/*************************************************************************/
/*  gpu_particles_2d.cpp                                                 */
/*************************************************************************/
/*                         This file is part of:                         */
/*                          PANDEMONIUM ENGINE                           */
/*             https://github.com/Relintai/pandemonium_engine            */
/*************************************************************************/
/* Copyright (c) 2022-present Péter Magyar.                              */
/* Copyright (c) 2014-2022 Godot Engine contributors (cf. AUTHORS.md).   */
/* Copyright (c) 2007-2022 Juan Linietsky, Ariel Manzur.                 */
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/* Permission is hereby granted, free of charge, to any person obtaining */
/* a copy of this software and associated documentation files (the       */
/* "Software"), to deal in the Software without restriction, including   */
/* without limitation the rights to use, copy, modify, merge, publish,   */
/* distribute, sublicense, and/or sell copies of the Software, and to    */
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/* the following conditions:                                             */
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/* The above copyright notice and this permission notice shall be        */
/* included in all copies or substantial portions of the Software.       */
/*                                                                       */
/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
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/*************************************************************************/

#include "gpu_particles_2d.h"

#include "core/os/os.h"
#include "scene/main/scene_string_names.h"
#include "scene/resources/material/particles_material.h"

#ifdef TOOLS_ENABLED
#include "core/config/engine.h"
#endif

void GPUParticles2D::set_emitting(bool p_emitting) {
	// Do not return even if `p_emitting == emitting` because `emitting` is just an approximation.

	if (p_emitting && one_shot) {
		if (!active && !emitting) {
			// Last cycle ended.
			active = true;
			time = 0;
			signal_canceled = false;
			emission_time = lifetime;
			active_time = lifetime * (2 - explosiveness_ratio);
		} else {
			signal_canceled = true;
		}
		set_process_internal(true);
	} else if (!p_emitting) {
		if (one_shot) {
			set_process_internal(true);
		} else {
			set_process_internal(false);
		}
	}

	emitting = p_emitting;
	RS::get_singleton()->particles_set_emitting(particles, p_emitting);
}

void GPUParticles2D::set_amount(int p_amount) {
	ERR_FAIL_COND_MSG(p_amount < 1, "Amount of particles cannot be smaller than 1.");
	amount = p_amount;
	RS::get_singleton()->particles_set_amount(particles, amount);
}
void GPUParticles2D::set_lifetime(float p_lifetime) {
	ERR_FAIL_COND_MSG(p_lifetime <= 0, "GPUParticles lifetime must be greater than 0.");
	lifetime = p_lifetime;
	RS::get_singleton()->particles_set_lifetime(particles, lifetime);
}

void GPUParticles2D::set_one_shot(bool p_enable) {
	one_shot = p_enable;
	RS::get_singleton()->particles_set_one_shot(particles, one_shot);

	if (is_emitting()) {
		set_process_internal(true);
		if (!one_shot) {
			RenderingServer::get_singleton()->particles_restart(particles);
		}
	}

	if (!one_shot) {
		set_process_internal(false);
	}
}
void GPUParticles2D::set_pre_process_time(float p_time) {
	pre_process_time = p_time;
	RS::get_singleton()->particles_set_pre_process_time(particles, pre_process_time);
}
void GPUParticles2D::set_explosiveness_ratio(float p_ratio) {
	explosiveness_ratio = p_ratio;
	RS::get_singleton()->particles_set_explosiveness_ratio(particles, explosiveness_ratio);
}
void GPUParticles2D::set_randomness_ratio(float p_ratio) {
	randomness_ratio = p_ratio;
	RS::get_singleton()->particles_set_randomness_ratio(particles, randomness_ratio);
}
void GPUParticles2D::set_visibility_rect(const Rect2 &p_visibility_rect) {
	visibility_rect = p_visibility_rect;
	AABB aabb;
	aabb.position.x = p_visibility_rect.position.x;
	aabb.position.y = p_visibility_rect.position.y;
	aabb.size.x = p_visibility_rect.size.x;
	aabb.size.y = p_visibility_rect.size.y;

	RS::get_singleton()->particles_set_custom_aabb(particles, aabb);

	_change_notify("visibility_rect");
	update();
}
void GPUParticles2D::set_use_local_coordinates(bool p_enable) {
	local_coords = p_enable;
	RS::get_singleton()->particles_set_use_local_coordinates(particles, local_coords);
	set_notify_transform(!p_enable);
	if (!p_enable && is_inside_tree()) {
		_update_particle_emission_transform();
	}
}

void GPUParticles2D::_update_particle_emission_transform() {
	Transform2D xf2d = get_global_transform();
	Transform xf;
	xf.basis.set_axis(0, Vector3(xf2d.get_axis(0).x, xf2d.get_axis(0).y, 0));
	xf.basis.set_axis(1, Vector3(xf2d.get_axis(1).x, xf2d.get_axis(1).y, 0));
	xf.set_origin(Vector3(xf2d.get_origin().x, xf2d.get_origin().y, 0));

	RS::get_singleton()->particles_set_emission_transform(particles, xf);
}

void GPUParticles2D::set_process_material(const Ref<Material> &p_material) {
	process_material = p_material;
	Ref<ParticlesMaterial> pm = p_material;
	if (pm.is_valid() && !pm->get_flag(ParticlesMaterial::FLAG_DISABLE_Z) && pm->get_gravity() == Vector3(0, -9.8, 0)) {
		// Likely a new (3D) material, modify it to match 2D space
		pm->set_flag(ParticlesMaterial::FLAG_DISABLE_Z, true);
		pm->set_gravity(Vector3(0, 98, 0));
	}
	RID material_rid;
	if (process_material.is_valid()) {
		material_rid = process_material->get_rid();
	}
	RS::get_singleton()->particles_set_process_material(particles, material_rid);

	update_configuration_warning();
}

void GPUParticles2D::set_speed_scale(float p_scale) {
	speed_scale = p_scale;
	RS::get_singleton()->particles_set_speed_scale(particles, p_scale);
}

#ifdef TOOLS_ENABLED
void GPUParticles2D::set_show_visibility_rect(bool p_show_visibility_rect) {
	show_visibility_rect = p_show_visibility_rect;
	update();
}
#endif

bool GPUParticles2D::is_emitting() const {
	return emitting;
}
int GPUParticles2D::get_amount() const {
	return amount;
}
float GPUParticles2D::get_lifetime() const {
	return lifetime;
}

bool GPUParticles2D::get_one_shot() const {
	return one_shot;
}
float GPUParticles2D::get_pre_process_time() const {
	return pre_process_time;
}
float GPUParticles2D::get_explosiveness_ratio() const {
	return explosiveness_ratio;
}
float GPUParticles2D::get_randomness_ratio() const {
	return randomness_ratio;
}
Rect2 GPUParticles2D::get_visibility_rect() const {
	return visibility_rect;
}
bool GPUParticles2D::get_use_local_coordinates() const {
	return local_coords;
}
Ref<Material> GPUParticles2D::get_process_material() const {
	return process_material;
}

float GPUParticles2D::get_speed_scale() const {
	return speed_scale;
}

void GPUParticles2D::set_draw_order(DrawOrder p_order) {
	draw_order = p_order;
	RS::get_singleton()->particles_set_draw_order(particles, RS::ParticlesDrawOrder(p_order));
}

GPUParticles2D::DrawOrder GPUParticles2D::get_draw_order() const {
	return draw_order;
}

void GPUParticles2D::set_fixed_fps(int p_count) {
	fixed_fps = p_count;
	RS::get_singleton()->particles_set_fixed_fps(particles, p_count);
}

int GPUParticles2D::get_fixed_fps() const {
	return fixed_fps;
}

void GPUParticles2D::set_fractional_delta(bool p_enable) {
	fractional_delta = p_enable;
	RS::get_singleton()->particles_set_fractional_delta(particles, p_enable);
}

bool GPUParticles2D::get_fractional_delta() const {
	return fractional_delta;
}

String GPUParticles2D::get_configuration_warning() const {
	String warning = Node2D::get_configuration_warning();

	if (OS::get_singleton()->get_current_video_driver() == OS::VIDEO_DRIVER_GLES2) {
		if (warning != String()) {
			warning += "\n\n";
		}
		warning += "- " + TTR("GPU-based particles are not supported by the GLES2 video driver.\nUse the CPUParticles2D node instead. You can use the \"Convert to CPUParticles2D\" toolbar option for this purpose.");
		return warning;
	}

#ifdef OSX_ENABLED
	if (warning != String()) {
		warning += "\n\n";
	}

	warning += "- " + TTR("On macOS, GPUParticles2D rendering is much slower than CPUParticles2D due to transform feedback being implemented on the CPU instead of the GPU.\nConsider using CPUParticles2D instead when targeting macOS.\nYou can use the \"Convert to CPUParticles2D\" toolbar option for this purpose.");
#endif

	if (process_material.is_null()) {
		if (warning != String()) {
			warning += "\n\n";
		}
		warning += "- " + TTR("A material to process the particles is not assigned, so no behavior is imprinted.");
	} else {
		CanvasItemMaterial *mat = Object::cast_to<CanvasItemMaterial>(get_material().ptr());

		if (get_material().is_null() || (mat && !mat->get_particles_animation())) {
			const ParticlesMaterial *process = Object::cast_to<ParticlesMaterial>(process_material.ptr());
			if (process &&
					(process->get_param(ParticlesMaterial::PARAM_ANIM_SPEED) != 0.0 || process->get_param(ParticlesMaterial::PARAM_ANIM_OFFSET) != 0.0 ||
							process->get_param_texture(ParticlesMaterial::PARAM_ANIM_SPEED).is_valid() || process->get_param_texture(ParticlesMaterial::PARAM_ANIM_OFFSET).is_valid())) {
				if (warning != String()) {
					warning += "\n\n";
				}
				warning += "- " + TTR("GPUParticles2D animation requires the usage of a CanvasItemMaterial with \"GPUParticles Animation\" enabled.");
			}
		}
	}

	return warning;
}

Rect2 GPUParticles2D::capture_rect() const {
	AABB aabb = RS::get_singleton()->particles_get_current_aabb(particles);
	Rect2 r;
	r.position.x = aabb.position.x;
	r.position.y = aabb.position.y;
	r.size.x = aabb.size.x;
	r.size.y = aabb.size.y;
	return r;
}

void GPUParticles2D::set_texture(const Ref<Texture> &p_texture) {
	texture = p_texture;
	update();
}

Ref<Texture> GPUParticles2D::get_texture() const {
	return texture;
}

void GPUParticles2D::set_normal_map(const Ref<Texture> &p_normal_map) {
	normal_map = p_normal_map;
	update();
}

Ref<Texture> GPUParticles2D::get_normal_map() const {
	return normal_map;
}

void GPUParticles2D::_validate_property(PropertyInfo &property) const {
}

void GPUParticles2D::restart() {
	RS::get_singleton()->particles_restart(particles);
	RS::get_singleton()->particles_set_emitting(particles, true);

	emitting = true;
	active = true;
	signal_canceled = false;
	time = 0;
	emission_time = lifetime;
	active_time = lifetime * (2 - explosiveness_ratio);
	if (one_shot) {
		set_process_internal(true);
	}
}

void GPUParticles2D::_notification(int p_what) {
	if (p_what == NOTIFICATION_DRAW) {
		RID texture_rid;
		if (texture.is_valid()) {
			texture_rid = texture->get_rid();
		}
		RID normal_rid;
		if (normal_map.is_valid()) {
			normal_rid = normal_map->get_rid();
		}

		RS::get_singleton()->canvas_item_add_particles(get_canvas_item(), particles, texture_rid, normal_rid);

#ifdef TOOLS_ENABLED
		if (show_visibility_rect) {
			draw_rect(visibility_rect, Color(0, 0.7, 0.9, 0.4), false);
		}
#endif
	}

	if (p_what == NOTIFICATION_PAUSED || p_what == NOTIFICATION_UNPAUSED) {
		if (can_process()) {
			RS::get_singleton()->particles_set_speed_scale(particles, speed_scale);
		} else {
			RS::get_singleton()->particles_set_speed_scale(particles, 0);
		}
	}

	if (p_what == NOTIFICATION_TRANSFORM_CHANGED) {
		_update_particle_emission_transform();
	}

	if (p_what == NOTIFICATION_INTERNAL_PROCESS) {
		if (one_shot) {
			time += get_process_delta_time();
			if (time > emission_time) {
				emitting = false;
				if (!active) {
					set_process_internal(false);
				}
			}
			if (time > active_time) {
				if (active && !signal_canceled) {
					emit_signal(SceneStringNames::get_singleton()->finished);
				}
				active = false;
				if (!emitting) {
					set_process_internal(false);
				}
			}
		}
	}
}

void GPUParticles2D::_bind_methods() {
	ClassDB::bind_method(D_METHOD("set_emitting", "emitting"), &GPUParticles2D::set_emitting);
	ClassDB::bind_method(D_METHOD("set_amount", "amount"), &GPUParticles2D::set_amount);
	ClassDB::bind_method(D_METHOD("set_lifetime", "secs"), &GPUParticles2D::set_lifetime);
	ClassDB::bind_method(D_METHOD("set_one_shot", "secs"), &GPUParticles2D::set_one_shot);
	ClassDB::bind_method(D_METHOD("set_pre_process_time", "secs"), &GPUParticles2D::set_pre_process_time);
	ClassDB::bind_method(D_METHOD("set_explosiveness_ratio", "ratio"), &GPUParticles2D::set_explosiveness_ratio);
	ClassDB::bind_method(D_METHOD("set_randomness_ratio", "ratio"), &GPUParticles2D::set_randomness_ratio);
	ClassDB::bind_method(D_METHOD("set_visibility_rect", "visibility_rect"), &GPUParticles2D::set_visibility_rect);
	ClassDB::bind_method(D_METHOD("set_use_local_coordinates", "enable"), &GPUParticles2D::set_use_local_coordinates);
	ClassDB::bind_method(D_METHOD("set_fixed_fps", "fps"), &GPUParticles2D::set_fixed_fps);
	ClassDB::bind_method(D_METHOD("set_fractional_delta", "enable"), &GPUParticles2D::set_fractional_delta);
	ClassDB::bind_method(D_METHOD("set_process_material", "material"), &GPUParticles2D::set_process_material);
	ClassDB::bind_method(D_METHOD("set_speed_scale", "scale"), &GPUParticles2D::set_speed_scale);

	ClassDB::bind_method(D_METHOD("is_emitting"), &GPUParticles2D::is_emitting);
	ClassDB::bind_method(D_METHOD("get_amount"), &GPUParticles2D::get_amount);
	ClassDB::bind_method(D_METHOD("get_lifetime"), &GPUParticles2D::get_lifetime);
	ClassDB::bind_method(D_METHOD("get_one_shot"), &GPUParticles2D::get_one_shot);
	ClassDB::bind_method(D_METHOD("get_pre_process_time"), &GPUParticles2D::get_pre_process_time);
	ClassDB::bind_method(D_METHOD("get_explosiveness_ratio"), &GPUParticles2D::get_explosiveness_ratio);
	ClassDB::bind_method(D_METHOD("get_randomness_ratio"), &GPUParticles2D::get_randomness_ratio);
	ClassDB::bind_method(D_METHOD("get_visibility_rect"), &GPUParticles2D::get_visibility_rect);
	ClassDB::bind_method(D_METHOD("get_use_local_coordinates"), &GPUParticles2D::get_use_local_coordinates);
	ClassDB::bind_method(D_METHOD("get_fixed_fps"), &GPUParticles2D::get_fixed_fps);
	ClassDB::bind_method(D_METHOD("get_fractional_delta"), &GPUParticles2D::get_fractional_delta);
	ClassDB::bind_method(D_METHOD("get_process_material"), &GPUParticles2D::get_process_material);
	ClassDB::bind_method(D_METHOD("get_speed_scale"), &GPUParticles2D::get_speed_scale);

	ClassDB::bind_method(D_METHOD("set_draw_order", "order"), &GPUParticles2D::set_draw_order);
	ClassDB::bind_method(D_METHOD("get_draw_order"), &GPUParticles2D::get_draw_order);

	ClassDB::bind_method(D_METHOD("set_texture", "texture"), &GPUParticles2D::set_texture);
	ClassDB::bind_method(D_METHOD("get_texture"), &GPUParticles2D::get_texture);

	ClassDB::bind_method(D_METHOD("set_normal_map", "texture"), &GPUParticles2D::set_normal_map);
	ClassDB::bind_method(D_METHOD("get_normal_map"), &GPUParticles2D::get_normal_map);

	ClassDB::bind_method(D_METHOD("capture_rect"), &GPUParticles2D::capture_rect);

	ClassDB::bind_method(D_METHOD("restart"), &GPUParticles2D::restart);

	ADD_SIGNAL(MethodInfo("finished"));

	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "emitting"), "set_emitting", "is_emitting");
	ADD_PROPERTY(PropertyInfo(Variant::INT, "amount", PROPERTY_HINT_EXP_RANGE, "1,1000000,1"), "set_amount", "get_amount");
	ADD_GROUP("Time", "");
	ADD_PROPERTY(PropertyInfo(Variant::REAL, "lifetime", PROPERTY_HINT_RANGE, "0.01,600.0,0.01,or_greater"), "set_lifetime", "get_lifetime");
	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "one_shot"), "set_one_shot", "get_one_shot");
	ADD_PROPERTY(PropertyInfo(Variant::REAL, "preprocess", PROPERTY_HINT_RANGE, "0.00,600.0,0.01"), "set_pre_process_time", "get_pre_process_time");
	ADD_PROPERTY(PropertyInfo(Variant::REAL, "speed_scale", PROPERTY_HINT_RANGE, "0,64,0.01"), "set_speed_scale", "get_speed_scale");
	ADD_PROPERTY(PropertyInfo(Variant::REAL, "explosiveness", PROPERTY_HINT_RANGE, "0,1,0.01"), "set_explosiveness_ratio", "get_explosiveness_ratio");
	ADD_PROPERTY(PropertyInfo(Variant::REAL, "randomness", PROPERTY_HINT_RANGE, "0,1,0.01"), "set_randomness_ratio", "get_randomness_ratio");
	ADD_PROPERTY(PropertyInfo(Variant::INT, "fixed_fps", PROPERTY_HINT_RANGE, "0,1000,1"), "set_fixed_fps", "get_fixed_fps");
	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "fract_delta"), "set_fractional_delta", "get_fractional_delta");
	ADD_GROUP("Drawing", "");
	ADD_PROPERTY(PropertyInfo(Variant::RECT2, "visibility_rect"), "set_visibility_rect", "get_visibility_rect");
	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "local_coords"), "set_use_local_coordinates", "get_use_local_coordinates");
	ADD_PROPERTY(PropertyInfo(Variant::INT, "draw_order", PROPERTY_HINT_ENUM, "Index,Lifetime"), "set_draw_order", "get_draw_order");
	ADD_GROUP("Process Material", "process_");
	ADD_PROPERTY(PropertyInfo(Variant::OBJECT, "process_material", PROPERTY_HINT_RESOURCE_TYPE, "ShaderMaterial,ParticlesMaterial"), "set_process_material", "get_process_material");
	ADD_GROUP("Textures", "");
	ADD_PROPERTY(PropertyInfo(Variant::OBJECT, "texture", PROPERTY_HINT_RESOURCE_TYPE, "Texture"), "set_texture", "get_texture");
	ADD_PROPERTY(PropertyInfo(Variant::OBJECT, "normal_map", PROPERTY_HINT_RESOURCE_TYPE, "Texture"), "set_normal_map", "get_normal_map");

	BIND_ENUM_CONSTANT(DRAW_ORDER_INDEX);
	BIND_ENUM_CONSTANT(DRAW_ORDER_LIFETIME);
}

GPUParticles2D::GPUParticles2D() {
	particles = RID_PRIME(RS::get_singleton()->particles_create());

	one_shot = false; // Needed so that set_emitting doesn't access uninitialized values
	set_emitting(true);
	set_one_shot(false);
	set_amount(8);
	set_lifetime(1);
	set_fixed_fps(0);
	set_fractional_delta(true);
	set_pre_process_time(0);
	set_explosiveness_ratio(0);
	set_randomness_ratio(0);
	set_visibility_rect(Rect2(Vector2(-100, -100), Vector2(200, 200)));
	set_use_local_coordinates(true);
	set_draw_order(DRAW_ORDER_INDEX);
	set_speed_scale(1);
#ifdef TOOLS_ENABLED
	show_visibility_rect = false;
#endif
}

GPUParticles2D::~GPUParticles2D() {
	if (particles.is_valid()) {
		RS::get_singleton()->free(particles);
	}
}