Mercurial > sdl-ios-xcode
view src/video/SDL_rect.c @ 2662:5470680ca587 gsoc2008_audio_resampling
Made a very significant optimization to the FIR filter which I believe I can take a little further. Right now the FIR filter size is 768 and I get some free() bugs, so this is something I need to debug.
author | Aaron Wishnick <schnarf@gmail.com> |
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date | Thu, 10 Jul 2008 07:02:18 +0000 |
parents | 12ea0fdc0df2 |
children | 99210400e8b9 |
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/* 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" #include "SDL_video.h" #include "SDL_rect_c.h" SDL_bool SDL_HasIntersection(const SDL_Rect * A, const SDL_Rect * B) { int Amin, Amax, Bmin, Bmax; /* Horizontal intersection */ Amin = A->x; Amax = Amin + A->w; Bmin = B->x; Bmax = Bmin + B->w; if (Bmin > Amin) Amin = Bmin; if (Bmax < Amax) Amax = Bmax; if (Amax <= Amin) return SDL_FALSE; /* Vertical intersection */ Amin = A->y; Amax = Amin + A->h; Bmin = B->y; Bmax = Bmin + B->h; if (Bmin > Amin) Amin = Bmin; if (Bmax < Amax) Amax = Bmax; if (Amax <= Amin) return SDL_FALSE; return SDL_TRUE; } SDL_bool SDL_IntersectRect(const SDL_Rect * A, const SDL_Rect * B, SDL_Rect * result) { int Amin, Amax, Bmin, Bmax; /* Horizontal intersection */ Amin = A->x; Amax = Amin + A->w; Bmin = B->x; Bmax = Bmin + B->w; if (Bmin > Amin) Amin = Bmin; result->x = Amin; if (Bmax < Amax) Amax = Bmax; result->w = Amax - Amin; /* Vertical intersection */ Amin = A->y; Amax = Amin + A->h; Bmin = B->y; Bmax = Bmin + B->h; if (Bmin > Amin) Amin = Bmin; result->y = Amin; if (Bmax < Amax) Amax = Bmax; result->h = Amax - Amin; return !SDL_RectEmpty(result); } void SDL_UnionRect(const SDL_Rect * A, const SDL_Rect * B, SDL_Rect * result) { int Amin, Amax, Bmin, Bmax; /* Horizontal union */ Amin = A->x; Amax = Amin + A->w; Bmin = B->x; Bmax = Bmin + B->w; if (Bmin < Amin) Amin = Bmin; result->x = Amin; if (Bmax > Amax) Amax = Bmax; result->w = Amax - Amin; /* Vertical intersection */ Amin = A->y; Amax = Amin + A->h; Bmin = B->y; Bmax = Bmin + B->h; if (Bmin < Amin) Amin = Bmin; result->y = Amin; if (Bmax > Amax) Amax = Bmax; result->h = Amax - Amin; } void SDL_AddDirtyRect(SDL_DirtyRectList * list, const SDL_Rect * rect) { SDL_DirtyRect *dirty; /* FIXME: At what point is this optimization too expensive? */ for (dirty = list->list; dirty; dirty = dirty->next) { if (SDL_HasIntersection(&dirty->rect, rect)) { SDL_UnionRect(&dirty->rect, rect, &dirty->rect); return; } } if (list->free) { dirty = list->free; list->free = dirty->next; } else { dirty = (SDL_DirtyRect *) SDL_malloc(sizeof(*dirty)); if (!dirty) { return; } } dirty->rect = *rect; dirty->next = list->list; list->list = dirty; } void SDL_ClearDirtyRects(SDL_DirtyRectList * list) { SDL_DirtyRect *prev, *curr; /* Skip to the end of the free list */ prev = NULL; for (curr = list->free; curr; curr = curr->next) { prev = curr; } /* Add the list entries to the end */ if (prev) { prev->next = list->list; } else { list->free = list->list; } list->list = NULL; } void SDL_FreeDirtyRects(SDL_DirtyRectList * list) { while (list->list) { SDL_DirtyRect *elem = list->list; list->list = elem->next; SDL_free(elem); } while (list->free) { SDL_DirtyRect *elem = list->free; list->free = elem->next; SDL_free(elem); } } /* vi: set ts=4 sw=4 expandtab: */