Mercurial > sdl-ios-xcode
view src/video/SDL_stretch.c @ 2153:760c1bd2d625
Reverted mousewheel support in 1.2, since it breaks binary compatibility.
author | Sam Lantinga <slouken@libsdl.org> |
---|---|
date | Fri, 06 Jul 2007 13:45:10 +0000 |
parents | 8055185ae4ed |
children | 7e5ff6cd05bf |
line wrap: on
line source
/* SDL - Simple DirectMedia Layer Copyright (C) 1997-2006 Sam Lantinga This library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with this library; if not, write to the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA Sam Lantinga slouken@libsdl.org */ #include "SDL_config.h" /* This a stretch blit implementation based on ideas given to me by Tomasz Cejner - thanks! :) April 27, 2000 - Sam Lantinga */ #include "SDL_video.h" #include "SDL_blit.h" /* This isn't ready for general consumption yet - it should be folded into the general blitting mechanism. */ #if ((defined(_MFC_VER) && defined(_M_IX86)/* && !defined(_WIN32_WCE) still needed? */) || \ defined(__WATCOMC__) || \ (defined(__GNUC__) && defined(__i386__))) && SDL_ASSEMBLY_ROUTINES #define USE_ASM_STRETCH #endif #ifdef USE_ASM_STRETCH #if defined(_M_IX86) || defined(i386) #define PREFIX16 0x66 #define STORE_BYTE 0xAA #define STORE_WORD 0xAB #define LOAD_BYTE 0xAC #define LOAD_WORD 0xAD #define RETURN 0xC3 #else #error Need assembly opcodes for this architecture #endif static unsigned char copy_row[4096]; static int generate_rowbytes(int src_w, int dst_w, int bpp) { static struct { int bpp; int src_w; int dst_w; } last; int i; int pos, inc; unsigned char *eip; unsigned char load, store; /* See if we need to regenerate the copy buffer */ if ((src_w == last.src_w) && (dst_w == last.dst_w) && (bpp == last.bpp)) { return (0); } last.bpp = bpp; last.src_w = src_w; last.dst_w = dst_w; switch (bpp) { case 1: load = LOAD_BYTE; store = STORE_BYTE; break; case 2: case 4: load = LOAD_WORD; store = STORE_WORD; break; default: SDL_SetError("ASM stretch of %d bytes isn't supported\n", bpp); return (-1); } pos = 0x10000; inc = (src_w << 16) / dst_w; eip = copy_row; for (i = 0; i < dst_w; ++i) { while (pos >= 0x10000L) { if (bpp == 2) { *eip++ = PREFIX16; } *eip++ = load; pos -= 0x10000L; } if (bpp == 2) { *eip++ = PREFIX16; } *eip++ = store; pos += inc; } *eip++ = RETURN; /* Verify that we didn't overflow (too late) */ if (eip > (copy_row + sizeof(copy_row))) { SDL_SetError("Copy buffer overflow"); return (-1); } return (0); } #else #define DEFINE_COPY_ROW(name, type) \ void name(type *src, int src_w, type *dst, int dst_w) \ { \ int i; \ int pos, inc; \ type pixel = 0; \ \ pos = 0x10000; \ inc = (src_w << 16) / dst_w; \ for ( i=dst_w; i>0; --i ) { \ while ( pos >= 0x10000L ) { \ pixel = *src++; \ pos -= 0x10000L; \ } \ *dst++ = pixel; \ pos += inc; \ } \ } /* *INDENT-OFF* */ DEFINE_COPY_ROW(copy_row1, Uint8) DEFINE_COPY_ROW(copy_row2, Uint16) DEFINE_COPY_ROW(copy_row4, Uint32) /* *INDENT-ON* */ #endif /* USE_ASM_STRETCH */ /* The ASM code doesn't handle 24-bpp stretch blits */ void copy_row3(Uint8 * src, int src_w, Uint8 * dst, int dst_w) { int i; int pos, inc; Uint8 pixel[3]; pos = 0x10000; inc = (src_w << 16) / dst_w; for (i = dst_w; i > 0; --i) { while (pos >= 0x10000L) { pixel[0] = *src++; pixel[1] = *src++; pixel[2] = *src++; pos -= 0x10000L; } *dst++ = pixel[0]; *dst++ = pixel[1]; *dst++ = pixel[2]; pos += inc; } } /* Perform a stretch blit between two surfaces of the same format. NOTE: This function is not safe to call from multiple threads! */ int SDL_SoftStretch(SDL_Surface * src, SDL_Rect * srcrect, SDL_Surface * dst, SDL_Rect * dstrect) { int src_locked; int dst_locked; int pos, inc; int dst_width; int dst_maxrow; int src_row, dst_row; Uint8 *srcp = NULL; Uint8 *dstp; SDL_Rect full_src; SDL_Rect full_dst; #if defined(USE_ASM_STRETCH) && defined(__GNUC__) int u1, u2; #endif const int bpp = dst->format->BytesPerPixel; if (src->format->BitsPerPixel != dst->format->BitsPerPixel) { SDL_SetError("Only works with same format surfaces"); return (-1); } /* Verify the blit rectangles */ if (srcrect) { if ((srcrect->x < 0) || (srcrect->y < 0) || ((srcrect->x + srcrect->w) > src->w) || ((srcrect->y + srcrect->h) > src->h)) { SDL_SetError("Invalid source blit rectangle"); return (-1); } } else { full_src.x = 0; full_src.y = 0; full_src.w = src->w; full_src.h = src->h; srcrect = &full_src; } if (dstrect) { if ((dstrect->x < 0) || (dstrect->y < 0) || ((dstrect->x + dstrect->w) > dst->w) || ((dstrect->y + dstrect->h) > dst->h)) { SDL_SetError("Invalid destination blit rectangle"); return (-1); } } else { full_dst.x = 0; full_dst.y = 0; full_dst.w = dst->w; full_dst.h = dst->h; dstrect = &full_dst; } /* Lock the destination if it's in hardware */ dst_locked = 0; if (SDL_MUSTLOCK(dst)) { if (SDL_LockSurface(dst) < 0) { SDL_SetError("Unable to lock destination surface"); return (-1); } dst_locked = 1; } /* Lock the source if it's in hardware */ src_locked = 0; if (SDL_MUSTLOCK(src)) { if (SDL_LockSurface(src) < 0) { if (dst_locked) { SDL_UnlockSurface(dst); } SDL_SetError("Unable to lock source surface"); return (-1); } src_locked = 1; } /* Set up the data... */ pos = 0x10000; inc = (srcrect->h << 16) / dstrect->h; src_row = srcrect->y; dst_row = dstrect->y; dst_width = dstrect->w * bpp; #ifdef USE_ASM_STRETCH /* Write the opcodes for this stretch */ if ((bpp != 3) && (generate_rowbytes(srcrect->w, dstrect->w, bpp) < 0)) { return (-1); } #endif /* Perform the stretch blit */ for (dst_maxrow = dst_row + dstrect->h; dst_row < dst_maxrow; ++dst_row) { dstp = (Uint8 *) dst->pixels + (dst_row * dst->pitch) + (dstrect->x * bpp); while (pos >= 0x10000L) { srcp = (Uint8 *) src->pixels + (src_row * src->pitch) + (srcrect->x * bpp); ++src_row; pos -= 0x10000L; } #ifdef USE_ASM_STRETCH switch (bpp) { case 3: copy_row3(srcp, srcrect->w, dstp, dstrect->w); break; default: #ifdef __GNUC__ __asm__ __volatile__("call *%4": "=&D"(u1), "=&S"(u2): "0"(dstp), "1"(srcp), "r"(copy_row):"memory"); #elif defined(_MSC_VER) || defined(__WATCOMC__) /* *INDENT-OFF* */ { void *code = copy_row; __asm { push edi push esi mov edi, dstp mov esi, srcp call dword ptr code pop esi pop edi } } /* *INDENT-ON* */ #else #error Need inline assembly for this compiler #endif break; } #else switch (bpp) { case 1: copy_row1(srcp, srcrect->w, dstp, dstrect->w); break; case 2: copy_row2((Uint16 *) srcp, srcrect->w, (Uint16 *) dstp, dstrect->w); break; case 3: copy_row3(srcp, srcrect->w, dstp, dstrect->w); break; case 4: copy_row4((Uint32 *) srcp, srcrect->w, (Uint32 *) dstp, dstrect->w); break; } #endif pos += inc; } /* We need to unlock the surfaces if they're locked */ if (dst_locked) { SDL_UnlockSurface(dst); } if (src_locked) { SDL_UnlockSurface(src); } return (0); } /* vi: set ts=4 sw=4 expandtab: */