resources/sksl/folding/MatrixNoOpFolding.sksl

uniform float2x2 testMatrix2x2;
uniform float3x3 testMatrix3x3;
uniform float4 testInputs;
uniform half4 colorRed, colorGreen;
uniform half unknownInput;

bool test_mat2_mat2() {
    float2x2 m, mm;
    const float2x2 i = float2x2(1.0);
    const float2x2 z = float2x2(0.0);
    const float2x2 s = float2x2(float4(1.0));

    m = testMatrix2x2 * i;
    m = i * testMatrix2x2;

    m = m * i;
    m = i * m;
    m *= i;

    m = m / s;
    m /= s;

    m = m + z;
    m = z + m;
    m += z;

    m = m - z;
    m = z - m;  // negates
    m -= z;

    mm = m * z;
    mm = z * m;

    return m == -testMatrix2x2 && mm == z;
}

bool test_mat3_mat3() {
    float3x3 m, mm;
    const float3x3 i = float3x3(1.0);
    const float3x3 z = float3x3(0.0);
    const float3x3 s = float3x3(float3(1.0), float3(1.0), float3(1.0));

    m = testMatrix3x3 * i;
    m = i * testMatrix3x3;

    m = m * i;
    m = i * m;
    m *= i;

    m = m / s;
    m /= s;

    m = m + z;
    m = z + m;
    m += z;

    m = m - z;
    m = z - m;  // negates
    m -= z;

    mm = m * z;
    mm = z * m;

    return m == -testMatrix3x3 && mm == z;
}

bool test_mat4_mat4() {
    float4x4 testMatrix4x4 = float4x4(testInputs, testInputs, testInputs, testInputs);

    float4x4 m, mm;
    const float4x4 i = float4x4(1.0);
    const float4x4 z = float4x4(0.0);
    const float4x4 s = float4x4(float4(1.0), float4(1.0), float4(1.0), float4(1.0));

    m = testMatrix4x4 * i;
    m = i * testMatrix4x4;

    m = m * i;
    m = i * m;
    m *= i;

    m = m / s;
    m /= s;

    m = m + z;
    m = z + m;
    m += z;

    m = m - z;
    m = z - m;  // negates
    m -= z;

    mm = m * z;
    mm = z * m;

    return m == -testMatrix4x4 && mm == z;
}

half4 main(float2 coords) {
    return test_mat2_mat2() &&
           test_mat3_mat3() &&
           test_mat4_mat4() ? colorGreen : colorRed;
}