resources/sksl/shared/MatrixIndexLookup.sksl

uniform half4 colorGreen, colorRed;
uniform float3x3 testMatrix3x3;
uniform float4x4 testMatrix4x4;

bool test3x3() {
    float3x3 matrix = testMatrix3x3;
    float3 expected = float3(1, 2, 3);
    for (int index=0; index<3; ++index) {
        if (matrix[index] != expected) {
            return false;
        }
        expected += 3;
    }
    return true;
}

bool test4x4() {
    float4x4 matrix = testMatrix4x4;
    float4 expected = float4(1, 2, 3, 4);
    for (int index=0; index<4; ++index) {
        if (matrix[index] != expected) {
            return false;
        }
        expected += 4;
    }
    return true;
}

half4 main(float2 coords) {
    return test3x3() && test4x4() ? colorGreen : colorRed;
}