Mercurial > sdl-ios-xcode
view src/video/SDL_blit_slow.c @ 4590:1ad70fb49fcb
Fix so many things that there is little place in this column to list them all but the result is that blending modes just work now for drawing primitives.
Fixes involved:
1. Fix handling of alpha channel when SDL_BLENDMODE_NONE is set.
2. Make xrendercolor use floating-point values for color channels and then convert to 16 bit ints.
3. Fix handling of visuals in SDL_x11modes.c so that a 32 bit ARGB visual is used.
4. Fix the background pixel value in SDL_x11window.c so that the window background has an alpha value of 0xFF and not 0.
author | Sunny Sachanandani <sunnysachanandani@gmail.com> |
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date | Fri, 09 Jul 2010 21:36:41 +0530 |
parents | f7b03b6838cb |
children | 791b3256fb22 |
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/* SDL - Simple DirectMedia Layer Copyright (C) 1997-2010 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 == 3) { 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: */