Mercurial > sdl-ios-xcode
view src/video/SDL_drawline.c @ 3363:90aec03bf9fd
Fixed bug #627
Increased accuracy of alpha blend calculation
author | Sam Lantinga <slouken@libsdl.org> |
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date | Sat, 10 Oct 2009 07:48:57 +0000 |
parents | 27d8b12e0e8e |
children | 0267b8b1595c |
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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_draw.h" int SDL_DrawLine(SDL_Surface * dst, int x1, int y1, int x2, int y2, Uint32 color) { /* This function doesn't work on surfaces < 8 bpp */ if (dst->format->BitsPerPixel < 8) { SDL_SetError("SDL_DrawLine(): Unsupported surface format"); return (-1); } /* Perform clipping */ if (!SDL_IntersectRectAndLine(&dst->clip_rect, &x1, &y1, &x2, &y2)) { return (0); } switch (dst->format->BytesPerPixel) { case 1: DRAWLINE(x1, y1, x2, y2, DRAW_FASTSETPIXEL1); break; case 2: DRAWLINE(x1, y1, x2, y2, DRAW_FASTSETPIXEL2); break; case 3: SDL_Unsupported(); return -1; case 4: DRAWLINE(x1, y1, x2, y2, DRAW_FASTSETPIXEL4); break; } return 0; } /* vi: set ts=4 sw=4 expandtab: */