#version 400 float _determinant2(mat2 m) { return m[0].x*m[1].y - m[0].y*m[1].x; } out vec4 sk_FragColor; uniform mat2 testMatrix2x2; uniform vec4 colorGreen; uniform vec4 colorRed; vec4 main() { return _determinant2(testMatrix2x2) == -2.0 ? colorGreen : colorRed; }