Scanline algorithm help

[broken cape]

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[spiral mirage]

u16 emSize = 32;

u16 glyphWidth = ((glyphDescription->xMax - glyphDescription->xMin) * emSize) / head->unitsPerEm;
u16 glyphHeight = ((glyphDescription->yMax - glyphDescription->yMin) * emSize) / head->unitsPerEm;

for (u16 y = 0; y < glyphHeight; y++) {
    bool intersections[64] = { 0 }; // assume glyphWidth is never greater than 64 for now

    u16 startIndex = 0;
    for (i16 i = 0; i < glyphDescription->numberOfContours; i++) {

        u16 length = (endPtsOfContours[i] + 1) - startIndex;

        for (u16 index = startIndex; index <= endPtsOfContours[i]; index++) {
            u16 nextIndex = startIndex + (((index + 1) - startIndex) % length);

            if ((flags[index] & ON_CURVE_POINT) && (flags[nextIndex] & ON_CURVE_POINT)) { // it's a straight line
                i16vec2 start = (points[index] * emSize) / (i16)head->unitsPerEm;
                i16vec2 end = (points[nextIndex] * emSize) / (i16)head->unitsPerEm;

                float yMax = __builtin_fmaxf(start.y, end.y);
                float yMin = __builtin_fminf(start.y, end.y);

                if (y <= yMin) continue;
                if (y > yMax) continue;

                float dx = end.x - start.x;
                float dy = end.y - start.y;

                float slope = dy / dx;

                // y = scanline coordinate
                float intersection = (y - start.y) * slope + start.x;

                if (intersection < 0.f)
                    intersection = start.x;

                intersections[(u16)intersection] = true;
            } else { // quadratic or cubic bezier, handled later

            }
        }

        startIndex = endPtsOfContours[i] + 1;
    }

    bool filling = false;
    for (u16 x = 0; x < glyphWidth; x++) {
        if (intersections[x])
            filling = !filling;

        imageData[y * 1024 + x] = filling ? 255 : 0;
    }
}

just noticed the fill code is wrong too

will fix that first
fixed

also signed overflow happening

I'll use this thread to rubberduck

[broken cape]

@spiral mirage

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[spiral mirage]

!solved

[broken cape]

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