WriteGL

Vertex Shader attribute vec4 a_position; varying vec2 vUV; void main() { vUV = (a_position.xy + 1.0) * .5; gl_Position = a_position; }

Fragment Shader precision mediump float; varying vec2 vUV; void main() { gl_FragColor = vec4(vUV, 0.0, 1.0); }