#version 450

vec2 positions[3] = vec2[] (
  vec2(0.0, -0.5),
  vec2(0.5, 0.5),
  vec2(-0.5, 0.5)
);

vec3 colors[3] = vec3[] (
  vec3(1.0, 0.0, 0.0),
  vec3(0.0, 1.0, 0.0),
  vec3(0.0, 0.0, 1.0)
);

layout (location = 0) out vec3 fragmentColor;

void main() {
  gl_Position = vec4(positions[gl_VertexIndex], 0.0, 1.0);
  fragmentColor = colors[gl_VertexIndex];
}