1 /*
2  * hextile.c
3  *
4  * Routines to implement Hextile Encoding
5  */
6 
7 /*
8  *  OSXvnc Copyright (C) 2001 Dan McGuirk <mcguirk@incompleteness.net>.
9  *  Original Xvnc code Copyright (C) 1999 AT&T Laboratories Cambridge.
10  *  All Rights Reserved.
11  *
12  *  This is free software; you can redistribute it and/or modify
13  *  it under the terms of the GNU General Public License as published by
14  *  the Free Software Foundation; either version 2 of the License, or
15  *  (at your option) any later version.
16  *
17  *  This software is distributed in the hope that it will be useful,
18  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
19  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
20  *  GNU General Public License for more details.
21  *
22  *  You should have received a copy of the GNU General Public License
23  *  along with this software; if not, write to the Free Software
24  *  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307,
25  *  USA.
26  */
27 
28 #include <rfb/rfb.h>
29 
30 static rfbBool sendHextiles8(rfbClientPtr cl, int x, int y, int w, int h);
31 static rfbBool sendHextiles16(rfbClientPtr cl, int x, int y, int w, int h);
32 static rfbBool sendHextiles32(rfbClientPtr cl, int x, int y, int w, int h);
33 
34 
35 /*
36  * rfbSendRectEncodingHextile - send a rectangle using hextile encoding.
37  */
38 
39 rfbBool
rfbSendRectEncodingHextile(rfbClientPtr cl,int x,int y,int w,int h)40 rfbSendRectEncodingHextile(rfbClientPtr cl,
41                            int x,
42                            int y,
43                            int w,
44                            int h)
45 {
46     rfbFramebufferUpdateRectHeader rect;
47 
48     if (cl->ublen + sz_rfbFramebufferUpdateRectHeader > UPDATE_BUF_SIZE) {
49         if (!rfbSendUpdateBuf(cl))
50             return FALSE;
51     }
52 
53     rect.r.x = Swap16IfLE(x);
54     rect.r.y = Swap16IfLE(y);
55     rect.r.w = Swap16IfLE(w);
56     rect.r.h = Swap16IfLE(h);
57     rect.encoding = Swap32IfLE(rfbEncodingHextile);
58 
59     memcpy(&cl->updateBuf[cl->ublen], (char *)&rect,
60            sz_rfbFramebufferUpdateRectHeader);
61     cl->ublen += sz_rfbFramebufferUpdateRectHeader;
62 
63     rfbStatRecordEncodingSent(cl, rfbEncodingHextile,
64           sz_rfbFramebufferUpdateRectHeader,
65           sz_rfbFramebufferUpdateRectHeader + w * (cl->format.bitsPerPixel / 8) * h);
66 
67     switch (cl->format.bitsPerPixel) {
68     case 8:
69         return sendHextiles8(cl, x, y, w, h);
70     case 16:
71         return sendHextiles16(cl, x, y, w, h);
72     case 32:
73         return sendHextiles32(cl, x, y, w, h);
74     }
75 
76     rfbLog("rfbSendRectEncodingHextile: bpp %d?\n", cl->format.bitsPerPixel);
77     return FALSE;
78 }
79 
80 
81 #define PUT_PIXEL8(pix) (cl->updateBuf[cl->ublen++] = (pix))
82 
83 #define PUT_PIXEL16(pix) (cl->updateBuf[cl->ublen++] = ((char*)&(pix))[0], \
84                           cl->updateBuf[cl->ublen++] = ((char*)&(pix))[1])
85 
86 #define PUT_PIXEL32(pix) (cl->updateBuf[cl->ublen++] = ((char*)&(pix))[0], \
87                           cl->updateBuf[cl->ublen++] = ((char*)&(pix))[1], \
88                           cl->updateBuf[cl->ublen++] = ((char*)&(pix))[2], \
89                           cl->updateBuf[cl->ublen++] = ((char*)&(pix))[3])
90 
91 
92 #define DEFINE_SEND_HEXTILES(bpp)                                               \
93                                                                                 \
94                                                                                 \
95 static rfbBool subrectEncode##bpp(rfbClientPtr cli, uint##bpp##_t *data,        \
96 		int w, int h, uint##bpp##_t bg, uint##bpp##_t fg, rfbBool mono);\
97 static void testColours##bpp(uint##bpp##_t *data, int size, rfbBool *mono,      \
98                   rfbBool *solid, uint##bpp##_t *bg, uint##bpp##_t *fg);        \
99                                                                                 \
100                                                                                 \
101 /*                                                                              \
102  * rfbSendHextiles                                                              \
103  */                                                                             \
104                                                                                 \
105 static rfbBool                                                                  \
106 sendHextiles##bpp(rfbClientPtr cl, int rx, int ry, int rw, int rh) {            \
107     int x, y, w, h;                                                             \
108     int startUblen;                                                             \
109     char *fbptr;                                                                \
110     uint##bpp##_t bg = 0, fg = 0, newBg, newFg;                                 \
111     rfbBool mono, solid;                                                        \
112     rfbBool validBg = FALSE;                                                    \
113     rfbBool validFg = FALSE;                                                    \
114     uint##bpp##_t clientPixelData[16*16*(bpp/8)];                               \
115                                                                                 \
116     for (y = ry; y < ry+rh; y += 16) {                                          \
117         for (x = rx; x < rx+rw; x += 16) {                                      \
118             w = h = 16;                                                         \
119             if (rx+rw - x < 16)                                                 \
120                 w = rx+rw - x;                                                  \
121             if (ry+rh - y < 16)                                                 \
122                 h = ry+rh - y;                                                  \
123                                                                                 \
124             if ((cl->ublen + 1 + (2 + 16 * 16) * (bpp/8)) >                     \
125                 UPDATE_BUF_SIZE) {                                              \
126                 if (!rfbSendUpdateBuf(cl))                                      \
127                     return FALSE;                                               \
128             }                                                                   \
129                                                                                 \
130             fbptr = (cl->scaledScreen->frameBuffer + (cl->scaledScreen->paddedWidthInBytes * y)   \
131                      + (x * (cl->scaledScreen->bitsPerPixel / 8)));                   \
132                                                                                 \
133             (*cl->translateFn)(cl->translateLookupTable, &(cl->screen->serverFormat),      \
134                                &cl->format, fbptr, (char *)clientPixelData,     \
135                                cl->scaledScreen->paddedWidthInBytes, w, h);           \
136                                                                                 \
137             startUblen = cl->ublen;                                             \
138             cl->updateBuf[startUblen] = 0;                                      \
139             cl->ublen++;                                                        \
140             rfbStatRecordEncodingSentAdd(cl, rfbEncodingHextile, 1);            \
141                                                                                 \
142             testColours##bpp(clientPixelData, w * h,                            \
143                              &mono, &solid, &newBg, &newFg);                    \
144                                                                                 \
145             if (!validBg || (newBg != bg)) {                                    \
146                 validBg = TRUE;                                                 \
147                 bg = newBg;                                                     \
148                 cl->updateBuf[startUblen] |= rfbHextileBackgroundSpecified;     \
149                 PUT_PIXEL##bpp(bg);                                             \
150             }                                                                   \
151                                                                                 \
152             if (solid) {                                                        \
153                 continue;                                                       \
154             }                                                                   \
155                                                                                 \
156             cl->updateBuf[startUblen] |= rfbHextileAnySubrects;                 \
157                                                                                 \
158             if (mono) {                                                         \
159                 if (!validFg || (newFg != fg)) {                                \
160                     validFg = TRUE;                                             \
161                     fg = newFg;                                                 \
162                     cl->updateBuf[startUblen] |= rfbHextileForegroundSpecified; \
163                     PUT_PIXEL##bpp(fg);                                         \
164                 }                                                               \
165             } else {                                                            \
166                 validFg = FALSE;                                                \
167                 cl->updateBuf[startUblen] |= rfbHextileSubrectsColoured;        \
168             }                                                                   \
169                                                                                 \
170             if (!subrectEncode##bpp(cl, clientPixelData, w, h, bg, fg, mono)) { \
171                 /* encoding was too large, use raw */                           \
172                 validBg = FALSE;                                                \
173                 validFg = FALSE;                                                \
174                 cl->ublen = startUblen;                                         \
175                 cl->updateBuf[cl->ublen++] = rfbHextileRaw;                     \
176                 (*cl->translateFn)(cl->translateLookupTable,                    \
177                                    &(cl->screen->serverFormat), &cl->format, fbptr,        \
178                                    (char *)clientPixelData,                     \
179                                    cl->scaledScreen->paddedWidthInBytes, w, h); \
180                                                                                 \
181                 memcpy(&cl->updateBuf[cl->ublen], (char *)clientPixelData,      \
182                        w * h * (bpp/8));                                        \
183                                                                                 \
184                 cl->ublen += w * h * (bpp/8);                                   \
185                 rfbStatRecordEncodingSentAdd(cl, rfbEncodingHextile,            \
186                              w * h * (bpp/8));                                  \
187             }                                                                   \
188         }                                                                       \
189     }                                                                           \
190                                                                                 \
191     return TRUE;                                                                \
192 }                                                                               \
193                                                                                 \
194                                                                                 \
195 static rfbBool                                                                  \
196 subrectEncode##bpp(rfbClientPtr cl, uint##bpp##_t *data, int w, int h,          \
197                    uint##bpp##_t bg, uint##bpp##_t fg, rfbBool mono)            \
198 {                                                                               \
199     uint##bpp##_t cl2;                                                          \
200     int x,y;                                                                    \
201     int i,j;                                                                    \
202     int hx=0,hy,vx=0,vy;                                                        \
203     int hyflag;                                                                 \
204     uint##bpp##_t *seg;                                                         \
205     uint##bpp##_t *line;                                                        \
206     int hw,hh,vw,vh;                                                            \
207     int thex,they,thew,theh;                                                    \
208     int numsubs = 0;                                                            \
209     int newLen;                                                                 \
210     int nSubrectsUblen;                                                         \
211                                                                                 \
212     nSubrectsUblen = cl->ublen;                                                 \
213     cl->ublen++;                                                                \
214     rfbStatRecordEncodingSentAdd(cl, rfbEncodingHextile, 1);                    \
215                                                                                 \
216     for (y=0; y<h; y++) {                                                       \
217         line = data+(y*w);                                                      \
218         for (x=0; x<w; x++) {                                                   \
219             if (line[x] != bg) {                                                \
220                 cl2 = line[x];                                                  \
221                 hy = y-1;                                                       \
222                 hyflag = 1;                                                     \
223                 for (j=y; j<h; j++) {                                           \
224                     seg = data+(j*w);                                           \
225                     if (seg[x] != cl2) {break;}                                 \
226                     i = x;                                                      \
227                     while ((seg[i] == cl2) && (i < w)) i += 1;                  \
228                     i -= 1;                                                     \
229                     if (j == y) vx = hx = i;                                    \
230                     if (i < vx) vx = i;                                         \
231                     if ((hyflag > 0) && (i >= hx)) {                            \
232                         hy += 1;                                                \
233                     } else {                                                    \
234                         hyflag = 0;                                             \
235                     }                                                           \
236                 }                                                               \
237                 vy = j-1;                                                       \
238                                                                                 \
239                 /* We now have two possible subrects: (x,y,hx,hy) and           \
240                  * (x,y,vx,vy).  We'll choose the bigger of the two.            \
241                  */                                                             \
242                 hw = hx-x+1;                                                    \
243                 hh = hy-y+1;                                                    \
244                 vw = vx-x+1;                                                    \
245                 vh = vy-y+1;                                                    \
246                                                                                 \
247                 thex = x;                                                       \
248                 they = y;                                                       \
249                                                                                 \
250                 if ((hw*hh) > (vw*vh)) {                                        \
251                     thew = hw;                                                  \
252                     theh = hh;                                                  \
253                 } else {                                                        \
254                     thew = vw;                                                  \
255                     theh = vh;                                                  \
256                 }                                                               \
257                                                                                 \
258                 if (mono) {                                                     \
259                     newLen = cl->ublen - nSubrectsUblen + 2;                    \
260                 } else {                                                        \
261                     newLen = cl->ublen - nSubrectsUblen + bpp/8 + 2;            \
262                 }                                                               \
263                                                                                 \
264                 if (newLen > (w * h * (bpp/8)))                                 \
265                     return FALSE;                                               \
266                                                                                 \
267                 numsubs += 1;                                                   \
268                                                                                 \
269                 if (!mono) PUT_PIXEL##bpp(cl2);                                 \
270                                                                                 \
271                 cl->updateBuf[cl->ublen++] = rfbHextilePackXY(thex,they);       \
272                 cl->updateBuf[cl->ublen++] = rfbHextilePackWH(thew,theh);       \
273                 rfbStatRecordEncodingSentAdd(cl, rfbEncodingHextile, 1);        \
274                                                                                 \
275                 /*                                                              \
276                  * Now mark the subrect as done.                                \
277                  */                                                             \
278                 for (j=they; j < (they+theh); j++) {                            \
279                     for (i=thex; i < (thex+thew); i++) {                        \
280                         data[j*w+i] = bg;                                       \
281                     }                                                           \
282                 }                                                               \
283             }                                                                   \
284         }                                                                       \
285     }                                                                           \
286                                                                                 \
287     cl->updateBuf[nSubrectsUblen] = numsubs;                                    \
288                                                                                 \
289     return TRUE;                                                                \
290 }                                                                               \
291                                                                                 \
292                                                                                 \
293 /*                                                                              \
294  * testColours() tests if there are one (solid), two (mono) or more             \
295  * colours in a tile and gets a reasonable guess at the best background         \
296  * pixel, and the foreground pixel for mono.                                    \
297  */                                                                             \
298                                                                                 \
299 static void                                                                     \
300 testColours##bpp(uint##bpp##_t *data, int size, rfbBool *mono, rfbBool *solid,  \
301                  uint##bpp##_t *bg, uint##bpp##_t *fg) {                        \
302     uint##bpp##_t colour1 = 0, colour2 = 0;                                     \
303     int n1 = 0, n2 = 0;                                                         \
304     *mono = TRUE;                                                               \
305     *solid = TRUE;                                                              \
306                                                                                 \
307     for (; size > 0; size--, data++) {                                          \
308                                                                                 \
309         if (n1 == 0)                                                            \
310             colour1 = *data;                                                    \
311                                                                                 \
312         if (*data == colour1) {                                                 \
313             n1++;                                                               \
314             continue;                                                           \
315         }                                                                       \
316                                                                                 \
317         if (n2 == 0) {                                                          \
318             *solid = FALSE;                                                     \
319             colour2 = *data;                                                    \
320         }                                                                       \
321                                                                                 \
322         if (*data == colour2) {                                                 \
323             n2++;                                                               \
324             continue;                                                           \
325         }                                                                       \
326                                                                                 \
327         *mono = FALSE;                                                          \
328         break;                                                                  \
329     }                                                                           \
330                                                                                 \
331     if (n1 > n2) {                                                              \
332         *bg = colour1;                                                          \
333         *fg = colour2;                                                          \
334     } else {                                                                    \
335         *bg = colour2;                                                          \
336         *fg = colour1;                                                          \
337     }                                                                           \
338 }
339 
340 DEFINE_SEND_HEXTILES(8)
341 DEFINE_SEND_HEXTILES(16)
342 DEFINE_SEND_HEXTILES(32)
343