From 735ff622a09a98498fd32ea06ac4c5fd335dfb2a Mon Sep 17 00:00:00 2001
From: Strangedusk <strangealt@protonmail.com>
Date: Wed, 3 Aug 2022 19:38:44 +0200
Subject: [PATCH] Batch rendering with colors

---
 src/Renderer.zig      | 30 ++++++++++++------------------
 src/shaders/vector.vs |  4 ++--
 2 files changed, 14 insertions(+), 20 deletions(-)

diff --git a/src/Renderer.zig b/src/Renderer.zig
index e912ab4..02d3fd0 100644
--- a/src/Renderer.zig
+++ b/src/Renderer.zig
@@ -8,7 +8,7 @@ const Self = @This();
 
 window: sdl.Window,
 context: sdl.gl.Context,
-color_loc: u32,
+//color_loc: u32,
 buffer: gl.Buffer,
 color: [4]f32,
 
@@ -44,7 +44,7 @@ pub fn init() !Self {
 
     // Shader stuff
     var mvp_loc: u32 = undefined;
-    var color_loc: u32 = undefined;
+    //var color_loc: u32 = undefined;
     const program = gl.Program.create();
     {
         const vs = gl.Shader.create(.vertex);
@@ -65,8 +65,8 @@ pub fn init() !Self {
 
         program.link();
 
-        mvp_loc = try program.uniformLocation("mvp").?;
-        color_loc = program.uniformLocation("color").?;
+        mvp_loc = program.uniformLocation("mvp").?;
+        //color_loc = program.uniformLocation("color").?;
     }
     program.use();
 
@@ -81,9 +81,6 @@ pub fn init() !Self {
         gl.uniformMatrix4fv(mvp_loc, false, &.{ortho.fields});
     }
 
-    const black = [4]f32{ 0.0, 0.0, 0.0, 1.0 };
-    gl.uniform4fv(color_loc, &.{black});
-
     var vertex_array = gl.VertexArray.gen();
     vertex_array.bind();
 
@@ -93,19 +90,16 @@ pub fn init() !Self {
     gl.vertexAttribPointer(0, 2, .float, false, @sizeOf(f32) * 6, @sizeOf(f32) * 0);
     gl.enableVertexAttribArray(0);
 
-    gl.vertexAttribPointer(1, 4, .float, false, @sizeOf(f32) * 6, @sizeOf(f32) * 4);
+    gl.vertexAttribPointer(1, 4, .float, false, @sizeOf(f32) * 6, @sizeOf(f32) * 2);
     gl.enableVertexAttribArray(1);
 
-    // gl.vertexAttribPointer(1, 2, .float, false, 0, 0);
-    // gl.enableVertexAttribArray(1);
-
     gl.clearColor(0.91, 0.97, 1.00, 1.00);
 
     // TODO: See if there's a more optimal solution to this, maybe activating only when necessary
     gl.enable(.blend);
     gl.blendFunc(.src_alpha, .one_minus_src_alpha);
 
-    return Self{ .window = window, .context = ctx, .color_loc = color_loc, .buffer = buf, .color = .{ 0, 0, 0, 0 } };
+    return Self{ .window = window, .context = ctx, .buffer = buf, .color = .{ 0, 0, 0, 0 } };
 }
 
 pub fn render(self: *Self) void {
@@ -176,17 +170,17 @@ fn renderRectangle(self: *Self, x: i32, y: i32, w: i32, h: i32) void {
     const i = self.vbo_index;
     const vertex_data = [36]f32{
         xf, yf, // up-left
-        0.5, 0.5, 0.5, 0.5,
+        self.color[0], self.color[1], self.color[2], self.color[3],
         xf + wf, yf, // up-right
-        0.5, 0.5, 0.5, 0.5,
+        self.color[0], self.color[1], self.color[2], self.color[3],
         xf,      yf + hf,
-        0.5, 0.5, 0.5, 0.5,
+        self.color[0], self.color[1], self.color[2], self.color[3],
         xf + wf, yf + hf, // down-right
-        0.5, 0.5, 0.5, 0.5,
+        self.color[0], self.color[1], self.color[2], self.color[3],
         xf + wf, yf,
-        0.5, 0.5, 0.5, 0.5,
+        self.color[0], self.color[1], self.color[2], self.color[3],
         xf, yf + hf, // down-left
-        0.5, 0.5, 0.5, 0.5,
+        self.color[0], self.color[1], self.color[2], self.color[3],
     };
     std.mem.copy(f32, self.vbo[i .. i + 36], &vertex_data);
     self.vbo_index += 36;
diff --git a/src/shaders/vector.vs b/src/shaders/vector.vs
index f996a99..02170fb 100644
--- a/src/shaders/vector.vs
+++ b/src/shaders/vector.vs
@@ -5,9 +5,9 @@ layout (location = 1) in vec4 v_color;
 
 uniform mat4 mvp;
 
-out color;
+out vec4 color;
 
 void main() {
-     color = v_color; // Taken by fragment.fs
+     color = v_color;
      gl_Position = mvp * vec4((pos + vec2(0.5, 0.5)), 0, 1);
 }