Mercurial > sdl-ios-xcode
view src/video/SDL_blit_slow.c @ 3417:64a60c5d502e
Automatically initialize the video system and create a renderer to simplify use.
author | Sam Lantinga <slouken@libsdl.org> |
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date | Wed, 28 Oct 2009 06:04:07 +0000 |
parents | 99210400e8b9 |
children | c5fe76962106 |
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/* SDL - Simple DirectMedia Layer Copyright (C) 1997-2009 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" #include "SDL_video.h" #include "SDL_blit.h" /* The ONE TRUE BLITTER * This puppy has to handle all the unoptimized cases - yes, it's slow. */ void SDL_Blit_Slow(SDL_BlitInfo * info) { const int flags = info->flags; const Uint32 modulateR = info->r; const Uint32 modulateG = info->g; const Uint32 modulateB = info->b; const Uint32 modulateA = info->a; Uint32 srcpixel; Uint32 srcR, srcG, srcB, srcA; Uint32 dstpixel; Uint32 dstR, dstG, dstB, dstA; int srcy, srcx; int posy, posx; int incy, incx; SDL_PixelFormat *src_fmt = info->src_fmt; SDL_PixelFormat *dst_fmt = info->dst_fmt; int srcbpp = src_fmt->BytesPerPixel; int dstbpp = dst_fmt->BytesPerPixel; srcy = 0; posy = 0; incy = (info->src_h << 16) / info->dst_h; incx = (info->src_w << 16) / info->dst_w; while (info->dst_h--) { Uint8 *src; Uint8 *dst = (Uint8 *) info->dst; int n = info->dst_w; srcx = -1; posx = 0x10000L; while (posy >= 0x10000L) { ++srcy; posy -= 0x10000L; } while (n--) { if (posx >= 0x10000L) { while (posx >= 0x10000L) { ++srcx; posx -= 0x10000L; } src = (info->src + (srcy * info->src_pitch) + (srcx * srcbpp)); } if (src_fmt->Amask) { DISEMBLE_RGBA(src, srcbpp, src_fmt, srcpixel, srcR, srcG, srcB, srcA); } else { DISEMBLE_RGB(src, srcbpp, src_fmt, srcpixel, srcR, srcG, srcB); srcA = 0xFF; } if (flags & SDL_COPY_COLORKEY) { /* srcpixel isn't set for 24 bpp */ if (srcbpp == 24) { srcpixel = (srcR << src_fmt->Rshift) | (srcG << src_fmt->Gshift) | (srcB << src_fmt->Bshift); } if (srcpixel == info->colorkey) { posx += incx; dst += dstbpp; continue; } } if (dst_fmt->Amask) { DISEMBLE_RGBA(dst, dstbpp, dst_fmt, dstpixel, dstR, dstG, dstB, dstA); } else { DISEMBLE_RGB(dst, dstbpp, dst_fmt, dstpixel, dstR, dstG, dstB); dstA = 0xFF; } if (flags & SDL_COPY_MODULATE_COLOR) { srcR = (srcR * modulateR) / 255; srcG = (srcG * modulateG) / 255; srcB = (srcB * modulateB) / 255; } if (flags & SDL_COPY_MODULATE_ALPHA) { srcA = (srcA * modulateA) / 255; } if (flags & (SDL_COPY_BLEND | SDL_COPY_ADD)) { /* This goes away if we ever use premultiplied alpha */ if (srcA < 255) { srcR = (srcR * srcA) / 255; srcG = (srcG * srcA) / 255; srcB = (srcB * srcA) / 255; } } switch (flags & (SDL_COPY_MASK | SDL_COPY_BLEND | SDL_COPY_ADD | SDL_COPY_MOD)) { case 0: dstR = srcR; dstG = srcG; dstB = srcB; dstA = srcA; break; case SDL_COPY_MASK: if (srcA) { dstR = srcR; dstG = srcG; dstB = srcB; } break; case SDL_COPY_BLEND: dstR = srcR + ((255 - srcA) * dstR) / 255; dstG = srcG + ((255 - srcA) * dstG) / 255; dstB = srcB + ((255 - srcA) * dstB) / 255; break; case SDL_COPY_ADD: dstR = srcR + dstR; if (dstR > 255) dstR = 255; dstG = srcG + dstG; if (dstG > 255) dstG = 255; dstB = srcB + dstB; if (dstB > 255) dstB = 255; break; case SDL_COPY_MOD: dstR = (srcR * dstR) / 255; dstG = (srcG * dstG) / 255; dstB = (srcB * dstB) / 255; break; } if (dst_fmt->Amask) { ASSEMBLE_RGBA(dst, dstbpp, dst_fmt, dstR, dstG, dstB, dstA); } else { ASSEMBLE_RGB(dst, dstbpp, dst_fmt, dstR, dstG, dstB); } posx += incx; dst += dstbpp; } posy += incy; info->dst += info->dst_pitch; } } /* vi: set ts=4 sw=4 expandtab: */