1 /***********************************************************
2
3 Copyright 1987, 1998 The Open Group
4
5 Permission to use, copy, modify, distribute, and sell this software and its
6 documentation for any purpose is hereby granted without fee, provided that
7 the above copyright notice appear in all copies and that both that
8 copyright notice and this permission notice appear in supporting
9 documentation.
10
11 The above copyright notice and this permission notice shall be included in
12 all copies or substantial portions of the Software.
13
14 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
17 OPEN GROUP BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
18 AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
19 CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
20
21 Except as contained in this notice, the name of The Open Group shall not be
22 used in advertising or otherwise to promote the sale, use or other dealings
23 in this Software without prior written authorization from The Open Group.
24
25 Copyright 1987 by Digital Equipment Corporation, Maynard, Massachusetts.
26
27 All Rights Reserved
28
29 Permission to use, copy, modify, and distribute this software and its
30 documentation for any purpose and without fee is hereby granted,
31 provided that the above copyright notice appear in all copies and that
32 both that copyright notice and this permission notice appear in
33 supporting documentation, and that the name of Digital not be
34 used in advertising or publicity pertaining to distribution of the
35 software without specific, written prior permission.
36
37 DIGITAL DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING
38 ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL
39 DIGITAL BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR
40 ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
41 WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
42 ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
43 SOFTWARE.
44
45 ******************************************************************/
46 #ifdef HAVE_DIX_CONFIG_H
47 #include <dix-config.h>
48 #endif
49
50 #include <X11/X.h>
51
52 #include "misc.h"
53 #include "scrnintstr.h"
54 #include "gcstruct.h"
55 #include "windowstr.h"
56 #include "pixmap.h"
57 #include "mi.h"
58 #include "miline.h"
59
60 /* Draw lineSolid, fillStyle-independent zero width lines.
61 *
62 * Must keep X and Y coordinates in "ints" at least until after they're
63 * translated and clipped to accomodate CoordModePrevious lines with very
64 * large coordinates.
65 *
66 * Draws the same pixels regardless of sign(dx) or sign(dy).
67 *
68 * Ken Whaley
69 *
70 */
71
72 /* largest positive value that can fit into a component of a point.
73 * Assumes that the point structure is {type x, y;} where type is
74 * a signed type.
75 */
76 #define MAX_COORDINATE ((1 << (((sizeof(DDXPointRec) >> 1) << 3) - 1)) - 1)
77
78 #define MI_OUTPUT_POINT(xx, yy)\
79 {\
80 if ( !new_span && yy == current_y)\
81 {\
82 if (xx < spans->x)\
83 spans->x = xx;\
84 ++*widths;\
85 }\
86 else\
87 {\
88 ++Nspans;\
89 ++spans;\
90 ++widths;\
91 spans->x = xx;\
92 spans->y = yy;\
93 *widths = 1;\
94 current_y = yy;\
95 new_span = FALSE;\
96 }\
97 }
98
99 void
miZeroLine(DrawablePtr pDraw,GCPtr pGC,int mode,int npt,DDXPointPtr pptInit)100 miZeroLine(DrawablePtr pDraw, GCPtr pGC, int mode, /* Origin or Previous */
101 int npt, /* number of points */
102 DDXPointPtr pptInit)
103 {
104 int Nspans, current_y = 0;
105 DDXPointPtr ppt;
106 DDXPointPtr pspanInit, spans;
107 int *pwidthInit, *widths, list_len;
108 int xleft, ytop, xright, ybottom;
109 int new_x1, new_y1, new_x2, new_y2;
110 int x = 0, y = 0, x1, y1, x2, y2, xstart, ystart;
111 int oc1, oc2;
112 int result;
113 int pt1_clipped, pt2_clipped = 0;
114 Bool new_span;
115 int signdx, signdy;
116 int clipdx, clipdy;
117 int width, height;
118 int adx, ady;
119 int octant;
120 unsigned int bias = miGetZeroLineBias(pDraw->pScreen);
121 int e, e1, e2, e3; /* Bresenham error terms */
122 int length; /* length of lines == # of pixels on major axis */
123
124 xleft = pDraw->x;
125 ytop = pDraw->y;
126 xright = pDraw->x + pDraw->width - 1;
127 ybottom = pDraw->y + pDraw->height - 1;
128
129 if (!pGC->miTranslate) {
130 /* do everything in drawable-relative coordinates */
131 xleft = 0;
132 ytop = 0;
133 xright -= pDraw->x;
134 ybottom -= pDraw->y;
135 }
136
137 /* it doesn't matter whether we're in drawable or screen coordinates,
138 * FillSpans simply cannot take starting coordinates outside of the
139 * range of a DDXPointRec component.
140 */
141 if (xright > MAX_COORDINATE)
142 xright = MAX_COORDINATE;
143 if (ybottom > MAX_COORDINATE)
144 ybottom = MAX_COORDINATE;
145
146 /* since we're clipping to the drawable's boundaries & coordinate
147 * space boundaries, we're guaranteed that the larger of width/height
148 * is the longest span we'll need to output
149 */
150 width = xright - xleft + 1;
151 height = ybottom - ytop + 1;
152 list_len = (height >= width) ? height : width;
153 pspanInit = xallocarray(list_len, sizeof(DDXPointRec));
154 pwidthInit = xallocarray(list_len, sizeof(int));
155 if (!pspanInit || !pwidthInit) {
156 free(pspanInit);
157 free(pwidthInit);
158 return;
159 }
160 Nspans = 0;
161 new_span = TRUE;
162 spans = pspanInit - 1;
163 widths = pwidthInit - 1;
164 ppt = pptInit;
165
166 xstart = ppt->x;
167 ystart = ppt->y;
168 if (pGC->miTranslate) {
169 xstart += pDraw->x;
170 ystart += pDraw->y;
171 }
172
173 /* x2, y2, oc2 copied to x1, y1, oc1 at top of loop to simplify
174 * iteration logic
175 */
176 x2 = xstart;
177 y2 = ystart;
178 oc2 = 0;
179 MIOUTCODES(oc2, x2, y2, xleft, ytop, xright, ybottom);
180
181 while (--npt > 0) {
182 x1 = x2;
183 y1 = y2;
184 oc1 = oc2;
185 ++ppt;
186
187 x2 = ppt->x;
188 y2 = ppt->y;
189 if (pGC->miTranslate && (mode != CoordModePrevious)) {
190 x2 += pDraw->x;
191 y2 += pDraw->y;
192 }
193 else if (mode == CoordModePrevious) {
194 x2 += x1;
195 y2 += y1;
196 }
197
198 oc2 = 0;
199 MIOUTCODES(oc2, x2, y2, xleft, ytop, xright, ybottom);
200
201 CalcLineDeltas(x1, y1, x2, y2, adx, ady, signdx, signdy, 1, 1, octant);
202
203 if (ady + 1 > (list_len - Nspans)) {
204 (*pGC->ops->FillSpans) (pDraw, pGC, Nspans, pspanInit,
205 pwidthInit, FALSE);
206 Nspans = 0;
207 spans = pspanInit - 1;
208 widths = pwidthInit - 1;
209 }
210 new_span = TRUE;
211 if (adx > ady) {
212 e1 = ady << 1;
213 e2 = e1 - (adx << 1);
214 e = e1 - adx;
215 length = adx; /* don't draw endpoint in main loop */
216
217 FIXUP_ERROR(e, octant, bias);
218
219 new_x1 = x1;
220 new_y1 = y1;
221 new_x2 = x2;
222 new_y2 = y2;
223 pt1_clipped = 0;
224 pt2_clipped = 0;
225
226 if ((oc1 | oc2) != 0) {
227 result = miZeroClipLine(xleft, ytop, xright, ybottom,
228 &new_x1, &new_y1, &new_x2, &new_y2,
229 adx, ady,
230 &pt1_clipped, &pt2_clipped,
231 octant, bias, oc1, oc2);
232 if (result == -1)
233 continue;
234
235 length = abs(new_x2 - new_x1);
236
237 /* if we've clipped the endpoint, always draw the full length
238 * of the segment, because then the capstyle doesn't matter
239 */
240 if (pt2_clipped)
241 length++;
242
243 if (pt1_clipped) {
244 /* must calculate new error terms */
245 clipdx = abs(new_x1 - x1);
246 clipdy = abs(new_y1 - y1);
247 e += (clipdy * e2) + ((clipdx - clipdy) * e1);
248 }
249 }
250
251 /* draw the segment */
252
253 x = new_x1;
254 y = new_y1;
255
256 e3 = e2 - e1;
257 e = e - e1;
258
259 while (length--) {
260 MI_OUTPUT_POINT(x, y);
261 e += e1;
262 if (e >= 0) {
263 y += signdy;
264 e += e3;
265 }
266 x += signdx;
267 }
268 }
269 else { /* Y major line */
270
271 e1 = adx << 1;
272 e2 = e1 - (ady << 1);
273 e = e1 - ady;
274 length = ady; /* don't draw endpoint in main loop */
275
276 SetYMajorOctant(octant);
277 FIXUP_ERROR(e, octant, bias);
278
279 new_x1 = x1;
280 new_y1 = y1;
281 new_x2 = x2;
282 new_y2 = y2;
283 pt1_clipped = 0;
284 pt2_clipped = 0;
285
286 if ((oc1 | oc2) != 0) {
287 result = miZeroClipLine(xleft, ytop, xright, ybottom,
288 &new_x1, &new_y1, &new_x2, &new_y2,
289 adx, ady,
290 &pt1_clipped, &pt2_clipped,
291 octant, bias, oc1, oc2);
292 if (result == -1)
293 continue;
294
295 length = abs(new_y2 - new_y1);
296
297 /* if we've clipped the endpoint, always draw the full length
298 * of the segment, because then the capstyle doesn't matter
299 */
300 if (pt2_clipped)
301 length++;
302
303 if (pt1_clipped) {
304 /* must calculate new error terms */
305 clipdx = abs(new_x1 - x1);
306 clipdy = abs(new_y1 - y1);
307 e += (clipdx * e2) + ((clipdy - clipdx) * e1);
308 }
309 }
310
311 /* draw the segment */
312
313 x = new_x1;
314 y = new_y1;
315
316 e3 = e2 - e1;
317 e = e - e1;
318
319 while (length--) {
320 MI_OUTPUT_POINT(x, y);
321 e += e1;
322 if (e >= 0) {
323 x += signdx;
324 e += e3;
325 }
326 y += signdy;
327 }
328 }
329 }
330
331 /* only do the capnotlast check on the last segment
332 * and only if the endpoint wasn't clipped. And then, if the last
333 * point is the same as the first point, do not draw it, unless the
334 * line is degenerate
335 */
336 if ((!pt2_clipped) && (pGC->capStyle != CapNotLast) &&
337 (((xstart != x2) || (ystart != y2)) || (ppt == pptInit + 1))) {
338 MI_OUTPUT_POINT(x, y);
339 }
340
341 if (Nspans > 0)
342 (*pGC->ops->FillSpans) (pDraw, pGC, Nspans, pspanInit,
343 pwidthInit, FALSE);
344
345 free(pwidthInit);
346 free(pspanInit);
347 }
348
349 void
miZeroDashLine(DrawablePtr dst,GCPtr pgc,int mode,int nptInit,DDXPointRec * pptInit)350 miZeroDashLine(DrawablePtr dst, GCPtr pgc, int mode, int nptInit, /* number of points in polyline */
351 DDXPointRec * pptInit /* points in the polyline */
352 )
353 {
354 /* XXX kludge until real zero-width dash code is written */
355 pgc->lineWidth = 1;
356 miWideDash(dst, pgc, mode, nptInit, pptInit);
357 pgc->lineWidth = 0;
358 }
359