From c53bc96a5d938e8839f86b7ca0e5e7616d02da70 Mon Sep 17 00:00:00 2001
From: Matt Thorson <mattmakesgames@gmail.com>
Date: Sun, 9 Aug 2020 18:28:55 -0700
Subject: [PATCH] Very basic rendering

---
 src/Core/Game.bf                       |  2 +-
 src/PlatformLayer/Batcher.bf           | 20 ++++++++++
 src/PlatformLayer/SDL2PlatformLayer.bf | 38 ++++++++++++++++---
 src/Struct/Matrix.bf                   | 52 +++++++++++++++++++-------
 4 files changed, 93 insertions(+), 19 deletions(-)

diff --git a/src/Core/Game.bf b/src/Core/Game.bf
index 84b8731..e3b733e 100644
--- a/src/Core/Game.bf
+++ b/src/Core/Game.bf
@@ -157,7 +157,7 @@ namespace Strawberry
 		private void Render()
 		{
 			PlatformLayer.RenderBegin();
-			Draw();
+			//Draw();
 			PlatformLayer.RenderEnd();
 		}
 
diff --git a/src/PlatformLayer/Batcher.bf b/src/PlatformLayer/Batcher.bf
index dace874..4d4b961 100644
--- a/src/PlatformLayer/Batcher.bf
+++ b/src/PlatformLayer/Batcher.bf
@@ -8,9 +8,29 @@ namespace Strawberry
 
 		Batch top => batchStack.Count > 0 ? batchStack[batchStack.Count - 1] : null;
 
+		public void PushQuad(Vertex a, Vertex b, Vertex c, Vertex d)
+		{
+			
+		}
+
 		private class Batch
 		{
+			uint32 bufferHandle;
 
+			List<Vertex> Vertices;
+
+			public this()
+			{
+				GL.glGenBuffers(1, &bufferHandle);
+				GL.glBindBuffer(GL.GL_ARRAY_BUFFER, bufferHandle);
+				GL.glDeleteBuffers(1, &bufferHandle);
+			}
+		}
+
+		private struct Vertex
+		{
+			public Vector Position;
+			public Color Color;
 		}
 	}
 }
diff --git a/src/PlatformLayer/SDL2PlatformLayer.bf b/src/PlatformLayer/SDL2PlatformLayer.bf
index d8a7a9f..64d30ea 100644
--- a/src/PlatformLayer/SDL2PlatformLayer.bf
+++ b/src/PlatformLayer/SDL2PlatformLayer.bf
@@ -11,11 +11,13 @@ namespace Strawberry
 		private SDL.Rect screenRect;
 		private SDL.Renderer* renderer;
 		private SDL2Shader shader;
-		private SDL.SDL_GLContext glContext;
-		private uint glProgram;
-		private uint glVertexShader;
 		private SDL.SDL_GameController*[] gamepads;
 		private bool* keyboard;
+		private uint32 vertexArray;
+		private uint32 vertexbuffer;
+
+		private SDL.SDL_GLContext glContext;
+		private uint glProgram;
 
 		public override void Init()
 		{
@@ -57,7 +59,7 @@ namespace Strawberry
 					// vertex shader
 					"""
 					#version 330
-					uniform mat4 u_matrix;
+					uniform mat3x2 u_matrix;
 					layout(location=0) in vec2 a_position;
 					layout(location=1) in vec2 a_tex;
 					layout(location=2) in vec4 a_color;
@@ -102,6 +104,19 @@ namespace Strawberry
 				GL.glGetProgramInfoLog(glProgram, 1024, &logLen, &log);
 				if (logLen > 0)
 					Calc.Log(&log, logLen);
+
+				GL.glGenVertexArrays(1, &vertexArray);
+				GL.glBindVertexArray(vertexArray);
+
+				float[?] g_vertex_buffer_data = .(
+				   -1.0f, -1.0f,
+				   1.0f, -1.0f,
+				   0.0f,  1.0f,
+				);
+
+				GL.glGenBuffers(1, &vertexbuffer);
+				GL.glBindBuffer(GL.GL_ARRAY_BUFFER, vertexbuffer);
+				GL.glBufferData(GL.GL_ARRAY_BUFFER, sizeof(float[6]), &g_vertex_buffer_data, GL.GL_STATIC_DRAW);
 			}
 
 			//Audio
@@ -146,11 +161,24 @@ namespace Strawberry
 		{
 			GL.glClearColor(Game.ClearColor.Rf, Game.ClearColor.Gf, Game.ClearColor.Bf, Game.ClearColor.Af);
 			GL.glClear(GL.GL_COLOR_BUFFER_BIT);
-			GL.glCreateProgram();
+			GL.glUseProgram(glProgram);
+
+			int loc = GL.glGetUniformLocation(glProgram, "u_matrix");
+			Matrix mat = Matrix.Identity;
+			GL.glUniformMatrix3x2fv(loc, 1, GL.GL_FALSE, &mat.Values);
+
+			GL.glEnableVertexAttribArray(0);
+			GL.glBindBuffer(GL.GL_ARRAY_BUFFER, vertexbuffer);
+			GL.glVertexAttribPointer(0, 2, GL.GL_FLOAT, GL.GL_FALSE, 0, (void*)0 );
+			// Draw the triangle !
+			GL.glDrawArrays(GL.GL_TRIANGLES, 0, 3); // Starting from vertex 0; 3 vertices total -> 1 triangle
+			GL.glDisableVertexAttribArray(0);
 		}
 
 		public override void RenderEnd()
 		{
+			GL.glUseProgram(0);
+			GL.glFlush();
 			SDL.GL_SwapWindow(window);
 		}
 
diff --git a/src/Struct/Matrix.bf b/src/Struct/Matrix.bf
index e356912..2b27d3d 100644
--- a/src/Struct/Matrix.bf
+++ b/src/Struct/Matrix.bf
@@ -13,22 +13,48 @@ namespace Strawberry
 	{
 		static public readonly Matrix Identity = Matrix(1, 0, 0, 1, 0, 0);
 
-		//       Row--vv--Column
-		public float M11;
-		public float M12;
-		public float M21;
-		public float M22;
-		public float M31;
-		public float M32;
+		public float[6] Values = .(0, 0, 0, 0, 0, 0);
 
 		public this(float m11, float m12, float m21, float m22, float m31, float m32)
 		{
-			M11 = m11;
-			M12 = m12;
-			M21 = m21;
-			M22 = m22;
-			M31 = m31;
-			M32 = m32;
+			Values = .(m11, m12, m21, m22, m31, m32);
+		}
+
+		//       Row--vv--Column
+		public float M11
+		{
+			get => Values[0];
+			set mut => Values[0] = value;
+		}
+
+		public float M12
+		{
+			get => Values[1];
+			set mut => Values[1] = value;
+		}
+
+		public float M21
+		{
+			get => Values[2];
+			set mut => Values[2] = value;
+		}
+
+		public float M22
+		{
+			get => Values[3];
+			set mut => Values[3] = value;
+		}
+
+		public float M31
+		{
+			get => Values[4];
+			set mut => Values[4] = value;
+		}
+
+		public float M32
+		{
+			get => Values[5];
+			set mut => Values[5] = value;
 		}
 
 		public bool IsIdentity