transform.c revision 168023fe 
1/* $Xorg: transform.c,v 1.4 2001/02/09 02:05:33 xorgcvs Exp $ */
2/*
3
4Copyright 1993, 1998  The Open Group
5
6Permission to use, copy, modify, distribute, and sell this software and its
7documentation for any purpose is hereby granted without fee, provided that
8the above copyright notice appear in all copies and that both that
9copyright notice and this permission notice appear in supporting
10documentation.
11
12The above copyright notice and this permission notice shall be included
13in all copies or substantial portions of the Software.
14
15THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
16OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
17MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
18IN NO EVENT SHALL THE OPEN GROUP BE LIABLE FOR ANY CLAIM, DAMAGES OR
19OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
20ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
21OTHER DEALINGS IN THE SOFTWARE.
22
23Except as contained in this notice, the name of The Open Group shall
24not be used in advertising or otherwise to promote the sale, use or
25other dealings in this Software without prior written authorization
26from The Open Group.
27
28*/
29/* $XFree86: xc/programs/oclock/transform.c,v 3.4 2001/07/25 15:05:15 dawes Exp $ */
30
31
32/*
33 * transformed coordinate system objects for X
34 */
35
36#include	<X11/Xlib.h>
37#include	"transform.h"
38#include	<stdlib.h>
39
40static XPoint *
41TranslatePoints(TPoint *points, int n_points,
42		Transform *t, int mode)
43{
44	XPoint	*xpoints;
45	int	i;
46	double	xoff = 0.0, yoff = 0.0;
47
48	xpoints = (XPoint *) malloc ((unsigned)n_points * sizeof (*xpoints));
49	if (!xpoints)
50		return NULL;
51	for (i = 0; i < n_points; i++) {
52		xpoints[i].x = Xx(points[i].x + xoff, points[i].y + yoff, t);
53		xpoints[i].y = Xy(points[i].x + xoff, points[i].y + yoff, t);
54		if (mode == CoordModePrevious) {
55			xoff += points[i].x;
56			yoff += points[i].y;
57		}
58	}
59	return xpoints;
60}
61
62void
63TFillPolygon (register Display *dpy, Drawable d, GC gc, Transform *t,
64	      TPoint *points, int n_points, int shape, int mode)
65{
66	XPoint	*xpoints;
67
68	xpoints = TranslatePoints (points, n_points, t, mode);
69	if (xpoints) {
70		XFillPolygon (dpy, d, gc, xpoints, n_points, shape,
71				CoordModeOrigin);
72		free (xpoints);
73	}
74}
75
76void
77TDrawArc (register Display *dpy, Drawable d, GC gc, Transform *t,
78	  double x, double y, double width, double height,
79	  int angle1, int angle2)
80{
81	int	xx, xy, xw, xh;
82
83	xx = Xx(x,y,t);
84	xy = Xy(x,y,t);
85	xw = Xwidth (width, height, t);
86	xh = Xheight (width, height, t);
87	if (xw < 0) {
88		xx += xw;
89		xw = -xw;
90	}
91	if (xh < 0) {
92		xy += xh;
93		xh = -xh;
94	}
95	XDrawArc (dpy, d, gc, xx, xy, xw, xh, angle1, angle2);
96}
97
98void
99TFillArc (register Display *dpy, Drawable d, GC gc, Transform *t,
100	  double x, double y, double width, double height,
101	  int angle1, int angle2)
102{
103	int	xx, xy, xw, xh;
104
105	xx = Xx(x,y,t);
106	xy = Xy(x,y,t);
107	xw = Xwidth (width, height, t);
108	xh = Xheight (width, height, t);
109	if (xw < 0) {
110		xx += xw;
111		xw = -xw;
112	}
113	if (xh < 0) {
114		xy += xh;
115		xh = -xh;
116	}
117	XFillArc (dpy, d, gc, xx, xy, xw, xh, angle1, angle2);
118}
119
120void
121SetTransform (Transform *t, int xx1, int xx2, int xy1, int xy2,
122	      double tx1, double tx2, double ty1, double ty2)
123{
124	t->mx = ((double) xx2 - xx1) / (tx2 - tx1);
125	t->bx = ((double) xx1) - t->mx * tx1;
126	t->my = ((double) xy2 - xy1) / (ty2 - ty1);
127	t->by = ((double) xy1) - t->my * ty1;
128}
129