#version 330 out vec2 texCoord; void main() { vec2 uv = vec2((gl_VertexID << 1) & 2, -(gl_VertexID & 2) + 1); vec4 pos = vec4(uv * vec2(2, -2) + vec2(-1, +1), 0, 1); gl_Position = pos; texCoord = uv; }