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comparison src/shape_path.c @ 100:1a1dda98730c

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Fix the bug of order of cross & inner product of vectors
author Thinker K.F. Li <thinker@branda.to>
date Wed, 10 Sep 2008 10:02:31 +0800
parents 4aa1c9673363
children d6f9af55b0d0
comparison
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99:4aa1c9673363 100:1a1dda98730c
56 * - udcx = ucx - umx 56 * - udcx = ucx - umx
57 * - udcy = ucy - umy 57 * - udcy = ucy - umy
58 * - udx = ux - umx 58 * - udx = ux - umx
59 * - udy = uy - umy 59 * - udy = uy - umy
60 * 60 *
61 * - udcx * udx + udcy * udy = 0 61 * - udx * udcx + udy * udcy = 0
62 * 62 *
63 * - udl2 = udx ** 2 + udy ** 2; 63 * - udl2 = udx ** 2 + udy ** 2;
64 * - udcx * udy - udcy * udx = sqrt((1 - udl2) * udl2) 64 * - udx * udcy - udy * udcx = sqrt((1 - udl2) * udl2)
65 * 65 *
66 * - udcy = -udcx * udx / udy 66 * - udcy = -udcx * udx / udy
67 * - udcx * udy + udcx * (udx ** 2) / udy = sqrt((1 - udl2) * udl2) 67 * - -udcx * (udx ** 2) / udy - udy * udcx = sqrt((1 - udl2) * udl2)
68 * - udcx * (udy + (udx ** 2) / udy) = sqrt((1 - udl2) * udl2) 68 * - -udcx * ((udx ** 2) / udy + udy) = sqrt((1 - udl2) * udl2)
69 * - udcx = sqrt((1 - udl2) * udl2) / (udy + (udx ** 2) / udy) 69 * - udcx = -sqrt((1 - udl2) * udl2) / ((udx ** 2) / udy + udy)
70 * or 70 * or
71 * - udcx = -udcy * udy / udx 71 * - udcx = -udcy * udy / udx
72 * - -udcy * (udy ** 2) / udx - udcy * udx = sqrt((1 - udl2) * udl2) 72 * - udx * udcy + udcy * (udy ** 2) / udx = sqrt((1 - udl2) * udl2)
73 * - -udcy * ((udy ** 2) / udx + udx) = sqrt((1 - udl2) * udl2) 73 * - udcy * (udx + (udy ** 2) / udx) = sqrt((1 - udl2) * udl2)
74 * - udcy = -sqrt((1 - udl2) * udl2) / ((udy ** 2) / udx + udx) 74 * - udcy = sqrt((1 - udl2) * udl2) / (udx + (udy ** 2) / udx)
75 * 75 *
76 * - cx = rx * ucx 76 * - cx = rx * ucx
77 * - cx = rx * (udcx + umx) 77 * - cx = rx * (udcx + umx)
78 * - cy = ry * ucy 78 * - cy = ry * ucy
79 * - cy = ry * (udcy + umy) 79 * - cy = ry * (udcy + umy)
108 udx2 = udx * udx; 108 udx2 = udx * udx;
109 udy2 = udy * udy; 109 udy2 = udy * udy;
110 udl2 = udx2 + udy2; 110 udl2 = udx2 + udy2;
111 111
112 if(udy != 0) { 112 if(udy != 0) {
113 udcx = sqrtf((1 - udl2) * udl2) / (udy + udx2 / udy); 113 udcx = -sqrtf((1 - udl2) * udl2) / (udy + udx2 / udy);
114 udcy = - udcx * udx / udy; 114 udcy = -udcx * udx / udy;
115 } else { 115 } else {
116 udcx = 0; 116 udcx = 0;
117 udcy = -sqrtf((1 - udl2) * udl2) / udx; 117 udcy = sqrtf((1 - udl2) * udl2) / udx;
118 } 118 }
119 119
120 reflect = 0; 120 reflect = 0;
121 if(large) 121 if(large)
122 reflect ^= 1; 122 reflect ^= 1;
214 } 214 }
215 215
216 #define INNER(x1, y1, x2, y2) ((x1) * (x2) + (y1) * (y2)) 216 #define INNER(x1, y1, x2, y2) ((x1) * (x2) + (y1) * (y2))
217 #define CROSS(x1, y1, x2, y2) ((x1) * (y2) - (y1) * (x2)) 217 #define CROSS(x1, y1, x2, y2) ((x1) * (y2) - (y1) * (x2))
218 218
219 /*! \brief Make path for arcs in a path.
220 */
219 void sh_path_arc_path(cairo_t *cr, const co_aix **args_p, 221 void sh_path_arc_path(cairo_t *cr, const co_aix **args_p,
220 const int **fix_args_p) { 222 const int **fix_args_p) {
221 co_aix cx, cy, x0, y0, x, y, xx, xy; 223 co_aix cx, cy, x0, y0, x, y, xx, xy;
222 co_aix dx, dy, dx0, dy0, dxx, dxy; 224 co_aix dx, dy, dx0, dy0, dxx, dxy;
223 co_aix xyratio; 225 co_aix xyratio;
255 /*! \note Why we calculate these numbers there? 257 /*! \note Why we calculate these numbers there?
256 * If we compute it when filling arguments, sh_path_arc_cmd_arg_fill(), 258 * If we compute it when filling arguments, sh_path_arc_cmd_arg_fill(),
257 * we can avoid to recompute it for every drawing. But, transforming of 259 * we can avoid to recompute it for every drawing. But, transforming of
258 * coordinate can effect value of the numbers. 260 * coordinate can effect value of the numbers.
259 */ 261 */
260 inner0 = INNER(dx0, dy0, dxx, dxy); 262 inner0 = INNER(dxx, dxy, dx0, dy0);
261 cross0 = CROSS(dx0, dy0, dxx, dxy); 263 cross0 = CROSS(dxx, dxy, dx0, dy0);
262 circle_h0 = sqrtf(rx2 - inner0 * inner0 / rx2); 264 circle_h0 = sqrtf(rx2 - inner0 * inner0 / rx2);
263 xyratio = cross0 / rx / circle_h0; 265 xyratio = cross0 / rx / circle_h0;
264 if(xyratio < 0) 266 if(xyratio < 0)
265 xyratio = -xyratio; 267 xyratio = -xyratio;
266 268
267 angle0 = acos(inner0 / rx2); 269 angle0 = acos(inner0 / rx2);
268 if(cross0 < 0) 270 if(cross0 < 0)
269 angle0 = PI * 2 - angle0; /* 3rd, 4th Quadrant */ 271 angle0 = PI * 2 - angle0; /* 3rd, 4th Quadrant */
270 272
271 inner = INNER(dx, dy, dxx, dxy); 273 inner = INNER(dxx, dxy, dx, dy);
272 cross = CROSS(dx, dy, dxx, dxy); 274 cross = CROSS(dxx, dxy, dx, dy);
273 angle = acos(inner / rx2); 275 angle = acos(inner / rx2);
274 if(cross < 0) 276 if(cross < 0)
275 angle = PI * 2 - angle; /* 3rd, 4th Quadrant */ 277 angle = PI * 2 - angle; /* 3rd, 4th Quadrant */
276 278
277 /* Make a path for arc */ 279 /* Make a path for arc */
700 free(path->user_data); 702 free(path->user_data);
701 free(path->dev_data); 703 free(path->dev_data);
702 free(path); 704 free(path);
703 return NULL; 705 return NULL;
704 } 706 }
705 memcpy(path->dev_data, path->user_data, cmd_cnt); 707 memcpy(path->dev_data, path->user_data, msz);
706 708
707 path->shape.free = sh_path_free; 709 path->shape.free = sh_path_free;
708 710
709 return (shape_t *)path; 711 return (shape_t *)path;
710 } 712 }