Being able to set the color

src/main.zig

@@ -28,6 +28,7 @@ pub fn main() !void {
     const ctx = try sdl.gl.createContext(window);
     defer sdl.gl.deleteContext(ctx);
 
+    var color_loc: u32 = undefined;
     const program = gl.Program.create();
     {
         const vs = gl.Shader.create(.vertex);
@@ -43,6 +44,7 @@ pub fn main() !void {
         program.attach(fs);
         defer program.detach(fs);
         program.link();
+        color_loc = program.uniformLocation("color").?;
     }
     program.use();
 
@@ -51,8 +53,11 @@ pub fn main() !void {
 
     const vertex_buffer = [_]f32{
         -1.0, -1.0, 0.0,
-        1.0, -1.0, 0.0,
+        -1.0, 1.0, 0.0,
         0.0, 1.0, 0.0,
+        1.0, 1.0, 0.0,
+        0.0, -1.0, 0.0,
+        1.0, -1.0, 0.0,
     };
 
     const buf = gl.Buffer.gen();
@@ -83,9 +88,14 @@ pub fn main() !void {
 
         gl.enableVertexAttribArray(0);
         buf.bind(.array_buffer);
-
         gl.vertexAttribPointer(0, 3, .float, false, 0, 0);
+
+        gl.uniform4f(color_loc, 0.45, 0.21, 0.70, 1);
         gl.drawArrays(.triangles, 0, 3);
+
+        gl.uniform4f(color_loc, 0.2, 0.5, 1.0, 1);
+        gl.drawArrays(.triangles, 3, 3);
+
         gl.disableVertexAttribArray(0);
 
         //current_state = switch (current_state) {

src/shaders/fragment.fs

@@ -1,7 +1,7 @@
 #version 330 core
 
-out vec3 color;
+uniform vec4 color;
 
 void main(){
-     color = vec3(1,0,0);
+     gl_FragColor = color;
 }