Function hasLinearArtifact

MyGUIEngine/src/msdfgen/core/MSDFErrorCorrection.cpp:331–342

/// Checks if a linear interpolation artifact will occur inbetween two horizontally or vertically adjacent texels a, b.
template <class ArtifactClassifier>
static bool hasLinearArtifact(const ArtifactClassifier &artifactClassifier, float am, const float *a, const float *b) {
    float bm = median(b[0], b[1], b[2]);
    return (
        // Out of the pair, only report artifacts for the texel further from the edge to minimize side effects.
        fabsf(am-.5f) >= fabsf(bm-.5f) && (
            // Check points where each pair of color channels meets.
            hasLinearArtifactInner(artifactClassifier, am, bm, a, b, a[1]-a[0], b[1]-b[0]) ||
            hasLinearArtifactInner(artifactClassifier, am, bm, a, b, a[2]-a[1], b[2]-b[1]) ||
            hasLinearArtifactInner(artifactClassifier, am, bm, a, b, a[0]-a[2], b[0]-b[2])
        )
    );
}

/// Checks if a bilinear interpolation artifact will occur inbetween two diagonally adjacent texels a, d (with b, c forming the other diagonal).
template <class ArtifactClassifier>