diff options
Diffstat (limited to 'Source/external/SDL2/src/render/software/SDL_rotate.c')
| -rw-r--r-- | Source/external/SDL2/src/render/software/SDL_rotate.c | 534 |
1 files changed, 534 insertions, 0 deletions
diff --git a/Source/external/SDL2/src/render/software/SDL_rotate.c b/Source/external/SDL2/src/render/software/SDL_rotate.c new file mode 100644 index 0000000..09e099c --- /dev/null +++ b/Source/external/SDL2/src/render/software/SDL_rotate.c @@ -0,0 +1,534 @@ +/* + +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 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) { + /* Without a colorkey, the target texture has to be white for the MOD 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; +} |