+}
+
+bool operator!=(const char *b, const String &a) {
+	return !(a == b);
+}
+
+String::String() {
+	_data = nullptr;
+	_actual_size = 0;
+	_size = 0;
+	_grow_by = 100;
+
+	ensure_capacity(100);
+
+	_data[0] = '\0';
+}
+
+String::String(const String &other) {
+	_data = nullptr;
+	_actual_size = 0;
+	_size = 0;
+	_grow_by = 100;
+
+	//+1 for the null terminator in case its needed
+	ensure_capacity(other.size() + 1);
+
+	for (int i = 0; i < other._size; ++i) {
+		_data[i] = other._data[i];
+	}
+
+	_data[other._size] = '\0';
+}
+
+String::String(const String &other, int grow_by) {
+	_data = nullptr;
+	_actual_size = 0;
+	_size = 0;
+	_grow_by = grow_by;
+
+	//+1 for the null terminator in case its needed
+	ensure_capacity(other.size() + 1);
+
+	for (int i = 0; i < other._size; ++i) {
+		_data[i] = other._data[i];
+	}
+
+	_data[_size] = '\0';
+}
+
+String::String(const char* p_c_str) {
+	_data = nullptr;
+	_actual_size = 0;
+	_size = 0;
+	_grow_by = 100;
+
+	operator+=(p_c_str);
+}
+
+String::String(const char* p_c_str, const int grow_by) {
+	_data = nullptr;
+	_actual_size = 0;
+	_size = 0;
+	_grow_by = grow_by;
+
+	operator+=(p_c_str);
+}
+
+String::String(int prealloc) {
+	_data = nullptr;
+	_actual_size = 0;
+	_size = 0;
+	_grow_by = 100;
+
+	ensure_capacity(prealloc);
+}
+
+String::String(int prealloc, int grow_by) {
+	_data = nullptr;
+	_actual_size = 0;
+	_size = 0;
+	_grow_by = grow_by;
+
+	ensure_capacity(prealloc);
+}

03_sdl_basics/17_sdl_widgets/string.h

@@ -0,0 +1,72 @@
+#ifndef STRING_H
+#define STRING_H
+
+#include <inttypes.h>
+
+class String {
+
+public:
+	void push_back(const char element);
+	void pop_back();
+	void remove(const int index);
+	void erase(const char element);
+	void clear();
+	bool empty() const;
+	char get(const int index);
+	const char get(const int index) const;
+	void set(const int index, const char value);
+
+	int size() const;
+	int capacity() const;
+	void ensure_capacity(const int capacity);
+	void resize(const int s);
+	void append_array(const String &other);
+	int find(const char val) const;
+
+	float to_float();
+	double to_double();
+	int to_int();
+	uint32_t to_uint();
+
+	char *c_str();
+	const char *c_str() const;
+
+	char *dataw();
+	const char *data() const;
+
+	const char operator[](const int index) const;
+	char operator[](const int index);
+
+	String &operator+=(const String &b);
+	String &operator+=(const char chr);
+	String &operator+=(const char *p_c_str);
+
+	friend String operator+(String lhs, const String &rhs);
+	friend String operator+(String lhs, const char *rhs);
+	friend String operator+(String lhs, const char rhs);
+
+	friend bool operator==(const String &a, const String &b);
+	friend bool operator!=(const String &a, const String &b);
+
+	friend bool operator==(const String &a, const char *b);
+	friend bool operator!=(const String &a, const char *b);
+
+	friend bool operator==(const char *b, const String &a);
+	friend bool operator!=(const char *b, const String &a);
+
+	String();
+	String(const String &other);
+	String(const String &other, const int grow_by);
+	String(const char* p_c_str);
+	String(const char* p_c_str, const int grow_by);
+	String(const int prealloc);
+	String(const int prealloc, const int grow_by);
+
+private:
+	char *_data;
+	int _actual_size;
+	int _size;
+	int _grow_by;
+};
+
+#endif

03_sdl_basics/17_sdl_widgets/text_image.cpp

@@ -0,0 +1,99 @@
+#include "text_image.h"
+
+TextImage::TextType TextImage::get_text_type() {
+	return _text_type;
+}
+void TextImage::set_text_type(const TextImage::TextType type) {
+	_text_type = type;
+}
+
+TrueTypeFont *TextImage::get_font() {
+	return _font;
+}
+void TextImage::set_font(TrueTypeFont *font) {
+	_font = font;
+}
+
+String TextImage::get_text() {
+	return _text;
+}
+void TextImage::set_text(const String &text) {
+	_text = text;
+
+	render_image();
+}
+
+Color TextImage::get_fg_color() {
+	return _fg;
+}
+void TextImage::get_fg_color(const Color &color) {
+	_fg = color;
+}
+
+Color TextImage::get_bg_color() {
+	return _bg;
+}
+void TextImage::get_bg_color(const Color &color) {
+	_bg = color;
+}
+
+Image *TextImage::get_image() {
+	return _image;
+}
+
+int TextImage::get_width() {
+	return _image->get_width();
+}
+int TextImage::get_height() {
+	return _image->get_height();
+}
+
+void TextImage::render_image() {
+	_image->free();
+
+	if (!_font) {
+		return;
+	}
+
+	switch (_text_type) {
+		case SOLID:
+			_font->render_text_solid(_text, _fg, _image);
+			break;
+		case SHADED:
+			_font->render_text_shaded(_text, _fg, _bg, _image);
+			break;
+		case BLENDED:
+			_font->render_text_blended(_text, _fg, _image);
+			break;
+		case BLENDED_WRAPPED:
+			_font->render_text_blended_wrapped(_text, _fg, 100, _image);
+			break;
+
+		default:
+			break;
+	}
+}
+
+TextImage::TextImage() {
+	_font = nullptr;
+	_text_type = BLENDED;
+	_image = new Image();
+}
+TextImage::TextImage(TrueTypeFont *font) {
+	_font = font;
+	_text_type = BLENDED;
+	_image = new Image();
+}
+TextImage::TextImage(TrueTypeFont *font, const String &text, const Color &fg, const Color &bg) {
+	_bg = bg;
+	_fg = fg;
+	_font = font;
+	_text_type = BLENDED;
+	_text = text;
+	_image = new Image();
+
+	render_image();
+}
+TextImage::~TextImage() {
+	delete _image;
+}

03_sdl_basics/17_sdl_widgets/text_image.h

@@ -0,0 +1,57 @@
+#ifndef TEXT_IMAGE_H
+#define TEXT_IMAGE_H
+
+#include <SDL.h>
+
+#include "color.h"
+#include "image.h"
+#include "string.h"
+#include "true_type_font.h"
+#include "vector2.h"
+
+class TextImage {
+public:
+	enum TextType {
+		SOLID,
+		SHADED,
+		BLENDED,
+		BLENDED_WRAPPED
+	};
+
+	TextType get_text_type();
+	void set_text_type(const TextType type);
+
+	TrueTypeFont *get_font();
+	void set_font(TrueTypeFont *font);
+
+	String get_text();
+	void set_text(const String &text);
+
+	Color get_fg_color();
+	void get_fg_color(const Color &color);
+
+	Color get_bg_color();
+	void get_bg_color(const Color &color);
+
+	Image *get_image();
+
+	int get_width();
+	int get_height();
+
+	void render_image();
+
+	TextImage();
+	TextImage(TrueTypeFont *font);
+	TextImage(TrueTypeFont *font, const String &text, const Color &fg = Color(), const Color &bg = Color());
+	virtual ~TextImage();
+
+private:
+	TrueTypeFont *_font;
+	String _text;
+	Image *_image;
+	TextType _text_type;
+	Color _fg;
+	Color _bg;
+};
+
+#endif

03_sdl_basics/17_sdl_widgets/text_sprite.cpp

@@ -0,0 +1,86 @@
+#include "text_sprite.h"
+
+TextImage::TextType TextSprite::get_text_type() {
+	return _text_image->get_text_type();
+}
+void TextSprite::set_text_type(const TextImage::TextType type) {
+	_text_image->set_text_type(type);
+}
+
+TrueTypeFont *TextSprite::get_font() {
+	return _text_image->get_font();
+}
+void TextSprite::set_font(TrueTypeFont *font) {
+	_text_image->set_font(font);
+}
+
+String TextSprite::get_text() {
+	return _text_image->get_text();
+}
+void TextSprite::set_text(const String &text) {
+	_text_image->set_text(text);
+
+	render_image();
+}
+
+Color TextSprite::get_fg_color() {
+	return _text_image->get_fg_color();
+}
+void TextSprite::get_fg_color(const Color &color) {
+	_text_image->get_fg_color(color);
+}
+
+Color TextSprite::get_bg_color() {
+	return _text_image->get_bg_color();
+}
+void TextSprite::get_bg_color(const Color &color) {
+	_text_image->get_bg_color(color);
+}
+
+Image *TextSprite::get_image() {
+	return _text_image->get_image();
+}
+
+int TextSprite::get_width() {
+	return _text_image->get_width();
+}
+int TextSprite::get_height() {
+	return _text_image->get_height();
+}
+
+void TextSprite::render_image() {
+    _text_image->render_image();
+
+	Image *img = _text_image->get_image();
+
+	_tex->set_image(img);
+
+	set_w(img->get_width());
+	set_h(img->get_height());
+
+	set_texture_clip_rect(Rect2(0, 0, img->get_width(), img->get_height()));
+}
+
+TextSprite::TextSprite() {
+	_text_image = new TextImage();
+	_tex = new Texture();
+
+	set_texture(_tex);
+}
+TextSprite::TextSprite(TrueTypeFont *font) {
+	_text_image = new TextImage(font);
+	_tex = new Texture();
+
+	set_texture(_tex);
+}
+TextSprite::TextSprite(TrueTypeFont *font, const String &text, const Color &fg, const Color &bg) {
+	_text_image = new TextImage(font, text, fg, bg);
+	_tex = new Texture();
+
+	set_texture(_tex);
+
+    render_image();
+}
+TextSprite::~TextSprite() {
+	delete _text_image;
+}

03_sdl_basics/17_sdl_widgets/text_sprite.h

@@ -0,0 +1,49 @@
+#ifndef TEXT_SPRITE_H
+#define TEXT_SPRITE_H
+
+#include <SDL.h>
+
+#include "sprite.h"
+
+#include "color.h"
+#include "image.h"
+#include "string.h"
+#include "true_type_font.h"
+#include "vector2.h"
+#include "text_image.h"
+
+class TextSprite : public Sprite {
+public:
+	TextImage::TextType get_text_type();
+	void set_text_type(const TextImage::TextType type);
+
+	TrueTypeFont *get_font();
+	void set_font(TrueTypeFont *font);
+
+	String get_text();
+	void set_text(const String &text);
+
+	Color get_fg_color();
+	void get_fg_color(const Color &color);
+
+	Color get_bg_color();
+	void get_bg_color(const Color &color);
+
+	Image *get_image();
+
+	int get_width();
+	int get_height();
+
+	void render_image();
+
+	TextSprite();
+	TextSprite(TrueTypeFont *font);
+	TextSprite(TrueTypeFont *font, const String &text, const Color &fg = Color(), const Color &bg = Color());
+	virtual ~TextSprite();
+
+private:
+    TextImage *_text_image;
+    Texture *_tex;
+};
+
+#endif

03_sdl_basics/17_sdl_widgets/texture.cpp

@@ -0,0 +1,166 @@
+#include "texture.h"
+
+#include "renderer.h"
+
+Color Texture::get_color_mod() const {
+	Uint8 r;
+	Uint8 g;
+	Uint8 b;
+	Uint8 a;
+
+	SDL_GetTextureColorMod(_texture, &r, &g, &b);
+	SDL_GetTextureAlphaMod(_texture, &a);
+
+	return Color(r, g, b, a);
+}
+void Texture::set_color_mod(const Color &color) {
+	SDL_SetTextureColorMod(_texture, color.r, color.g, color.b);
+	SDL_SetTextureAlphaMod(_texture, color.a);
+}
+
+SDL_BlendMode Texture::get_blend_mode() const {
+	SDL_BlendMode blendMode;
+
+	SDL_GetTextureBlendMode(_texture, &blendMode);
+
+	return blendMode;
+}
+void Texture::set_blend_mode(const SDL_BlendMode blend_mode) {
+	SDL_SetTextureBlendMode(_texture, blend_mode);
+}
+
+SDL_ScaleMode Texture::get_texture_scale_mode() const {
+	SDL_ScaleMode scale_mode;
+
+	SDL_GetTextureScaleMode(_texture, &scale_mode);
+
+	return scale_mode;
+}
+void Texture::set_texture_scale_mode(const SDL_ScaleMode scale_mode) {
+	SDL_SetTextureScaleMode(_texture, scale_mode);
+}
+
+Image *Texture::get_image() {
+	return _image;
+}
+void Texture::set_image(Image *image) {
+	if (_texture) {
+		free();
+	}
+
+	_image = image;
+
+	refresh();
+}
+
+int Texture::get_width() const {
+	Uint32 format;
+	int access;
+	int w;
+	int h;
+
+	if (SDL_QueryTexture(_texture, &format, &access, &w, &h)) {
+		return 0;
+	}
+
+	return w;
+}
+int Texture::get_height() const {
+	Uint32 format;
+	int access;
+	int w;
+	int h;
+
+	if (SDL_QueryTexture(_texture, &format, &access, &w, &h)) {
+		return 0;
+	}
+
+	return h;
+}
+Uint32 Texture::get_format() const {
+	Uint32 format;
+	int access;
+	int w;
+	int h;
+
+	if (SDL_QueryTexture(_texture, &format, &access, &w, &h)) {
+		return 0;
+	}
+
+	return format;
+}
+int Texture::get_access() const {
+	Uint32 format;
+	int access;
+	int w;
+	int h;
+
+	if (SDL_QueryTexture(_texture, &format, &access, &w, &h)) {
+		return 0;
+	}
+
+	return access;
+}
+
+void Texture::create(int access, int w, int h) {
+	if (_texture) {
+		free();
+	}
+
+	_image = nullptr;
+
+	_texture = SDL_CreateTexture(Renderer::get_singleton()->get_renderer(), SDL_PIXELFORMAT_RGBA8888, access, w, h);
+}
+void Texture::refresh() {
+	if (_image == nullptr) {
+		return;
+	}
+
+	if (_image->get_surface() == nullptr) {
+		return;
+	}
+
+	if (_texture) {
+		free();
+	}
+
+	_texture = SDL_CreateTextureFromSurface(Renderer::get_singleton()->get_renderer(), _image->get_surface());
+}
+void Texture::free() {
+    if (_texture) {
+        SDL_DestroyTexture(_texture);
+
+		_texture = nullptr;
+    }
+}
+
+SDL_Texture *Texture::get_texture() {
+    return _texture;
+}
+SDL_Texture *Texture::get_texture() const {
+	return _texture;
+}
+
+bool Texture::is_render_target() {
+	if (_texture == Renderer::get_singleton()->get_render_target()) {
+		return true;
+	}
+
+	return false;
+}
+
+Texture::Texture() {
+	_image = nullptr;
+	_texture = nullptr;
+}
+Texture::Texture(Image *image) {
+	_image = nullptr;
+	_texture = nullptr;
+
+	set_image(image);
+}
+Texture::~Texture() {
+	if (_texture) {
+		free();
+	}
+}

03_sdl_basics/17_sdl_widgets/texture.h

@@ -0,0 +1,44 @@
+#ifndef TEXTURE_H
+#define TEXTURE_H
+
+#include "image.h"
+#include <SDL.h>
+
+class Texture {
+public:
+    Color get_color_mod() const;
+    void set_color_mod(const Color &color);
+
+    SDL_BlendMode get_blend_mode() const;
+    void set_blend_mode(const SDL_BlendMode blend_mode);
+
+    SDL_ScaleMode get_texture_scale_mode() const;
+    void set_texture_scale_mode(const SDL_ScaleMode scale_mode);
+
+    Image *get_image();
+    void set_image(Image *image);
+
+    int get_width() const;
+    int get_height() const;
+    Uint32 get_format() const;
+    int get_access() const;
+
+    void create(const int access, const int w, const int h);
+    void refresh();
+    void free();
+
+    SDL_Texture *get_texture();
+    SDL_Texture *get_texture() const;
+
+    bool is_render_target();
+
+    Texture();
+    Texture(Image *image);
+    virtual ~Texture();
+
+private:
+    Image *_image;
+    SDL_Texture *_texture;
+};
+
+#endif

03_sdl_basics/17_sdl_widgets/true_type_font.cpp

@@ -0,0 +1,316 @@
+#include "true_type_font.h"
+
+int TrueTypeFont::get_style() {
+	return TTF_GetFontStyle(_font);
+}
+void TrueTypeFont::set_style(const int style) {
+	TTF_SetFontStyle(_font, style);
+}
+
+int TrueTypeFont::get_outline() {
+	return TTF_GetFontOutline(_font);
+}
+void TrueTypeFont::set_outline(const int outline) {
+	TTF_SetFontOutline(_font, outline);
+}
+
+int TrueTypeFont::get_hinting() {
+	return TTF_GetFontHinting(_font);
+}
+void TrueTypeFont::set_hinting(const int hinting) {
+	TTF_SetFontHinting(_font, hinting);
+}
+
+int TrueTypeFont::get_height() {
+	return TTF_FontHeight(_font);
+}
+int TrueTypeFont::get_ascent() {
+	return TTF_FontAscent(_font);
+}
+int TrueTypeFont::get_descent() {
+	return TTF_FontDescent(_font);
+}
+int TrueTypeFont::get_line_skip() {
+	return TTF_FontLineSkip(_font);
+}
+
+int TrueTypeFont::get_kerning() {
+	return TTF_GetFontKerning(_font);
+}
+void TrueTypeFont::set_kerning(const int allowed) {
+	TTF_SetFontKerning(_font, allowed);
+}
+
+long TrueTypeFont::get_faces() {
+	return TTF_FontFaces(_font);
+}
+
+int TrueTypeFont::get_face_is_fixed_width() {
+	return TTF_FontFaceIsFixedWidth(_font);
+}
+
+char *TrueTypeFont::get_face_family_name() {
+	return TTF_FontFaceFamilyName(_font);
+}
+
+char *TrueTypeFont::get_face_style_name() {
+	return TTF_FontFaceStyleName(_font);
+}
+
+bool TrueTypeFont::is_glyph_provided(Uint16 ch) {
+	return TTF_GlyphIsProvided(_font, ch);
+}
+
+TrueTypeFont::GlyphMetric TrueTypeFont::glyph_metrics(Uint16 ch) {
+	TrueTypeFont::GlyphMetric g;
+
+	TTF_GlyphMetrics(_font, ch, &g.minx, &g.maxx, &g.miny, &g.maxy, &g.advance);
+
+	return g;
+}
+
+Vector2 TrueTypeFont::get_size_text(const String &text) {
+	int w;
+	int h;
+
+	TTF_SizeText(_font, text.c_str(), &w, &h);
+
+	return Vector2(w, h);
+}
+
+Vector2 TrueTypeFont::get_size_utf8(const String &text) {
+	int w;
+	int h;
+
+	TTF_SizeUTF8(_font, text.c_str(), &w, &h);
+
+	return Vector2(w, h);
+}
+
+Image *TrueTypeFont::render_text_solid(const String &text, const Color &fg, Image *img) {
+	if (!_font) {
+		if (img) {
+			img->free();
+		}
+
+		return img;
+	}
+
+	if (!img) {
+		img = new Image();
+	}
+
+	img->set_surface(TTF_RenderText_Solid(_font, text.c_str(), fg.to_sdl_color()));
+
+	return img;
+}
+
+Image *TrueTypeFont::render_utf8_solid(const String &text, const Color &fg, Image *img) {
+	if (!_font) {
+		if (img) {
+			img->free();
+		}
+
+		return img;
+	}
+
+	if (!img) {
+		img = new Image();
+	}
+
+	img->set_surface(TTF_RenderUTF8_Solid(_font, text.c_str(), fg.to_sdl_color()));
+
+	return img;
+}
+
+Image *TrueTypeFont::render_glyph_solid(const Uint16 ch, const Color &fg, Image *img) {
+	if (!_font) {
+		if (img) {
+			img->free();
+		}
+
+		return img;
+	}
+
+	if (!img) {
+		img = new Image();
+	}
+
+	img->set_surface(TTF_RenderGlyph_Solid(_font, ch, fg.to_sdl_color()));
+
+	return img;
+}
+
+Image *TrueTypeFont::render_text_shaded(const String &text, const Color &fg, const Color &bg, Image *img) {
+	if (!_font) {
+		if (img) {
+			img->free();
+		}
+
+		return img;
+	}
+
+	if (!img) {
+		img = new Image();
+	}
+
+	img->set_surface(TTF_RenderText_Shaded(_font, text.c_str(), fg.to_sdl_color(), bg.to_sdl_color()));
+
+	return img;
+}
+
+Image *TrueTypeFont::render_utf8_shaded(const String &text, const Color &fg, const Color &bg, Image *img) {
+	if (!_font) {
+		if (img) {
+			img->free();
+		}
+
+		return img;
+	}
+
+	if (!img) {
+		img = new Image();
+	}
+
+	img->set_surface(TTF_RenderUTF8_Shaded(_font, text.c_str(), fg.to_sdl_color(), bg.to_sdl_color()));
+
+	return img;
+}
+
+Image *TrueTypeFont::render_glyph_shaded(const Uint16 ch, const Color &fg, const Color &bg, Image *img) {
+	if (!_font) {
+		if (img) {
+			img->free();
+		}
+
+		return img;
+	}
+
+	if (!img) {
+		img = new Image();
+	}
+
+	img->set_surface(TTF_RenderGlyph_Shaded(_font, ch, fg.to_sdl_color(), bg.to_sdl_color()));
+
+	return img;
+}
+
+Image *TrueTypeFont::render_text_blended(const String &text, const Color &fg, Image *img) {
+	if (!_font) {
+		if (img) {
+			img->free();
+		}
+
+		return img;
+	}
+
+	if (!img) {
+		img = new Image();
+	}
+
+	img->set_surface(TTF_RenderText_Blended(_font, text.c_str(), fg.to_sdl_color()));
+
+	return img;
+}
+
+Image *TrueTypeFont::render_utf8_blended(const String &text, const Color &fg, Image *img) {
+	if (!_font) {
+		if (img) {
+			img->free();
+		}
+
+		return img;
+	}
+
+	if (!img) {
+		img = new Image();
+	}
+
+	img->set_surface(TTF_RenderUTF8_Blended(_font, text.c_str(), fg.to_sdl_color()));
+
+	return img;
+}
+
+Image *TrueTypeFont::render_text_blended_wrapped(const String &text, const Color &fg, Uint32 wrap_length, Image *img) {
+	if (!_font) {
+		if (img) {
+			img->free();
+		}
+
+		return img;
+	}
+
+	if (!img) {
+		img = new Image();
+	}
+
+	img->set_surface(TTF_RenderText_Blended_Wrapped(_font, text.c_str(), fg.to_sdl_color(), wrap_length));
+
+	return img;
+}
+
+Image *TrueTypeFont::render_utf8_blended_wrapped(const String &text, const Color &fg, Uint32 wrap_length, Image *img) {
+	if (!_font) {
+		if (img) {
+			img->free();
+		}
+
+		return img;
+	}
+
+	if (!img) {
+		img = new Image();
+	}
+
+	img->set_surface(TTF_RenderUTF8_Blended_Wrapped(_font, text.c_str(), fg.to_sdl_color(), wrap_length));
+
+	return img;
+}
+
+Image *TrueTypeFont::render_glyph_blended(const Uint16 ch, const Color &fg, Image *img) {
+	if (!_font) {
+		if (img) {
+			img->free();
+		}
+
+		return img;
+	}
+
+	if (!img) {
+		img = new Image();
+	}
+
+	img->set_surface(TTF_RenderGlyph_Blended(_font, ch, fg.to_sdl_color()));
+
+	return img;
+}
+
+void TrueTypeFont::load(const String &file_name, const int ptsize, const int index) {
+	if (index == -1) {
+		_font = TTF_OpenFont(file_name.c_str(), ptsize);
+	} else {
+		_font = TTF_OpenFontIndex(file_name.c_str(), ptsize, index);
+	}
+}
+
+void TrueTypeFont::free() {
+	if (_font) {
+		TTF_CloseFont(_font);
+
+		_font = nullptr;
+	}
+}
+
+TrueTypeFont::TrueTypeFont() {
+	_font = nullptr;
+}
+
+TrueTypeFont::TrueTypeFont(const String &file_name, const int ptsize, const int index) {
+	_font = nullptr;
+
+	load(file_name, ptsize, index);
+}
+
+TrueTypeFont::~TrueTypeFont() {
+	free();
+}

03_sdl_basics/17_sdl_widgets/true_type_font.h

@@ -0,0 +1,80 @@
+#ifndef TURE_TYPE_FONT_H
+#define TURE_TYPE_FONT_H
+
+#include <SDL.h>
+#include <SDL_ttf.h>
+
+#include "color.h"
+#include "string.h"
+#include "vector2.h"
+#include "image.h"
+
+class TrueTypeFont {
+public:
+	struct GlyphMetric {
+		int minx;
+		int maxx;
+		int miny;
+		int maxy;
+		int advance;
+	};
+
+	int get_style();
+	void set_style(const int style);
+
+	int get_outline();
+	void set_outline(const int outline);
+
+	int get_hinting();
+	void set_hinting(const int hinting);
+
+	int get_height();
+	int get_ascent();
+	int get_descent();
+	int get_line_skip();
+
+	int get_kerning();
+	void set_kerning(const int allowed);
+
+	long get_faces();
+
+	int get_face_is_fixed_width();
+	char *get_face_family_name();
+	char *get_face_style_name();
+
+	bool is_glyph_provided(Uint16 ch);
+
+	GlyphMetric glyph_metrics(Uint16 ch);
+
+	Vector2 get_size_text(const String &text);
+	Vector2 get_size_utf8(const String &text);
+	Vector2 get_size_unicode(const String &text);
+
+	Image *render_text_solid(const String &text, const Color &fg, Image *img = nullptr);
+	Image *render_utf8_solid(const String &text, const Color &fg, Image *img = nullptr);
+    Image *render_glyph_solid(const Uint16 ch, const Color &fg, Image *img = nullptr);
+
+	Image *render_text_shaded(const String &text, const Color &fg, const Color &bg, Image *img = nullptr);
+	Image *render_utf8_shaded(const String &text, const Color &fg, const Color &bg, Image *img = nullptr);
+	Image *render_glyph_shaded(const Uint16 ch, const Color &fg, const Color &bg, Image *img = nullptr);
+
+	Image *render_text_blended(const String &text, const Color &fg, Image *img = nullptr);
+	Image *render_utf8_blended(const String &text, const Color &fg, Image *img = nullptr);
+
+	Image *render_text_blended_wrapped(const String &text, const Color &fg, Uint32 wrap_length, Image *img = nullptr);
+	Image *render_utf8_blended_wrapped(const String &text, const Color &fg, Uint32 wrap_length, Image *img = nullptr);
+
+	Image *render_glyph_blended(const Uint16 ch, const Color &fg, Image *img = nullptr);
+
+	void load(const String &file_name, const int ptsize, const int index = -1);
+	void free();
+
+	TrueTypeFont();
+	TrueTypeFont(const String &file_name, const int ptsize, const int index = -1);
+	~TrueTypeFont();
+
+private:
+	TTF_Font *_font;
+};
+
+#endif

03_sdl_basics/17_sdl_widgets/vector.h

@@ -0,0 +1,213 @@
+#ifndef VECTOR_H
+#define VECTOR_H
+
+template <class T>
+class Vector {
+
+public:
+	void push_back(const T &element);
+	void pop_back();
+	void remove(const int index);
+	void remove_keep_order(const int index);
+	void erase(const T &element);
+	void clear();
+	bool empty() const;
+	T get(const int index);
+	const T &get(const int index) const;
+	void set(const int index, const T &value);
+
+	int size() const;
+	int capacity() const;
+	void ensure_capacity(const int capacity);
+	void resize(const int s);
+	void append_array(const Vector<T> &other);
+	int find(const T &val) const;
+
+	int *dataw();
+	const int *data() const;
+
+	const T &operator[](const int index) const;
+	T &operator[](const int index);
+
+	Vector();
+	Vector(int prealloc);
+	Vector(int prealloc, int grow_by);
+
+private:
+	T *_data;
+	int _actual_size;
+	int _size;
+	int _grow_by;
+};
+
+template <class T>
+void Vector<T>::push_back(const T &element) {
+	ensure_capacity(_size + 1);
+
+	_data[_size++] = element;
+}
+
+template <class T>
+void Vector<T>::pop_back() {
+	if (_size == 0) {
+		return;
+	}
+
+	--_size;
+}
+
+template <class T>
+void Vector<T>::remove(const int index) {
+	_data[index] = _data[_size - 1];
+
+	--_size;
+}
+
+template <class T>
+void Vector<T>::remove_keep_order(const int index) {
+	--_size;
+
+	for (int i = index; i < _size; ++i) {
+		_data[i] = _data[i + 1];
+	}
+}
+
+template <class T>
+void Vector<T>::erase(const T &element) {
+	int index = find(element);
+
+	if (index != -1) {
+		remove(index);
+	}
+}
+
+template <class T>
+void Vector<T>::clear() {
+	_size = 0;
+}
+
+template <class T>
+bool Vector<T>::empty() const {
+	return _size == 0;
+}
+
+template <class T>
+T Vector<T>::get(const int index) {
+	return _data[index];
+}
+
+template <class T>
+const T &Vector<T>::get(const int index) const {
+	return _data[index];
+}
+
+template <class T>
+void Vector<T>::set(const int index, const T &value) {
+	_data[index] = value;
+}
+
+template <class T>
+int Vector<T>::size() const {
+	return _size;
+}
+
+template <class T>
+int Vector<T>::capacity() const {
+	return _actual_size;
+}
+
+template <class T>
+void Vector<T>::ensure_capacity(const int capacity) {
+	if (capacity <= _actual_size) {
+		return;
+	}
+
+	int tsize = capacity + _grow_by;
+
+	T *nd = new T[tsize];
+
+	for (int i = 0; i < _size; ++i) {
+		nd[i] = _data[i];
+	}
+
+	delete[] _data;
+
+	_data = nd;
+}
+
+template <class T>
+void Vector<T>::resize(const int s) {
+	ensure_capacity(s);
+
+	_size = s;
+}
+
+template <class T>
+void Vector<T>::append_array(const Vector<T> &other) {
+	ensure_capacity(_size + other._size);
+
+	for (int i = 0; i < other._size; ++i) {
+		_data[_size++] = other._data[i];
+	}
+}
+
+template <class T>
+int Vector<T>::find(const T &val) const {
+	for (int i = 0; i < _size; ++i) {
+		if (_data[i] == val) {
+			return i;
+		}
+	}
+
+	return -1;
+}
+
+template <class T>
+int *Vector<T>::dataw() {
+	return _data;
+}
+
+template <class T>
+const int *Vector<T>::data() const {
+	return _data;
+}
+
+template <class T>
+const T &Vector<T>::operator[](const int index) const {
+	return _data[index];
+}
+
+template <class T>
+T &Vector<T>::operator[](const int index) {
+	return _data[index];
+}
+
+template <class T>
+Vector<T>::Vector() {
+	_data = nullptr;
+	_actual_size = 0;
+	_size = 0;
+	_grow_by = 100;
+}
+
+template <class T>
+Vector<T>::Vector(int prealloc) {
+	_data = nullptr;
+	_actual_size = 0;
+	_size = 0;
+	_grow_by = 100;
+
+	ensure_capacity(prealloc);
+}
+
+template <class T>
+Vector<T>::Vector(int prealloc, int grow_by) {
+	_data = nullptr;
+	_actual_size = 0;
+	_size = 0;
+	_grow_by = grow_by;
+
+	ensure_capacity(prealloc);
+}
+
+#endif

03_sdl_basics/17_sdl_widgets/vector2.cpp

@@ -0,0 +1,172 @@
+#include "vector2.h"
+
+#include <cmath>
+
+#define EPSILON 0.00001
+
+Vector2 Vector2::abs() const {
+	Vector2 b;
+
+	b.x = x >= 0 ? x : -x;
+	b.y = y >= 0 ? y : -y;
+
+	return b;
+}
+
+float Vector2::angle() const {
+	return atan2(x, y);
+}
+
+float Vector2::angle_to(const Vector2 &b) const {
+	return atan2(cross(b), dot(b));
+}
+
+float Vector2::cross(const Vector2 &b) const {
+	return x * b.y - y * b.x;
+}
+
+Vector2 Vector2::clamped(float len) const {
+	return normalized() * len;
+}
+
+Vector2 Vector2::direction_to(const Vector2 &b) const {
+	return (b - *this).normalized();
+}
+
+float Vector2::distance_to_squared(const Vector2 &b) const {
+	return (x - b.x) * (x - b.x) + (y - b.y) * (y - b.y);
+}
+
+float Vector2::distance_to(const Vector2 &b) const {
+	return sqrt((x - b.x) * (x - b.x) + (y - b.y) * (y - b.y));
+}
+
+float Vector2::dot(const Vector2 &b) const {
+	return x * b.x + y * b.y;
+}
+
+bool Vector2::is_equal_approx(const Vector2 &b) const {
+	if (x + EPSILON < b.x && x - EPSILON > b.x && y + EPSILON < b.y && y - EPSILON > b.y) {
+		return true;
+	}
+
+	return false;
+}
+
+float Vector2::length() const {
+	return sqrt(x * x + y * y);
+}
+
+float Vector2::length_squared() const {
+	return x * x + y * y;
+}
+
+Vector2 Vector2::lerp(const Vector2 &b, const float t) const {
+	Vector2 v;
+
+	v.x = x + (t * (b.x - x));
+	v.y = y + (t * (b.y - y));
+
+	return v;
+}
+
+Vector2 Vector2::normalized() const {
+	Vector2 v;
+
+	float l = length_squared();
+
+	if (l != 0) {
+		l = sqrt(l);
+
+		v.x = x / l;
+		v.y = y / l;
+	}
+
+	return v;
+}
+
+void Vector2::normalize() {
+	float l = length_squared();
+
+	if (l != 0) {
+		l = sqrt(l);
+
+		x = x / l;
+		y = y / l;
+	}
+}
+
+void Vector2::add(const Vector2 &b) {
+	x += b.x;
+	y += b.y;
+}
+
+void Vector2::sub(const Vector2 &b) {
+	x -= b.x;
+	y -= b.y;
+}
+
+Vector2::Vector2() {
+	x = 0;
+	y = 0;
+}
+
+Vector2::Vector2(const Vector2 &b) {
+	x = b.x;
+	y = b.y;
+}
+
+Vector2::Vector2(const float p_x, const float p_y) {
+	x = p_x;
+	y = p_y;
+}
+
+Vector2 &Vector2::operator+=(const Vector2 &b) {
+	x += b.x;
+	y += b.y;
+
+	return *this;
+}
+
+Vector2 &Vector2::operator-=(const Vector2 &b) {
+	x -= b.x;
+	y -= b.y;
+
+	return *this;
+}
+
+Vector2 &Vector2::operator*=(const float b) {
+	x *= b;
+	y *= b;
+
+	return *this;
+}
+
+Vector2 operator*(Vector2 lhs, const float rhs) {
+	lhs.x *= rhs;
+	lhs.y *= rhs;
+
+	return lhs;
+}
+
+Vector2 operator+(Vector2 lhs, const Vector2 &rhs) {
+	lhs.x += rhs.x;
+	lhs.y += rhs.y;
+
+	return lhs;
+}
+
+Vector2 operator-(Vector2 lhs, const Vector2 &rhs) {
+	lhs.x -= rhs.x;
+	lhs.y -= rhs.y;
+
+	return lhs;
+}
+
+bool operator==(const Vector2 &a, const Vector2 &b) {
+	return a.is_equal_approx(b);
+}
+
+bool operator!=(const Vector2 &a, const Vector2 &b) {
+	return !(a == b);
+}

03_sdl_basics/17_sdl_widgets/vector2.h

@@ -0,0 +1,48 @@
+#ifndef VECTOR2_H
+#define VECTOR2_H
+
+class Vector2 {
+public:
+	Vector2 abs() const;
+	float angle() const;
+	float angle_to(const Vector2 &b) const;
+	float cross(const Vector2 &b) const;
+	Vector2 clamped(float len) const;
+	Vector2 direction_to(const Vector2 &b) const;
+	float distance_to_squared(const Vector2 &b) const;
+	float distance_to(const Vector2 &b) const;
+	float dot(const Vector2 &b) const;
+	bool is_equal_approx(const Vector2 &b) const;
+
+	float length() const;
+	float length_squared() const;
+
+	Vector2 lerp(const Vector2 &b, const float t) const;
+
+	Vector2 normalized() const;
+	void normalize();
+
+	void add(const Vector2 &b);
+	void sub(const Vector2 &b);
+
+	Vector2();
+	Vector2(const Vector2 &b);
+	Vector2(const float p_x, const float p_y);
+
+	Vector2 &operator+=(const Vector2 &b);
+	Vector2 &operator-=(const Vector2 &b);
+
+	friend Vector2 operator+(Vector2 lhs, const Vector2 &rhs);
+	friend Vector2 operator-(Vector2 lhs, const Vector2 &rhs);
+
+	Vector2 &operator*=(const float b);
+	friend Vector2 operator*(Vector2 lhs, const float rhs);
+
+	friend bool operator==(const Vector2 &a, const Vector2 &b);
+	friend bool operator!=(const Vector2 &a, const Vector2 &b);
+
+	float x;
+	float y;
+};
+
+#endif

03_sdl_basics/17_sdl_widgets/vector3.cpp

@@ -0,0 +1,190 @@
+#include "vector3.h"
+
+#include <cmath>
+
+#define EPSILON 0.00001
+
+Vector3 Vector3::abs() const {
+	Vector3 b;
+
+	b.x = x >= 0 ? x : -x;
+	b.y = y >= 0 ? y : -y;
+	b.z = z >= 0 ? z : -z;
+
+	return b;
+}
+
+float Vector3::angle_to(const Vector3 &b) const {
+	return atan2(cross(b).length(), dot(b));
+}
+
+Vector3 Vector3::cross(const Vector3 &b) const {
+	Vector3 v;
+
+	v.x = (y * b.z) - (z * b.y);
+	v.y = (z * b.x) - (x * b.z);
+	v.z = (x * b.y) - (y * b.x);
+
+	return v;
+}
+
+Vector3 Vector3::clamped(float len) const {
+	return normalized() * len;
+}
+
+Vector3 Vector3::direction_to(const Vector3 &b) const {
+	return (b - *this).normalized();
+}
+
+float Vector3::distance_to_squared(const Vector3 &b) const {
+	return (b - *this).length_squared();
+}
+
+float Vector3::distance_to(const Vector3 &b) const {
+	return (b - *this).length();
+}
+
+float Vector3::dot(const Vector3 &b) const {
+	return x * b.x + y * b.y + z * b.z;
+}
+
+bool Vector3::is_equal_approx(const Vector3 &b) const {
+	if (x + EPSILON < b.x && x - EPSILON > b.x && y + EPSILON < b.y && y - EPSILON > b.y &&
+			z + EPSILON < b.z && z - EPSILON > b.z) {
+		return true;
+	}
+
+	return false;
+}
+
+float Vector3::length() const {
+	return sqrt(x * x + y * y + z * z);
+}
+
+float Vector3::length_squared() const {
+	return x * x + y * y + z * z;
+}
+
+Vector3 Vector3::lerp(const Vector3 &b, const float t) const {
+	Vector3 v;
+
+	v.x = x + (t * (b.x - x));
+	v.y = y + (t * (b.y - y));
+	v.z = z + (t * (b.z - z));
+
+	return v;
+}
+
+Vector3 Vector3::normalized() const {
+	Vector3 v;
+
+	float l = length_squared();
+
+	if (l != 0) {
+		l = sqrt(l);
+
+		v.x = x / l;
+		v.y = y / l;
+		v.z = z / l;
+	}
+
+	return v;
+}
+
+void Vector3::normalize() {
+	float l = length_squared();
+
+	if (l != 0) {
+		l = sqrt(l);
+
+		x = x / l;
+		y = y / l;
+		z = z / l;
+	}
+}
+
+void Vector3::add(const Vector3 &b) {
+	x += b.x;
+	y += b.y;
+	z += b.z;
+}
+
+void Vector3::sub(const Vector3 &b) {
+	x -= b.x;
+	y -= b.y;
+	z -= b.z;
+}
+
+Vector3::Vector3() {
+	x = 0;
+	y = 0;
+	z = 0;
+}
+
+Vector3::Vector3(const Vector3 &b) {
+	x = b.x;
+	y = b.y;
+	z = b.z;
+}
+
+Vector3::Vector3(const float p_x, const float p_y, const float p_z) {
+	x = p_x;
+	y = p_y;
+	z = p_z;
+}
+
+Vector3 &Vector3::operator+=(const Vector3 &b) {
+	x += b.x;
+	y += b.y;
+	z += b.z;
+
+	return *this;
+}
+
+Vector3 &Vector3::operator-=(const Vector3 &b) {
+	x -= b.x;
+	y -= b.y;
+	z -= b.z;
+
+	return *this;
+}
+
+Vector3 &Vector3::operator*=(const float b) {
+	x *= b;
+	y *= b;
+	z *= b;
+
+	return *this;
+}
+
+Vector3 operator*(Vector3 lhs, const float rhs) {
+	lhs.x *= rhs;
+	lhs.y *= rhs;
+	lhs.z *= rhs;
+
+	return lhs;
+}
+
+Vector3 operator+(Vector3 lhs, const Vector3 &rhs) {
+	lhs.x += rhs.x;
+	lhs.y += rhs.y;
+	lhs.z += rhs.z;
+
+	return lhs;
+}
+
+Vector3 operator-(Vector3 lhs, const Vector3 &rhs) {
+	lhs.x -= rhs.x;
+	lhs.y -= rhs.y;
+	lhs.z -= rhs.z;
+
+	return lhs;
+}
+
+bool operator==(const Vector3 &a, const Vector3 &b) {
+	return a.is_equal_approx(b);
+}
+
+bool operator!=(const Vector3 &a, const Vector3 &b) {
+	return !(a == b);
+}

03_sdl_basics/17_sdl_widgets/vector3.h

@@ -0,0 +1,48 @@
+#ifndef VECTOR3_H
+#define VECTOR3_H
+
+class Vector3 {
+public:
+	Vector3 abs() const;
+	float angle_to(const Vector3 &b) const;
+	Vector3 cross(const Vector3 &b) const;
+	Vector3 clamped(float len) const;
+	Vector3 direction_to(const Vector3 &b) const;
+	float distance_to_squared(const Vector3 &b) const;
+	float distance_to(const Vector3 &b) const;
+	float dot(const Vector3 &b) const;
+	bool is_equal_approx(const Vector3 &b) const;
+
+	float length() const;
+	float length_squared() const;
+
+	Vector3 lerp(const Vector3 &b, const float t) const;
+
+	Vector3 normalized() const;
+	void normalize();
+
+	void add(const Vector3 &b);
+	void sub(const Vector3 &b);
+
+	Vector3();
+	Vector3(const Vector3 &b);
+	Vector3(const float p_x, const float p_y, const float p_z);
+
+	Vector3 &operator+=(const Vector3 &b);
+	Vector3 &operator-=(const Vector3 &b);
+
+	friend Vector3 operator+(Vector3 lhs, const Vector3 &rhs);
+	friend Vector3 operator-(Vector3 lhs, const Vector3 &rhs);
+
+	Vector3 &operator*=(const float b);
+	friend Vector3 operator*(Vector3 lhs, const float rhs);
+
+	friend bool operator==(const Vector3 &a, const Vector3 &b);
+	friend bool operator!=(const Vector3 &a, const Vector3 &b);
+
+	float x;
+	float y;
+	float z;
+};
+
+#endif