qimagescale.cpp

奇趣公司比较新的qt/emd版本

                        pix += sow;
                        rr = R_VAL(pix) * XAP;
                        gg = G_VAL(pix) * XAP;
                        bb = B_VAL(pix) * XAP;
                        pix --;
                        rr += R_VAL(pix) * INV_XAP;
                        gg += G_VAL(pix) * INV_XAP;
                        bb += B_VAL(pix) * INV_XAP;
                        r = ((rr * YAP) + (r * INV_YAP)) >> 16;
                        g = ((gg * YAP) + (g * INV_YAP)) >> 16;
                        b = ((bb * YAP) + (b * INV_YAP)) >> 16;
                        *dptr++ = qRgba(r, g, b, 0xff);
                    }
                    else{
                        pix = ypoints[dyy + y] + xpoints[x];
                        r = R_VAL(pix) * INV_YAP;
                        g = G_VAL(pix) * INV_YAP;
                        b = B_VAL(pix) * INV_YAP;
                        pix += sow;
                        r += R_VAL(pix) * YAP;
                        g += G_VAL(pix) * YAP;
                        b += B_VAL(pix) * YAP;
                        r >>= 8;
                        g >>= 8;
                        b >>= 8;
                        *dptr++ = qRgba(r, g, b, 0xff);
                    }
                }
            }
            else{
                for(x = dxx; x < end; x++){
                    int r = 0, g = 0, b = 0;
                    unsigned int *pix;

                    if(XAP > 0){
                        pix = ypoints[dyy + y] + xpoints[x];
                        r = R_VAL(pix) * INV_XAP;
                        g = G_VAL(pix) * INV_XAP;
                        b = B_VAL(pix) * INV_XAP;
                        pix++;
                        r += R_VAL(pix) * XAP;
                        g += G_VAL(pix) * XAP;
                        b += B_VAL(pix) * XAP;
                        r >>= 8;
                        g >>= 8;
                        b >>= 8;
                        *dptr++ = qRgba(r, g, b, 0xff);
                    }
                    else
                        *dptr++ = sptr[xpoints[x] ];
                }
            }
        }
    }
    /* if we're scaling down vertically */
    else if(isi->xup_yup == 1){
        /*\ 'Correct' version, with math units prepared for MMXification \*/
        int Cy, j;
        unsigned int *pix;
        int r, g, b, rr, gg, bb;
        int yap;

        /* go through every scanline in the output buffer */
        for(y = 0; y < dh; y++){
            Cy = YAP >> 16;
            yap = YAP & 0xffff;

            dptr = dest + dx + ((y + dy) * dow);
            for(x = dxx; x < end; x++){
                pix = ypoints[dyy + y] + xpoints[x];
                r = (R_VAL(pix) * yap) >> 10;
                g = (G_VAL(pix) * yap) >> 10;
                b = (B_VAL(pix) * yap) >> 10;
                pix += sow;
                for(j = (1 << 14) - yap; j > Cy; j -= Cy){
                    r += (R_VAL(pix) * Cy) >> 10;
                    g += (G_VAL(pix) * Cy) >> 10;
                    b += (B_VAL(pix) * Cy) >> 10;
                    pix += sow;
                }
                if(j > 0){
                    r += (R_VAL(pix) * j) >> 10;
                    g += (G_VAL(pix) * j) >> 10;
                    b += (B_VAL(pix) * j) >> 10;
                }
                if(XAP > 0){
                    pix = ypoints[dyy + y] + xpoints[x] + 1;
                    rr = (R_VAL(pix) * yap) >> 10;
                    gg = (G_VAL(pix) * yap) >> 10;
                    bb = (B_VAL(pix) * yap) >> 10;
                    pix += sow;
                    for(j = (1 << 14) - yap; j > Cy; j -= Cy){
                        rr += (R_VAL(pix) * Cy) >> 10;
                        gg += (G_VAL(pix) * Cy) >> 10;
                        bb += (B_VAL(pix) * Cy) >> 10;
                        pix += sow;
                    }
                    if(j > 0){
                        rr += (R_VAL(pix) * j) >> 10;
                        gg += (G_VAL(pix) * j) >> 10;
                        bb += (B_VAL(pix) * j) >> 10;
                    }
                    r = r * INV_XAP;
                    g = g * INV_XAP;
                    b = b * INV_XAP;
                    r = (r + ((rr * XAP))) >> 12;
                    g = (g + ((gg * XAP))) >> 12;
                    b = (b + ((bb * XAP))) >> 12;
                }
                else{
                    r >>= 4;
                    g >>= 4;
                    b >>= 4;
                }
                *dptr = qRgba(r, g, b, 0xff);
                dptr++;
            }
        }
    }
    /* if we're scaling down horizontally */
    else if(isi->xup_yup == 2){
        /*\ 'Correct' version, with math units prepared for MMXification \*/
        int Cx, j;
        unsigned int *pix;
        int r, g, b, rr, gg, bb;
        int xap;

        /* go through every scanline in the output buffer */
        for(y = 0; y < dh; y++){
            dptr = dest + dx + ((y + dy) * dow);
            for(x = dxx; x < end; x++){
                Cx = XAP >> 16;
                xap = XAP & 0xffff;

                pix = ypoints[dyy + y] + xpoints[x];
                r = (R_VAL(pix) * xap) >> 10;
                g = (G_VAL(pix) * xap) >> 10;
                b = (B_VAL(pix) * xap) >> 10;
                pix++;
                for(j = (1 << 14) - xap; j > Cx; j -= Cx){
                    r += (R_VAL(pix) * Cx) >> 10;
                    g += (G_VAL(pix) * Cx) >> 10;
                    b += (B_VAL(pix) * Cx) >> 10;
                    pix++;
                }
                if(j > 0){
                    r += (R_VAL(pix) * j) >> 10;
                    g += (G_VAL(pix) * j) >> 10;
                    b += (B_VAL(pix) * j) >> 10;
                }
                if(YAP > 0){
                    pix = ypoints[dyy + y] + xpoints[x] + sow;
                    rr = (R_VAL(pix) * xap) >> 10;
                    gg = (G_VAL(pix) * xap) >> 10;
                    bb = (B_VAL(pix) * xap) >> 10;
                    pix++;
                    for(j = (1 << 14) - xap; j > Cx; j -= Cx){
                        rr += (R_VAL(pix) * Cx) >> 10;
                        gg += (G_VAL(pix) * Cx) >> 10;
                        bb += (B_VAL(pix) * Cx) >> 10;
                        pix++;
                    }
                    if(j > 0){
                        rr += (R_VAL(pix) * j) >> 10;
                        gg += (G_VAL(pix) * j) >> 10;
                        bb += (B_VAL(pix) * j) >> 10;
                    }
                    r = r * INV_YAP;
                    g = g * INV_YAP;
                    b = b * INV_YAP;
                    r = (r + ((rr * YAP))) >> 12;
                    g = (g + ((gg * YAP))) >> 12;
                    b = (b + ((bb * YAP))) >> 12;
                }
                else{
                    r >>= 4;
                    g >>= 4;
                    b >>= 4;
                }
                *dptr = qRgba(r, g, b, 0xff);
                dptr++;
            }
        }
    }
    /* fully optimized (i think) - onyl change of algorithm can help */
    /* if we're scaling down horizontally & vertically */
    else{
        /*\ 'Correct' version, with math units prepared for MMXification \*/
        int Cx, Cy, i, j;
        unsigned int *pix;
        int r, g, b, rx, gx, bx;
        int xap, yap;

        for(y = 0; y < dh; y++){
            Cy = YAP >> 16;
            yap = YAP & 0xffff;

            dptr = dest + dx + ((y + dy) * dow);
            for(x = dxx; x < end; x++){
                Cx = XAP >> 16;
                xap = XAP & 0xffff;

                sptr = ypoints[dyy + y] + xpoints[x];
                pix = sptr;
                sptr += sow;
                rx = (R_VAL(pix) * xap) >> 9;
                gx = (G_VAL(pix) * xap) >> 9;
                bx = (B_VAL(pix) * xap) >> 9;
                pix++;
                for(i = (1 << 14) - xap; i > Cx; i -= Cx){
                    rx += (R_VAL(pix) * Cx) >> 9;
                    gx += (G_VAL(pix) * Cx) >> 9;
                    bx += (B_VAL(pix) * Cx) >> 9;
                    pix++;
                }
                if(i > 0){
                    rx += (R_VAL(pix) * i) >> 9;
                    gx += (G_VAL(pix) * i) >> 9;
                    bx += (B_VAL(pix) * i) >> 9;
                }

                r = (rx * yap) >> 14;
                g = (gx * yap) >> 14;
                b = (bx * yap) >> 14;

                for(j = (1 << 14) - yap; j > Cy; j -= Cy){
                    pix = sptr;
                    sptr += sow;
                    rx = (R_VAL(pix) * xap) >> 9;
                    gx = (G_VAL(pix) * xap) >> 9;
                    bx = (B_VAL(pix) * xap) >> 9;
                    pix++;
                    for(i = (1 << 14) - xap; i > Cx; i -= Cx){
                        rx += (R_VAL(pix) * Cx) >> 9;
                        gx += (G_VAL(pix) * Cx) >> 9;
                        bx += (B_VAL(pix) * Cx) >> 9;
                        pix++;
                    }
                    if(i > 0){
                        rx += (R_VAL(pix) * i) >> 9;
                        gx += (G_VAL(pix) * i) >> 9;
                        bx += (B_VAL(pix) * i) >> 9;
                    }

                    r += (rx * Cy) >> 14;
                    g += (gx * Cy) >> 14;
                    b += (bx * Cy) >> 14;
                }
                if(j > 0){
                    pix = sptr;
                    sptr += sow;
                    rx = (R_VAL(pix) * xap) >> 9;
                    gx = (G_VAL(pix) * xap) >> 9;
                    bx = (B_VAL(pix) * xap) >> 9;
                    pix++;
                    for(i = (1 << 14) - xap; i > Cx; i -= Cx){
                        rx += (R_VAL(pix) * Cx) >> 9;
                        gx += (G_VAL(pix) * Cx) >> 9;
                        bx += (B_VAL(pix) * Cx) >> 9;
                        pix++;
                    }
                    if(i > 0){
                        rx += (R_VAL(pix) * i) >> 9;
                        gx += (G_VAL(pix) * i) >> 9;
                        bx += (B_VAL(pix) * i) >> 9;
                    }

                    r += (rx * j) >> 14;
                    g += (gx * j) >> 14;
                    b += (bx * j) >> 14;
                }

                *dptr = qRgb(r >> 5, g >> 5, b >> 5);
                dptr++;
            }
        }
    }
}

#if 0
static void qt_qimageScaleAARGBASetup(QImageScaleInfo *isi, unsigned int *dest,
                                      int dxx, int dyy, int dx, int dy, int dw,
                                      int dh, int dow, int sow)
{
    qInitDrawhelperAsm();
    qt_qimageScaleAARGBA(isi, dest, dxx, dyy, dx, dy, dw, dh, dow, sow);
}

static void qt_qimageScaleAARGBSetup(QImageScaleInfo *isi, unsigned int *dest,
                                 int dxx, int dyy, int dx, int dy, int dw,
                                 int dh, int dow, int sow)
{
    qInitDrawhelperAsm();
    qt_qimageScaleAARGB(isi, dest, dxx, dyy, dx, dy, dw, dh, dow, sow);
}
#endif

QImage qSmoothScaleImageAutoConvert(QImage &src, int dw, int dh)
{
    QImage buffer;
    if (src.isNull())
        return buffer;

    if (src.format() == QImage::Format_ARGB32_Premultiplied)
        src = src.convertToFormat(QImage::Format_ARGB32);
    else if (src.depth() < 32) {
        if (src.hasAlphaChannel())
            src = src.convertToFormat(QImage::Format_ARGB32);
        else
            src = src.convertToFormat(QImage::Format_RGB32);
    }

    return qSmoothScaleImage(src, dw, dh);
}


QImage qSmoothScaleImage(const QImage &src, int dw, int dh)
{
    QImage buffer;
    if (src.isNull() || dw <= 0 || dh <= 0)
        return buffer;

    int w = src.width();
    int h = src.height();
    QImageScaleInfo *scaleinfo =
        qimageCalcScaleInfo(src, w, h, dw, dh, true);
    if (!scaleinfo)
        return buffer;

    buffer = QImage(dw, dh, src.format());
    if (buffer.isNull()) {
        qWarning("QImage: out of memory, returning null");
        return QImage();
    }

    if (src.format() == QImage::Format_ARGB32)
        qt_qimageScaleArgb(scaleinfo, (unsigned int *)buffer.scanLine(0),
                           0, 0, 0, 0, dw, dh, dw, w);
    else
        qt_qimageScaleRgb(scaleinfo, (unsigned int *)buffer.scanLine(0),
                          0, 0, 0, 0, dw, dh, dw, w);

    qimageFreeScaleInfo(scaleinfo);

    return buffer;
}