1 cfa37a7b 2004-04-10 devnull .TH DRAW 3
3 058b0118 2005-01-03 devnull Image, draw, drawop, gendraw, gendrawop, drawreplxy, drawrepl,
4 058b0118 2005-01-03 devnull replclipr, line, lineop, poly, polyop, fillpoly, fillpolyop, bezier, bezierop,
5 058b0118 2005-01-03 devnull bezspline, bezsplineop, bezsplinepts, fillbezier, fillbezierop,
6 058b0118 2005-01-03 devnull fillbezspline, fillbezsplineop, ellipse, ellipseop,
7 058b0118 2005-01-03 devnull fillellipse, fillellipseop, arc, arcop, fillarc, fillarcop,
8 058b0118 2005-01-03 devnull icossin, icossin2, border, string, stringop, stringn, stringnop,
9 058b0118 2005-01-03 devnull runestring, runestringop, runestringn, runestringnop, stringbg,
10 058b0118 2005-01-03 devnull stringbgop, stringnbg, stringnbgop, runestringbg, runestringbgop,
11 058b0118 2005-01-03 devnull runestringnbg, runestringnbgop, _string, ARROW, drawsetdebug \- graphics functions
17 cfa37a7b 2004-04-10 devnull .SH SYNOPSIS
24 cfa37a7b 2004-04-10 devnull #include <u.h>
25 cfa37a7b 2004-04-10 devnull #include <libc.h>
26 cfa37a7b 2004-04-10 devnull #include <draw.h>
29 cfa37a7b 2004-04-10 devnull struct Image
31 cfa37a7b 2004-04-10 devnull Display *display; /* display holding data */
32 cfa37a7b 2004-04-10 devnull int id; /* id of system-held Image */
33 cfa37a7b 2004-04-10 devnull Rectangle r; /* rectangle in data area, local coords */
34 cfa37a7b 2004-04-10 devnull Rectangle clipr; /* clipping region */
35 cfa37a7b 2004-04-10 devnull ulong chan; /* pixel channel format descriptor */
36 cfa37a7b 2004-04-10 devnull int depth; /* number of bits per pixel */
37 cfa37a7b 2004-04-10 devnull int repl; /* flag: data replicates to tile clipr */
38 cfa37a7b 2004-04-10 devnull Screen *screen; /* 0 if not a window */
39 cfa37a7b 2004-04-10 devnull Image *next; /* next in list of windows */
42 cfa37a7b 2004-04-10 devnull typedef enum
44 cfa37a7b 2004-04-10 devnull /* Porter-Duff compositing operators */
45 cfa37a7b 2004-04-10 devnull Clear = 0,
47 cfa37a7b 2004-04-10 devnull SinD = 8,
48 cfa37a7b 2004-04-10 devnull DinS = 4,
49 cfa37a7b 2004-04-10 devnull SoutD = 2,
50 cfa37a7b 2004-04-10 devnull DoutS = 1,
52 cfa37a7b 2004-04-10 devnull S = SinD|SoutD,
53 cfa37a7b 2004-04-10 devnull SoverD = SinD|SoutD|DoutS,
54 cfa37a7b 2004-04-10 devnull SatopD = SinD|DoutS,
55 cfa37a7b 2004-04-10 devnull SxorD = SoutD|DoutS,
57 cfa37a7b 2004-04-10 devnull D = DinS|DoutS,
58 cfa37a7b 2004-04-10 devnull DoverS = DinS|DoutS|SoutD,
59 cfa37a7b 2004-04-10 devnull DatopS = DinS|SoutD,
60 cfa37a7b 2004-04-10 devnull DxorS = DoutS|SoutD, /* == SxorD */
62 cfa37a7b 2004-04-10 devnull Ncomp = 12,
63 cfa37a7b 2004-04-10 devnull } Drawop;
66 cfa37a7b 2004-04-10 devnull .ta +\w'\fL 'u +\w'\fL 'u +6n +4n
67 cfa37a7b 2004-04-10 devnull void draw(Image *dst, Rectangle r, Image *src,
68 cfa37a7b 2004-04-10 devnull Image *mask, Point p)
70 cfa37a7b 2004-04-10 devnull void drawop(Image *dst, Rectangle r, Image *src,
71 cfa37a7b 2004-04-10 devnull Image *mask, Point p, Drawop op)
73 cfa37a7b 2004-04-10 devnull void gendraw(Image *dst, Rectangle r, Image *src, Point sp,
74 cfa37a7b 2004-04-10 devnull Image *mask, Point mp)
76 cfa37a7b 2004-04-10 devnull void gendrawop(Image *dst, Rectangle r, Image *src, Point sp,
77 cfa37a7b 2004-04-10 devnull Image *mask, Point mp, Drawop op)
79 cfa37a7b 2004-04-10 devnull int drawreplxy(int min, int max, int x)
81 cfa37a7b 2004-04-10 devnull Point drawrepl(Rectangle r, Point p)
83 cfa37a7b 2004-04-10 devnull void replclipr(Image *i, int repl, Rectangle clipr)
85 cfa37a7b 2004-04-10 devnull void line(Image *dst, Point p0, Point p1, int end0, int end1,
86 cfa37a7b 2004-04-10 devnull int radius, Image *src, Point sp)
88 cfa37a7b 2004-04-10 devnull void lineop(Image *dst, Point p0, Point p1, int end0, int end1,
89 cfa37a7b 2004-04-10 devnull int radius, Image *src, Point sp, Drawop op)
91 cfa37a7b 2004-04-10 devnull void poly(Image *dst, Point *p, int np, int end0, int end1,
92 cfa37a7b 2004-04-10 devnull int radius, Image *src, Point sp)
94 cfa37a7b 2004-04-10 devnull void polyop(Image *dst, Point *p, int np, int end0, int end1,
95 cfa37a7b 2004-04-10 devnull int radius, Image *src, Point sp, Drawop op)
97 cfa37a7b 2004-04-10 devnull void fillpoly(Image *dst, Point *p, int np, int wind,
98 cfa37a7b 2004-04-10 devnull Image *src, Point sp)
100 cfa37a7b 2004-04-10 devnull void fillpolyop(Image *dst, Point *p, int np, int wind,
101 cfa37a7b 2004-04-10 devnull Image *src, Point sp, Drawop op)
103 cfa37a7b 2004-04-10 devnull int bezier(Image *dst, Point p0, Point p1, Point p2, Point p3,
104 cfa37a7b 2004-04-10 devnull int end0, int end1, int radius, Image *src, Point sp)
106 cfa37a7b 2004-04-10 devnull int bezierop(Image *dst, Point p0, Point p1, Point p2, Point p3,
107 cfa37a7b 2004-04-10 devnull int end0, int end1, int radius, Image *src, Point sp,
108 cfa37a7b 2004-04-10 devnull Drawop op)
110 cfa37a7b 2004-04-10 devnull int bezspline(Image *dst, Point *pt, int npt, int end0, int end1,
111 cfa37a7b 2004-04-10 devnull int radius, Image *src, Point sp)
113 cfa37a7b 2004-04-10 devnull int bezsplineop(Image *dst, Point *pt, int npt, int end0, int end1,
114 cfa37a7b 2004-04-10 devnull int radius, Image *src, Point sp, Drawop op)
116 cfa37a7b 2004-04-10 devnull int bezsplinepts(Point *pt, int npt, Point **pp)
118 cfa37a7b 2004-04-10 devnull int fillbezier(Image *dst, Point p0, Point p1, Point p2, Point p3,
119 cfa37a7b 2004-04-10 devnull int w, Image *src, Point sp)
121 cfa37a7b 2004-04-10 devnull int fillbezierop(Image *dst, Point p0, Point p1, Point p2, Point p3,
122 cfa37a7b 2004-04-10 devnull int w, Image *src, Point sp, Drawop op)
124 cfa37a7b 2004-04-10 devnull int fillbezspline(Image *dst, Point *pt, int npt, int w,
125 cfa37a7b 2004-04-10 devnull Image *src, Point sp)
127 cfa37a7b 2004-04-10 devnull int fillbezsplineop(Image *dst, Point *pt, int npt, int w,
128 cfa37a7b 2004-04-10 devnull Image *src, Point sp, Drawop op)
130 cfa37a7b 2004-04-10 devnull void ellipse(Image *dst, Point c, int a, int b, int thick,
131 cfa37a7b 2004-04-10 devnull Image *src, Point sp)
133 cfa37a7b 2004-04-10 devnull void ellipseop(Image *dst, Point c, int a, int b, int thick,
134 cfa37a7b 2004-04-10 devnull Image *src, Point sp, Drawop op)
136 cfa37a7b 2004-04-10 devnull void fillellipse(Image *dst, Point c, int a, int b,
137 cfa37a7b 2004-04-10 devnull Image *src, Point sp)
139 cfa37a7b 2004-04-10 devnull void fillellipseop(Image *dst, Point c, int a, int b,
140 cfa37a7b 2004-04-10 devnull Image *src, Point sp, Drawop op)
142 cfa37a7b 2004-04-10 devnull void arc(Image *dst, Point c, int a, int b, int thick,
143 cfa37a7b 2004-04-10 devnull Image *src, Point sp, int alpha, int phi)
145 cfa37a7b 2004-04-10 devnull void arcop(Image *dst, Point c, int a, int b, int thick,
146 cfa37a7b 2004-04-10 devnull Image *src, Point sp, int alpha, int phi, Drawop op)
148 cfa37a7b 2004-04-10 devnull void fillarc(Image *dst, Point c, int a, int b, Image *src,
149 cfa37a7b 2004-04-10 devnull Point sp, int alpha, int phi)
151 cfa37a7b 2004-04-10 devnull void fillarcop(Image *dst, Point c, int a, int b, Image *src,
152 cfa37a7b 2004-04-10 devnull Point sp, int alpha, int phi, Drawop op)
154 cfa37a7b 2004-04-10 devnull int icossin(int deg, int *cosp, int *sinp)
156 cfa37a7b 2004-04-10 devnull int icossin2(int x, int y, int *cosp, int *sinp)
158 cfa37a7b 2004-04-10 devnull void border(Image *dst, Rectangle r, int i, Image *color, Point sp)
161 cfa37a7b 2004-04-10 devnull Point string(Image *dst, Point p, Image *src, Point sp,
162 cfa37a7b 2004-04-10 devnull Font *f, char *s)
164 cfa37a7b 2004-04-10 devnull Point stringop(Image *dst, Point p, Image *src, Point sp,
165 cfa37a7b 2004-04-10 devnull Font *f, char *s, Drawop op)
167 cfa37a7b 2004-04-10 devnull Point stringn(Image *dst, Point p, Image *src, Point sp,
168 cfa37a7b 2004-04-10 devnull Font *f, char *s, int len)
170 cfa37a7b 2004-04-10 devnull Point stringnop(Image *dst, Point p, Image *src, Point sp,
171 cfa37a7b 2004-04-10 devnull Font *f, char *s, int len, Drawop op)
173 cfa37a7b 2004-04-10 devnull Point runestring(Image *dst, Point p, Image *src, Point sp,
174 cfa37a7b 2004-04-10 devnull Font *f, Rune *r)
176 cfa37a7b 2004-04-10 devnull Point runestringop(Image *dst, Point p, Image *src, Point sp,
177 cfa37a7b 2004-04-10 devnull Font *f, Rune *r, Drawop op)
179 cfa37a7b 2004-04-10 devnull Point runestringn(Image *dst, Point p, Image *src, Point sp,
180 cfa37a7b 2004-04-10 devnull Font *f, Rune *r, int len)
182 cfa37a7b 2004-04-10 devnull Point runestringnop(Image *dst, Point p, Image *src, Point sp,
183 cfa37a7b 2004-04-10 devnull Font *f, Rune *r, int len, Drawop op)
185 cfa37a7b 2004-04-10 devnull Point stringbg(Image *dst, Point p, Image *src, Point sp,
186 cfa37a7b 2004-04-10 devnull Font *f, char *s, Image *bg, Point bgp)
188 cfa37a7b 2004-04-10 devnull Point stringbgop(Image *dst, Point p, Image *src, Point sp,
189 cfa37a7b 2004-04-10 devnull Font *f, char *s, Image *bg, Point bgp, Drawop op)
191 cfa37a7b 2004-04-10 devnull Point stringnbg(Image *dst, Point p, Image *src, Point sp,
192 cfa37a7b 2004-04-10 devnull Font *f, char *s, int len, Image *bg, Point bgp)
194 cfa37a7b 2004-04-10 devnull Point stringnbgop(Image *dst, Point p, Image *src, Point sp,
195 cfa37a7b 2004-04-10 devnull Font *f, char *s, int len, Image *bg, Point bgp, Drawop op)
197 cfa37a7b 2004-04-10 devnull Point runestringbg(Image *dst, Point p, Image *src, Point sp,
198 cfa37a7b 2004-04-10 devnull Font *f, Rune *r, Image *bg, Point bgp)
200 cfa37a7b 2004-04-10 devnull Point runestringbgop(Image *dst, Point p, Image *src, Point sp,
201 cfa37a7b 2004-04-10 devnull Font *f, Rune *r, Image *bg, Point bgp, Drawop op)
203 cfa37a7b 2004-04-10 devnull Point runestringnbg(Image *dst, Point p, Image *src, Point sp,
204 cfa37a7b 2004-04-10 devnull Font *f, Rune *r, int len, Image *bg, Point bgp)
206 cfa37a7b 2004-04-10 devnull Point runestringnbgop(Image *dst, Point p, Image *src, Point sp,
207 cfa37a7b 2004-04-10 devnull Font *f, Rune *r, int len, Image *bg, Point bgp, Drawop op)
209 cfa37a7b 2004-04-10 devnull Point _string(Image *dst, Point p, Image *src,
210 cfa37a7b 2004-04-10 devnull Point sp, Font *f, char *s, Rune *r, int len,
211 cfa37a7b 2004-04-10 devnull Rectangle clipr, Image *bg, Point bgp, Drawop op)
213 cfa37a7b 2004-04-10 devnull void drawsetdebug(int on)
218 cfa37a7b 2004-04-10 devnull /* line ends */
219 cfa37a7b 2004-04-10 devnull Endsquare = 0,
220 cfa37a7b 2004-04-10 devnull Enddisc = 1,
221 cfa37a7b 2004-04-10 devnull Endarrow = 2,
222 cfa37a7b 2004-04-10 devnull Endmask = 0x1F
225 cfa37a7b 2004-04-10 devnull #define ARROW(a, b, c) (Endarrow|((a)<<5)|((b)<<14)|((c)<<23))
226 cfa37a7b 2004-04-10 devnull .SH DESCRIPTION
228 cfa37a7b 2004-04-10 devnull .B Image
229 cfa37a7b 2004-04-10 devnull type defines rectangular pictures and the methods to draw upon them;
230 cfa37a7b 2004-04-10 devnull it is also the building block for higher level objects such as
231 cfa37a7b 2004-04-10 devnull windows and fonts.
232 cfa37a7b 2004-04-10 devnull In particular, a window is represented as an
233 cfa37a7b 2004-04-10 devnull .BR Image ;
234 cfa37a7b 2004-04-10 devnull no special operators are needed to draw on a window.
238 cfa37a7b 2004-04-10 devnull The coordinates of the rectangle in the plane for which the
239 cfa37a7b 2004-04-10 devnull .B Image
240 cfa37a7b 2004-04-10 devnull has defined pixel values.
241 cfa37a7b 2004-04-10 devnull It should not be modified after the image is created.
243 cfa37a7b 2004-04-10 devnull .B clipr
244 cfa37a7b 2004-04-10 devnull The clipping rectangle: operations that read or write
245 cfa37a7b 2004-04-10 devnull the image will not access pixels outside
246 cfa37a7b 2004-04-10 devnull .BR clipr .
247 cfa37a7b 2004-04-10 devnull Frequently,
248 cfa37a7b 2004-04-10 devnull .B clipr
249 cfa37a7b 2004-04-10 devnull is the same as
251 cfa37a7b 2004-04-10 devnull but it may differ; see in particular the discussion of
252 cfa37a7b 2004-04-10 devnull .BR repl .
253 cfa37a7b 2004-04-10 devnull The clipping region may be modified dynamically using
254 cfa37a7b 2004-04-10 devnull .I replclipr
255 cfa37a7b 2004-04-10 devnull .RI ( q.v. ).
258 cfa37a7b 2004-04-10 devnull The pixel channel format descriptor, as described in
259 058b0118 2005-01-03 devnull .IR image (7).
260 cfa37a7b 2004-04-10 devnull The value should not be modified after the image is created.
262 cfa37a7b 2004-04-10 devnull .B depth
264 cfa37a7b 2004-04-10 devnull number of bits per pixel in the picture;
265 cfa37a7b 2004-04-10 devnull it is identically
266 cfa37a7b 2004-04-10 devnull .B chantodepth(chan)
268 bf8a59fa 2004-04-11 devnull .IR graphics (3))
269 cfa37a7b 2004-04-10 devnull and is provided as a convenience.
270 cfa37a7b 2004-04-10 devnull The value should not be modified after the image is created.
273 cfa37a7b 2004-04-10 devnull A boolean value specifying whether the image is tiled to cover
274 cfa37a7b 2004-04-10 devnull the plane when used as a source for a drawing operation.
277 cfa37a7b 2004-04-10 devnull is zero, operations are restricted to the intersection of
280 cfa37a7b 2004-04-10 devnull .BR clipr .
285 cfa37a7b 2004-04-10 devnull defines the tile to be replicated and
286 cfa37a7b 2004-04-10 devnull .B clipr
287 cfa37a7b 2004-04-10 devnull defines the portion of the plane covered by the tiling, in other words,
289 cfa37a7b 2004-04-10 devnull is replicated to cover
290 cfa37a7b 2004-04-10 devnull .BR clipr ;
291 cfa37a7b 2004-04-10 devnull in such cases
294 cfa37a7b 2004-04-10 devnull .B clipr
295 cfa37a7b 2004-04-10 devnull are independent.
297 cfa37a7b 2004-04-10 devnull For example, a replicated image with
299 cfa37a7b 2004-04-10 devnull set to ((0,\ 0),\ (1,\ 1)) and
300 cfa37a7b 2004-04-10 devnull .B clipr
301 cfa37a7b 2004-04-10 devnull set to ((0,\ 0),\ (100,\ 100)),
302 cfa37a7b 2004-04-10 devnull with the single pixel of
304 cfa37a7b 2004-04-10 devnull set to blue,
305 cfa37a7b 2004-04-10 devnull behaves identically to an image with
308 cfa37a7b 2004-04-10 devnull .B clipr
309 cfa37a7b 2004-04-10 devnull both set to ((0,\ 0),\ (100,\ 100)) and all pixels set to blue.
310 cfa37a7b 2004-04-10 devnull However,
311 cfa37a7b 2004-04-10 devnull the first image requires far less memory.
312 cfa37a7b 2004-04-10 devnull The replication flag may be modified dynamically using
313 cfa37a7b 2004-04-10 devnull .I replclipr
314 cfa37a7b 2004-04-10 devnull .RI ( q.v. ).
316 cfa37a7b 2004-04-10 devnull Most of the drawing functions come in two forms:
317 cfa37a7b 2004-04-10 devnull a basic form, and an extended form that takes an extra
318 cfa37a7b 2004-04-10 devnull .B Drawop
319 cfa37a7b 2004-04-10 devnull to specify a Porter-Duff compositing operator to use.
320 cfa37a7b 2004-04-10 devnull The basic forms assume the operator is
321 cfa37a7b 2004-04-10 devnull .BR SoverD ,
322 cfa37a7b 2004-04-10 devnull which suffices for the vast majority of applications.
323 cfa37a7b 2004-04-10 devnull The extended forms are named by adding an
324 cfa37a7b 2004-04-10 devnull .RB - op
325 cfa37a7b 2004-04-10 devnull suffix to the basic form.
326 cfa37a7b 2004-04-10 devnull Only the basic forms are listed below.
328 cfa37a7b 2004-04-10 devnull .BI draw( dst\fP,\fP\ r\fP,\fP\ src\fP,\fP\ mask\fP,\fP\ p )
330 cfa37a7b 2004-04-10 devnull is the standard drawing function.
331 cfa37a7b 2004-04-10 devnull Only those pixels within the intersection of
332 cfa37a7b 2004-04-10 devnull .IB dst ->r
334 cfa37a7b 2004-04-10 devnull .IB dst ->clipr
335 cfa37a7b 2004-04-10 devnull will be affected;
338 cfa37a7b 2004-04-10 devnull .IB dst ->repl\fR.
339 cfa37a7b 2004-04-10 devnull The operation proceeds as follows
340 cfa37a7b 2004-04-10 devnull (this is a description of the behavior, not the implementation):
345 cfa37a7b 2004-04-10 devnull is set in
348 cfa37a7b 2004-04-10 devnull .IR mask ,
349 cfa37a7b 2004-04-10 devnull replicate their contents to fill
350 cfa37a7b 2004-04-10 devnull their clip rectangles.
352 cfa37a7b 2004-04-10 devnull Translate
358 cfa37a7b 2004-04-10 devnull is aligned with
359 cfa37a7b 2004-04-10 devnull .IB r .min\fR.
363 cfa37a7b 2004-04-10 devnull to the intersection of
366 cfa37a7b 2004-04-10 devnull .IB dst ->r\fR.
368 cfa37a7b 2004-04-10 devnull Intersect
371 cfa37a7b 2004-04-10 devnull .IB src ->clipr\fR.
373 cfa37a7b 2004-04-10 devnull .IB src ->repl
374 cfa37a7b 2004-04-10 devnull is false, also intersect
377 cfa37a7b 2004-04-10 devnull .IB src ->r\fR.
379 cfa37a7b 2004-04-10 devnull Intersect
382 cfa37a7b 2004-04-10 devnull .IB mask ->clipr\fR.
384 cfa37a7b 2004-04-10 devnull .IB mask ->repl
385 cfa37a7b 2004-04-10 devnull is false, also intersect
388 cfa37a7b 2004-04-10 devnull .IB mask ->r\fR.
390 cfa37a7b 2004-04-10 devnull For each location in
392 cfa37a7b 2004-04-10 devnull combine the
394 cfa37a7b 2004-04-10 devnull pixel with the
396 cfa37a7b 2004-04-10 devnull pixel using the alpha value
397 cfa37a7b 2004-04-10 devnull corresponding to the
402 cfa37a7b 2004-04-10 devnull has an explicit alpha channel, the alpha value
403 cfa37a7b 2004-04-10 devnull corresponding to the
405 cfa37a7b 2004-04-10 devnull pixel is simply that pixel's alpha channel.
406 cfa37a7b 2004-04-10 devnull Otherwise, the alpha value is the NTSC greyscale equivalent
407 cfa37a7b 2004-04-10 devnull of the color value, with white meaning opaque and black transparent.
408 cfa37a7b 2004-04-10 devnull In terms of the Porter-Duff compositing algebra,
410 cfa37a7b 2004-04-10 devnull replaces the
412 cfa37a7b 2004-04-10 devnull pixels with
413 cfa37a7b 2004-04-10 devnull .RI ( src
415 cfa37a7b 2004-04-10 devnull .IR mask )
417 cfa37a7b 2004-04-10 devnull .IR dst .
418 cfa37a7b 2004-04-10 devnull (In the extended form,
419 cfa37a7b 2004-04-10 devnull ``over'' is replaced by
420 cfa37a7b 2004-04-10 devnull .IR op ).
423 cfa37a7b 2004-04-10 devnull The various
424 cfa37a7b 2004-04-10 devnull pixel channel formats
425 cfa37a7b 2004-04-10 devnull involved need not be identical.
426 cfa37a7b 2004-04-10 devnull If the channels involved are smaller than 8-bits, they will
427 cfa37a7b 2004-04-10 devnull be promoted before the calculation by replicating the extant bits;
428 cfa37a7b 2004-04-10 devnull after the calculation, they will be truncated to their proper sizes.
430 cfa37a7b 2004-04-10 devnull \f5gendraw(\f2dst\fP, \f2r\fP, \f2src\fP, \f2p0\fP, \f2mask\fP, \f2p1\f5)\fP
431 cfa37a7b 2004-04-10 devnull Similar to
433 cfa37a7b 2004-04-10 devnull except that
434 cfa37a7b 2004-04-10 devnull .I gendraw
435 cfa37a7b 2004-04-10 devnull aligns the source and mask differently:
437 cfa37a7b 2004-04-10 devnull is aligned so
439 cfa37a7b 2004-04-10 devnull corresponds to
440 cfa37a7b 2004-04-10 devnull .IB r .min
443 cfa37a7b 2004-04-10 devnull is aligned so
445 cfa37a7b 2004-04-10 devnull corresponds to
446 cfa37a7b 2004-04-10 devnull .IB r .min .
447 cfa37a7b 2004-04-10 devnull For most purposes with simple masks and source images,
449 cfa37a7b 2004-04-10 devnull is sufficient, but
450 cfa37a7b 2004-04-10 devnull .B gendraw
451 cfa37a7b 2004-04-10 devnull is the general operator and the one all other drawing primitives are built upon.
453 cfa37a7b 2004-04-10 devnull .BI drawreplxy( min , max , x\f5)
456 cfa37a7b 2004-04-10 devnull to be in the half-open interval [\fImin\fP, \fImax\fP) by adding
457 cfa37a7b 2004-04-10 devnull or subtracting a multiple of \fImax-min\fP.
459 cfa37a7b 2004-04-10 devnull .BI drawrepl( r , p )
460 cfa37a7b 2004-04-10 devnull Clips the point \fIp\fP to be within the rectangle \fIr\fP
461 cfa37a7b 2004-04-10 devnull by translating the point horizontally by an integer multiple of rectangle width
462 cfa37a7b 2004-04-10 devnull and vertically by the height.
464 cfa37a7b 2004-04-10 devnull .BI replclipr( i , repl , clipr\f5)
465 cfa37a7b 2004-04-10 devnull Because the image data is stored on the server, local modifications to the
466 cfa37a7b 2004-04-10 devnull .B Image
467 cfa37a7b 2004-04-10 devnull data structure itself will have no effect.
468 cfa37a7b 2004-04-10 devnull .I Repclipr
469 cfa37a7b 2004-04-10 devnull modifies the local
470 cfa37a7b 2004-04-10 devnull .B Image
471 cfa37a7b 2004-04-10 devnull data structure's
474 cfa37a7b 2004-04-10 devnull .B clipr
475 cfa37a7b 2004-04-10 devnull fields, and notifies the server of their modification.
477 cfa37a7b 2004-04-10 devnull \f5line(\f2dst\fP, \f2p0\fP, \f2p1\fP, \f2end0\fP, \f2end1\fP, \f2thick\fP, \f2src\fP, \f2sp\fP)
479 cfa37a7b 2004-04-10 devnull draws in
481 cfa37a7b 2004-04-10 devnull a line of width
482 cfa37a7b 2004-04-10 devnull .RI 1+2* thick
483 cfa37a7b 2004-04-10 devnull pixels joining points
486 cfa37a7b 2004-04-10 devnull .IR p1 .
487 cfa37a7b 2004-04-10 devnull The line is drawn using pixels from the
489 cfa37a7b 2004-04-10 devnull image aligned so
491 cfa37a7b 2004-04-10 devnull in the source corresponds to
493 cfa37a7b 2004-04-10 devnull in the destination.
494 cfa37a7b 2004-04-10 devnull The line touches both
497 cfa37a7b 2004-04-10 devnull .IR p1 ,
502 cfa37a7b 2004-04-10 devnull specify how the ends of the line are drawn.
503 cfa37a7b 2004-04-10 devnull .B Endsquare
504 cfa37a7b 2004-04-10 devnull terminates the line perpendicularly to the direction of the line; a thick line with
505 cfa37a7b 2004-04-10 devnull .B Endsquare
506 cfa37a7b 2004-04-10 devnull on both ends will be a rectangle.
507 cfa37a7b 2004-04-10 devnull .B Enddisc
508 cfa37a7b 2004-04-10 devnull terminates the line by drawing a disc of diameter
509 cfa37a7b 2004-04-10 devnull .RI 1+2* thick
510 cfa37a7b 2004-04-10 devnull centered on the end point.
511 cfa37a7b 2004-04-10 devnull .B Endarrow
512 cfa37a7b 2004-04-10 devnull terminates the line with an arrowhead whose tip touches the endpoint.
514 cfa37a7b 2004-04-10 devnull The macro
515 cfa37a7b 2004-04-10 devnull .B ARROW
516 cfa37a7b 2004-04-10 devnull permits explicit control of the shape of the arrow.
517 cfa37a7b 2004-04-10 devnull If all three parameters are zero, it produces the default arrowhead,
518 cfa37a7b 2004-04-10 devnull otherwise,
520 cfa37a7b 2004-04-10 devnull sets the distance along line from end of the regular line to tip,
522 cfa37a7b 2004-04-10 devnull sets the distance along line from the barb to the tip,
525 cfa37a7b 2004-04-10 devnull sets the distance perpendicular to the line from edge of line to the tip of the barb,
526 cfa37a7b 2004-04-10 devnull all in pixels.
529 cfa37a7b 2004-04-10 devnull and the other geometrical operators are equivalent to calls to
530 cfa37a7b 2004-04-10 devnull .I gendraw
531 cfa37a7b 2004-04-10 devnull using a mask produced by the geometric procedure.
533 cfa37a7b 2004-04-10 devnull \f5poly(\f2dst\fP, \f2p\fP, \f2np\fP, \f2end0\fP, \f2end1\fP, \f2thick\fP, \f2src\fP, \f2sp\fP)
535 cfa37a7b 2004-04-10 devnull draws a general polygon; it
536 cfa37a7b 2004-04-10 devnull is conceptually equivalent to a series of calls to
538 cfa37a7b 2004-04-10 devnull joining adjacent points in the
539 cfa37a7b 2004-04-10 devnull array of
540 cfa37a7b 2004-04-10 devnull .B Points
542 cfa37a7b 2004-04-10 devnull which has
544 cfa37a7b 2004-04-10 devnull elements.
545 cfa37a7b 2004-04-10 devnull The ends of the polygon are specified as in
546 cfa37a7b 2004-04-10 devnull .IR line ;
547 cfa37a7b 2004-04-10 devnull interior lines are terminated with
548 cfa37a7b 2004-04-10 devnull .B Enddisc
549 cfa37a7b 2004-04-10 devnull to make smooth joins.
550 cfa37a7b 2004-04-10 devnull The source is aligned so
552 cfa37a7b 2004-04-10 devnull corresponds to
553 cfa37a7b 2004-04-10 devnull .IB p [0]\f1.
555 cfa37a7b 2004-04-10 devnull \f5fillpoly(\f2dst\fP, \f2p\fP, \f2np\fP, \f2wind\fP, \f2src\fP, \f2sp\fP)
556 cfa37a7b 2004-04-10 devnull .I Fillpoly
559 cfa37a7b 2004-04-10 devnull but fills in the resulting polygon rather than outlining it.
560 cfa37a7b 2004-04-10 devnull The source is aligned so
562 cfa37a7b 2004-04-10 devnull corresponds to
563 cfa37a7b 2004-04-10 devnull .IB p [0]\f1.
564 cfa37a7b 2004-04-10 devnull The winding rule parameter
566 cfa37a7b 2004-04-10 devnull resolves ambiguities about what to fill if the polygon is self-intersecting.
570 cfa37a7b 2004-04-10 devnull .BR ~0 ,
571 cfa37a7b 2004-04-10 devnull a pixel is inside the polygon if the polygon's winding number about the point
572 cfa37a7b 2004-04-10 devnull is non-zero.
577 cfa37a7b 2004-04-10 devnull a pixel is inside if the winding number is odd.
578 cfa37a7b 2004-04-10 devnull Complementary values (0 or ~1) cause outside pixels to be filled.
579 cfa37a7b 2004-04-10 devnull The meaning of other values is undefined.
580 cfa37a7b 2004-04-10 devnull The polygon is closed with a line if necessary.
582 cfa37a7b 2004-04-10 devnull \f5bezier(\f2dst\fP, \f2a\fP, \f2b\fP, \f2c\fP, \f2d\fP, \f2end0\fP, \f2end1\fP, \f2thick\fP, \f2src\fP, \f2sp\fP)
583 cfa37a7b 2004-04-10 devnull .I Bezier
584 cfa37a7b 2004-04-10 devnull draws the
585 cfa37a7b 2004-04-10 devnull cubic Bezier curve defined by
586 cfa37a7b 2004-04-10 devnull .B Points
592 cfa37a7b 2004-04-10 devnull The end styles are determined by
595 cfa37a7b 2004-04-10 devnull .IR end1 ;
596 cfa37a7b 2004-04-10 devnull the thickness of the curve is
597 cfa37a7b 2004-04-10 devnull .RI 1+2* thick .
598 cfa37a7b 2004-04-10 devnull The source is aligned so
602 cfa37a7b 2004-04-10 devnull corresponds to
605 cfa37a7b 2004-04-10 devnull .IR dst .
607 cfa37a7b 2004-04-10 devnull \f5bezspline(\f2dst\fP, \f2p\fP, \f2end0\fP, \f2end1\fP, \f2thick\fP, \f2src\fP, \f2sp\fP)
608 cfa37a7b 2004-04-10 devnull .I Bezspline
609 cfa37a7b 2004-04-10 devnull takes the same arguments as
611 cfa37a7b 2004-04-10 devnull but draws a quadratic B-spline (despite its name) rather than a polygon.
612 cfa37a7b 2004-04-10 devnull If the first and last points in
614 cfa37a7b 2004-04-10 devnull are equal, the spline has periodic end conditions.
616 cfa37a7b 2004-04-10 devnull \f5bezsplinepts(\f2pt\fP, \f2npt\fP, \f2pp\fP)
617 cfa37a7b 2004-04-10 devnull .I Bezsplinepts
618 cfa37a7b 2004-04-10 devnull returns in
620 cfa37a7b 2004-04-10 devnull a list of points making up the open polygon that
621 cfa37a7b 2004-04-10 devnull .I bezspline
622 cfa37a7b 2004-04-10 devnull would draw.
623 cfa37a7b 2004-04-10 devnull The caller is responsible for freeing
624 cfa37a7b 2004-04-10 devnull .IR *pp .
626 cfa37a7b 2004-04-10 devnull \f5fillbezier(\f2dst\fP, \f2a\fP, \f2b\fP, \f2c\fP, \f2d\fP, \f2wind\fP, \f2src\fP, \f2sp\fP)
627 cfa37a7b 2004-04-10 devnull .I Fillbezier
629 cfa37a7b 2004-04-10 devnull .I bezier
631 cfa37a7b 2004-04-10 devnull .I fillpoly
633 cfa37a7b 2004-04-10 devnull .IR poly .
635 cfa37a7b 2004-04-10 devnull \f5fillbezspline(\f2dst\fP, \f2p\fP, \f2wind\fP, \f2src\fP, \f2sp\fP)
636 cfa37a7b 2004-04-10 devnull .I Fillbezspline
638 cfa37a7b 2004-04-10 devnull .I fillpoly
639 cfa37a7b 2004-04-10 devnull but fills the quadratic B-spline rather than the polygon outlined by
641 cfa37a7b 2004-04-10 devnull The spline is closed with a line if necessary.
643 cfa37a7b 2004-04-10 devnull \f5ellipse(\f2dst\fP, \f2c\fP, \f2a\fP, \f2b\fP, \f2thick\fP, \f2src\fP, \f2sp\fP)
644 cfa37a7b 2004-04-10 devnull .I Ellipse
645 cfa37a7b 2004-04-10 devnull draws in
647 cfa37a7b 2004-04-10 devnull an ellipse centered on
649 cfa37a7b 2004-04-10 devnull with horizontal and vertical semiaxes
653 cfa37a7b 2004-04-10 devnull The source is aligned so
657 cfa37a7b 2004-04-10 devnull corresponds to
660 cfa37a7b 2004-04-10 devnull .IR dst .
661 cfa37a7b 2004-04-10 devnull The ellipse is drawn with thickness
662 cfa37a7b 2004-04-10 devnull .RI 1+2* thick .
664 cfa37a7b 2004-04-10 devnull \f5fillellipse(\f2dst\fP, \f2c\fP, \f2a\fP, \f2b\fP, \f2src\fP, \f2sp\fP)
665 cfa37a7b 2004-04-10 devnull .I Fillellipse
667 cfa37a7b 2004-04-10 devnull .I ellipse
668 cfa37a7b 2004-04-10 devnull but fills the ellipse rather than outlining it.
670 cfa37a7b 2004-04-10 devnull \f5arc(\f2dst\fP, \f2c\fP, \f2a\fP, \f2b\fP, \f2thick\fP, \f2src\fP, \f2sp\fP, \f2alpha\fP, \f2phi\fP)
673 cfa37a7b 2004-04-10 devnull .IR ellipse ,
674 cfa37a7b 2004-04-10 devnull but draws only that portion of the ellipse starting at angle
675 cfa37a7b 2004-04-10 devnull .I alpha
676 cfa37a7b 2004-04-10 devnull and extending through an angle of
677 cfa37a7b 2004-04-10 devnull .IR phi .
678 cfa37a7b 2004-04-10 devnull The angles are measured in degrees counterclockwise from the positive
682 cfa37a7b 2004-04-10 devnull \f5fillarc(\f2dst\fP, \f2c\fP, \f2a\fP, \f2b\fP, \f2src\fP, \f2sp\fP, \f2alpha\fP, \f2phi\fP)
683 cfa37a7b 2004-04-10 devnull .I Fillarc
685 cfa37a7b 2004-04-10 devnull .IR arc ,
686 cfa37a7b 2004-04-10 devnull but fills the sector with the source color.
688 cfa37a7b 2004-04-10 devnull \f5icossin(\f2deg\fP, \f2cosp\fP, \f2sinp\fP)
689 cfa37a7b 2004-04-10 devnull .I Icossin
690 cfa37a7b 2004-04-10 devnull stores in
691 cfa37a7b 2004-04-10 devnull .BI * cosp
693 cfa37a7b 2004-04-10 devnull .BI * sinp
694 cfa37a7b 2004-04-10 devnull scaled integers representing the cosine and sine of the angle
695 cfa37a7b 2004-04-10 devnull .IR deg ,
696 cfa37a7b 2004-04-10 devnull measured in integer degrees.
697 cfa37a7b 2004-04-10 devnull The values are scaled so cos(0) is 1024.
699 cfa37a7b 2004-04-10 devnull \f5icossin2(\f2x\fP, \f2y\fP, \f2cosp\fP, \f2sinp\fP)
700 cfa37a7b 2004-04-10 devnull .I Icossin2
701 cfa37a7b 2004-04-10 devnull is analogous to
702 cfa37a7b 2004-04-10 devnull .IR icossin,
703 cfa37a7b 2004-04-10 devnull with the angle represented not in degrees but implicitly by the point
704 cfa37a7b 2004-04-10 devnull .RI ( x , y ).
705 cfa37a7b 2004-04-10 devnull It is to
706 cfa37a7b 2004-04-10 devnull .I icossin
708 cfa37a7b 2004-04-10 devnull .B atan2
712 bf8a59fa 2004-04-11 devnull .IR sin (3)).
714 cfa37a7b 2004-04-10 devnull .BI border( dst\fP,\fP\ r\fP,\fP\ i\fP,\fP\ color\fP,\fP\ sp\fP)
715 cfa37a7b 2004-04-10 devnull .I Border
716 cfa37a7b 2004-04-10 devnull draws an outline of rectangle
718 cfa37a7b 2004-04-10 devnull in the specified
719 cfa37a7b 2004-04-10 devnull .IR color .
720 cfa37a7b 2004-04-10 devnull The outline has width
722 cfa37a7b 2004-04-10 devnull if positive, the border goes inside the rectangle; negative, outside.
723 cfa37a7b 2004-04-10 devnull The source is aligned so
725 cfa37a7b 2004-04-10 devnull corresponds to
726 cfa37a7b 2004-04-10 devnull .IB r .min .
728 cfa37a7b 2004-04-10 devnull .BI string( dst\fP,\fP\ p\fP,\fP\ src\fP,\fP\ sp\fP,\fP\ font\fP,\fP\ s )
729 cfa37a7b 2004-04-10 devnull .I String
730 cfa37a7b 2004-04-10 devnull draws in
732 cfa37a7b 2004-04-10 devnull characters specified by the string
735 cfa37a7b 2004-04-10 devnull .IR font ;
736 cfa37a7b 2004-04-10 devnull it is equivalent to a series of calls to
737 cfa37a7b 2004-04-10 devnull .I gendraw
738 cfa37a7b 2004-04-10 devnull using source
740 cfa37a7b 2004-04-10 devnull and masks determined by the character shapes.
741 cfa37a7b 2004-04-10 devnull The text is positioned with the left of the first character at
742 cfa37a7b 2004-04-10 devnull .IB p .x
743 cfa37a7b 2004-04-10 devnull and the top of the line of text at
744 cfa37a7b 2004-04-10 devnull .IB p .y\f1.
745 cfa37a7b 2004-04-10 devnull The source is positioned so
749 cfa37a7b 2004-04-10 devnull corresponds to
752 cfa37a7b 2004-04-10 devnull .IR dst .
753 cfa37a7b 2004-04-10 devnull .I String
754 cfa37a7b 2004-04-10 devnull returns a
755 cfa37a7b 2004-04-10 devnull .B Point
756 cfa37a7b 2004-04-10 devnull that is the position of the next character that would be drawn if the string were longer.
758 cfa37a7b 2004-04-10 devnull For characters with undefined
759 cfa37a7b 2004-04-10 devnull or zero-width images in the font, the character at font position 0 (NUL) is drawn.
761 cfa37a7b 2004-04-10 devnull The other string routines are variants of this basic form, and
762 cfa37a7b 2004-04-10 devnull have names that encode their variant behavior.
763 cfa37a7b 2004-04-10 devnull Routines whose names contain
765 cfa37a7b 2004-04-10 devnull accept a string of Runes rather than
766 cfa37a7b 2004-04-10 devnull .SM UTF\c
767 cfa37a7b 2004-04-10 devnull -encoded bytes.
768 cfa37a7b 2004-04-10 devnull Routines ending in
770 cfa37a7b 2004-04-10 devnull accept an argument,
772 cfa37a7b 2004-04-10 devnull that defines the number of characters to draw rather than accepting a NUL-terminated
774 cfa37a7b 2004-04-10 devnull Routines containing
776 cfa37a7b 2004-04-10 devnull draw the background behind the characters in the specified color
777 cfa37a7b 2004-04-10 devnull .RI ( bg )
779 cfa37a7b 2004-04-10 devnull alignment
780 cfa37a7b 2004-04-10 devnull .RI ( bgp );
781 cfa37a7b 2004-04-10 devnull normally the text is drawn leaving the background intact.
783 cfa37a7b 2004-04-10 devnull The routine
784 cfa37a7b 2004-04-10 devnull .I _string
785 cfa37a7b 2004-04-10 devnull captures all this behavior into a single operator. Whether it draws a
788 cfa37a7b 2004-04-10 devnull or Rune string depends on whether
792 cfa37a7b 2004-04-10 devnull is null (the string length is always determined by
793 cfa37a7b 2004-04-10 devnull .IR len ).
796 cfa37a7b 2004-04-10 devnull is non-null, it is used as a background color.
798 cfa37a7b 2004-04-10 devnull .I clipr
799 cfa37a7b 2004-04-10 devnull argument allows further management of clipping when drawing the string;
800 cfa37a7b 2004-04-10 devnull it is intersected with the usual clipping rectangles to further limit the extent of the text.
802 cfa37a7b 2004-04-10 devnull .BI drawsetdebug( on )
803 cfa37a7b 2004-04-10 devnull Turns on or off debugging output (usually
804 cfa37a7b 2004-04-10 devnull to a serial line) according to whether
806 cfa37a7b 2004-04-10 devnull is non-zero.
807 cfa37a7b 2004-04-10 devnull .SH SOURCE
808 c3674de4 2005-01-11 devnull .B \*9/src/libdraw
809 cfa37a7b 2004-04-10 devnull .SH SEE ALSO
810 bf8a59fa 2004-04-11 devnull .IR graphics (3),
811 bf8a59fa 2004-04-11 devnull .IR stringsize (3),
812 058b0118 2005-01-03 devnull .IR color (7),
813 058b0118 2005-01-03 devnull .IR utf (7),
814 bf8a59fa 2004-04-11 devnull .IR addpt (3)
816 cfa37a7b 2004-04-10 devnull T. Porter, T. Duff.
817 cfa37a7b 2004-04-10 devnull ``Compositing Digital Images'',
818 cfa37a7b 2004-04-10 devnull .I "Computer Graphics
819 cfa37a7b 2004-04-10 devnull (Proc. SIGGRAPH), 18:3, pp. 253-259, 1984.
820 cfa37a7b 2004-04-10 devnull .SH DIAGNOSTICS
821 cfa37a7b 2004-04-10 devnull These routines call the graphics error function on fatal errors.
822 cfa37a7b 2004-04-10 devnull .SH BUGS
823 cfa37a7b 2004-04-10 devnull Anti-aliased characters can be drawn by defining a font
824 cfa37a7b 2004-04-10 devnull with multiple bits per pixel, but there are
825 cfa37a7b 2004-04-10 devnull no anti-aliasing geometric primitives.
