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#ifndef QBLENDFUNCTIONS_P_H

#define QBLENDFUNCTIONS_P_H

#include <qmath.h>

#include "qdrawhelper_p.h"

QT_BEGIN_NAMESPACE

//

//  W A R N I N G

//  -------------

//

// This file is not part of the Qt API.  It exists purely as an

// implementation detail.  This header file may change from version to

// version without notice, or even be removed.

//

// We mean it.

//

template <typename SRC, typename T>

void qt_scale_image_16bit(uchar *destPixels, int dbpl,

                          const uchar *srcPixels, int sbpl,

                          const QRectF &targetRect,

                          const QRectF &srcRect,

                          const QRect &clip,

                          T blender)

{

    qreal sx = targetRect.width() / (qreal) srcRect.width();

    qreal sy = targetRect.height() / (qreal) srcRect.height();

    int ix = 0x00010000 / sx;

    int iy = 0x00010000 / sy;

//     qDebug() << "scale:" << endl

//              << " - target" << targetRect << endl

//              << " - source" << srcRect << endl

//              << " - clip" << clip << endl

//              << " - sx=" << sx << " sy=" << sy << " ix=" << ix << " iy=" << iy;

    int cx1 = clip.x();

    int cx2 = clip.x() + clip.width();

    int cy1 = clip.top();

    int cy2 = clip.y() + clip.height();

    int tx1 = qRound(targetRect.left());

    int tx2 = qRound(targetRect.right());

    int ty1 = qRound(targetRect.top());

    int ty2 = qRound(targetRect.bottom());

    if (tx2 < tx1)

        qSwap(tx2, tx1);

    if (ty2 < ty1)

        qSwap(ty2, ty1);

    if (tx1 < cx1)

        tx1 = cx1;

    if (tx2 >= cx2)

        tx2 = cx2;

    if (tx1 >= tx2)

        return;

    if (ty1 < cy1)

        ty1 = cy1;

    if (ty2 >= cy2)

       ty2 = cy2;

    if (ty1 >= ty2)

        return;

    int h = ty2 - ty1;

    int w = tx2 - tx1;

    quint32 basex;

    quint32 srcy;

    if (sx < 0) {

        int dstx = qFloor((tx1 + qreal(0.5) - targetRect.right()) * ix) + 1;

        basex = quint32(srcRect.right() * 65536) + dstx;

    } else {

        int dstx = qCeil((tx1 + qreal(0.5) - targetRect.left()) * ix) - 1;

        basex = quint32(srcRect.left() * 65536) + dstx;

    }

    if (sy < 0) {

        int dsty = qFloor((ty1 + qreal(0.5) - targetRect.bottom()) * iy) + 1;

        srcy = quint32(srcRect.bottom() * 65536) + dsty;

    } else {

        int dsty = qCeil((ty1 + qreal(0.5) - targetRect.top()) * iy) - 1;

        srcy = quint32(srcRect.top() * 65536) + dsty;

    }

    quint16 *dst = ((quint16 *) (destPixels + ty1 * dbpl)) + tx1;

    while (h--) {

        const SRC *src = (const SRC *) (srcPixels + (srcy >> 16) * sbpl);

        int srcx = basex;

        int x = 0;

        for (; x<w-7; x+=8) {

            blender.write(&dst[x], src[srcx >> 16]); srcx += ix;

            blender.write(&dst[x+1], src[srcx >> 16]); srcx += ix;

            blender.write(&dst[x+2], src[srcx >> 16]); srcx += ix;

            blender.write(&dst[x+3], src[srcx >> 16]); srcx += ix;

            blender.write(&dst[x+4], src[srcx >> 16]); srcx += ix;

            blender.write(&dst[x+5], src[srcx >> 16]); srcx += ix;

            blender.write(&dst[x+6], src[srcx >> 16]); srcx += ix;

            blender.write(&dst[x+7], src[srcx >> 16]); srcx += ix;

        }

        for (; x<w; ++x) {

            blender.write(&dst[x], src[srcx >> 16]);

            srcx += ix;

        }

        blender.flush(&dst[x]);

        dst = (quint16 *)(((uchar *) dst) + dbpl);

        srcy += iy;

    }

}

template <typename T> void qt_scale_image_32bit(uchar *destPixels, int dbpl,

                                                const uchar *srcPixels, int sbpl,

                                                const QRectF &targetRect,

                                                const QRectF &srcRect,

                                                const QRect &clip,

                                                T blender)

{

    qreal sx = targetRect.width() / (qreal) srcRect.width();

    qreal sy = targetRect.height() / (qreal) srcRect.height();

    int ix = 0x00010000 / sx;

    int iy = 0x00010000 / sy;

//     qDebug() << "scale:" << endl

//              << " - target" << targetRect << endl

//              << " - source" << srcRect << endl

//              << " - clip" << clip << endl

//              << " - sx=" << sx << " sy=" << sy << " ix=" << ix << " iy=" << iy;

    int cx1 = clip.x();

    int cx2 = clip.x() + clip.width();

    int cy1 = clip.top();

    int cy2 = clip.y() + clip.height();

    int tx1 = qRound(targetRect.left());

    int tx2 = qRound(targetRect.right());

    int ty1 = qRound(targetRect.top());

    int ty2 = qRound(targetRect.bottom());

    if (tx2 < tx1)

        qSwap(tx2, tx1);

    if (ty2 < ty1)

        qSwap(ty2, ty1);

    if (tx1 < cx1)

        tx1 = cx1;

    if (tx2 >= cx2)

        tx2 = cx2;

    if (tx1 >= tx2)

        return;

    if (ty1 < cy1)

        ty1 = cy1;

    if (ty2 >= cy2)

       ty2 = cy2;

    if (ty1 >= ty2)

        return;

    int h = ty2 - ty1;

    int w = tx2 - tx1;

    quint32 basex;

    quint32 srcy;

    if (sx < 0) {

        int dstx = qFloor((tx1 + qreal(0.5) - targetRect.right()) * ix) + 1;

        basex = quint32(srcRect.right() * 65536) + dstx;

    } else {

        int dstx = qCeil((tx1 + qreal(0.5) - targetRect.left()) * ix) - 1;

        basex = quint32(srcRect.left() * 65536) + dstx;

    }

    if (sy < 0) {

        int dsty = qFloor((ty1 + qreal(0.5) - targetRect.bottom()) * iy) + 1;

        srcy = quint32(srcRect.bottom() * 65536) + dsty;

    } else {

        int dsty = qCeil((ty1 + qreal(0.5) - targetRect.top()) * iy) - 1;

        srcy = quint32(srcRect.top() * 65536) + dsty;

    }

    quint32 *dst = ((quint32 *) (destPixels + ty1 * dbpl)) + tx1;

    while (h--) {

        const uint *src = (const quint32 *) (srcPixels + (srcy >> 16) * sbpl);

        int srcx = basex;

        int x = 0;

        for (; x<w; ++x) {

            blender.write(&dst[x], src[srcx >> 16]);

            srcx += ix;

        }

        blender.flush(&dst[x]);

        dst = (quint32 *)(((uchar *) dst) + dbpl);

        srcy += iy;

    }

}

struct QTransformImageVertex

{

    qreal x, y, u, v; // destination coordinates (x, y) and source coordinates (u, v)

};

template <class SrcT, class DestT, class Blender>

void qt_transform_image_rasterize(DestT *destPixels, int dbpl,

                                  const SrcT *srcPixels, int sbpl,

                                  const QTransformImageVertex &topLeft, const QTransformImageVertex &bottomLeft,

                                  const QTransformImageVertex &topRight, const QTransformImageVertex &bottomRight,

                                  const QRect &sourceRect,

                                  const QRect &clip,

                                  qreal topY, qreal bottomY,

                                  int dudx, int dvdx, int dudy, int dvdy, int u0, int v0,

                                  Blender blender)

{

    int fromY = qMax(qRound(topY), clip.top());

    int toY = qMin(qRound(bottomY), clip.top() + clip.height());

    if (fromY >= toY)

        return;

    qreal leftSlope = (bottomLeft.x - topLeft.x) / (bottomLeft.y - topLeft.y);

    qreal rightSlope = (bottomRight.x - topRight.x) / (bottomRight.y - topRight.y);

    int dx_l = int(leftSlope * 0x10000);

    int dx_r = int(rightSlope * 0x10000);

    int x_l = int((topLeft.x + (0.5 + fromY - topLeft.y) * leftSlope + 0.5) * 0x10000);

    int x_r = int((topRight.x + (0.5 + fromY - topRight.y) * rightSlope + 0.5) * 0x10000);

    int fromX, toX, x1, x2, u, v, i, ii;

    DestT *line;

    for (int y = fromY; y < toY; ++y) {

        line = reinterpret_cast<DestT *>(reinterpret_cast<uchar *>(destPixels) + y * dbpl);

        fromX = qMax(x_l >> 16, clip.left());

        toX = qMin(x_r >> 16, clip.left() + clip.width());

        if (fromX < toX) {

            // Because of rounding, we can get source coordinates outside the source image.

            // Clamp these coordinates to the source rect to avoid segmentation fault and

            // garbage on the screen.

            // Find the first pixel on the current scan line where the source coordinates are within the source rect.

            x1 = fromX;

            u = x1 * dudx + y * dudy + u0;

            v = x1 * dvdx + y * dvdy + v0;

            for (; x1 < toX; ++x1) {

                int uu = u >> 16;

                int vv = v >> 16;

                if (uu >= sourceRect.left() && uu < sourceRect.left() + sourceRect.width()

                    && vv >= sourceRect.top() && vv < sourceRect.top() + sourceRect.height()) {

                    break;

                }

                u += dudx;

                v += dvdx;

            }

            // Find the last pixel on the current scan line where the source coordinates are within the source rect.

            x2 = toX;

            u = (x2 - 1) * dudx + y * dudy + u0;

            v = (x2 - 1) * dvdx + y * dvdy + v0;

            for (; x2 > x1; --x2) {

                int uu = u >> 16;

                int vv = v >> 16;

                if (uu >= sourceRect.left() && uu < sourceRect.left() + sourceRect.width()

                    && vv >= sourceRect.top() && vv < sourceRect.top() + sourceRect.height()) {

                    break;

                }

                u -= dudx;

                v -= dvdx;

            }

            // Set up values at the beginning of the scan line.

            u = fromX * dudx + y * dudy + u0;

            v = fromX * dvdx + y * dvdy + v0;

            line += fromX;

            // Beginning of the scan line, with per-pixel checks.

            i = x1 - fromX;

            while (i) {

                int uu = qBound(sourceRect.left(), u >> 16, sourceRect.left() + sourceRect.width() - 1);

                int vv = qBound(sourceRect.top(), v >> 16, sourceRect.top() + sourceRect.height() - 1);

                blender.write(line, reinterpret_cast<const SrcT *>(reinterpret_cast<const uchar *>(srcPixels) + vv * sbpl)[uu]);

                u += dudx;

                v += dvdx;

                ++line;

                --i;

            }

            // Middle of the scan line, without checks.

            // Manual loop unrolling.

            i = x2 - x1;

            ii = i >> 3;

            while (ii) {

                blender.write(&line[0], reinterpret_cast<const SrcT *>(reinterpret_cast<const uchar *>(srcPixels) + (v >> 16) * sbpl)[u >> 16]); u += dudx; v += dvdx;

                blender.write(&line[1], reinterpret_cast<const SrcT *>(reinterpret_cast<const uchar *>(srcPixels) + (v >> 16) * sbpl)[u >> 16]); u += dudx; v += dvdx;

                blender.write(&line[2], reinterpret_cast<const SrcT *>(reinterpret_cast<const uchar *>(srcPixels) + (v >> 16) * sbpl)[u >> 16]); u += dudx; v += dvdx;

                blender.write(&line[3], reinterpret_cast<const SrcT *>(reinterpret_cast<const uchar *>(srcPixels) + (v >> 16) * sbpl)[u >> 16]); u += dudx; v += dvdx;

                blender.write(&line[4], reinterpret_cast<const SrcT *>(reinterpret_cast<const uchar *>(srcPixels) + (v >> 16) * sbpl)[u >> 16]); u += dudx; v += dvdx;

                blender.write(&line[5], reinterpret_cast<const SrcT *>(reinterpret_cast<const uchar *>(srcPixels) + (v >> 16) * sbpl)[u >> 16]); u += dudx; v += dvdx;

                blender.write(&line[6], reinterpret_cast<const SrcT *>(reinterpret_cast<const uchar *>(srcPixels) + (v >> 16) * sbpl)[u >> 16]); u += dudx; v += dvdx;

                blender.write(&line[7], reinterpret_cast<const SrcT *>(reinterpret_cast<const uchar *>(srcPixels) + (v >> 16) * sbpl)[u >> 16]); u += dudx; v += dvdx;

                line += 8;

                --ii;

            }

            switch (i & 7) {

                case 7: blender.write(line, reinterpret_cast<const SrcT *>(reinterpret_cast<const uchar *>(srcPixels) + (v >> 16) * sbpl)[u >> 16]); u += dudx; v += dvdx; ++line;

                case 6: blender.write(line, reinterpret_cast<const SrcT *>(reinterpret_cast<const uchar *>(srcPixels) + (v >> 16) * sbpl)[u >> 16]); u += dudx; v += dvdx; ++line;

                case 5: blender.write(line, reinterpret_cast<const SrcT *>(reinterpret_cast<const uchar *>(srcPixels) + (v >> 16) * sbpl)[u >> 16]); u += dudx; v += dvdx; ++line;

                case 4: blender.write(line, reinterpret_cast<const SrcT *>(reinterpret_cast<const uchar *>(srcPixels) + (v >> 16) * sbpl)[u >> 16]); u += dudx; v += dvdx; ++line;

                case 3: blender.write(line, reinterpret_cast<const SrcT *>(reinterpret_cast<const uchar *>(srcPixels) + (v >> 16) * sbpl)[u >> 16]); u += dudx; v += dvdx; ++line;

                case 2: blender.write(line, reinterpret_cast<const SrcT *>(reinterpret_cast<const uchar *>(srcPixels) + (v >> 16) * sbpl)[u >> 16]); u += dudx; v += dvdx; ++line;

                case 1: blender.write(line, reinterpret_cast<const SrcT *>(reinterpret_cast<const uchar *>(srcPixels) + (v >> 16) * sbpl)[u >> 16]); u += dudx; v += dvdx; ++line;

            }

            // End of the scan line, with per-pixel checks.

            i = toX - x2;

            while (i) {

                int uu = qBound(sourceRect.left(), u >> 16, sourceRect.left() + sourceRect.width() - 1);

                int vv = qBound(sourceRect.top(), v >> 16, sourceRect.top() + sourceRect.height() - 1);

                blender.write(line, reinterpret_cast<const SrcT *>(reinterpret_cast<const uchar *>(srcPixels) + vv * sbpl)[uu]);

                u += dudx;

                v += dvdx;

                ++line;

                --i;

            }

            blender.flush(line);

        }

        x_l += dx_l;

        x_r += dx_r;

    }

}

template <class SrcT, class DestT, class Blender>

void qt_transform_image(DestT *destPixels, int dbpl,

                        const SrcT *srcPixels, int sbpl,

                        const QRectF &targetRect,

                        const QRectF &sourceRect,

                        const QRect &clip,

                        const QTransform &targetRectTransform,

                        Blender blender)

{

    enum Corner

    {

        TopLeft,

        TopRight,

        BottomRight,

        BottomLeft

    };

    // map source rectangle to destination.

    QTransformImageVertex v[4];

    v[TopLeft].u = v[BottomLeft].u = sourceRect.left();

    v[TopLeft].v = v[TopRight].v = sourceRect.top();

    v[TopRight].u = v[BottomRight].u = sourceRect.right();

    v[BottomLeft].v = v[BottomRight].v = sourceRect.bottom();

    targetRectTransform.map(targetRect.left(), targetRect.top(), &v[TopLeft].x, &v[TopLeft].y);

    targetRectTransform.map(targetRect.right(), targetRect.top(), &v[TopRight].x, &v[TopRight].y);

    targetRectTransform.map(targetRect.left(), targetRect.bottom(), &v[BottomLeft].x, &v[BottomLeft].y);

    targetRectTransform.map(targetRect.right(), targetRect.bottom(), &v[BottomRight].x, &v[BottomRight].y);

    // find topmost vertex.

    int topmost = 0;

    for (int i = 1; i < 4; ++i) {

        if (v[i].y < v[topmost].y)

            topmost = i;

    }

    // rearrange array such that topmost vertex is at index 0.

    switch (topmost) {

    case 1:

        {

            QTransformImageVertex t = v[0];

            for (int i = 0; i < 3; ++i)

                v[i] = v[i+1];

            v[3] = t;

        }

        break;

    case 2:

        qSwap(v[0], v[2]);

        qSwap(v[1], v[3]);

        break;

    case 3:

        {

            QTransformImageVertex t = v[3];

            for (int i = 3; i > 0; --i)

                v[i] = v[i-1];

            v[0] = t;

        }

        break;

    }

    // if necessary, swap vertex 1 and 3 such that 1 is to the left of 3.

    qreal dx1 = v[1].x - v[0].x;

    qreal dy1 = v[1].y - v[0].y;

    qreal dx2 = v[3].x - v[0].x;

    qreal dy2 = v[3].y - v[0].y;

    if (dx1 * dy2 - dx2 * dy1 > 0)

        qSwap(v[1], v[3]);

    QTransformImageVertex u = {v[1].x - v[0].x, v[1].y - v[0].y, v[1].u - v[0].u, v[1].v - v[0].v};

    QTransformImageVertex w = {v[2].x - v[0].x, v[2].y - v[0].y, v[2].u - v[0].u, v[2].v - v[0].v};

    qreal det = u.x * w.y - u.y * w.x;

    if (det == 0)

        return;

    qreal invDet = 1.0 / det;

    qreal m11, m12, m21, m22, mdx, mdy;

    m11 = (u.u * w.y - u.y * w.u) * invDet;

    m12 = (u.x * w.u - u.u * w.x) * invDet;

    m21 = (u.v * w.y - u.y * w.v) * invDet;

    m22 = (u.x * w.v - u.v * w.x) * invDet;

    mdx = v[0].u - m11 * v[0].x - m12 * v[0].y;

    mdy = v[0].v - m21 * v[0].x - m22 * v[0].y;

    int dudx = int(m11 * 0x10000);

    int dvdx = int(m21 * 0x10000);

    int dudy = int(m12 * 0x10000);

    int dvdy = int(m22 * 0x10000);

    int u0 = qCeil((0.5 * m11 + 0.5 * m12 + mdx) * 0x10000) - 1;

    int v0 = qCeil((0.5 * m21 + 0.5 * m22 + mdy) * 0x10000) - 1;

    int x1 = qFloor(sourceRect.left());

    int y1 = qFloor(sourceRect.top());

    int x2 = qCeil(sourceRect.right());

    int y2 = qCeil(sourceRect.bottom());

    QRect sourceRectI(x1, y1, x2 - x1, y2 - y1);

    // rasterize trapezoids.

    if (v[1].y < v[3].y) {

        qt_transform_image_rasterize(destPixels, dbpl, srcPixels, sbpl, v[0], v[1], v[0], v[3], sourceRectI, clip, v[0].y, v[1].y, dudx, dvdx, dudy, dvdy, u0, v0, blender);

        qt_transform_image_rasterize(destPixels, dbpl, srcPixels, sbpl, v[1], v[2], v[0], v[3], sourceRectI, clip, v[1].y, v[3].y, dudx, dvdx, dudy, dvdy, u0, v0, blender);

        qt_transform_image_rasterize(destPixels, dbpl, srcPixels, sbpl, v[1], v[2], v[3], v[2], sourceRectI, clip, v[3].y, v[2].y, dudx, dvdx, dudy, dvdy, u0, v0, blender);

    } else {

        qt_transform_image_rasterize(destPixels, dbpl, srcPixels, sbpl, v[0], v[1], v[0], v[3], sourceRectI, clip, v[0].y, v[3].y, dudx, dvdx, dudy, dvdy, u0, v0, blender);

        qt_transform_image_rasterize(destPixels, dbpl, srcPixels, sbpl, v[0], v[1], v[3], v[2], sourceRectI, clip, v[3].y, v[1].y, dudx, dvdx, dudy, dvdy, u0, v0, blender);

        qt_transform_image_rasterize(destPixels, dbpl, srcPixels, sbpl, v[1], v[2], v[3], v[2], sourceRectI, clip, v[1].y, v[2].y, dudx, dvdx, dudy, dvdy, u0, v0, blender);

    }

}

QT_END_NAMESPACE

#endif // QBLENDFUNCTIONS_P_H