Attempt color with batch rendering

src/Renderer.zig

@@ -65,7 +65,7 @@ pub fn init() !Self {
 
         program.link();
 
-        mvp_loc = program.uniformLocation("mvp").?;
+        mvp_loc = try program.uniformLocation("mvp").?;
         color_loc = program.uniformLocation("color").?;
     }
     program.use();
@@ -81,16 +81,24 @@ 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();
 
     const buf = gl.Buffer.gen();
     buf.bind(.array_buffer);
 
-    gl.vertexAttribPointer(0, 2, .float, false, 0, 0);
-
+    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.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
@@ -101,20 +109,22 @@ pub fn init() !Self {
 }
 
 pub fn render(self: *Self) void {
-    std.debug.print("Numer of rendered elements: {}\n", .{self.test_counter});
+    std.debug.print("Number of rendered elements: {}\n", .{self.test_counter});
     self.test_counter = 0;
 
     self.buffer.data(f32, &self.vbo, .static_draw);
 
-    {
-        var i: usize = 0;
-        while (i < self.vbo_index) {
-            gl.uniform4fv(self.color_loc, &.{self.colors[i]});
-            std.debug.print("Color: {any}\n", .{self.colors[i]});
-            gl.drawArrays(.triangles, i, 12);
-            i += 12;
-        }
-    }
+    // {
+    //     var i: usize = 0;
+    //     while (i < self.vbo_index) {
+    //         gl.uniform4fv(self.color_loc, &.{self.colors[i]});
+    //         //std.debug.print("Color: {any}\n", .{self.colors[i]});
+    //         gl.drawArrays(.triangles, i, 12);
+    //         i += 12;
+    //     }
+    // }
+
+    gl.drawArrays(.triangles, 0, self.vbo_index);
 
     self.vbo_index = 0;
 
@@ -164,31 +174,22 @@ fn renderRectangle(self: *Self, x: i32, y: i32, w: i32, h: i32) void {
     var hf = @intToFloat(f32, h);
 
     const i = self.vbo_index;
-    self.colors[i + 0] = self.color;
-    self.colors[i + 1] = self.color;
-    self.colors[i + 2] = self.color;
-    self.colors[i + 3] = self.color;
-    self.colors[i + 4] = self.color;
-    self.colors[i + 5] = self.color;
-    self.colors[i + 6] = self.color;
-    self.colors[i + 7] = self.color;
-    self.colors[i + 8] = self.color;
-    self.colors[i + 9] = self.color;
-    self.colors[i + 10] = self.color;
-    self.colors[i + 11] = self.color;
-    self.vbo[i + 0] = xf;
-    self.vbo[i + 1] = yf; // up-left
-    self.vbo[i + 2] = xf + wf;
-    self.vbo[i + 3] = yf; // up-right
-    self.vbo[i + 4] = xf;
-    self.vbo[i + 5] = yf + hf; // down-left
-    self.vbo[i + 6] = xf + wf;
-    self.vbo[i + 7] = yf + hf; // down-right
-    self.vbo[i + 8] = xf + wf;
-    self.vbo[i + 9] = yf; // up-right
-    self.vbo[i + 10] = xf;
-    self.vbo[i + 11] = yf + hf; // down-left
-    self.vbo_index += 12;
+    const vertex_data = [36]f32{
+        xf, yf, // up-left
+        0.5, 0.5, 0.5, 0.5,
+        xf + wf, yf, // up-right
+        0.5, 0.5, 0.5, 0.5,
+        xf,      yf + hf,
+        0.5, 0.5, 0.5, 0.5,
+        xf + wf, yf + hf, // down-right
+        0.5, 0.5, 0.5, 0.5,
+        xf + wf, yf,
+        0.5, 0.5, 0.5, 0.5,
+        xf, yf + hf, // down-left
+        0.5, 0.5, 0.5, 0.5,
+    };
+    std.mem.copy(f32, self.vbo[i .. i + 36], &vertex_data);
+    self.vbo_index += 36;
 }
 
 pub const OutputSize = struct { width: c_int, height: c_int };

src/main.zig

@@ -38,8 +38,8 @@ pub fn main() !void {
         const delay = SDL.getTicks64() - start;
 
         std.debug.print("{} ms\n", .{delay});
-        if (delay < 16) {
-            SDL.delay(16 - @intCast(u32, delay));
+        if (delay < 17) {
+            SDL.delay(17 - @intCast(u32, delay));
         }
     }
 }

src/shaders/fragment.fs

@@ -1,6 +1,6 @@
 #version 330 core
 
-uniform vec4 color;
+in vec4 color;
 
 void main(){
      gl_FragColor = color;

src/shaders/vector.vs

@@ -1,8 +1,13 @@
 #version 330 core
 
-uniform mat4 mvp;
 layout (location = 0) in vec2 pos;
+layout (location = 1) in vec4 v_color;
+
+uniform mat4 mvp;
+
+out color;
 
 void main() {
+     color = v_color; // Taken by fragment.fs
      gl_Position = mvp * vec4((pos + vec2(0.5, 0.5)), 0, 1);
 }