/* SDL_rotozoom.c - rotozoomer for 32bit or 8bit surfaces LGPL (c) A. Schiffler */ #ifdef WIN32 #include #endif #include #include #include "SDL_rotozoom.h" #define MAX(a,b) (((a) > (b)) ? (a) : (b)) /* 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 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 sgap, 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 */ 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; } /* * Pointer setup */ sp = csp = (tColorRGBA *) src->pixels; dp = (tColorRGBA *) dst->pixels; sgap = src->pitch - src->w * 4; 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++; sp += (*csax >> 16); /* * Advance destination pointer */ dp++; } /* * Advance source pointer */ csay++; csp = (tColorRGBA *) ((Uint8 *) csp + (*csay >> 16) * src->pitch); /* * 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) { 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 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, *spb; 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 * 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 ((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; } } /* 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 zoom, 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 *= zoom; *canglezoom *= zoom; 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 rotozoomSurfaceSize(int width, int height, double angle, double zoom, int *dstwidth, int *dstheight) { double dummy_sanglezoom, dummy_canglezoom; rotozoomSurfaceSizeTrig(width, height, angle, zoom, dstwidth, dstheight, &dummy_sanglezoom, &dummy_canglezoom); } /* Publically available rotozoom function */ SDL_Surface *rotozoomSurface(SDL_Surface * src, double angle, double zoom, int smooth) { SDL_Surface *rz_src; SDL_Surface *rz_dst; double zoominv; double sanglezoom, canglezoom, sanglezoominv, canglezoominv; int dstwidthhalf, dstwidth, dstheighthalf, dstheight; double x, y, cx, cy, sx, sy; 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, 0x000000ff, 0x0000ff00, 0x00ff0000, 0xff000000); SDL_BlitSurface(src, NULL, rz_src, NULL); src_converted = 1; is32bit = 1; } /* * Sanity check zoom factor */ if (zoom < VALUE_LIMIT) { zoom = VALUE_LIMIT; } zoominv = 65536.0 / (zoom * zoom); /* * 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, zoom, &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), 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, zoom, zoom, &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, 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); 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; /* * 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, 0x000000ff, 0x0000ff00, 0x00ff0000, 0xff000000); SDL_BlitSurface(src, NULL, rz_src, NULL); src_converted = 1; is32bit = 1; } /* 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, 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); 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); }