added rotation

shaders/basic.vert

@@ -7,8 +7,10 @@ layout(location = 2) in vec4 a_color;
 out vec4 v_color;
 out vec2 v_texCoord;
 
+uniform mat4 u_model;
+
 void main() {
-    gl_Position = vec4(a_position, 1.0f);
+    gl_Position = u_model * vec4(a_position, 1.0f);
     v_color = a_color;
     v_texCoord = a_texCoord;
 }