1 #include <u.h>
2 #include <libc.h>
3 #include <draw.h>
4 #include <memdraw.h>
5 #include <memlayer.h>
6
7 enum
8 {
9 Arrow1 = 8,
10 Arrow2 = 10,
11 Arrow3 = 3,
12 };
13
14 static
15 int
lmin(int a,int b)16 lmin(int a, int b)
17 {
18 if(a < b)
19 return a;
20 return b;
21 }
22
23 static
24 int
lmax(int a,int b)25 lmax(int a, int b)
26 {
27 if(a > b)
28 return a;
29 return b;
30 }
31
32 #ifdef NOTUSED
33 /*
34 * Rather than line clip, we run the Bresenham loop over the full line,
35 * and clip on each pixel. This is more expensive but means that
36 * lines look the same regardless of how the windowing has tiled them.
37 * For speed, we check for clipping outside the loop and make the
38 * test easy when possible.
39 */
40
41 static
42 void
horline1(Memimage * dst,Point p0,Point p1,int srcval,Rectangle clipr)43 horline1(Memimage *dst, Point p0, Point p1, int srcval, Rectangle clipr)
44 {
45 int x, y, dy, deltay, deltax, maxx;
46 int dd, easy, e, bpp, m, m0;
47 uchar *d;
48
49 deltax = p1.x - p0.x;
50 deltay = p1.y - p0.y;
51 dd = dst->width*sizeof(ulong);
52 dy = 1;
53 if(deltay < 0){
54 dd = -dd;
55 deltay = -deltay;
56 dy = -1;
57 }
58 maxx = lmin(p1.x, clipr.max.x-1);
59 bpp = dst->depth;
60 m0 = 0xFF^(0xFF>>bpp);
61 m = m0 >> (p0.x&(7/dst->depth))*bpp;
62 easy = ptinrect(p0, clipr) && ptinrect(p1, clipr);
63 e = 2*deltay - deltax;
64 y = p0.y;
65 d = byteaddr(dst, p0);
66 deltay *= 2;
67 deltax = deltay - 2*deltax;
68 for(x=p0.x; x<=maxx; x++){
69 if(easy || (clipr.min.x<=x && clipr.min.y<=y && y<clipr.max.y))
70 *d ^= (*d^srcval) & m;
71 if(e > 0){
72 y += dy;
73 d += dd;
74 e += deltax;
75 }else
76 e += deltay;
77 d++;
78 m >>= bpp;
79 if(m == 0)
80 m = m0;
81 }
82 }
83
84 static
85 void
verline1(Memimage * dst,Point p0,Point p1,int srcval,Rectangle clipr)86 verline1(Memimage *dst, Point p0, Point p1, int srcval, Rectangle clipr)
87 {
88 int x, y, deltay, deltax, maxy;
89 int easy, e, bpp, m, m0, dd;
90 uchar *d;
91
92 deltax = p1.x - p0.x;
93 deltay = p1.y - p0.y;
94 dd = 1;
95 if(deltax < 0){
96 dd = -1;
97 deltax = -deltax;
98 }
99 maxy = lmin(p1.y, clipr.max.y-1);
100 bpp = dst->depth;
101 m0 = 0xFF^(0xFF>>bpp);
102 m = m0 >> (p0.x&(7/dst->depth))*bpp;
103 easy = ptinrect(p0, clipr) && ptinrect(p1, clipr);
104 e = 2*deltax - deltay;
105 x = p0.x;
106 d = byteaddr(dst, p0);
107 deltax *= 2;
108 deltay = deltax - 2*deltay;
109 for(y=p0.y; y<=maxy; y++){
110 if(easy || (clipr.min.y<=y && clipr.min.x<=x && x<clipr.max.x))
111 *d ^= (*d^srcval) & m;
112 if(e > 0){
113 x += dd;
114 d += dd;
115 e += deltay;
116 }else
117 e += deltax;
118 d += dst->width*sizeof(ulong);
119 m >>= bpp;
120 if(m == 0)
121 m = m0;
122 }
123 }
124
125 static
126 void
horliner(Memimage * dst,Point p0,Point p1,Memimage * src,Point dsrc,Rectangle clipr)127 horliner(Memimage *dst, Point p0, Point p1, Memimage *src, Point dsrc, Rectangle clipr)
128 {
129 int x, y, sx, sy, deltay, deltax, minx, maxx;
130 int bpp, m, m0;
131 uchar *d, *s;
132
133 deltax = p1.x - p0.x;
134 deltay = p1.y - p0.y;
135 sx = drawreplxy(src->r.min.x, src->r.max.x, p0.x+dsrc.x);
136 minx = lmax(p0.x, clipr.min.x);
137 maxx = lmin(p1.x, clipr.max.x-1);
138 bpp = dst->depth;
139 m0 = 0xFF^(0xFF>>bpp);
140 m = m0 >> (minx&(7/dst->depth))*bpp;
141 for(x=minx; x<=maxx; x++){
142 y = p0.y + (deltay*(x-p0.x)+deltax/2)/deltax;
143 if(clipr.min.y<=y && y<clipr.max.y){
144 d = byteaddr(dst, Pt(x, y));
145 sy = drawreplxy(src->r.min.y, src->r.max.y, y+dsrc.y);
146 s = byteaddr(src, Pt(sx, sy));
147 *d ^= (*d^*s) & m;
148 }
149 if(++sx >= src->r.max.x)
150 sx = src->r.min.x;
151 m >>= bpp;
152 if(m == 0)
153 m = m0;
154 }
155 }
156
157 static
158 void
verliner(Memimage * dst,Point p0,Point p1,Memimage * src,Point dsrc,Rectangle clipr)159 verliner(Memimage *dst, Point p0, Point p1, Memimage *src, Point dsrc, Rectangle clipr)
160 {
161 int x, y, sx, sy, deltay, deltax, miny, maxy;
162 int bpp, m, m0;
163 uchar *d, *s;
164
165 deltax = p1.x - p0.x;
166 deltay = p1.y - p0.y;
167 sy = drawreplxy(src->r.min.y, src->r.max.y, p0.y+dsrc.y);
168 miny = lmax(p0.y, clipr.min.y);
169 maxy = lmin(p1.y, clipr.max.y-1);
170 bpp = dst->depth;
171 m0 = 0xFF^(0xFF>>bpp);
172 for(y=miny; y<=maxy; y++){
173 if(deltay == 0) /* degenerate line */
174 x = p0.x;
175 else
176 x = p0.x + (deltax*(y-p0.y)+deltay/2)/deltay;
177 if(clipr.min.x<=x && x<clipr.max.x){
178 m = m0 >> (x&(7/dst->depth))*bpp;
179 d = byteaddr(dst, Pt(x, y));
180 sx = drawreplxy(src->r.min.x, src->r.max.x, x+dsrc.x);
181 s = byteaddr(src, Pt(sx, sy));
182 *d ^= (*d^*s) & m;
183 }
184 if(++sy >= src->r.max.y)
185 sy = src->r.min.y;
186 }
187 }
188
189 static
190 void
horline(Memimage * dst,Point p0,Point p1,Memimage * src,Point dsrc,Rectangle clipr)191 horline(Memimage *dst, Point p0, Point p1, Memimage *src, Point dsrc, Rectangle clipr)
192 {
193 int x, y, deltay, deltax, minx, maxx;
194 int bpp, m, m0;
195 uchar *d, *s;
196
197 deltax = p1.x - p0.x;
198 deltay = p1.y - p0.y;
199 minx = lmax(p0.x, clipr.min.x);
200 maxx = lmin(p1.x, clipr.max.x-1);
201 bpp = dst->depth;
202 m0 = 0xFF^(0xFF>>bpp);
203 m = m0 >> (minx&(7/dst->depth))*bpp;
204 for(x=minx; x<=maxx; x++){
205 y = p0.y + (deltay*(x-p0.x)+deltay/2)/deltax;
206 if(clipr.min.y<=y && y<clipr.max.y){
207 d = byteaddr(dst, Pt(x, y));
208 s = byteaddr(src, addpt(dsrc, Pt(x, y)));
209 *d ^= (*d^*s) & m;
210 }
211 m >>= bpp;
212 if(m == 0)
213 m = m0;
214 }
215 }
216
217 static
218 void
verline(Memimage * dst,Point p0,Point p1,Memimage * src,Point dsrc,Rectangle clipr)219 verline(Memimage *dst, Point p0, Point p1, Memimage *src, Point dsrc, Rectangle clipr)
220 {
221 int x, y, deltay, deltax, miny, maxy;
222 int bpp, m, m0;
223 uchar *d, *s;
224
225 deltax = p1.x - p0.x;
226 deltay = p1.y - p0.y;
227 miny = lmax(p0.y, clipr.min.y);
228 maxy = lmin(p1.y, clipr.max.y-1);
229 bpp = dst->depth;
230 m0 = 0xFF^(0xFF>>bpp);
231 for(y=miny; y<=maxy; y++){
232 if(deltay == 0) /* degenerate line */
233 x = p0.x;
234 else
235 x = p0.x + deltax*(y-p0.y)/deltay;
236 if(clipr.min.x<=x && x<clipr.max.x){
237 m = m0 >> (x&(7/dst->depth))*bpp;
238 d = byteaddr(dst, Pt(x, y));
239 s = byteaddr(src, addpt(dsrc, Pt(x, y)));
240 *d ^= (*d^*s) & m;
241 }
242 }
243 }
244 #endif /* NOTUSED */
245
246 static Memimage*
membrush(int radius)247 membrush(int radius)
248 {
249 static Memimage *brush;
250 static int brushradius;
251
252 if(brush==nil || brushradius!=radius){
253 freememimage(brush);
254 brush = allocmemimage(Rect(0, 0, 2*radius+1, 2*radius+1), memopaque->chan);
255 if(brush != nil){
256 memfillcolor(brush, DTransparent); /* zeros */
257 memellipse(brush, Pt(radius, radius), radius, radius, -1, memopaque, Pt(radius, radius), S);
258 }
259 brushradius = radius;
260 }
261 return brush;
262 }
263
264 static
265 void
discend(Point p,int radius,Memimage * dst,Memimage * src,Point dsrc,int op)266 discend(Point p, int radius, Memimage *dst, Memimage *src, Point dsrc, int op)
267 {
268 Memimage *disc;
269 Rectangle r;
270
271 disc = membrush(radius);
272 if(disc != nil){
273 r.min.x = p.x - radius;
274 r.min.y = p.y - radius;
275 r.max.x = p.x + radius+1;
276 r.max.y = p.y + radius+1;
277 memdraw(dst, r, src, addpt(r.min, dsrc), disc, Pt(0,0), op);
278 }
279 }
280
281 static
282 void
arrowend(Point tip,Point * pp,int end,int sin,int cos,int radius)283 arrowend(Point tip, Point *pp, int end, int sin, int cos, int radius)
284 {
285 int x1, x2, x3;
286
287 /* before rotation */
288 if(end == Endarrow){
289 x1 = Arrow1;
290 x2 = Arrow2;
291 x3 = Arrow3;
292 }else{
293 x1 = (end>>5) & 0x1FF; /* distance along line from end of line to tip */
294 x2 = (end>>14) & 0x1FF; /* distance along line from barb to tip */
295 x3 = (end>>23) & 0x1FF; /* distance perpendicular from edge of line to barb */
296 }
297
298 /* comments follow track of right-facing arrowhead */
299 pp->x = tip.x+((2*radius+1)*sin/2-x1*cos); /* upper side of shaft */
300 pp->y = tip.y-((2*radius+1)*cos/2+x1*sin);
301 pp++;
302 pp->x = tip.x+((2*radius+2*x3+1)*sin/2-x2*cos); /* upper barb */
303 pp->y = tip.y-((2*radius+2*x3+1)*cos/2+x2*sin);
304 pp++;
305 pp->x = tip.x;
306 pp->y = tip.y;
307 pp++;
308 pp->x = tip.x+(-(2*radius+2*x3+1)*sin/2-x2*cos); /* lower barb */
309 pp->y = tip.y-(-(2*radius+2*x3+1)*cos/2+x2*sin);
310 pp++;
311 pp->x = tip.x+(-(2*radius+1)*sin/2-x1*cos); /* lower side of shaft */
312 pp->y = tip.y+((2*radius+1)*cos/2-x1*sin);
313 }
314
315 void
_memimageline(Memimage * dst,Point p0,Point p1,int end0,int end1,int radius,Memimage * src,Point sp,Rectangle clipr,int op)316 _memimageline(Memimage *dst, Point p0, Point p1, int end0, int end1, int radius, Memimage *src, Point sp, Rectangle clipr, int op)
317 {
318 /*
319 * BUG: We should really really pick off purely horizontal and purely
320 * vertical lines and handle them separately with calls to memimagedraw
321 * on rectangles.
322 */
323
324 int hor;
325 int sin, cos, dx, dy, t;
326 Rectangle oclipr, r;
327 Point q, pts[10], *pp, d;
328
329 if(radius < 0)
330 return;
331 if(rectclip(&clipr, dst->r) == 0)
332 return;
333 if(rectclip(&clipr, dst->clipr) == 0)
334 return;
335 d = subpt(sp, p0);
336 if(rectclip(&clipr, rectsubpt(src->clipr, d)) == 0)
337 return;
338 if((src->flags&Frepl)==0 && rectclip(&clipr, rectsubpt(src->r, d))==0)
339 return;
340 /* this means that only verline() handles degenerate lines (p0==p1) */
341 hor = (abs(p1.x-p0.x) > abs(p1.y-p0.y));
342 /*
343 * Clipping is a little peculiar. We can't use Sutherland-Cohen
344 * clipping because lines are wide. But this is probably just fine:
345 * we do all math with the original p0 and p1, but clip when deciding
346 * what pixels to draw. This means the layer code can call this routine,
347 * using clipr to define the region being written, and get the same set
348 * of pixels regardless of the dicing.
349 */
350 if((hor && p0.x>p1.x) || (!hor && p0.y>p1.y)){
351 q = p0;
352 p0 = p1;
353 p1 = q;
354 t = end0;
355 end0 = end1;
356 end1 = t;
357 }
358
359 if((p0.x == p1.x || p0.y == p1.y) && (end0&0x1F) == Endsquare && (end1&0x1F) == Endsquare){
360 r.min = p0;
361 r.max = p1;
362 if(p0.x == p1.x){
363 r.min.x -= radius;
364 r.max.x += radius+1;
365 }
366 else{
367 r.min.y -= radius;
368 r.max.y += radius+1;
369 }
370 oclipr = dst->clipr;
371 sp = addpt(r.min, d);
372 dst->clipr = clipr;
373 memimagedraw(dst, r, src, sp, memopaque, sp, op);
374 dst->clipr = oclipr;
375 return;
376 }
377
378 /* Hard: */
379 /* draw thick line using polygon fill */
380 icossin2(p1.x-p0.x, p1.y-p0.y, &cos, &sin);
381 dx = (sin*(2*radius+1))/2;
382 dy = (cos*(2*radius+1))/2;
383 pp = pts;
384 oclipr = dst->clipr;
385 dst->clipr = clipr;
386 q.x = ICOSSCALE*p0.x+ICOSSCALE/2-cos/2;
387 q.y = ICOSSCALE*p0.y+ICOSSCALE/2-sin/2;
388 switch(end0 & 0x1F){
389 case Enddisc:
390 discend(p0, radius, dst, src, d, op);
391 /* fall through */
392 case Endsquare:
393 default:
394 pp->x = q.x-dx;
395 pp->y = q.y+dy;
396 pp++;
397 pp->x = q.x+dx;
398 pp->y = q.y-dy;
399 pp++;
400 break;
401 case Endarrow:
402 arrowend(q, pp, end0, -sin, -cos, radius);
403 _memfillpolysc(dst, pts, 5, ~0, src, addpt(pts[0], mulpt(d, ICOSSCALE)), 1, 10, 1, op);
404 pp[1] = pp[4];
405 pp += 2;
406 }
407 q.x = ICOSSCALE*p1.x+ICOSSCALE/2+cos/2;
408 q.y = ICOSSCALE*p1.y+ICOSSCALE/2+sin/2;
409 switch(end1 & 0x1F){
410 case Enddisc:
411 discend(p1, radius, dst, src, d, op);
412 /* fall through */
413 case Endsquare:
414 default:
415 pp->x = q.x+dx;
416 pp->y = q.y-dy;
417 pp++;
418 pp->x = q.x-dx;
419 pp->y = q.y+dy;
420 pp++;
421 break;
422 case Endarrow:
423 arrowend(q, pp, end1, sin, cos, radius);
424 _memfillpolysc(dst, pp, 5, ~0, src, addpt(pp[0], mulpt(d, ICOSSCALE)), 1, 10, 1, op);
425 pp[1] = pp[4];
426 pp += 2;
427 }
428 _memfillpolysc(dst, pts, pp-pts, ~0, src, addpt(pts[0], mulpt(d, ICOSSCALE)), 0, 10, 1, op);
429 dst->clipr = oclipr;
430 return;
431 }
432
433 void
memimageline(Memimage * dst,Point p0,Point p1,int end0,int end1,int radius,Memimage * src,Point sp,int op)434 memimageline(Memimage *dst, Point p0, Point p1, int end0, int end1, int radius, Memimage *src, Point sp, int op)
435 {
436 _memimageline(dst, p0, p1, end0, end1, radius, src, sp, dst->clipr, op);
437 }
438
439 /*
440 * Simple-minded conservative code to compute bounding box of line.
441 * Result is probably a little larger than it needs to be.
442 */
443 static
444 void
addbbox(Rectangle * r,Point p)445 addbbox(Rectangle *r, Point p)
446 {
447 if(r->min.x > p.x)
448 r->min.x = p.x;
449 if(r->min.y > p.y)
450 r->min.y = p.y;
451 if(r->max.x < p.x+1)
452 r->max.x = p.x+1;
453 if(r->max.y < p.y+1)
454 r->max.y = p.y+1;
455 }
456
457 int
memlineendsize(int end)458 memlineendsize(int end)
459 {
460 int x3;
461
462 if((end&0x3F) != Endarrow)
463 return 0;
464 if(end == Endarrow)
465 x3 = Arrow3;
466 else
467 x3 = (end>>23) & 0x1FF;
468 return x3;
469 }
470
471 Rectangle
memlinebbox(Point p0,Point p1,int end0,int end1,int radius)472 memlinebbox(Point p0, Point p1, int end0, int end1, int radius)
473 {
474 Rectangle r, r1;
475 int extra;
476
477 r.min.x = 10000000;
478 r.min.y = 10000000;
479 r.max.x = -10000000;
480 r.max.y = -10000000;
481 extra = lmax(memlineendsize(end0), memlineendsize(end1));
482 r1 = insetrect(canonrect(Rpt(p0, p1)), -(radius+extra));
483 addbbox(&r, r1.min);
484 addbbox(&r, r1.max);
485 return r;
486 }
487