Mercurial > sdl-ios-xcode
view src/video/SDL_rect.c @ 3100:7dc982143c06
Date: Sun, 22 Mar 2009 12:52:29 +0000
From: Luke Benstead
Subject: OpenGL 3.0 Context Creation
I've attached a patch which implements OpenGL 3.x context creation on
the latest SVN. I've added two options to SDL_GL_SetAttribute, these
are SDL_GL_CONTEXT_MAJOR_VERSION and SDL_GL_CONTEXT_MINOR_VERSION.
These default to 2 and 1 respectively. If the major version is less
than 3 then the current context creation method is used, otherwise the
appropriate new context creation function is called (depending on the
platform).
Sample code:
if (SDL_Init(SDL_INIT_VIDEO) != 0) {
printf("Unable to initialize SDL: %s\n", SDL_GetError());
return 1;
}
SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 3); //Without these 2 lines, SDL will create a GL 2.x context
SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 0);
SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1);
SDL_Surface* screen = SDL_SetVideoMode( 640, 480, 16, SDL_OPENGL | SDL_FULLSCREEN );
I've implemented context creation on both Win32 and X and run basic
tests on both. This patch doesn't provide access to all the options
allowed by the new context creation (e.g. shared contexts, forward
compatible contexts) but they can be added pretty easily.
author | Sam Lantinga <slouken@libsdl.org> |
---|---|
date | Tue, 24 Mar 2009 10:43:53 +0000 |
parents | 47965eacde88 |
children | 0267b8b1595c |
line wrap: on
line source
/* 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_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; } SDL_bool SDL_IntersectRectAndLine(const SDL_Rect * rect, int *X1, int *Y1, int *X2, int *Y2) { int x1, y1; int x2, y2; int rectx1; int recty1; int rectx2; int recty2; if (!rect || !X1 || !Y1 || !X2 || !Y2) { return SDL_FALSE; } x1 = *X1; y1 = *Y1; x2 = *X2; y2 = *Y2; rectx1 = rect->x; recty1 = rect->y; rectx2 = rect->x + rect->w - 1; recty2 = rect->y + rect->h - 1; /* Check to see if entire line is inside rect */ if (x1 >= rectx1 && x1 <= rectx2 && x2 >= rectx1 && x2 <= rectx2 && y1 >= recty1 && y1 <= recty2 && y2 >= recty1 && y2 <= recty2) { return SDL_TRUE; } /* Check to see if entire line is to one side of rect */ if ((x1 < rectx1 && x2 < rectx1) || (x1 > rectx2 && x2 > rectx2) || (y1 < recty1 && y2 < recty1) || (y1 > recty2 && y2 > recty2)) { return SDL_FALSE; } if (y1 == y2) { /* Horizontal line, easy to clip */ if (x1 < rectx1) { *X1 = rectx1; } else if (x1 > rectx2) { *X1 = rectx2; } if (x2 < rectx1) { *X2 = rectx1; } else if (x2 > rectx2) { *X2 = rectx2; } return SDL_TRUE; } if (x1 == x2) { /* Vertical line, easy to clip */ if (y1 < recty1) { *Y1 = recty1; } else if (y1 > recty2) { *Y1 = recty2; } if (y2 < recty1) { *Y2 = recty1; } else if (y2 > recty2) { *Y2 = recty2; } return SDL_TRUE; } else { /* The task of clipping a line with finite slope ratios in a fixed- * precision coordinate space is not as immediately simple as it is * with coordinates of arbitrary precision. If the ratio of slopes * between the input line segment and the result line segment is not * a whole number, you have in fact *moved* the line segment a bit, * and there can be no avoiding it without more precision */ int *x_result_[] = { X1, X2, NULL }, **x_result = x_result_; int *y_result_[] = { Y1, Y2, NULL }, **y_result = y_result_; SDL_bool intersection = SDL_FALSE; double b, m, left, right, bottom, top; int xl, xh, yl, yh; /* solve mx+b line formula */ m = (double) (y1 - y2) / (double) (x1 - x2); b = y2 - m * (double) x2; /* find some linear intersections */ left = (m * (double) rectx1) + b; right = (m * (double) rectx2) + b; top = (recty1 - b) / m; bottom = (recty2 - b) / m; /* sort end-points' x and y components individually */ if (x1 < x2) { xl = x1; xh = x2; } else { xl = x2; xh = x1; } if (y1 < y2) { yl = y1; yh = y2; } else { yl = y2; yh = y1; } #define RISING(a, b, c) (((a)<=(b))&&((b)<=(c))) /* check for a point that's entirely inside the rect */ if (RISING(rectx1, x1, rectx2) && RISING(recty1, y1, recty2)) { x_result++; y_result++; intersection = SDL_TRUE; } else /* it was determined earlier that *both* end-points are not contained */ if (RISING(rectx1, x2, rectx2) && RISING(recty1, y2, recty2)) { **(x_result++) = x2; **(y_result++) = y2; intersection = SDL_TRUE; } if (RISING(recty1, left, recty2) && RISING(xl, rectx1, xh)) { **(x_result++) = rectx1; **(y_result++) = (int) left; intersection = SDL_TRUE; } if (*x_result == NULL) return intersection; if (RISING(recty1, right, recty2) && RISING(xl, rectx2, xh)) { **(x_result++) = rectx2; **(y_result++) = (int) right; intersection = SDL_TRUE; } if (*x_result == NULL) return intersection; if (RISING(rectx1, top, rectx2) && RISING(yl, recty1, yh)) { **(x_result++) = (int) top; **(y_result++) = recty1; intersection = SDL_TRUE; } if (*x_result == NULL) return intersection; if (RISING(rectx1, bottom, rectx2) && RISING(yl, recty2, yh)) { **(x_result++) = (int) bottom; **(y_result++) = recty2; intersection = SDL_TRUE; } return intersection; } return SDL_FALSE; } 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: */