/* SDL_rotozoom.c


   The SDL_rotozoom sources were copied from the SDL_gfx library and
   are relicensed, only for the purposes of TuxMath, to GPL.  Original
   license was GNU Lesser Public License, Version 2 (or later).
   Thanks to Andreas Schiffler.

   SDL_gfx website: http://www.ferzkopp.net/Software/SDL_gfx-2.0/

   Slight modification and relicensing for tuxmath:
   Copyright (C) 2008, 2009, 2010, 2011.
Authors: David Bruce, Tim Holy, Brendan Luchen.
email: <tuxmath-devel@lists.sourceforge.net>



SDL_rotozoom.c is part of "Tux, of Math Command", a.k.a. "tuxmath".

Tuxmath is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.

Tuxmath is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/



#ifdef WIN32
#include <windows.h>
#endif

#include <stdlib.h>
#include <string.h>

#include "SDL_rotozoom.h"

#define MAX(a,b)    (((a) > (b)) ? (a) : (b))


/* 

   32bit integer-factor averaging Shrinker

   Shrinks 32bit RGBA/ABGR 'src' surface to 'dst' surface.

*/

int shrinkSurfaceRGBA(SDL_Surface * src, SDL_Surface * dst, int factorx, int factory)
{
    int x, y, dx, dy, sgap, dgap, ra, ga, ba, aa;
    int n_average;
    tColorRGBA *sp, *osp, *oosp;
    tColorRGBA *dp;

    /*
     * Averaging integer shrink
     */

    /* Precalculate division factor */
    n_average = factorx*factory;

    /*
     * Scan destination
     */
    sp = (tColorRGBA *) src->pixels;
    sgap = src->pitch - src->w * 4;

    dp = (tColorRGBA *) dst->pixels;
    dgap = dst->pitch - dst->w * 4;

    for (y = 0; y < dst->h; y++) {

        osp=sp;
        for (x = 0; x < dst->w; x++) {

            /* Trace out source box and accumulate */
            oosp=sp;
            ra=ga=ba=aa=0;
            for (dy=0; dy < factory; dy++) {
                for (dx=0; dx < factorx; dx++) {
                    ra += sp->r;
                    ga += sp->g;
                    ba += sp->b;
                    aa += sp->a;

                    sp++;
                } // src dx loop
                sp = (tColorRGBA *)((Uint8*)sp + (src->pitch - 4*factorx)); // next y
            } // src dy loop

            // next box-x
            sp = (tColorRGBA *)((Uint8*)oosp + 4*factorx);

            /* Store result in destination */
            dp->r = ra/n_average;
            dp->g = ga/n_average;
            dp->b = ba/n_average;
            dp->a = aa/n_average;

            /*
             * Advance destination pointer 
             */
            dp++;
        } // dst x loop

        // next box-y
        sp = (tColorRGBA *)((Uint8*)osp + src->pitch*factory);

        /*
         * Advance destination pointers 
         */
        dp = (tColorRGBA *) ((Uint8 *) dp + dgap);
    } // dst y loop

    return (0);
}

/* 

   8bit integer-factor averaging Shrinker

   Shrinks 8bit Y 'src' surface to 'dst' surface.

*/

int shrinkSurfaceY(SDL_Surface * src, SDL_Surface * dst, int factorx, int factory)
{
    int x, y, dx, dy, sgap, dgap, a;
    int n_average;
    Uint8 *sp, *osp, *oosp;
    Uint8 *dp;

    /*
     * Averaging integer shrink
     */

    /* Precalculate division factor */
    n_average = factorx*factory;

    /*
     * Scan destination
     */
    sp = (Uint8 *) src->pixels;
    sgap = src->pitch - src->w;

    dp = (Uint8 *) dst->pixels;
    dgap = dst->pitch - dst->w;

    for (y = 0; y < dst->h; y++) {    

        osp=sp;
        for (x = 0; x < dst->w; x++) {

            /* Trace out source box and accumulate */
            oosp=sp;
            a=0;
            for (dy=0; dy < factory; dy++) {
                for (dx=0; dx < factorx; dx++) {
                    a += (*sp);           
                    sp++; // next x
                } // src dx loop         
                sp = (Uint8 *)((Uint8*)sp + (src->pitch - factorx)); // next y
            } // src dy loop

            // next box-x
            sp = (Uint8 *)((Uint8*)oosp + factorx);

            /* Store result in destination */
            *dp = a/n_average;

            /*
             * Advance destination pointer 
             */
            dp++;
        } // dst x loop

        // next box-y
        sp = (Uint8 *)((Uint8*)osp + src->pitch*factory);

        /*
         * Advance destination pointers 
         */
        dp = (Uint8 *)((Uint8 *)dp + dgap);
    } // dst y loop

    return (0);
}

/* 

   32bit Zoomer with optional anti-aliasing by bilinear interpolation.

   Zoomes 32bit RGBA/ABGR 'src' surface to 'dst' surface.

*/

int zoomSurfaceRGBA(SDL_Surface * src, SDL_Surface * dst, int flipx, int flipy, int smooth)
{
    int x, y, sx, sy, *sax, *say, *csax, *csay, csx, csy, ex, ey, t1, t2, sstep;
    tColorRGBA *c00, *c01, *c10, *c11;
    tColorRGBA *sp, *csp, *dp;
    int dgap;

    /*
     * Variable setup 
     */
    if (smooth) {
        /*
         * For interpolation: assume source dimension is one pixel 
         */
        /*
         * smaller to avoid overflow on right and bottom edge.     
         */
        sx = (int) (65536.0 * (float) (src->w - 1) / (float) dst->w);
        sy = (int) (65536.0 * (float) (src->h - 1) / (float) dst->h);
    } else {
        sx = (int) (65536.0 * (float) src->w / (float) dst->w);
        sy = (int) (65536.0 * (float) src->h / (float) dst->h);
    }

    /*
     * Allocate memory for row increments 
     */
    if ((sax = (int *) malloc((dst->w + 1) * sizeof(Uint32))) == NULL) {
        return (-1);
    }
    if ((say = (int *) malloc((dst->h + 1) * sizeof(Uint32))) == NULL) {
        free(sax);
        return (-1);
    }

    /*
     * Precalculate row increments 
     */
    sp = csp = (tColorRGBA *) src->pixels;
    dp = (tColorRGBA *) dst->pixels;

    if (flipx) csp += (src->w-1);
    if (flipy) csp  = (tColorRGBA*)( (Uint8*)csp + src->pitch*(src->h-1) );

    csx = 0;
    csax = sax;
    for (x = 0; x <= dst->w; x++) {
        *csax = csx;
        csax++;
        csx &= 0xffff;
        csx += sx;
    }
    csy = 0;
    csay = say;
    for (y = 0; y <= dst->h; y++) {
        *csay = csy;
        csay++;
        csy &= 0xffff;
        csy += sy;
    }

    dgap = dst->pitch - dst->w * 4;

    /*
     * Switch between interpolating and non-interpolating code 
     */
    if (smooth) {

        /*
         * Interpolating Zoom 
         */

        /*
         * Scan destination 
         */
        csay = say;
        for (y = 0; y < dst->h; y++) {
            /*
             * Setup color source pointers 
             */
            c00 = csp;
            c01 = csp;
            c01++;
            c10 = (tColorRGBA *) ((Uint8 *) csp + src->pitch);
            c11 = c10;
            c11++;
            csax = sax;
            for (x = 0; x < dst->w; x++) {

                /*
                 * Interpolate colors 
                 */
                ex = (*csax & 0xffff);
                ey = (*csay & 0xffff);
                t1 = ((((c01->r - c00->r) * ex) >> 16) + c00->r) & 0xff;
                t2 = ((((c11->r - c10->r) * ex) >> 16) + c10->r) & 0xff;
                dp->r = (((t2 - t1) * ey) >> 16) + t1;
                t1 = ((((c01->g - c00->g) * ex) >> 16) + c00->g) & 0xff;
                t2 = ((((c11->g - c10->g) * ex) >> 16) + c10->g) & 0xff;
                dp->g = (((t2 - t1) * ey) >> 16) + t1;
                t1 = ((((c01->b - c00->b) * ex) >> 16) + c00->b) & 0xff;
                t2 = ((((c11->b - c10->b) * ex) >> 16) + c10->b) & 0xff;
                dp->b = (((t2 - t1) * ey) >> 16) + t1;
                t1 = ((((c01->a - c00->a) * ex) >> 16) + c00->a) & 0xff;
                t2 = ((((c11->a - c10->a) * ex) >> 16) + c10->a) & 0xff;
                dp->a = (((t2 - t1) * ey) >> 16) + t1;

                /*
                 * Advance source pointers 
                 */
                csax++;
                sstep = (*csax >> 16);
                c00 += sstep;
                c01 += sstep;
                c10 += sstep;
                c11 += sstep;
                /*
                 * Advance destination pointer 
                 */
                dp++;
            }
            /*
             * Advance source pointer 
             */
            csay++;
            csp = (tColorRGBA *) ((Uint8 *) csp + (*csay >> 16) * src->pitch);
            /*
             * Advance destination pointers 
             */
            dp = (tColorRGBA *) ((Uint8 *) dp + dgap);
        }

    } else {

        /*
         * Non-Interpolating Zoom 
         */

        csay = say;
        for (y = 0; y < dst->h; y++) {
            sp = csp;
            csax = sax;
            for (x = 0; x < dst->w; x++) {
                /*
                 * Draw 
                 */
                *dp = *sp;
                /*
                 * Advance source pointers 
                 */
                csax++;
                sstep = (*csax >> 16);
                if (flipx) sstep = -sstep;
                sp += sstep;
                /*
                 * Advance destination pointer 
                 */
                dp++;
            }
            /*
             * Advance source pointer 
             */
            csay++;
            sstep = (*csay >> 16) * src->pitch;
            if (flipy) sstep = -sstep;
            csp = (tColorRGBA *) ((Uint8 *) csp + sstep);

            /*
             * Advance destination pointers 
             */
            dp = (tColorRGBA *) ((Uint8 *) dp + dgap);
        }

    }

    /*
     * Remove temp arrays 
     */
    free(sax);
    free(say);

    return (0);
}

/* 

   8bit Zoomer without smoothing.

   Zoomes 8bit palette/Y 'src' surface to 'dst' surface.

*/

int zoomSurfaceY(SDL_Surface * src, SDL_Surface * dst, int flipx, int flipy)
{
    Uint32 x, y, sx, sy, *sax, *say, *csax, *csay, csx, csy;
    Uint8 *sp, *dp, *csp;
    int dgap;

    /*
     * Variable setup 
     */
    sx = (Uint32) (65536.0 * (float) src->w / (float) dst->w);
    sy = (Uint32) (65536.0 * (float) src->h / (float) dst->h);

    /*
     * Allocate memory for row increments 
     */
    if ((sax = (Uint32 *) malloc(dst->w * sizeof(Uint32))) == NULL) {
        return (-1);
    }
    if ((say = (Uint32 *) malloc(dst->h * sizeof(Uint32))) == NULL) {
        if (sax != NULL) {
            free(sax);
        }
        return (-1);
    }

    /*
     * Precalculate row increments 
     */
    csx = 0;
    csax = sax;
    for (x = 0; x < dst->w; x++) {
        csx += sx;
        *csax = (csx >> 16);
        csx &= 0xffff;
        csax++;
    }
    csy = 0;
    csay = say;
    for (y = 0; y < dst->h; y++) {
        csy += sy;
        *csay = (csy >> 16);
        csy &= 0xffff;
        csay++;
    }

    csx = 0;
    csax = sax;
    for (x = 0; x < dst->w; x++) {
        csx += (*csax);
        csax++;
    }
    csy = 0;
    csay = say;
    for (y = 0; y < dst->h; y++) {
        csy += (*csay);
        csay++;
    }

    /*
     * Pointer setup 
     */
    sp = csp = (Uint8 *) src->pixels;
    dp = (Uint8 *) dst->pixels;
    dgap = dst->pitch - dst->w;

    /*
     * Draw 
     */
    csay = say;
    for (y = 0; y < dst->h; y++) {
        csax = sax;
        sp = csp;
        for (x = 0; x < dst->w; x++) {
            /*
             * Draw 
             */
            *dp = *sp;
            /*
             * Advance source pointers 
             */
            sp += (*csax);
            csax++;
            /*
             * Advance destination pointer 
             */
            dp++;
        }
        /*
         * Advance source pointer (for row) 
         */
        csp += ((*csay) * src->pitch);
        csay++;
        /*
         * Advance destination pointers 
         */
        dp += dgap;
    }

    /*
     * Remove temp arrays 
     */
    free(sax);
    free(say);

    return (0);
}

/* 

   32bit Rotozoomer with optional anti-aliasing by bilinear interpolation.

   Rotates and zoomes 32bit RGBA/ABGR 'src' surface to 'dst' surface.

*/

void transformSurfaceRGBA(SDL_Surface * src, SDL_Surface * dst, int cx, int cy, int isin, int icos, int flipx, int flipy, int smooth)
{
    int x, y, t1, t2, dx, dy, xd, yd, sdx, sdy, ax, ay, ex, ey, sw, sh;
    tColorRGBA c00, c01, c10, c11;
    tColorRGBA *pc, *sp;
    int gap;

    c00.r = c00.g = c00.b = c00.a = 0;
    c01.r = c01.g = c01.b = c01.a = 0;
    c10.r = c10.g = c10.b = c10.a = 0;
    c11.r = c11.g = c11.b = c11.a = 0;
    /*
     * Variable setup 
     */
    xd = ((src->w - dst->w) << 15);
    yd = ((src->h - dst->h) << 15);
    ax = (cx << 16) - (icos * cx);
    ay = (cy << 16) - (isin * cx);
    sw = src->w - 1;
    sh = src->h - 1;
    pc = dst->pixels;
    gap = dst->pitch - dst->w * 4;

    /*
     * Switch between interpolating and non-interpolating code 
     */
    if (smooth) {
        for (y = 0; y < dst->h; y++) {
            dy = cy - y;
            sdx = (ax + (isin * dy)) + xd;
            sdy = (ay - (icos * dy)) + yd;
            for (x = 0; x < dst->w; x++) {
                dx = (sdx >> 16);
                dy = (sdy >> 16);
                if ((dx >= -1) && (dy >= -1) && (dx < src->w) && (dy < src->h)) {
                    if ((dx >= 0) && (dy >= 0) && (dx < sw) && (dy < sh)) {
                        sp = (tColorRGBA *) ((Uint8 *) src->pixels + src->pitch * dy);
                        sp += dx;
                        c00 = *sp;
                        sp += 1;
                        c01 = *sp;
                        sp = (tColorRGBA *) ((Uint8 *) sp + src->pitch);
                        sp -= 1;
                        c10 = *sp;
                        sp += 1;
                        c11 = *sp;
                    } else if ((dx == sw) && (dy == sh)) {
                        sp = (tColorRGBA *) ((Uint8 *) src->pixels + src->pitch * dy);
                        sp += dx;
                        c00 = *sp;
                        c01 = *sp;
                        c10 = *sp;
                        c11 = *sp;
                    } else if ((dx == -1) && (dy == -1)) {
                        sp = (tColorRGBA *) (src->pixels);
                        c00 = *sp;
                        c01 = *sp;
                        c10 = *sp;
                        c11 = *sp;
                    } else if ((dx == -1) && (dy == sh)) {
                        sp = (tColorRGBA *) (src->pixels);
                        sp = (tColorRGBA *) ((Uint8 *) src->pixels + src->pitch * dy);
                        c00 = *sp;
                        c01 = *sp;
                        c10 = *sp;
                        c11 = *sp;
                    } else if ((dx == sw) && (dy == -1)) {
                        sp = (tColorRGBA *) (src->pixels);
                        sp += dx;
                        c00 = *sp;
                        c01 = *sp;
                        c10 = *sp;
                        c11 = *sp;
                    } else if (dx == -1) {
                        sp = (tColorRGBA *) ((Uint8 *) src->pixels + src->pitch * dy);
                        c00 = *sp;
                        c01 = *sp;
                        c10 = *sp;
                        sp = (tColorRGBA *) ((Uint8 *) sp + src->pitch);
                        c11 = *sp;
                    } else if (dy == -1) {
                        sp = (tColorRGBA *) (src->pixels);
                        sp += dx;
                        c00 = *sp;
                        c01 = *sp;
                        c10 = *sp;
                        sp += 1;
                        c11 = *sp;
                    } else if (dx == sw) {
                        sp = (tColorRGBA *) ((Uint8 *) src->pixels + src->pitch * dy);
                        sp += dx;
                        c00 = *sp;
                        c01 = *sp;
                        sp = (tColorRGBA *) ((Uint8 *) sp + src->pitch);
                        c10 = *sp;
                        c11 = *sp;
                    } else if (dy == sh) {
                        sp = (tColorRGBA *) ((Uint8 *) src->pixels + src->pitch * dy);
                        sp += dx;
                        c00 = *sp;
                        sp += 1;
                        c01 = *sp;
                        c10 = *sp;
                        c11 = *sp;
                    }
                    /*
                     * Interpolate colors 
                     */
                    ex = (sdx & 0xffff);
                    ey = (sdy & 0xffff);
                    t1 = ((((c01.r - c00.r) * ex) >> 16) + c00.r) & 0xff;
                    t2 = ((((c11.r - c10.r) * ex) >> 16) + c10.r) & 0xff;
                    pc->r = (((t2 - t1) * ey) >> 16) + t1;
                    t1 = ((((c01.g - c00.g) * ex) >> 16) + c00.g) & 0xff;
                    t2 = ((((c11.g - c10.g) * ex) >> 16) + c10.g) & 0xff;
                    pc->g = (((t2 - t1) * ey) >> 16) + t1;
                    t1 = ((((c01.b - c00.b) * ex) >> 16) + c00.b) & 0xff;
                    t2 = ((((c11.b - c10.b) * ex) >> 16) + c10.b) & 0xff;
                    pc->b = (((t2 - t1) * ey) >> 16) + t1;
                    t1 = ((((c01.a - c00.a) * ex) >> 16) + c00.a) & 0xff;
                    t2 = ((((c11.a - c10.a) * ex) >> 16) + c10.a) & 0xff;
                    pc->a = (((t2 - t1) * ey) >> 16) + t1;
                }
                sdx += icos;
                sdy += isin;
                pc++;
            }
            pc = (tColorRGBA *) ((Uint8 *) pc + gap);
        }
    } else {
        for (y = 0; y < dst->h; y++) {
            dy = cy - y;
            sdx = (ax + (isin * dy)) + xd;
            sdy = (ay - (icos * dy)) + yd;
            for (x = 0; x < dst->w; x++) {
                dx = (short) (sdx >> 16);
                dy = (short) (sdy >> 16);
                if (flipx) dx = (src->w-1)-dx;
                if (flipy) dy = (src->h-1)-dy;
                if ((dx >= 0) && (dy >= 0) && (dx < src->w) && (dy < src->h)) {
                    sp = (tColorRGBA *) ((Uint8 *) src->pixels + src->pitch * dy);
                    sp += dx;
                    *pc = *sp;
                }
                sdx += icos;
                sdy += isin;
                pc++;
            }
            pc = (tColorRGBA *) ((Uint8 *) pc + gap);
        }
    }
}

/* 

   8bit Rotozoomer without smoothing

   Rotates and zoomes 8bit palette/Y 'src' surface to 'dst' surface.

*/

void transformSurfaceY(SDL_Surface * src, SDL_Surface * dst, int cx, int cy, int isin, int icos)
{
    int x, y, dx, dy, xd, yd, sdx, sdy, ax, ay, sw, sh;
    tColorY *pc, *sp;
    int gap;

    /*
     * Variable setup 
     */
    xd = ((src->w - dst->w) << 15);
    yd = ((src->h - dst->h) << 15);
    ax = (cx << 16) - (icos * cx);
    ay = (cy << 16) - (isin * cx);
    sw = src->w - 1;
    sh = src->h - 1;
    pc = dst->pixels;
    gap = dst->pitch - dst->w;
    /*
     * Clear surface to colorkey 
     */
    memset(pc, (unsigned char) (src->format->colorkey & 0xff), dst->pitch * dst->h);
    /*
     * Iterate through destination surface 
     */
    for (y = 0; y < dst->h; y++) {
        dy = cy - y;
        sdx = (ax + (isin * dy)) + xd;
        sdy = (ay - (icos * dy)) + yd;
        for (x = 0; x < dst->w; x++) {
            dx = (short) (sdx >> 16);
            dy = (short) (sdy >> 16);
            if ((dx >= 0) && (dy >= 0) && (dx < src->w) && (dy < src->h)) {
                sp = (tColorY *) (src->pixels);
                sp += (src->pitch * dy + dx);
                *pc = *sp;
            }
            sdx += icos;
            sdy += isin;
            pc++;
        }
        pc += gap;
    }
}


/* 

   32bit specialized 90degree rotator

   Rotates and zooms 'src' surface to 'dst' surface in 90degree increments.

   (contributed by Jeff Schiller)

*/
SDL_Surface* rotateSurface90Degrees(SDL_Surface* pSurf, int numClockwiseTurns) 
{
    int row, col;

    // Has to be a valid surface pointer and only 32-bit surfaces (for now)
    if (!pSurf || pSurf->format->BitsPerPixel != 32) { return NULL; }

    // normalize numClockwiseTurns
    while(numClockwiseTurns < 0) { numClockwiseTurns += 4; }
    numClockwiseTurns = (numClockwiseTurns % 4);

    // if it's even, our new width will be the same as the source surface
    int newWidth = (numClockwiseTurns % 2) ? (pSurf->h) : (pSurf->w);
    int newHeight = (numClockwiseTurns % 2) ? (pSurf->w) : (pSurf->h);
    SDL_Surface* pSurfOut = SDL_CreateRGBSurface( pSurf->flags, newWidth, newHeight, pSurf->format->BitsPerPixel,
            pSurf->format->Rmask,
            pSurf->format->Gmask, 
            pSurf->format->Bmask, 
            pSurf->format->Amask);
    if(!pSurfOut) {
        return NULL;
    }

    if(numClockwiseTurns != 0) {
        SDL_LockSurface(pSurf);
        SDL_LockSurface(pSurfOut);
        switch(numClockwiseTurns) {
            // rotate clockwise
            case 1: // rotated 90 degrees clockwise
                {
                    Uint32* srcBuf = NULL;
                    Uint32* dstBuf = NULL;

                    for (row = 0; row < pSurf->h; ++row) {
                        srcBuf = (Uint32*)(pSurf->pixels) + (row*pSurf->pitch/4);
                        dstBuf = (Uint32*)(pSurfOut->pixels) + (pSurfOut->w - row - 1);
                        for (col = 0; col < pSurf->w; ++col) {
                            *dstBuf = *srcBuf;
                            ++srcBuf;
                            dstBuf += pSurfOut->pitch/4;
                        } // for(col)
                    } // for(row)
                }
                break;

            case 2: // rotated 180 degrees clockwise
                {
                    Uint32* srcBuf = NULL;
                    Uint32* dstBuf = NULL;

                    for(row = 0; row < pSurf->h; ++row) {
                        srcBuf = (Uint32*)(pSurf->pixels) + (row*pSurf->pitch/4);
                        dstBuf = (Uint32*)(pSurfOut->pixels) + ((pSurfOut->h - row - 1)*pSurfOut->pitch/4) + (pSurfOut->w - 1);
                        for(col = 0; col < pSurf->w; ++col) {
                            *dstBuf = *srcBuf;
                            ++srcBuf;
                            --dstBuf;
                        } // for(col)
                    } // for(row)
                }
                break;

            case 3:
                {
                    Uint32* srcBuf = NULL;
                    Uint32* dstBuf = NULL;

                    for(row = 0; row < pSurf->h; ++row) {
                        srcBuf = (Uint32*)(pSurf->pixels) + (row*pSurf->pitch/4);
                        dstBuf = (Uint32*)(pSurfOut->pixels) + row + ((pSurfOut->h - 1)*pSurfOut->pitch/4);
                        for(col = 0; col < pSurf->w; ++col) {
                            *dstBuf = *srcBuf;
                            ++srcBuf;
                            dstBuf -= pSurfOut->pitch/4;
                        } // for(col)
                    } // for(row)
                }
                break;
        } // switch

        SDL_UnlockSurface(pSurf);
        SDL_UnlockSurface(pSurfOut);
    } // if numClockwiseTurns > 0
    else {
        // simply copy surface to output
        if(SDL_BlitSurface(pSurf, NULL, pSurfOut, NULL)) {
            return NULL;
        }
    }
    return pSurfOut;
}

/* 

   rotozoomSurface()

   Rotates and zoomes a 32bit or 8bit 'src' surface to newly created 'dst' surface.
   'angle' is the rotation in degrees. 'zoom' a scaling factor. If 'smooth' is 1
   then the destination 32bit surface is anti-aliased. If the surface is not 8bit
   or 32bit RGBA/ABGR it will be converted into a 32bit RGBA format on the fly.

*/

#define VALUE_LIMIT	0.001


/* Local rotozoom-size function with trig result return */

void rotozoomSurfaceSizeTrig(int width, int height, double angle, double zoomx, double zoomy, int *dstwidth, int *dstheight, 
        double *canglezoom, double *sanglezoom)
{
    double x, y, cx, cy, sx, sy;
    double radangle;
    int dstwidthhalf, dstheighthalf;

    /*
     * Determine destination width and height by rotating a centered source box 
     */
    radangle = angle * (M_PI / 180.0);
    *sanglezoom = sin(radangle);
    *canglezoom = cos(radangle);
    *sanglezoom *= zoomx;
    *canglezoom *= zoomx;
    x = width / 2;
    y = height / 2;
    cx = *canglezoom * x;
    cy = *canglezoom * y;
    sx = *sanglezoom * x;
    sy = *sanglezoom * y;

    dstwidthhalf = MAX((int)
            ceil(MAX(MAX(MAX(fabs(cx + sy), fabs(cx - sy)), fabs(-cx + sy)), fabs(-cx - sy))), 1);
    dstheighthalf = MAX((int)
            ceil(MAX(MAX(MAX(fabs(sx + cy), fabs(sx - cy)), fabs(-sx + cy)), fabs(-sx - cy))), 1);
    *dstwidth = 2 * dstwidthhalf;
    *dstheight = 2 * dstheighthalf;
}


/* Publically available rotozoom-size function */

void rotozoomSurfaceSizeXY(int width, int height, double angle, double zoomx, double zoomy, int *dstwidth, int *dstheight)
{
    double dummy_sanglezoom, dummy_canglezoom;

    rotozoomSurfaceSizeTrig(width, height, angle, zoomx, zoomy, dstwidth, dstheight, &dummy_sanglezoom, &dummy_canglezoom);
}

/* Publically available rotozoom-size function */

void rotozoomSurfaceSize(int width, int height, double angle, double zoom, int *dstwidth, int *dstheight)
{
    double dummy_sanglezoom, dummy_canglezoom;

    rotozoomSurfaceSizeTrig(width, height, angle, zoom, zoom, dstwidth, dstheight, &dummy_sanglezoom, &dummy_canglezoom);
}

/* Publically available rotozoom function */

SDL_Surface *rotozoomSurface(SDL_Surface * src, double angle, double zoom, int smooth)
{
    return rotozoomSurfaceXY(src, angle, zoom, zoom, smooth);
}

/* Publically available rotozoom function */

SDL_Surface *rotozoomSurfaceXY(SDL_Surface * src, double angle, double zoomx, double zoomy, int smooth)
{
    SDL_Surface *rz_src;
    SDL_Surface *rz_dst;
    double zoominv;
    double sanglezoom, canglezoom, sanglezoominv, canglezoominv;
    int dstwidthhalf, dstwidth, dstheighthalf, dstheight;
    int is32bit;
    int i, src_converted;
    int flipx,flipy;

    /*
     * Sanity check 
     */
    if (src == NULL)
        return (NULL);

    /*
     * Determine if source surface is 32bit or 8bit 
     */
    is32bit = (src->format->BitsPerPixel == 32);
    if ((is32bit) || (src->format->BitsPerPixel == 8)) {
        /*
         * Use source surface 'as is' 
         */
        rz_src = src;
        src_converted = 0;
    } else {
        /*
         * New source surface is 32bit with a defined RGBA ordering 
         */
        rz_src =
            SDL_CreateRGBSurface(SDL_SWSURFACE, src->w, src->h, 32, 
#if SDL_BYTEORDER == SDL_LIL_ENDIAN
                    0x000000ff, 0x0000ff00, 0x00ff0000, 0xff000000
#else
                    0xff000000,  0x00ff0000, 0x0000ff00, 0x000000ff
#endif
                    );
        SDL_BlitSurface(src, NULL, rz_src, NULL);
        src_converted = 1;
        is32bit = 1;
    }

    /*
     * Sanity check zoom factor 
     */
    flipx = (zoomx<0);
    if (flipx) zoomx=-zoomx;
    flipy = (zoomy<0);
    if (flipy) zoomy=-zoomy;
    if (zoomx < VALUE_LIMIT) zoomx = VALUE_LIMIT;
    if (zoomy < VALUE_LIMIT) zoomy = VALUE_LIMIT;
    zoominv = 65536.0 / (zoomx * zoomx);

    /*
     * Check if we have a rotozoom or just a zoom 
     */
    if (fabs(angle) > VALUE_LIMIT) {

        /*
         * Angle!=0: full rotozoom 
         */
        /*
         * ----------------------- 
         */

        /* Determine target size */
        rotozoomSurfaceSizeTrig(rz_src->w, rz_src->h, angle, zoomx, zoomy, &dstwidth, &dstheight, &canglezoom, &sanglezoom);

        /*
         * Calculate target factors from sin/cos and zoom 
         */
        sanglezoominv = sanglezoom;
        canglezoominv = canglezoom;
        sanglezoominv *= zoominv;
        canglezoominv *= zoominv;

        /* Calculate half size */
        dstwidthhalf = dstwidth / 2;
        dstheighthalf = dstheight / 2;

        /*
         * Alloc space to completely contain the rotated surface 
         */
        rz_dst = NULL;
        if (is32bit) {
            /*
             * Target surface is 32bit with source RGBA/ABGR ordering 
             */
            rz_dst =
                SDL_CreateRGBSurface(SDL_SWSURFACE, dstwidth, dstheight, 32,
                        rz_src->format->Rmask, rz_src->format->Gmask,
                        rz_src->format->Bmask, rz_src->format->Amask);
        } else {
            /*
             * Target surface is 8bit 
             */
            rz_dst = SDL_CreateRGBSurface(SDL_SWSURFACE, dstwidth, dstheight, 8, 0, 0, 0, 0);
        }

        /*
         * Lock source surface 
         */
        SDL_LockSurface(rz_src);
        /*
         * Check which kind of surface we have 
         */
        if (is32bit) {
            /*
             * Call the 32bit transformation routine to do the rotation (using alpha) 
             */
            transformSurfaceRGBA(rz_src, rz_dst, dstwidthhalf, dstheighthalf,
                    (int) (sanglezoominv), (int) (canglezoominv), 
                    flipx, flipy,
                    smooth);
            /*
             * Turn on source-alpha support 
             */
            SDL_SetAlpha(rz_dst, SDL_SRCALPHA, 255);
        } else {
            /*
             * Copy palette and colorkey info 
             */
            for (i = 0; i < rz_src->format->palette->ncolors; i++) {
                rz_dst->format->palette->colors[i] = rz_src->format->palette->colors[i];
            }
            rz_dst->format->palette->ncolors = rz_src->format->palette->ncolors;
            /*
             * Call the 8bit transformation routine to do the rotation 
             */
            transformSurfaceY(rz_src, rz_dst, dstwidthhalf, dstheighthalf,
                    (int) (sanglezoominv), (int) (canglezoominv));
            SDL_SetColorKey(rz_dst, SDL_SRCCOLORKEY | SDL_RLEACCEL, rz_src->format->colorkey);
        }
        /*
         * Unlock source surface 
         */
        SDL_UnlockSurface(rz_src);

    } else {

        /*
         * Angle=0: Just a zoom 
         */
        /*
         * -------------------- 
         */

        /*
         * Calculate target size
         */
        zoomSurfaceSize(rz_src->w, rz_src->h, zoomx, zoomy, &dstwidth, &dstheight);

        /*
         * Alloc space to completely contain the zoomed surface 
         */
        rz_dst = NULL;
        if (is32bit) {
            /*
             * Target surface is 32bit with source RGBA/ABGR ordering 
             */
            rz_dst =
                SDL_CreateRGBSurface(SDL_SWSURFACE, dstwidth, dstheight, 32,
                        rz_src->format->Rmask, rz_src->format->Gmask,
                        rz_src->format->Bmask, rz_src->format->Amask);
        } else {
            /*
             * Target surface is 8bit 
             */
            rz_dst = SDL_CreateRGBSurface(SDL_SWSURFACE, dstwidth, dstheight, 8, 0, 0, 0, 0);
        }

        /*
         * Lock source surface 
         */
        SDL_LockSurface(rz_src);
        /*
         * Check which kind of surface we have 
         */
        if (is32bit) {
            /*
             * Call the 32bit transformation routine to do the zooming (using alpha) 
             */
            zoomSurfaceRGBA(rz_src, rz_dst, flipx, flipy, smooth);
            /*
             * Turn on source-alpha support 
             */
            SDL_SetAlpha(rz_dst, SDL_SRCALPHA, 255);
        } else {
            /*
             * Copy palette and colorkey info 
             */
            for (i = 0; i < rz_src->format->palette->ncolors; i++) {
                rz_dst->format->palette->colors[i] = rz_src->format->palette->colors[i];
            }
            rz_dst->format->palette->ncolors = rz_src->format->palette->ncolors;
            /*
             * Call the 8bit transformation routine to do the zooming 
             */
            zoomSurfaceY(rz_src, rz_dst, flipx, flipy);
            SDL_SetColorKey(rz_dst, SDL_SRCCOLORKEY | SDL_RLEACCEL, rz_src->format->colorkey);
        }
        /*
         * Unlock source surface 
         */
        SDL_UnlockSurface(rz_src);
    }

    /*
     * Cleanup temp surface 
     */
    if (src_converted) {
        SDL_FreeSurface(rz_src);
    }

    /*
     * Return destination surface 
     */
    return (rz_dst);
}

/* 

   zoomSurface()

   Zoomes a 32bit or 8bit 'src' surface to newly created 'dst' surface.
   'zoomx' and 'zoomy' are scaling factors for width and height. If 'smooth' is 1
   then the destination 32bit surface is anti-aliased. If the surface is not 8bit
   or 32bit RGBA/ABGR it will be converted into a 32bit RGBA format on the fly.

*/

#define VALUE_LIMIT	0.001

void zoomSurfaceSize(int width, int height, double zoomx, double zoomy, int *dstwidth, int *dstheight)
{
    /*
     * Sanity check zoom factors 
     */
    if (zoomx < VALUE_LIMIT) {
        zoomx = VALUE_LIMIT;
    }
    if (zoomy < VALUE_LIMIT) {
        zoomy = VALUE_LIMIT;
    }

    /*
     * Calculate target size 
     */
    *dstwidth = (int) ((double) width * zoomx);
    *dstheight = (int) ((double) height * zoomy);
    if (*dstwidth < 1) {
        *dstwidth = 1;
    }
    if (*dstheight < 1) {
        *dstheight = 1;
    }
}

SDL_Surface *zoomSurface(SDL_Surface * src, double zoomx, double zoomy, int smooth)
{
    SDL_Surface *rz_src;
    SDL_Surface *rz_dst;
    int dstwidth, dstheight;
    int is32bit;
    int i, src_converted;
    int flipx, flipy;

    /*
     * Sanity check 
     */
    if (src == NULL)
        return (NULL);

    /*
     * Determine if source surface is 32bit or 8bit 
     */
    is32bit = (src->format->BitsPerPixel == 32);
    if ((is32bit) || (src->format->BitsPerPixel == 8)) {
        /*
         * Use source surface 'as is' 
         */
        rz_src = src;
        src_converted = 0;
    } else {
        /*
         * New source surface is 32bit with a defined RGBA ordering 
         */
        rz_src =
            SDL_CreateRGBSurface(SDL_SWSURFACE, src->w, src->h, 32, 
#if SDL_BYTEORDER == SDL_LIL_ENDIAN
                    0x000000ff, 0x0000ff00, 0x00ff0000, 0xff000000
#else
                    0xff000000,  0x00ff0000, 0x0000ff00, 0x000000ff
#endif
                    );
        SDL_BlitSurface(src, NULL, rz_src, NULL);
        src_converted = 1;
        is32bit = 1;
    }

    flipx = (zoomx<0);
    if (flipx) zoomx = -zoomx;
    flipy = (zoomy<0);
    if (flipy) zoomy = -zoomy;

    /* Get size if target */
    zoomSurfaceSize(rz_src->w, rz_src->h, zoomx, zoomy, &dstwidth, &dstheight);

    /*
     * Alloc space to completely contain the zoomed surface 
     */
    rz_dst = NULL;
    if (is32bit) {
        /*
         * Target surface is 32bit with source RGBA/ABGR ordering 
         */
        rz_dst =
            SDL_CreateRGBSurface(SDL_SWSURFACE, dstwidth, dstheight, 32,
                    rz_src->format->Rmask, rz_src->format->Gmask,
                    rz_src->format->Bmask, rz_src->format->Amask);
    } else {
        /*
         * Target surface is 8bit 
         */
        rz_dst = SDL_CreateRGBSurface(SDL_SWSURFACE, dstwidth, dstheight, 8, 0, 0, 0, 0);
    }

    /*
     * Lock source surface 
     */
    SDL_LockSurface(rz_src);
    /*
     * Check which kind of surface we have 
     */
    if (is32bit) {
        /*
         * Call the 32bit transformation routine to do the zooming (using alpha) 
         */
        zoomSurfaceRGBA(rz_src, rz_dst, flipx, flipy, smooth);
        /*
         * Turn on source-alpha support 
         */
        SDL_SetAlpha(rz_dst, SDL_SRCALPHA, 255);
    } else {
        /*
         * Copy palette and colorkey info 
         */
        for (i = 0; i < rz_src->format->palette->ncolors; i++) {
            rz_dst->format->palette->colors[i] = rz_src->format->palette->colors[i];
        }
        rz_dst->format->palette->ncolors = rz_src->format->palette->ncolors;
        /*
         * Call the 8bit transformation routine to do the zooming 
         */
        zoomSurfaceY(rz_src, rz_dst, flipx, flipy);
        SDL_SetColorKey(rz_dst, SDL_SRCCOLORKEY | SDL_RLEACCEL, rz_src->format->colorkey);
    }
    /*
     * Unlock source surface 
     */
    SDL_UnlockSurface(rz_src);

    /*
     * Cleanup temp surface 
     */
    if (src_converted) {
        SDL_FreeSurface(rz_src);
    }

    /*
     * Return destination surface 
     */
    return (rz_dst);
}

SDL_Surface *shrinkSurface(SDL_Surface * src, int factorx, int factory)
{
    SDL_Surface *rz_src;
    SDL_Surface *rz_dst;
    int dstwidth, dstheight;
    int is32bit;
    int i, src_converted;

    /*
     * Sanity check 
     */
    if (src == NULL)
        return (NULL);

    /*
     * Determine if source surface is 32bit or 8bit 
     */
    is32bit = (src->format->BitsPerPixel == 32);
    if ((is32bit) || (src->format->BitsPerPixel == 8)) {
        /*
         * Use source surface 'as is' 
         */
        rz_src = src;
        src_converted = 0;
    } else {
        /*
         * New source surface is 32bit with a defined RGBA ordering 
         */
        rz_src =
            SDL_CreateRGBSurface(SDL_SWSURFACE, src->w, src->h, 32, 
#if SDL_BYTEORDER == SDL_LIL_ENDIAN
                    0x000000ff, 0x0000ff00, 0x00ff0000, 0xff000000
#else
                    0xff000000,  0x00ff0000, 0x0000ff00, 0x000000ff
#endif
                    );
        SDL_BlitSurface(src, NULL, rz_src, NULL);
        src_converted = 1;
        is32bit = 1;
    }

    /* Get size for target */
    dstwidth=rz_src->w/factorx;
    while (dstwidth*factorx>rz_src->w) { dstwidth--; }
    dstheight=rz_src->h/factory;
    while (dstheight*factory>rz_src->h) { dstheight--; }

    /*
     * Alloc space to completely contain the shrunken surface 
     */
    rz_dst = NULL;
    if (is32bit) {
        /*
         * Target surface is 32bit with source RGBA/ABGR ordering 
         */
        rz_dst =
            SDL_CreateRGBSurface(SDL_SWSURFACE, dstwidth, dstheight, 32,
                    rz_src->format->Rmask, rz_src->format->Gmask,
                    rz_src->format->Bmask, rz_src->format->Amask);
    } else {
        /*
         * Target surface is 8bit 
         */
        rz_dst = SDL_CreateRGBSurface(SDL_SWSURFACE, dstwidth, dstheight, 8, 0, 0, 0, 0);
    }

    /*
     * Lock source surface 
     */
    SDL_LockSurface(rz_src);
    /*
     * Check which kind of surface we have 
     */
    if (is32bit) {
        /*
         * Call the 32bit transformation routine to do the shrinking (using alpha) 
         */
        shrinkSurfaceRGBA(rz_src, rz_dst, factorx, factory);
        /*
         * Turn on source-alpha support 
         */
        SDL_SetAlpha(rz_dst, SDL_SRCALPHA, 255);
    } else {
        /*
         * Copy palette and colorkey info 
         */
        for (i = 0; i < rz_src->format->palette->ncolors; i++) {
            rz_dst->format->palette->colors[i] = rz_src->format->palette->colors[i];
        }
        rz_dst->format->palette->ncolors = rz_src->format->palette->ncolors;
        /*
         * Call the 8bit transformation routine to do the shrinking 
         */
        shrinkSurfaceY(rz_src, rz_dst, factorx, factory);
        SDL_SetColorKey(rz_dst, SDL_SRCCOLORKEY | SDL_RLEACCEL, rz_src->format->colorkey);
    }
    /*
     * Unlock source surface 
     */
    SDL_UnlockSurface(rz_src);

    /*
     * Cleanup temp surface 
     */
    if (src_converted) {
        SDL_FreeSurface(rz_src);
    }

    /*
     * Return destination surface 
     */
    return (rz_dst);
}
