in vec2 position; void main() { // Coordinates are [0.0;1.0], transform to [-1.0; 1.0] vec2 pos = position; pos.x = pos.x * 2.0 - 1.0; pos.y = pos.y * 2.0 - 1.0; gl_Position = vec4(pos, 0.0, 1.0); }