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#include <private/qimagescale_p.h>

#include <private/qdrawhelper_p.h>

#include "qimage.h"

#include "qcolor.h"

QT_BEGIN_NAMESPACE

namespace QImageScale {

    struct QImageScaleInfo;

}

typedef void (*qt_qimageScaleFunc)(QImageScale::QImageScaleInfo *isi, unsigned int *dest,

                                   int dxx, int dyy, int dx, int dy, int dw,

                                   int dh, int dow, int sow);

static void qt_qimageScaleAARGB(QImageScale::QImageScaleInfo *isi, unsigned int *dest,

                         int dxx, int dyy, int dx, int dy, int dw,

                         int dh, int dow, int sow);

static void qt_qimageScaleAARGBA(QImageScale::QImageScaleInfo *isi, unsigned int *dest,

                          int dxx, int dyy, int dx, int dy, int dw,

                          int dh, int dow, int sow);

qt_qimageScaleFunc qt_qimageScaleArgb = qt_qimageScaleAARGBA;

qt_qimageScaleFunc qt_qimageScaleRgb  = qt_qimageScaleAARGB;

/*

 * Copyright (C) 2004, 2005 Daniel M. Duley

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 *

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer.

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in the

 *    documentation and/or other materials provided with the distribution.

 *

 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR

 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES

 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.

 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,

 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT

 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,

 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY

 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF

 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 *

 */

/* OTHER CREDITS:

 *

 * This is the normal smoothscale method, based on Imlib2's smoothscale.

 *

 * Originally I took the algorithm used in NetPBM and Qt and added MMX/3dnow

 * optimizations. It ran in about 1/2 the time as Qt. Then I ported Imlib's

 * C algorithm and it ran at about the same speed as my MMX optimized one...

 * Finally I ported Imlib's MMX version and it ran in less than half the

 * time as my MMX algorithm, (taking only a quarter of the time Qt does).

 * After further optimization it seems to run at around 1/6th.

 *

 * Changes include formatting, namespaces and other C++'ings, removal of old

 * #ifdef'ed code, and removal of unneeded border calculation code.

 *

 * Imlib2 is (C) Carsten Haitzler and various contributors. The MMX code

 * is by Willem Monsuwe <willem@stack.nl>. All other modifications are

 * (C) Daniel M. Duley.

 */

namespace QImageScale {

    struct QImageScaleInfo {

        int *xpoints;

        unsigned int **ypoints;

        int *xapoints, *yapoints;

        int xup_yup;

    };

    unsigned int** qimageCalcYPoints(unsigned int *src, int sw, int sh,

                                     int dh);

    int* qimageCalcXPoints(int sw, int dw);

    int* qimageCalcApoints(int s, int d, int up);

    QImageScaleInfo* qimageFreeScaleInfo(QImageScaleInfo *isi);

    QImageScaleInfo *qimageCalcScaleInfo(const QImage &img, int sw, int sh,

                                         int dw, int dh, char aa);

}

using namespace QImageScale;

//

// Code ported from Imlib...

//

// FIXME: replace with qRed, etc... These work on pointers to pixels, not

// pixel values

#define A_VAL(p) (qAlpha(*p))

#define R_VAL(p) (qRed(*p))

#define G_VAL(p) (qGreen(*p))

#define B_VAL(p) (qBlue(*p))

#define INV_XAP                   (256 - xapoints[x])

#define XAP                       (xapoints[x])

#define INV_YAP                   (256 - yapoints[dyy + y])

#define YAP                       (yapoints[dyy + y])

unsigned int** QImageScale::qimageCalcYPoints(unsigned int *src,

                                              int sw, int sh, int dh)

{

    unsigned int **p;

    int i, j = 0;

    int val, inc, rv = 0;

    if(dh < 0){

        dh = -dh;

        rv = 1;

    }

    p = new unsigned int* [dh+1];

    int up = qAbs(dh) >= sh;

    val = up ? 0x8000 * sh / dh - 0x8000 : 0;

    inc = (sh << 16) / dh;

    for(i = 0; i < dh; i++){

        p[j++] = src + qMax(0, val >> 16) * sw;

        val += inc;

    }

    if(rv){

        for(i = dh / 2; --i >= 0; ){

            unsigned int *tmp = p[i];

            p[i] = p[dh - i - 1];

            p[dh - i - 1] = tmp;

        }

    }

    return(p);

}

int* QImageScale::qimageCalcXPoints(int sw, int dw)

{

    int *p, i, j = 0;

    int val, inc, rv = 0;

    if(dw < 0){

        dw = -dw;

        rv = 1;

    }

    p = new int[dw+1];

    int up = qAbs(dw) >= sw;

    val = up ? 0x8000 * sw / dw - 0x8000 : 0;

    inc = (sw << 16) / dw;

    for(i = 0; i < dw; i++){

        p[j++] = qMax(0, val >> 16);

        val += inc;

    }

    if(rv){

        for(i = dw / 2; --i >= 0; ){

            int tmp = p[i];

            p[i] = p[dw - i - 1];

            p[dw - i - 1] = tmp;

        }

    }

   return(p);

}

int* QImageScale::qimageCalcApoints(int s, int d, int up)

{

    int *p, i, j = 0, rv = 0;

    if(d < 0){

        rv = 1;

        d = -d;

    }

    p = new int[d];

    /* scaling up */

    if(up){

        int val, inc;

        val = 0x8000 * s / d - 0x8000;

        inc = (s << 16) / d;

        for(i = 0; i < d; i++){

            int pos = val >> 16;

            if (pos < 0)

                p[j++] = 0;

            else if (pos >= (s - 1))

                p[j++] = 0;

            else

                p[j++] = (val >> 8) - ((val >> 8) & 0xffffff00);

            val += inc;

        }

    }

    /* scaling down */

    else{

        int val, inc, ap, Cp;

        val = 0;

        inc = (s << 16) / d;

        Cp = ((d << 14) / s) + 1;

        for(i = 0; i < d; i++){

            ap = ((0x100 - ((val >> 8) & 0xff)) * Cp) >> 8;

            p[j] = ap | (Cp << 16);

            j++;

            val += inc;

        }

    }

    if(rv){

        int tmp;

        for(i = d / 2; --i >= 0; ){

            tmp = p[i];

            p[i] = p[d - i - 1];

            p[d - i - 1] = tmp;

        }

    }

    return(p);

}

QImageScaleInfo* QImageScale::qimageFreeScaleInfo(QImageScaleInfo *isi)

{

    if(isi){

        delete[] isi->xpoints;

        delete[] isi->ypoints;

        delete[] isi->xapoints;

        delete[] isi->yapoints;

        delete isi;

    }

    return 0;

}

QImageScaleInfo* QImageScale::qimageCalcScaleInfo(const QImage &img,

                                                  int sw, int sh,

                                                  int dw, int dh, char aa)

{

    QImageScaleInfo *isi;

    int scw, sch;

    scw = dw * qlonglong(img.width()) / sw;

    sch = dh * qlonglong(img.height()) / sh;

    isi = new QImageScaleInfo;

    if(!isi)

        return 0;

    memset(isi, 0, sizeof(QImageScaleInfo));

    isi->xup_yup = (qAbs(dw) >= sw) + ((qAbs(dh) >= sh) << 1);

    isi->xpoints = qimageCalcXPoints(img.width(), scw);

    if(!isi->xpoints)

        return(qimageFreeScaleInfo(isi));

    isi->ypoints = qimageCalcYPoints((unsigned int *)img.scanLine(0),

                                     img.bytesPerLine() / 4, img.height(), sch);

    if (!isi->ypoints)

        return(qimageFreeScaleInfo(isi));

    if(aa) {

        isi->xapoints = qimageCalcApoints(img.width(), scw, isi->xup_yup & 1);

        if(!isi->xapoints)

            return(qimageFreeScaleInfo(isi));

        isi->yapoints = qimageCalcApoints(img.height(), sch, isi->xup_yup & 2);

        if(!isi->yapoints)

            return(qimageFreeScaleInfo(isi));

    }

    return(isi);

}

/* FIXME: NEED to optimise ScaleAARGBA - currently its "ok" but needs work*/

/* scale by area sampling */

static void qt_qimageScaleAARGBA(QImageScaleInfo *isi, unsigned int *dest,

                                 int dxx, int dyy, int dx, int dy, int dw,

                                 int dh, int dow, int sow)

{

    unsigned int *sptr, *dptr;

    int x, y, end;

    unsigned int **ypoints = isi->ypoints;

    int *xpoints = isi->xpoints;

    int *xapoints = isi->xapoints;

    int *yapoints = isi->yapoints;

    end = dxx + dw;

    /* scaling up both ways */

    if(isi->xup_yup == 3){

        /* go through every scanline in the output buffer */

        for(y = 0; y < dh; y++){

            /* calculate the source line we'll scan from */

            dptr = dest + dx + ((y + dy) * dow);

            sptr = ypoints[dyy + y];

            if(YAP > 0){

                for(x = dxx; x < end; x++){

                    int r, g, b, a;

                    int rr, gg, bb, aa;

                    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;

                        a = A_VAL(pix) * INV_XAP;

                        pix++;

                        r += R_VAL(pix) * XAP;

                        g += G_VAL(pix) * XAP;

                        b += B_VAL(pix) * XAP;

                        a += A_VAL(pix) * XAP;

                        pix += sow;

                        rr = R_VAL(pix) * XAP;

                        gg = G_VAL(pix) * XAP;

                        bb = B_VAL(pix) * XAP;

                        aa = A_VAL(pix) * XAP;

                        pix--;

                        rr += R_VAL(pix) * INV_XAP;

                        gg += G_VAL(pix) * INV_XAP;

                        bb += B_VAL(pix) * INV_XAP;

                        aa += A_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;

                        a = ((aa * YAP) + (a * INV_YAP)) >> 16;

                        *dptr++ = qRgba(r, g, b, a);

                    }

                    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;

                        a = A_VAL(pix) * INV_YAP;

                        pix += sow;

                        r += R_VAL(pix) * YAP;

                        g += G_VAL(pix) * YAP;

                        b += B_VAL(pix) * YAP;

                        a += A_VAL(pix) * YAP;

                        r >>= 8;

                        g >>= 8;

                        b >>= 8;

                        a >>= 8;

                        *dptr++ = qRgba(r, g, b, a);

                    }

                }

            }

            else{

                for(x = dxx; x < end; x++){

                    int r, g, b, a;

                    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;

                        a = A_VAL(pix) * INV_XAP;

                        pix++;

                        r += R_VAL(pix) * XAP;

                        g += G_VAL(pix) * XAP;

                        b += B_VAL(pix) * XAP;

                        a += A_VAL(pix) * XAP;

                        r >>= 8;

                        g >>= 8;

                        b >>= 8;

                        a >>= 8;

                        *dptr++ = qRgba(r, g, b, a);

                    }

                    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, a, rr, gg, bb, aa;

        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;

                g = G_VAL(pix) * yap;

                b = B_VAL(pix) * yap;

                a = A_VAL(pix) * yap;

                for(j = (1 << 14) - yap; j > Cy; j -= Cy){

                    pix += sow;

                    r += R_VAL(pix) * Cy;

                    g += G_VAL(pix) * Cy;

                    b += B_VAL(pix) * Cy;

                    a += A_VAL(pix) * Cy;

                }

                if(j > 0){

                    pix += sow;

                    r += R_VAL(pix) * j;

                    g += G_VAL(pix) * j;

                    b += B_VAL(pix) * j;

                    a += A_VAL(pix) * j;

                }

                if(XAP > 0){

                    pix = ypoints[dyy + y] + xpoints[x] + 1;

                    rr = R_VAL(pix) * yap;

                    gg = G_VAL(pix) * yap;

                    bb = B_VAL(pix) * yap;

                    aa = A_VAL(pix) * yap;

                    for(j = (1 << 14) - yap; j > Cy; j -= Cy){

                        pix += sow;

                        rr += R_VAL(pix) * Cy;

                        gg += G_VAL(pix) * Cy;

                        bb += B_VAL(pix) * Cy;

                        aa += A_VAL(pix) * Cy;

                    }

                    if(j > 0){

                        pix += sow;

                        rr += R_VAL(pix) * j;

                        gg += G_VAL(pix) * j;

                        bb += B_VAL(pix) * j;

                        aa += A_VAL(pix) * j;

                    }

                    r = r * INV_XAP;

                    g = g * INV_XAP;

                    b = b * INV_XAP;

                    a = a * INV_XAP;

                    r = (r + ((rr * XAP))) >> 12;

                    g = (g + ((gg * XAP))) >> 12;

                    b = (b + ((bb * XAP))) >> 12;

                    a = (a + ((aa * XAP))) >> 12;

                }

                else{

                    r >>= 4;

                    g >>= 4;

                    b >>= 4;

                    a >>= 4;

                }

                *dptr = qRgba(r >> 10, g >> 10, b >> 10, a >> 10);

                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, a, rr, gg, bb, aa;

        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;

                g = G_VAL(pix) * xap;

                b = B_VAL(pix) * xap;

                a = A_VAL(pix) * xap;

                for(j = (1 << 14) - xap; j > Cx; j -= Cx){

                    pix++;

                    r += R_VAL(pix) * Cx;

                    g += G_VAL(pix) * Cx;

                    b += B_VAL(pix) * Cx;

                    a += A_VAL(pix) * Cx;

                }

                if(j > 0){

                    pix++;

                    r += R_VAL(pix) * j;

                    g += G_VAL(pix) * j;

                    b += B_VAL(pix) * j;

                    a += A_VAL(pix) * j;

                }

                if(YAP > 0){

                    pix = ypoints[dyy + y] + xpoints[x] + sow;

                    rr = R_VAL(pix) * xap;

                    gg = G_VAL(pix) * xap;

                    bb = B_VAL(pix) * xap;

                    aa = A_VAL(pix) * xap;

                    for(j = (1 << 14) - xap; j > Cx; j -= Cx){

                        pix++;

                        rr += R_VAL(pix) * Cx;

                        gg += G_VAL(pix) * Cx;

                        bb += B_VAL(pix) * Cx;

                        aa += A_VAL(pix) * Cx;