1uniform half4 colorGreen, colorRed;
2
3inline bool shouldLoop(half4 v) {
4    return v != colorGreen;
5}
6
7half4 main(float2 coords) {
8    half4 result = colorRed;
9    while (shouldLoop(result)) {
10        result = colorGreen;
11    }
12    return result;
13}
14