162 lines
		
	
	
		
			3.9 KiB
		
	
	
	
		
			C
		
	
	
	
			
		
		
	
	
			162 lines
		
	
	
		
			3.9 KiB
		
	
	
	
		
			C
		
	
	
	
| /*
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|  * Copyright © 2004 Keith Packard
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|  *
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|  * Permission to use, copy, modify, distribute, and sell this software and its
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|  * documentation for any purpose is hereby granted without fee, provided that
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|  * the above copyright notice appear in all copies and that both that
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|  * copyright notice and this permission notice appear in supporting
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|  * documentation, and that the name of Keith Packard not be used in
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|  * advertising or publicity pertaining to distribution of the software without
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|  * specific, written prior permission.  Keith Packard makes no
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|  * representations about the suitability of this software for any purpose.  It
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|  * is provided "as is" without express or implied warranty.
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|  *
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|  * KEITH PACKARD DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
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|  * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
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|  * EVENT SHALL KEITH PACKARD BE LIABLE FOR ANY SPECIAL, INDIRECT OR
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|  * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
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|  * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
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|  * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
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|  * PERFORMANCE OF THIS SOFTWARE.
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|  */
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| 
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| #ifdef HAVE_DIX_CONFIG_H
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| #include <dix-config.h>
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| #endif
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| 
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| #include "fb.h"
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| 
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| #ifdef RENDER
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| 
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| #include "picturestr.h"
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| #include "mipict.h"
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| #include "renderedge.h"
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| #include "fbpict.h"
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| 
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| void
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| fbAddTraps (PicturePtr	pPicture,
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| 	    INT16	x_off,
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| 	    INT16	y_off,
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| 	    int		ntrap,
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| 	    xTrap	*traps)
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| {
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|     pixman_image_t *image = image_from_pict (pPicture, FALSE);
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| 
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|     if (!image)
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| 	return;
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|     
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|     pixman_add_traps (image, x_off, y_off, ntrap, (pixman_trap_t *)traps);
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| 
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|     free_pixman_pict (pPicture, image);
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| }
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| 
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| void
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| fbRasterizeTrapezoid (PicturePtr    pPicture,
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| 		      xTrapezoid  *trap,
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| 		      int	    x_off,
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| 		      int	    y_off)
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| {
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|     pixman_image_t *image = image_from_pict (pPicture, FALSE);
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| 
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|     if (!image)
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| 	return;
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| 
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|     pixman_rasterize_trapezoid (image, (pixman_trapezoid_t *)trap, x_off, y_off);
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| 
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|     free_pixman_pict (pPicture, image);
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| }
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| 
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| static int
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| _GreaterY (xPointFixed *a, xPointFixed *b)
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| {
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|     if (a->y == b->y)
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| 	return a->x > b->x;
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|     return a->y > b->y;
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| }
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| 
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| /*
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|  * Note that the definition of this function is a bit odd because
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|  * of the X coordinate space (y increasing downwards).
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|  */
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| static int
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| _Clockwise (xPointFixed *ref, xPointFixed *a, xPointFixed *b)
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| {
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|     xPointFixed	ad, bd;
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| 
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|     ad.x = a->x - ref->x;
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|     ad.y = a->y - ref->y;
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|     bd.x = b->x - ref->x;
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|     bd.y = b->y - ref->y;
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| 
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|     return ((xFixed_32_32) bd.y * ad.x - (xFixed_32_32) ad.y * bd.x) < 0;
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| }
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| 
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| /* FIXME -- this could be made more efficient */
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| void
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| fbAddTriangles (PicturePtr  pPicture,
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| 		INT16	    x_off,
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| 		INT16	    y_off,
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| 		int	    ntri,
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| 		xTriangle *tris)
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| {
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|     xPointFixed	  *top, *left, *right, *tmp;
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|     xTrapezoid	    trap;
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| 
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|     for (; ntri; ntri--, tris++)
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|     {
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| 	top = &tris->p1;
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| 	left = &tris->p2;
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| 	right = &tris->p3;
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| 	if (_GreaterY (top, left)) {
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| 	    tmp = left; left = top; top = tmp;
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| 	}
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| 	if (_GreaterY (top, right)) {
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| 	    tmp = right; right = top; top = tmp;
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| 	}
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| 	if (_Clockwise (top, right, left)) {
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| 	    tmp = right; right = left; left = tmp;
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| 	}
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| 	
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| 	/*
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| 	 * Two cases:
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| 	 *
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| 	 *		+		+
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| 	 *	       / \             / \
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| 	 *	      /   \           /   \
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| 	 *	     /     +         +     \
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| 	 *      /    --           --    \
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| 	 *     /   --               --   \
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| 	 *    / ---                   --- \
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| 	 *	 +--                         --+
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| 	 */
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| 	
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| 	trap.top = top->y;
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| 	trap.left.p1 = *top;
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| 	trap.left.p2 = *left;
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| 	trap.right.p1 = *top;
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| 	trap.right.p2 = *right;
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| 	if (right->y < left->y)
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| 	    trap.bottom = right->y;
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| 	else
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| 	    trap.bottom = left->y;
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| 	fbRasterizeTrapezoid (pPicture, &trap, x_off, y_off);
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| 	if (right->y < left->y)
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| 	{
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| 	    trap.top = right->y;
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| 	    trap.bottom = left->y;
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| 	    trap.right.p1 = *right;
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| 	    trap.right.p2 = *left;
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| 	}
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| 	else
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| 	{
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| 	    trap.top = left->y;
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| 	    trap.bottom = right->y;
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| 	    trap.left.p1 = *left;
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| 	    trap.left.p2 = *right;
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| 	}
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| 	fbRasterizeTrapezoid (pPicture, &trap, x_off, y_off);
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|     }
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| }
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| 
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| #endif /* RENDER */
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