Shaders!

shaders/simple_shader.vert

@@ -0,0 +1,10 @@
+#version 450
+
+vec2 positions[3] = vec2[] (
+    vec2(0.0, -0.5),
+    vec2(0.5, 0.5),
+    vec2(-0.5, 0.5)
+);
+void main() {
+  gl_Position = vec4(positions[gl_VertexIndex], 0.0, 1.0);
+}