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diff --git a/src/sdl2gfx/SDL_rotozoom.c b/src/sdl2gfx/SDL_rotozoom.c
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+/*
+
+SDL2_rotozoom.c: rotozoomer, zoomer and shrinker for 32bit or 8bit surfaces
+
+Copyright (C) 2012 Andreas Schiffler
+
+This software is provided 'as-is', without any express or implied
+warranty. In no event will the authors be held liable for any damages
+arising from the use of this software.
+
+Permission is granted to anyone to use this software for any purpose,
+including commercial applications, and to alter it and redistribute it
+freely, subject to the following restrictions:
+
+1. The origin of this software must not be misrepresented; you must not
+claim that you wrote the original software. If you use this software
+in a product, an acknowledgment in the product documentation would be
+appreciated but is not required.
+
+2. Altered source versions must be plainly marked as such, and must not be
+misrepresented as being the original software.
+
+3. This notice may not be removed or altered from any source
+distribution.
+
+Andreas Schiffler -- aschiffler at ferzkopp dot net
+
+*/
+
+#ifdef WIN32
+#include <windows.h>
+#endif
+
+#include <stdlib.h>
+#include <string.h>
+
+#include "SDL_rotozoom.h"
+
+/* ---- Internally used structures */
+
+/*!
+\brief A 32 bit RGBA pixel.
+*/
+typedef struct tColorRGBA {
+ Uint8 r;
+ Uint8 g;
+ Uint8 b;
+ Uint8 a;
+} tColorRGBA;
+
+/*!
+\brief A 8bit Y/palette pixel.
+*/
+typedef struct tColorY {
+ Uint8 y;
+} tColorY;
+
+/*!
+\brief Returns maximum of two numbers a and b.
+*/
+#define MAX(a,b) (((a) > (b)) ? (a) : (b))
+
+/*!
+\brief Number of guard rows added to destination surfaces.
+
+This is a simple but effective workaround for observed issues.
+These rows allocate extra memory and are then hidden from the surface.
+Rows are added to the end of destination surfaces when they are allocated.
+This catches any potential overflows which seem to happen with
+just the right src image dimensions and scale/rotation and can lead
+to a situation where the program can segfault.
+*/
+#define GUARD_ROWS (2)
+
+/*!
+\brief Lower limit of absolute zoom factor or rotation degrees.
+*/
+#define VALUE_LIMIT 0.001
+
+/*!
+\brief Returns colorkey info for a surface
+*/
+Uint32 _colorkey(SDL_Surface *src)
+{
+ Uint32 key = 0;
+ SDL_GetColorKey(src, &key);
+ return key;
+}
+
+
+/*!
+\brief Internal 32 bit integer-factor averaging Shrinker.
+
+Shrinks 32 bit RGBA/ABGR 'src' surface to 'dst' surface.
+Averages color and alpha values values of src pixels to calculate dst pixels.
+Assumes src and dst surfaces are of 32 bit depth.
+Assumes dst surface was allocated with the correct dimensions.
+
+\param src The surface to shrink (input).
+\param dst The shrunken surface (output).
+\param factorx The horizontal shrinking ratio.
+\param factory The vertical shrinking ratio.
+
+\return 0 for success or -1 for error.
+*/
+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);
+}
+
+/*!
+\brief Internal 8 bit integer-factor averaging shrinker.
+
+Shrinks 8bit Y 'src' surface to 'dst' surface.
+Averages color (brightness) values values of src pixels to calculate dst pixels.
+Assumes src and dst surfaces are of 8 bit depth.
+Assumes dst surface was allocated with the correct dimensions.
+
+\param src The surface to shrink (input).
+\param dst The shrunken surface (output).
+\param factorx The horizontal shrinking ratio.
+\param factory The vertical shrinking ratio.
+
+\return 0 for success or -1 for error.
+*/
+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);
+ /* next x */
+ sp++;
+ }
+ /* end src dx loop */
+ /* next y */
+ sp = (Uint8 *)((Uint8*)sp + (src->pitch - factorx));
+ }
+ /* end src dy loop */
+
+ /* next box-x */
+ sp = (Uint8 *)((Uint8*)oosp + factorx);
+
+ /* Store result in destination */
+ *dp = a/n_average;
+
+ /*
+ * Advance destination pointer
+ */
+ dp++;
+ }
+ /* end dst x loop */
+
+ /* next box-y */
+ sp = (Uint8 *)((Uint8*)osp + src->pitch*factory);
+
+ /*
+ * Advance destination pointers
+ */
+ dp = (Uint8 *)((Uint8 *)dp + dgap);
+ }
+ /* end dst y loop */
+
+ return (0);
+}
+
+/*!
+\brief Internal 32 bit Zoomer with optional anti-aliasing by bilinear interpolation.
+
+Zooms 32 bit RGBA/ABGR 'src' surface to 'dst' surface.
+Assumes src and dst surfaces are of 32 bit depth.
+Assumes dst surface was allocated with the correct dimensions.
+
+\param src The surface to zoom (input).
+\param dst The zoomed surface (output).
+\param flipx Flag indicating if the image should be horizontally flipped.
+\param flipy Flag indicating if the image should be vertically flipped.
+\param smooth Antialiasing flag; set to SMOOTHING_ON to enable.
+
+\return 0 for success or -1 for error.
+*/
+int _zoomSurfaceRGBA(SDL_Surface * src, SDL_Surface * dst, int flipx, int flipy, int smooth)
+{
+ int x, y, sx, sy, ssx, ssy, *sax, *say, *csax, *csay, *salast, csx, csy, ex, ey, cx, cy, sstep, sstepx, sstepy;
+ tColorRGBA *c00, *c01, *c10, *c11;
+ tColorRGBA *sp, *csp, *dp;
+ int spixelgap, spixelw, spixelh, dgap, t1, t2;
+
+ /*
+ * Allocate memory for row/column 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
+ */
+ spixelw = (src->w - 1);
+ spixelh = (src->h - 1);
+ if (smooth) {
+ sx = (int) (65536.0 * (float) spixelw / (float) (dst->w - 1));
+ sy = (int) (65536.0 * (float) spixelh / (float) (dst->h - 1));
+ } else {
+ sx = (int) (65536.0 * (float) (src->w) / (float) (dst->w));
+ sy = (int) (65536.0 * (float) (src->h) / (float) (dst->h));
+ }
+
+ /* Maximum scaled source size */
+ ssx = (src->w << 16) - 1;
+ ssy = (src->h << 16) - 1;
+
+ /* Precalculate horizontal row increments */
+ csx = 0;
+ csax = sax;
+ for (x = 0; x <= dst->w; x++) {
+ *csax = csx;
+ csax++;
+ csx += sx;
+
+ /* Guard from overflows */
+ if (csx > ssx) {
+ csx = ssx;
+ }
+ }
+
+ /* Precalculate vertical row increments */
+ csy = 0;
+ csay = say;
+ for (y = 0; y <= dst->h; y++) {
+ *csay = csy;
+ csay++;
+ csy += sy;
+
+ /* Guard from overflows */
+ if (csy > ssy) {
+ csy = ssy;
+ }
+ }
+
+ sp = (tColorRGBA *) src->pixels;
+ dp = (tColorRGBA *) dst->pixels;
+ dgap = dst->pitch - dst->w * 4;
+ spixelgap = src->pitch/4;
+
+ if (flipx) sp += spixelw;
+ if (flipy) sp += (spixelgap * spixelh);
+
+ /*
+ * Switch between interpolating and non-interpolating code
+ */
+ if (smooth) {
+
+ /*
+ * Interpolating Zoom
+ */
+ csay = say;
+ for (y = 0; y < dst->h; y++) {
+ csp = sp;
+ csax = sax;
+ for (x = 0; x < dst->w; x++) {
+ /*
+ * Setup color source pointers
+ */
+ ex = (*csax & 0xffff);
+ ey = (*csay & 0xffff);
+ cx = (*csax >> 16);
+ cy = (*csay >> 16);
+ sstepx = cx < spixelw;
+ sstepy = cy < spixelh;
+ c00 = sp;
+ c01 = sp;
+ c10 = sp;
+ if (sstepy) {
+ if (flipy) {
+ c10 -= spixelgap;
+ } else {
+ c10 += spixelgap;
+ }
+ }
+ c11 = c10;
+ if (sstepx) {
+ if (flipx) {
+ c01--;
+ c11--;
+ } else {
+ c01++;
+ c11++;
+ }
+ }
+
+ /*
+ * Draw and interpolate colors
+ */
+ 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 pointer x
+ */
+ salast = csax;
+ csax++;
+ sstep = (*csax >> 16) - (*salast >> 16);
+ if (flipx) {
+ sp -= sstep;
+ } else {
+ sp += sstep;
+ }
+
+ /*
+ * Advance destination pointer x
+ */
+ dp++;
+ }
+ /*
+ * Advance source pointer y
+ */
+ salast = csay;
+ csay++;
+ sstep = (*csay >> 16) - (*salast >> 16);
+ sstep *= spixelgap;
+ if (flipy) {
+ sp = csp - sstep;
+ } else {
+ sp = csp + sstep;
+ }
+
+ /*
+ * Advance destination pointer y
+ */
+ dp = (tColorRGBA *) ((Uint8 *) dp + dgap);
+ }
+ } else {
+ /*
+ * Non-Interpolating Zoom
+ */
+ csay = say;
+ for (y = 0; y < dst->h; y++) {
+ csp = sp;
+ csax = sax;
+ for (x = 0; x < dst->w; x++) {
+ /*
+ * Draw
+ */
+ *dp = *sp;
+
+ /*
+ * Advance source pointer x
+ */
+ salast = csax;
+ csax++;
+ sstep = (*csax >> 16) - (*salast >> 16);
+ if (flipx) sstep = -sstep;
+ sp += sstep;
+
+ /*
+ * Advance destination pointer x
+ */
+ dp++;
+ }
+ /*
+ * Advance source pointer y
+ */
+ salast = csay;
+ csay++;
+ sstep = (*csay >> 16) - (*salast >> 16);
+ sstep *= spixelgap;
+ if (flipy) sstep = -sstep;
+ sp = csp + sstep;
+
+ /*
+ * Advance destination pointer y
+ */
+ dp = (tColorRGBA *) ((Uint8 *) dp + dgap);
+ }
+ }
+
+ /*
+ * Remove temp arrays
+ */
+ free(sax);
+ free(say);
+
+ return (0);
+}
+
+/*!
+
+\brief Internal 8 bit Zoomer without smoothing.
+
+Zooms 8bit palette/Y 'src' surface to 'dst' surface.
+Assumes src and dst surfaces are of 8 bit depth.
+Assumes dst surface was allocated with the correct dimensions.
+
+\param src The surface to zoom (input).
+\param dst The zoomed surface (output).
+\param flipx Flag indicating if the image should be horizontally flipped.
+\param flipy Flag indicating if the image should be vertically flipped.
+
+\return 0 for success or -1 for error.
+*/
+int _zoomSurfaceY(SDL_Surface * src, SDL_Surface * dst, int flipx, int flipy)
+{
+ int x, y;
+ Uint32 *sax, *say, *csax, *csay;
+ int csx, csy;
+ Uint8 *sp, *dp, *csp;
+ int dgap;
+
+ /*
+ * Allocate memory for row increments
+ */
+ if ((sax = (Uint32 *) malloc((dst->w + 1) * sizeof(Uint32))) == NULL) {
+ return (-1);
+ }
+ if ((say = (Uint32 *) malloc((dst->h + 1) * sizeof(Uint32))) == NULL) {
+ free(sax);
+ return (-1);
+ }
+
+ /*
+ * Pointer setup
+ */
+ sp = csp = (Uint8 *) src->pixels;
+ dp = (Uint8 *) dst->pixels;
+ dgap = dst->pitch - dst->w;
+
+ if (flipx) csp += (src->w-1);
+ if (flipy) csp = ( (Uint8*)csp + src->pitch*(src->h-1) );
+
+ /*
+ * Precalculate row increments
+ */
+ csx = 0;
+ csax = sax;
+ for (x = 0; x < dst->w; x++) {
+ csx += src->w;
+ *csax = 0;
+ while (csx >= dst->w) {
+ csx -= dst->w;
+ (*csax)++;
+ }
+ (*csax) = (*csax) * (flipx ? -1 : 1);
+ csax++;
+ }
+ csy = 0;
+ csay = say;
+ for (y = 0; y < dst->h; y++) {
+ csy += src->h;
+ *csay = 0;
+ while (csy >= dst->h) {
+ csy -= dst->h;
+ (*csay)++;
+ }
+ (*csay) = (*csay) * (flipy ? -1 : 1);
+ csay++;
+ }
+
+ /*
+ * 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);
+}
+
+/*!
+\brief Internal 32 bit rotozoomer with optional anti-aliasing.
+
+Rotates and zooms 32 bit RGBA/ABGR 'src' surface to 'dst' surface based on the control
+parameters by scanning the destination surface and applying optionally anti-aliasing
+by bilinear interpolation.
+Assumes src and dst surfaces are of 32 bit depth.
+Assumes dst surface was allocated with the correct dimensions.
+
+\param src Source surface.
+\param dst Destination surface.
+\param cx Horizontal center coordinate.
+\param cy Vertical center coordinate.
+\param isin Integer version of sine of angle.
+\param icos Integer version of cosine of angle.
+\param flipx Flag indicating horizontal mirroring should be applied.
+\param flipy Flag indicating vertical mirroring should be applied.
+\param smooth Flag indicating anti-aliasing should be used.
+*/
+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, cswap;
+ tColorRGBA *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 = (tColorRGBA*) 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 (flipx) dx = sw - dx;
+ if (flipy) dy = sh - dy;
+ if ((dx > -1) && (dy > -1) && (dx < (src->w-1)) && (dy < (src->h-1))) {
+ sp = (tColorRGBA *)src->pixels;;
+ sp += ((src->pitch/4) * dy);
+ sp += dx;
+ c00 = *sp;
+ sp += 1;
+ c01 = *sp;
+ sp += (src->pitch/4);
+ c11 = *sp;
+ sp -= 1;
+ c10 = *sp;
+ if (flipx) {
+ cswap = c00; c00=c01; c01=cswap;
+ cswap = c10; c10=c11; c11=cswap;
+ }
+ if (flipy) {
+ cswap = c00; c00=c10; c10=cswap;
+ cswap = c01; c01=c11; c11=cswap;
+ }
+ /*
+ * 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);
+ }
+ }
+}
+
+/*!
+
+\brief Rotates and zooms 8 bit palette/Y 'src' surface to 'dst' surface without smoothing.
+
+Rotates and zooms 8 bit RGBA/ABGR 'src' surface to 'dst' surface based on the control
+parameters by scanning the destination surface.
+Assumes src and dst surfaces are of 8 bit depth.
+Assumes dst surface was allocated with the correct dimensions.
+
+\param src Source surface.
+\param dst Destination surface.
+\param cx Horizontal center coordinate.
+\param cy Vertical center coordinate.
+\param isin Integer version of sine of angle.
+\param icos Integer version of cosine of angle.
+\param flipx Flag indicating horizontal mirroring should be applied.
+\param flipy Flag indicating vertical mirroring should be applied.
+*/
+void transformSurfaceY(SDL_Surface * src, SDL_Surface * dst, int cx, int cy, int isin, int icos, int flipx, int flipy)
+{
+ 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 = (tColorY*) dst->pixels;
+ gap = dst->pitch - dst->w;
+ /*
+ * Clear surface to colorkey
+ */
+ memset(pc, (int)(_colorkey(src) & 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 (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 = (tColorY *) (src->pixels);
+ sp += (src->pitch * dy + dx);
+ *pc = *sp;
+ }
+ sdx += icos;
+ sdy += isin;
+ pc++;
+ }
+ pc += gap;
+ }
+}
+
+/*!
+\brief Rotates a 32 bit surface in increments of 90 degrees.
+
+Specialized 90 degree rotator which rotates a 'src' surface in 90 degree
+increments clockwise returning a new surface. Faster than rotozoomer since
+not scanning or interpolation takes place. Input surface must be 32 bit.
+(code contributed by J. Schiller, improved by C. Allport and A. Schiffler)
+
+\param src Source surface to rotate.
+\param numClockwiseTurns Number of clockwise 90 degree turns to apply to the source.
+
+\returns The new, rotated surface; or NULL for surfaces with incorrect input format.
+*/
+SDL_Surface* rotateSurface90Degrees(SDL_Surface* src, int numClockwiseTurns)
+{
+ int row, col, newWidth, newHeight;
+ int bpp, src_ipr, dst_ipr;
+ SDL_Surface* dst;
+ Uint32* srcBuf;
+ Uint32* dstBuf;
+
+ /* Has to be a valid surface pointer and only 32-bit surfaces (for now) */
+ if (!src || src->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 */
+ newWidth = (numClockwiseTurns % 2) ? (src->h) : (src->w);
+ newHeight = (numClockwiseTurns % 2) ? (src->w) : (src->h);
+ dst = SDL_CreateRGBSurface( src->flags, newWidth, newHeight, src->format->BitsPerPixel,
+ src->format->Rmask,
+ src->format->Gmask,
+ src->format->Bmask,
+ src->format->Amask);
+ if(!dst) {
+ return NULL;
+ }
+
+ if (SDL_MUSTLOCK(dst)) {
+ SDL_LockSurface(dst);
+ }
+ if (SDL_MUSTLOCK(dst)) {
+ SDL_LockSurface(dst);
+ }
+
+ /* Calculate int-per-row */
+ bpp = src->format->BitsPerPixel / 8;
+ src_ipr = src->pitch / bpp;
+ dst_ipr = dst->pitch / bpp;
+
+ switch(numClockwiseTurns) {
+ case 0: /* Make a copy of the surface */
+ {
+ /* Unfortunately SDL_BlitSurface cannot be used to make a copy of the surface
+ since it does not preserve alpha. */
+
+ if (src->pitch == dst->pitch) {
+ /* If the pitch is the same for both surfaces, the memory can be copied all at once. */
+ memcpy(dst->pixels, src->pixels, (src->h * src->pitch));
+ }
+ else
+ {
+ /* If the pitch differs, copy each row separately */
+ srcBuf = (Uint32*)(src->pixels);
+ dstBuf = (Uint32*)(dst->pixels);
+ for (row = 0; row < src->h; row++) {
+ memcpy(dstBuf, srcBuf, dst->w * bpp);
+ srcBuf += src_ipr;
+ dstBuf += dst_ipr;
+ } /* end for(col) */
+ } /* end for(row) */
+ }
+ break;
+
+ /* rotate clockwise */
+ case 1: /* rotated 90 degrees clockwise */
+ {
+ for (row = 0; row < src->h; ++row) {
+ srcBuf = (Uint32*)(src->pixels) + (row * src_ipr);
+ dstBuf = (Uint32*)(dst->pixels) + (dst->w - row - 1);
+ for (col = 0; col < src->w; ++col) {
+ *dstBuf = *srcBuf;
+ ++srcBuf;
+ dstBuf += dst_ipr;
+ }
+ /* end for(col) */
+ }
+ /* end for(row) */
+ }
+ break;
+
+ case 2: /* rotated 180 degrees clockwise */
+ {
+ for (row = 0; row < src->h; ++row) {
+ srcBuf = (Uint32*)(src->pixels) + (row * src_ipr);
+ dstBuf = (Uint32*)(dst->pixels) + ((dst->h - row - 1) * dst_ipr) + (dst->w - 1);
+ for (col = 0; col < src->w; ++col) {
+ *dstBuf = *srcBuf;
+ ++srcBuf;
+ --dstBuf;
+ }
+ }
+ }
+ break;
+
+ case 3:
+ {
+ for (row = 0; row < src->h; ++row) {
+ srcBuf = (Uint32*)(src->pixels) + (row * src_ipr);
+ dstBuf = (Uint32*)(dst->pixels) + row + ((dst->h - 1) * dst_ipr);
+ for (col = 0; col < src->w; ++col) {
+ *dstBuf = *srcBuf;
+ ++srcBuf;
+ dstBuf -= dst_ipr;
+ }
+ }
+ }
+ break;
+ }
+ /* end switch */
+
+ if (SDL_MUSTLOCK(src)) {
+ SDL_UnlockSurface(src);
+ }
+ if (SDL_MUSTLOCK(dst)) {
+ SDL_UnlockSurface(dst);
+ }
+
+ return dst;
+}
+
+
+/*!
+\brief Internal target surface sizing function for rotozooms with trig result return.
+
+\param width The source surface width.
+\param height The source surface height.
+\param angle The angle to rotate in degrees.
+\param zoomx The horizontal scaling factor.
+\param zoomy The vertical scaling factor.
+\param dstwidth The calculated width of the destination surface.
+\param dstheight The calculated height of the destination surface.
+\param canglezoom The sine of the angle adjusted by the zoom factor.
+\param sanglezoom The cosine of the angle adjusted by the zoom factor.
+
+*/
+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 = (double)(width / 2);
+ y = (double)(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;
+}
+
+/*!
+\brief Returns the size of the resulting target surface for a rotozoomSurfaceXY() call.
+
+\param width The source surface width.
+\param height The source surface height.
+\param angle The angle to rotate in degrees.
+\param zoomx The horizontal scaling factor.
+\param zoomy The vertical scaling factor.
+\param dstwidth The calculated width of the rotozoomed destination surface.
+\param dstheight The calculated height of the rotozoomed destination surface.
+*/
+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);
+}
+
+/*!
+\brief Returns the size of the resulting target surface for a rotozoomSurface() call.
+
+\param width The source surface width.
+\param height The source surface height.
+\param angle The angle to rotate in degrees.
+\param zoom The scaling factor.
+\param dstwidth The calculated width of the rotozoomed destination surface.
+\param dstheight The calculated height of the rotozoomed destination surface.
+*/
+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);
+}
+
+/*!
+\brief Rotates and zooms a surface and optional anti-aliasing.
+
+Rotates and zoomes a 32bit or 8bit 'src' surface to newly created 'dst' surface.
+'angle' is the rotation in degrees and 'zoom' a scaling factor. If 'smooth' is set
+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.
+
+\param src The surface to rotozoom.
+\param angle The angle to rotate in degrees.
+\param zoom The scaling factor.
+\param smooth Antialiasing flag; set to SMOOTHING_ON to enable.
+
+\return The new rotozoomed surface.
+*/
+SDL_Surface *rotozoomSurface(SDL_Surface * src, double angle, double zoom, int smooth)
+{
+ return rotozoomSurfaceXY(src, angle, zoom, zoom, smooth);
+}
+
+/*!
+\brief Rotates and zooms a surface with different horizontal and vertival scaling factors and optional anti-aliasing.
+
+Rotates and zooms a 32bit or 8bit 'src' surface to newly created 'dst' surface.
+'angle' is the rotation in degrees, 'zoomx and 'zoomy' scaling factors. If 'smooth' is set
+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.
+
+\param src The surface to rotozoom.
+\param angle The angle to rotate in degrees.
+\param zoomx The horizontal scaling factor.
+\param zoomy The vertical scaling factor.
+\param smooth Antialiasing flag; set to SMOOTHING_ON to enable.
+
+\return The new rotozoomed surface.
+*/
+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<0.0);
+ if (flipx) zoomx=-zoomx;
+ flipy = (zoomy<0.0);
+ 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 + GUARD_ROWS, 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 + GUARD_ROWS, 8, 0, 0, 0, 0);
+ }
+
+ /* Check target */
+ if (rz_dst == NULL)
+ return NULL;
+
+ /* Adjust for guard rows */
+ rz_dst->h = dstheight;
+
+ /*
+ * Lock source surface
+ */
+ if (SDL_MUSTLOCK(rz_src)) {
+ 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);
+ } 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),
+ flipx, flipy);
+ }
+ /*
+ * Unlock source surface
+ */
+ if (SDL_MUSTLOCK(rz_src)) {
+ 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 + GUARD_ROWS, 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 + GUARD_ROWS, 8, 0, 0, 0, 0);
+ }
+
+ /* Check target */
+ if (rz_dst == NULL)
+ return NULL;
+
+ /* Adjust for guard rows */
+ rz_dst->h = dstheight;
+
+ /*
+ * Lock source surface
+ */
+ if (SDL_MUSTLOCK(rz_src)) {
+ 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);
+
+ } 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);
+ }
+
+ /*
+ * Unlock source surface
+ */
+ if (SDL_MUSTLOCK(rz_src)) {
+ SDL_UnlockSurface(rz_src);
+ }
+ }
+
+ /*
+ * Cleanup temp surface
+ */
+ if (src_converted) {
+ SDL_FreeSurface(rz_src);
+ }
+
+ /*
+ * Return destination surface
+ */
+ return (rz_dst);
+}
+
+/*!
+\brief Calculates the size of the target surface for a zoomSurface() call.
+
+The minimum size of the target surface is 1. The input factors can be positive or negative.
+
+\param width The width of the source surface to zoom.
+\param height The height of the source surface to zoom.
+\param zoomx The horizontal zoom factor.
+\param zoomy The vertical zoom factor.
+\param dstwidth Pointer to an integer to store the calculated width of the zoomed target surface.
+\param dstheight Pointer to an integer to store the calculated height of the zoomed target surface.
+*/
+void zoomSurfaceSize(int width, int height, double zoomx, double zoomy, int *dstwidth, int *dstheight)
+{
+ /*
+ * Make zoom factors positive
+ */
+ int flipx, flipy;
+ flipx = (zoomx<0.0);
+ if (flipx) zoomx = -zoomx;
+ flipy = (zoomy<0.0);
+ if (flipy) zoomy = -zoomy;
+
+ /*
+ * Sanity check zoom factors
+ */
+ if (zoomx < VALUE_LIMIT) {
+ zoomx = VALUE_LIMIT;
+ }
+ if (zoomy < VALUE_LIMIT) {
+ zoomy = VALUE_LIMIT;
+ }
+
+ /*
+ * Calculate target size
+ */
+ *dstwidth = (int) floor(((double) width * zoomx) + 0.5);
+ *dstheight = (int) floor(((double) height * zoomy) + 0.5);
+ if (*dstwidth < 1) {
+ *dstwidth = 1;
+ }
+ if (*dstheight < 1) {
+ *dstheight = 1;
+ }
+}
+
+/*!
+\brief Zoom a surface by independent horizontal and vertical factors with optional smoothing.
+
+Zooms a 32bit or 8bit 'src' surface to newly created 'dst' surface.
+'zoomx' and 'zoomy' are scaling factors for width and height. If 'smooth' is on
+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.
+If zoom factors are negative, the image is flipped on the axes.
+
+\param src The surface to zoom.
+\param zoomx The horizontal zoom factor.
+\param zoomy The vertical zoom factor.
+\param smooth Antialiasing flag; set to SMOOTHING_ON to enable.
+
+\return The new, zoomed surface.
+*/
+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
+ );
+ if (rz_src == NULL) {
+ return NULL;
+ }
+ SDL_BlitSurface(src, NULL, rz_src, NULL);
+ src_converted = 1;
+ is32bit = 1;
+ }
+
+ flipx = (zoomx<0.0);
+ if (flipx) zoomx = -zoomx;
+ flipy = (zoomy<0.0);
+ 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 + GUARD_ROWS, 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 + GUARD_ROWS, 8, 0, 0, 0, 0);
+ }
+
+ /* Check target */
+ if (rz_dst == NULL) {
+ /*
+ * Cleanup temp surface
+ */
+ if (src_converted) {
+ SDL_FreeSurface(rz_src);
+ }
+ return NULL;
+ }
+
+ /* Adjust for guard rows */
+ rz_dst->h = dstheight;
+
+ /*
+ * Lock source surface
+ */
+ if (SDL_MUSTLOCK(rz_src)) {
+ 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);
+ } 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);
+ }
+ /*
+ * Unlock source surface
+ */
+ if (SDL_MUSTLOCK(rz_src)) {
+ SDL_UnlockSurface(rz_src);
+ }
+
+ /*
+ * Cleanup temp surface
+ */
+ if (src_converted) {
+ SDL_FreeSurface(rz_src);
+ }
+
+ /*
+ * Return destination surface
+ */
+ return (rz_dst);
+}
+
+/*!
+\brief Shrink a surface by an integer ratio using averaging.
+
+Shrinks a 32bit or 8bit 'src' surface to a newly created 'dst' surface.
+'factorx' and 'factory' are the shrinking ratios (i.e. 2=1/2 the size,
+3=1/3 the size, etc.) The destination surface is antialiased by averaging
+the source box RGBA or Y information. If the surface is not 8bit
+or 32bit RGBA/ABGR it will be converted into a 32bit RGBA format on the fly.
+The input surface is not modified. The output surface is newly allocated.
+
+\param src The surface to shrink.
+\param factorx The horizontal shrinking ratio.
+\param factory The vertical shrinking ratio.
+
+\return The new, shrunken surface.
+*/
+/*@null@*/
+SDL_Surface *shrinkSurface(SDL_Surface *src, int factorx, int factory)
+{
+ int result;
+ SDL_Surface *rz_src;
+ SDL_Surface *rz_dst = NULL;
+ int dstwidth, dstheight;
+ int is32bit;
+ int i, src_converted;
+ int haveError = 0;
+
+ /*
+ * 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
+ );
+ if (rz_src==NULL) {
+ haveError = 1;
+ goto exitShrinkSurface;
+ }
+
+ SDL_BlitSurface(src, NULL, rz_src, NULL);
+ src_converted = 1;
+ is32bit = 1;
+ }
+
+ /*
+ * Lock the surface
+ */
+ if (SDL_MUSTLOCK(rz_src)) {
+ if (SDL_LockSurface(rz_src) < 0) {
+ haveError = 1;
+ goto exitShrinkSurface;
+ }
+ }
+
+ /* 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
+ * (with added guard rows)
+ */
+ if (is32bit==1) {
+ /*
+ * Target surface is 32bit with source RGBA/ABGR ordering
+ */
+ rz_dst =
+ SDL_CreateRGBSurface(SDL_SWSURFACE, dstwidth, dstheight + GUARD_ROWS, 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 + GUARD_ROWS, 8, 0, 0, 0, 0);
+ }
+
+ /* Check target */
+ if (rz_dst == NULL) {
+ haveError = 1;
+ goto exitShrinkSurface;
+ }
+
+ /* Adjust for guard rows */
+ rz_dst->h = dstheight;
+
+ /*
+ * Check which kind of surface we have
+ */
+ if (is32bit==1) {
+ /*
+ * Call the 32bit transformation routine to do the shrinking (using alpha)
+ */
+ result = _shrinkSurfaceRGBA(rz_src, rz_dst, factorx, factory);
+ if ((result!=0) || (rz_dst==NULL)) {
+ haveError = 1;
+ goto exitShrinkSurface;
+ }
+ } 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
+ */
+ result = _shrinkSurfaceY(rz_src, rz_dst, factorx, factory);
+ if (result!=0) {
+ haveError = 1;
+ goto exitShrinkSurface;
+ }
+ }
+
+exitShrinkSurface:
+ if (rz_src!=NULL) {
+ /*
+ * Unlock source surface
+ */
+ if (SDL_MUSTLOCK(rz_src)) {
+ SDL_UnlockSurface(rz_src);
+ }
+
+ /*
+ * Cleanup temp surface
+ */
+ if (src_converted==1) {
+ SDL_FreeSurface(rz_src);
+ }
+ }
+
+ /* Check error state; maybe need to cleanup destination */
+ if (haveError==1) {
+ if (rz_dst!=NULL) {
+ SDL_FreeSurface(rz_dst);
+ }
+ rz_dst=NULL;
+ }
+
+ /*
+ * Return destination surface
+ */
+ return (rz_dst);
+}