From 083d5ac92517c31096e79f9500fad0b5330fa6fe Mon Sep 17 00:00:00 2001
From: Relintai <relintai@protonmail.com>
Date: Fri, 12 Jan 2024 23:45:26 +0100
Subject: [PATCH] Added helper methods to Mesh.

---
 sfw/render_core/mesh.cpp | 68 ++++++++++++++++++++++++++++++++++++++++
 sfw/render_core/mesh.h   |  7 +++++
 2 files changed, 75 insertions(+)

diff --git a/sfw/render_core/mesh.cpp b/sfw/render_core/mesh.cpp
index d57bd04..0f25ac2 100644
--- a/sfw/render_core/mesh.cpp
+++ b/sfw/render_core/mesh.cpp
@@ -46,6 +46,74 @@ void Mesh::add_triangle(uint32_t i1, uint32_t i2, uint32_t i3) {
 	indices.push_back(i3);
 }
 
+void Mesh::flip_faces() {
+	if (normals.size() > 0 && indices.size() > 0) {
+		{
+			int nc = normals.size();
+			float *w = normals.ptrw();
+			for (int i = 0; i < nc; i++) {
+				w[i] = -w[i];
+			}
+		}
+
+		{
+			int ic = indices.size();
+			uint32_t *w = indices.ptrw();
+			for (int i = 0; i < ic; i += 3) {
+				SWAP(w[i + 0], w[i + 1]);
+			}
+		}
+	}
+}
+
+void Mesh::update_aabb() {
+	aabb = AABB();
+
+	if (vertex_dimesions == 2) {
+		int size = vertices.size();
+
+		if (size < 2) {
+			return;
+		}
+
+		const float *v = vertices.ptr();
+
+		aabb.position.x = v[0];
+		aabb.position.y = v[1];
+
+		Vector3 vert;
+
+		for (int i = 0; i < size; i += 2) {
+			vert.x = v[i];
+			vert.y = v[i + 1];
+
+			aabb.expand_to(vert);
+		}
+	} else if (vertex_dimesions == 3) {
+		int size = vertices.size();
+
+		if (size < 3) {
+			return;
+		}
+
+		const float *v = vertices.ptr();
+
+		aabb.position.x = v[0];
+		aabb.position.y = v[1];
+		aabb.position.z = v[2];
+
+		Vector3 vert;
+
+		for (int i = 0; i < size; i += 2) {
+			vert.x = v[i];
+			vert.y = v[i + 1];
+			vert.z = v[i + 2];
+
+			aabb.expand_to(vert);
+		}
+	}
+}
+
 void Mesh::clear() {
 	vertices.clear();
 	normals.clear();
diff --git a/sfw/render_core/mesh.h b/sfw/render_core/mesh.h
index 5c20f43..335c91c 100644
--- a/sfw/render_core/mesh.h
+++ b/sfw/render_core/mesh.h
@@ -5,6 +5,7 @@
 #include "core/vector.h"
 #include "core/int_types.h"
 #include "core/color.h"
+#include "core/aabb.h"
 
 #include "object/resource.h"
 
@@ -27,6 +28,10 @@ public:
 	void add_index(uint32_t index);
 	void add_triangle(uint32_t i1, uint32_t i2, uint32_t i3);
 
+	void flip_faces();
+
+	void update_aabb();
+
 	void clear();
 
 	void upload();
@@ -48,6 +53,8 @@ public:
 	Vector<float> uvs;
 	Vector<uint32_t> indices;
 
+	AABB aabb;
+
 protected:
 	uint32_t vertices_vbo_size;
 	uint32_t normals_vbo_size;