| /* |
| |
| SDL_rotate.c: rotates 32bit or 8bit surfaces |
| |
| Shamelessly stolen from SDL_gfx by Andreas Schiffler. Original copyright follows: |
| |
| Copyright (C) 2001-2011 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 |
| |
| */ |
| #include "../../SDL_internal.h" |
| |
| #if SDL_VIDEO_RENDER_SW && !SDL_RENDER_DISABLED |
| |
| #if defined(__WIN32__) |
| #include "../../core/windows/SDL_windows.h" |
| #endif |
| |
| #include <stdlib.h> |
| #include <string.h> |
| |
| #include "SDL.h" |
| #include "SDL_rotate.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 Returns colorkey info for a surface |
| */ |
| static Uint32 |
| _colorkey(SDL_Surface *src) |
| { |
| Uint32 key = 0; |
| if (SDL_HasColorKey(src)) { |
| SDL_GetColorKey(src, &key); |
| } |
| return key; |
| } |
| |
| |
| /* ! |
| \brief Internal target surface sizing function for rotations 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 dstwidth The calculated width of the destination surface. |
| \param dstheight The calculated height of the destination surface. |
| \param cangle The sine of the angle |
| \param sangle The cosine of the angle |
| |
| */ |
| void |
| SDLgfx_rotozoomSurfaceSizeTrig(int width, int height, double angle, |
| int *dstwidth, int *dstheight, |
| double *cangle, double *sangle) |
| { |
| /* The trig code below gets the wrong size (due to FP inaccuracy?) when angle is a multiple of 90 degrees */ |
| int angle90 = (int)(angle/90); |
| if(angle90 == angle/90) { /* if the angle is a multiple of 90 degrees */ |
| angle90 %= 4; |
| if(angle90 < 0) angle90 += 4; /* 0:0 deg, 1:90 deg, 2:180 deg, 3:270 deg */ |
| if(angle90 & 1) { |
| *dstwidth = height; |
| *dstheight = width; |
| *cangle = 0; |
| *sangle = angle90 == 1 ? -1 : 1; /* reversed because our rotations are clockwise */ |
| } else { |
| *dstwidth = width; |
| *dstheight = height; |
| *cangle = angle90 == 0 ? 1 : -1; |
| *sangle = 0; |
| } |
| } else { |
| 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); /* reverse the angle because our rotations are clockwise */ |
| *sangle = SDL_sin(radangle); |
| *cangle = SDL_cos(radangle); |
| x = (double)(width / 2); |
| y = (double)(height / 2); |
| cx = *cangle * x; |
| cy = *cangle * y; |
| sx = *sangle * x; |
| sy = *sangle * y; |
| |
| dstwidthhalf = MAX((int) |
| SDL_ceil(MAX(MAX(MAX(SDL_fabs(cx + sy), SDL_fabs(cx - sy)), SDL_fabs(-cx + sy)), SDL_fabs(-cx - sy))), 1); |
| dstheighthalf = MAX((int) |
| SDL_ceil(MAX(MAX(MAX(SDL_fabs(sx + cy), SDL_fabs(sx - cy)), SDL_fabs(-sx + cy)), SDL_fabs(-sx - cy))), 1); |
| *dstwidth = 2 * dstwidthhalf; |
| *dstheight = 2 * dstheighthalf; |
| } |
| } |
| |
| /* Computes source pointer X/Y increments for a rotation that's a multiple of 90 degrees. */ |
| static void |
| computeSourceIncrements90(SDL_Surface * src, int bpp, int angle, int flipx, int flipy, |
| int *sincx, int *sincy, int *signx, int *signy) |
| { |
| int pitch = flipy ? -src->pitch : src->pitch; |
| if (flipx) { |
| bpp = -bpp; |
| } |
| switch (angle) { /* 0:0 deg, 1:90 deg, 2:180 deg, 3:270 deg */ |
| case 0: *sincx = bpp; *sincy = pitch - src->w * *sincx; *signx = *signy = 1; break; |
| case 1: *sincx = -pitch; *sincy = bpp - *sincx * src->h; *signx = 1; *signy = -1; break; |
| case 2: *sincx = -bpp; *sincy = -src->w * *sincx - pitch; *signx = *signy = -1; break; |
| case 3: default: *sincx = pitch; *sincy = -*sincx * src->h - bpp; *signx = -1; *signy = 1; break; |
| } |
| if (flipx) { |
| *signx = -*signx; |
| } |
| if (flipy) { |
| *signy = -*signy; |
| } |
| } |
| |
| /* Performs a relatively fast rotation/flip when the angle is a multiple of 90 degrees. */ |
| #define TRANSFORM_SURFACE_90(pixelType) \ |
| int dy, dincy = dst->pitch - dst->w*sizeof(pixelType), sincx, sincy, signx, signy; \ |
| Uint8 *sp = (Uint8*)src->pixels, *dp = (Uint8*)dst->pixels, *de; \ |
| \ |
| computeSourceIncrements90(src, sizeof(pixelType), angle, flipx, flipy, &sincx, &sincy, &signx, &signy); \ |
| if (signx < 0) sp += (src->w-1)*sizeof(pixelType); \ |
| if (signy < 0) sp += (src->h-1)*src->pitch; \ |
| \ |
| for (dy = 0; dy < dst->h; sp += sincy, dp += dincy, dy++) { \ |
| if (sincx == sizeof(pixelType)) { /* if advancing src and dest equally, use memcpy */ \ |
| SDL_memcpy(dp, sp, dst->w*sizeof(pixelType)); \ |
| sp += dst->w*sizeof(pixelType); \ |
| dp += dst->w*sizeof(pixelType); \ |
| } else { \ |
| for (de = dp + dst->w*sizeof(pixelType); dp != de; sp += sincx, dp += sizeof(pixelType)) { \ |
| *(pixelType*)dp = *(pixelType*)sp; \ |
| } \ |
| } \ |
| } |
| |
| static void |
| transformSurfaceRGBA90(SDL_Surface * src, SDL_Surface * dst, int angle, int flipx, int flipy) |
| { |
| TRANSFORM_SURFACE_90(tColorRGBA); |
| } |
| |
| static void |
| transformSurfaceY90(SDL_Surface * src, SDL_Surface * dst, int angle, int flipx, int flipy) |
| { |
| TRANSFORM_SURFACE_90(tColorY); |
| } |
| |
| #undef TRANSFORM_SURFACE_90 |
| |
| /* ! |
| \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. |
| */ |
| static 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 *) ((Uint8 *) src->pixels + src->pitch * dy) + 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 = (sdx >> 16); |
| dy = (sdy >> 16); |
| if ((unsigned)dx < (unsigned)src->w && (unsigned)dy < (unsigned)src->h) { |
| if(flipx) dx = sw - dx; |
| if(flipy) dy = sh - dy; |
| *pc = *((tColorRGBA *)((Uint8 *)src->pixels + src->pitch * dy) + dx); |
| } |
| 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. |
| */ |
| static 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; |
| tColorY *pc; |
| 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); |
| pc = (tColorY*) dst->pixels; |
| gap = dst->pitch - dst->w; |
| /* |
| * Clear surface to colorkey |
| */ |
| SDL_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 = (sdx >> 16); |
| dy = (sdy >> 16); |
| if ((unsigned)dx < (unsigned)src->w && (unsigned)dy < (unsigned)src->h) { |
| if (flipx) dx = (src->w-1)-dx; |
| if (flipy) dy = (src->h-1)-dy; |
| *pc = *((tColorY *)src->pixels + src->pitch * dy + dx); |
| } |
| sdx += icos; |
| sdy += isin; |
| pc++; |
| } |
| pc += gap; |
| } |
| } |
| |
| |
| /* ! |
| \brief Rotates and zooms a surface with different horizontal and vertival scaling factors and optional anti-aliasing. |
| |
| Rotates a 32-bit or 8-bit 'src' surface to newly created 'dst' surface. |
| 'angle' is the rotation in degrees, 'centerx' and 'centery' the rotation center. If 'smooth' is set |
| then the destination 32-bit surface is anti-aliased. 8-bit surfaces must have a colorkey. 32-bit |
| surfaces must have a 8888 layout with red, green, blue and alpha masks (any ordering goes). |
| The blend mode of the 'src' surface has some effects on generation of the 'dst' surface: The NONE |
| mode will set the BLEND mode on the 'dst' surface. The MOD mode either generates a white 'dst' |
| surface and sets the colorkey or fills the it with the colorkey before copying the pixels. |
| When using the NONE and MOD modes, color and alpha modulation must be applied before using this function. |
| |
| \param src The surface to rotozoom. |
| \param angle The angle to rotate in degrees. |
| \param centerx The horizontal coordinate of the center of rotation |
| \param zoomy The vertical coordinate of the center of rotation |
| \param smooth Antialiasing flag; set to SMOOTHING_ON to enable. |
| \param flipx Set to 1 to flip the image horizontally |
| \param flipy Set to 1 to flip the image vertically |
| \param dstwidth The destination surface width |
| \param dstheight The destination surface height |
| \param cangle The angle cosine |
| \param sangle The angle sine |
| \return The new rotated surface. |
| |
| */ |
| |
| SDL_Surface * |
| SDLgfx_rotateSurface(SDL_Surface * src, double angle, int centerx, int centery, int smooth, int flipx, int flipy, int dstwidth, int dstheight, double cangle, double sangle) |
| { |
| SDL_Surface *rz_dst; |
| int is8bit, angle90; |
| int i; |
| SDL_BlendMode blendmode; |
| Uint32 colorkey = 0; |
| int colorKeyAvailable = SDL_FALSE; |
| double sangleinv, cangleinv; |
| |
| /* Sanity check */ |
| if (src == NULL) |
| return NULL; |
| |
| if (SDL_HasColorKey(src)) { |
| if (SDL_GetColorKey(src, &colorkey) == 0) { |
| colorKeyAvailable = SDL_TRUE; |
| } |
| } |
| |
| /* This function requires a 32-bit surface or 8-bit surface with a colorkey */ |
| is8bit = src->format->BitsPerPixel == 8 && colorKeyAvailable; |
| if (!(is8bit || (src->format->BitsPerPixel == 32 && src->format->Amask))) |
| return NULL; |
| |
| /* Calculate target factors from sin/cos and zoom */ |
| sangleinv = sangle*65536.0; |
| cangleinv = cangle*65536.0; |
| |
| /* Alloc space to completely contain the rotated surface */ |
| rz_dst = NULL; |
| if (is8bit) { |
| /* Target surface is 8 bit */ |
| rz_dst = SDL_CreateRGBSurface(0, dstwidth, dstheight + GUARD_ROWS, 8, 0, 0, 0, 0); |
| if (rz_dst != NULL) { |
| for (i = 0; i < src->format->palette->ncolors; i++) { |
| rz_dst->format->palette->colors[i] = src->format->palette->colors[i]; |
| } |
| rz_dst->format->palette->ncolors = src->format->palette->ncolors; |
| } |
| } else { |
| /* Target surface is 32 bit with source RGBA ordering */ |
| rz_dst = SDL_CreateRGBSurface(0, dstwidth, dstheight + GUARD_ROWS, 32, |
| src->format->Rmask, src->format->Gmask, |
| src->format->Bmask, src->format->Amask); |
| } |
| |
| /* Check target */ |
| if (rz_dst == NULL) |
| return NULL; |
| |
| /* Adjust for guard rows */ |
| rz_dst->h = dstheight; |
| |
| SDL_GetSurfaceBlendMode(src, &blendmode); |
| |
| if (colorKeyAvailable == SDL_TRUE) { |
| /* If available, the colorkey will be used to discard the pixels that are outside of the rotated area. */ |
| SDL_SetColorKey(rz_dst, SDL_TRUE, colorkey); |
| SDL_FillRect(rz_dst, NULL, colorkey); |
| } else if (blendmode == SDL_BLENDMODE_NONE) { |
| blendmode = SDL_BLENDMODE_BLEND; |
| } else if (blendmode == SDL_BLENDMODE_MOD || blendmode == SDL_BLENDMODE_MUL) { |
| /* Without a colorkey, the target texture has to be white for the MOD and MUL blend mode so |
| * that the pixels outside the rotated area don't affect the destination surface. |
| */ |
| colorkey = SDL_MapRGBA(rz_dst->format, 255, 255, 255, 0); |
| SDL_FillRect(rz_dst, NULL, colorkey); |
| /* Setting a white colorkey for the destination surface makes the final blit discard |
| * all pixels outside of the rotated area. This doesn't interfere with anything because |
| * white pixels are already a no-op and the MOD blend mode does not interact with alpha. |
| */ |
| SDL_SetColorKey(rz_dst, SDL_TRUE, colorkey); |
| } |
| |
| SDL_SetSurfaceBlendMode(rz_dst, blendmode); |
| |
| /* Lock source surface */ |
| if (SDL_MUSTLOCK(src)) { |
| SDL_LockSurface(src); |
| } |
| |
| /* check if the rotation is a multiple of 90 degrees so we can take a fast path and also somewhat reduce |
| * the off-by-one problem in _transformSurfaceRGBA that expresses itself when the rotation is near |
| * multiples of 90 degrees. |
| */ |
| angle90 = (int)(angle/90); |
| if (angle90 == angle/90) { |
| angle90 %= 4; |
| if (angle90 < 0) angle90 += 4; /* 0:0 deg, 1:90 deg, 2:180 deg, 3:270 deg */ |
| } else { |
| angle90 = -1; |
| } |
| |
| if (is8bit) { |
| /* Call the 8-bit transformation routine to do the rotation */ |
| if(angle90 >= 0) { |
| transformSurfaceY90(src, rz_dst, angle90, flipx, flipy); |
| } else { |
| transformSurfaceY(src, rz_dst, centerx, centery, (int)sangleinv, (int)cangleinv, |
| flipx, flipy); |
| } |
| } else { |
| /* Call the 32-bit transformation routine to do the rotation */ |
| if (angle90 >= 0) { |
| transformSurfaceRGBA90(src, rz_dst, angle90, flipx, flipy); |
| } else { |
| _transformSurfaceRGBA(src, rz_dst, centerx, centery, (int)sangleinv, (int)cangleinv, |
| flipx, flipy, smooth); |
| } |
| } |
| |
| /* Unlock source surface */ |
| if (SDL_MUSTLOCK(src)) { |
| SDL_UnlockSurface(src); |
| } |
| |
| /* Return rotated surface */ |
| return rz_dst; |
| } |
| |
| #endif /* SDL_VIDEO_RENDER_SW && !SDL_RENDER_DISABLED */ |
