xref: /freebsd/lib/libvgl/simple.c (revision c7432537b1a67e964ed1d7b35977049301dc9189) 
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1991-1997 Søren Schmidt
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer
12  *    in this position and unchanged.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. The name of the author may not be used to endorse or promote products
17  *    derived from this software without specific prior written permission
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
20  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
21  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
22  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
23  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
24  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
28  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29  */
30 
31 #include <sys/cdefs.h>
32 __FBSDID("$FreeBSD$");
33 
34 #include <signal.h>
35 #include <sys/fbio.h>
36 #include <sys/kbio.h>
37 #include <sys/endian.h>
38 #include "vgl.h"
39 
40 static int VGLBlank;
41 static byte VGLBorderColor;
42 static byte VGLSavePaletteRed[256];
43 static byte VGLSavePaletteGreen[256];
44 static byte VGLSavePaletteBlue[256];
45 
46 #define ABS(a)		(((a)<0) ? -(a) : (a))
47 #define SGN(a)		(((a)<0) ? -1 : 1)
48 #define min(x, y)	(((x) < (y)) ? (x) : (y))
49 #define max(x, y)	(((x) > (y)) ? (x) : (y))
50 
51 void
52 VGLSetXY(VGLBitmap *object, int x, int y, u_long color)
53 {
54   int offset, undermouse;
55 
56   VGLCheckSwitch();
57   if (x>=0 && x<object->VXsize && y>=0 && y<object->VYsize) {
58     if (object == VGLDisplay) {
59       undermouse = VGLMouseFreezeXY(x, y);
60       VGLSetXY(&VGLVDisplay, x, y, color);
61     } else if (object->Type != MEMBUF)
62       return;		/* invalid */
63     else
64       undermouse = 0;
65     if (!undermouse) {
66       offset = (y * object->VXsize + x) * object->PixelBytes;
67       switch (object->Type) {
68       case VIDBUF8S:
69       case VIDBUF16S:
70       case VIDBUF24S:
71       case VIDBUF32S:
72         offset = VGLSetSegment(offset);
73         /* FALLTHROUGH */
74       case MEMBUF:
75       case VIDBUF8:
76       case VIDBUF16:
77       case VIDBUF24:
78       case VIDBUF32:
79         color = htole32(color);
80         switch (object->PixelBytes) {
81         case 1:
82           memcpy(&object->Bitmap[offset], &color, 1);
83           break;
84         case 2:
85           memcpy(&object->Bitmap[offset], &color, 2);
86           break;
87         case 3:
88           memcpy(&object->Bitmap[offset], &color, 3);
89           break;
90         case 4:
91           memcpy(&object->Bitmap[offset], &color, 4);
92           break;
93         }
94         break;
95       case VIDBUF8X:
96         outb(0x3c4, 0x02);
97         outb(0x3c5, 0x01 << (x&0x3));
98 	object->Bitmap[(unsigned)(VGLAdpInfo.va_line_width*y)+(x/4)] = ((byte)color);
99 	break;
100       case VIDBUF4S:
101 	offset = VGLSetSegment(y*VGLAdpInfo.va_line_width + x/8);
102 	goto set_planar;
103       case VIDBUF4:
104 	offset = y*VGLAdpInfo.va_line_width + x/8;
105 set_planar:
106         outb(0x3c4, 0x02); outb(0x3c5, 0x0f);
107         outb(0x3ce, 0x00); outb(0x3cf, (byte)color & 0x0f);	/* set/reset */
108         outb(0x3ce, 0x01); outb(0x3cf, 0x0f);		/* set/reset enable */
109         outb(0x3ce, 0x08); outb(0x3cf, 0x80 >> (x%8));	/* bit mask */
110 	object->Bitmap[offset] |= (byte)color;
111       }
112     }
113     if (object == VGLDisplay)
114       VGLMouseUnFreeze();
115   }
116 }
117 
118 static u_long
119 __VGLGetXY(VGLBitmap *object, int x, int y)
120 {
121   int offset;
122   u_long color;
123 
124   offset = (y * object->VXsize + x) * object->PixelBytes;
125   switch (object->PixelBytes) {
126   case 1:
127     memcpy(&color, &object->Bitmap[offset], 1);
128     return le32toh(color) & 0xff;
129   case 2:
130     memcpy(&color, &object->Bitmap[offset], 2);
131     return le32toh(color) & 0xffff;
132   case 3:
133     memcpy(&color, &object->Bitmap[offset], 3);
134     return le32toh(color) & 0xffffff;
135   case 4:
136     memcpy(&color, &object->Bitmap[offset], 4);
137     return le32toh(color);
138   }
139   return 0;		/* invalid */
140 }
141 
142 u_long
143 VGLGetXY(VGLBitmap *object, int x, int y)
144 {
145   VGLCheckSwitch();
146   if (x<0 || x>=object->VXsize || y<0 || y>=object->VYsize)
147     return 0;
148   if (object == VGLDisplay)
149     object = &VGLVDisplay;
150   else if (object->Type != MEMBUF)
151     return 0;		/* invalid */
152   return __VGLGetXY(object, x, y);
153 }
154 
155  /*
156   * Symmetric Double Step Line Algorithm by Brian Wyvill from
157   * "Graphics Gems", Academic Press, 1990.
158   */
159 
160 #define SL_SWAP(a,b)           {a^=b; b^=a; a^=b;}
161 #define SL_ABSOLUTE(i,j,k)     ( (i-j)*(k = ( (i-j)<0 ? -1 : 1)))
162 
163 void
164 plot(VGLBitmap * object, int x, int y, int flag, u_long color)
165 {
166   /* non-zero flag indicates the pixels need swapping back. */
167   if (flag)
168     VGLSetXY(object, y, x, color);
169   else
170     VGLSetXY(object, x, y, color);
171 }
172 
173 
174 void
175 VGLLine(VGLBitmap *object, int x1, int y1, int x2, int y2, u_long color)
176 {
177   int dx, dy, incr1, incr2, D, x, y, xend, c, pixels_left;
178   int sign_x, sign_y, step, reverse, i;
179 
180   dx = SL_ABSOLUTE(x2, x1, sign_x);
181   dy = SL_ABSOLUTE(y2, y1, sign_y);
182   /* decide increment sign by the slope sign */
183   if (sign_x == sign_y)
184     step = 1;
185   else
186     step = -1;
187 
188   if (dy > dx) {	/* chooses axis of greatest movement (make dx) */
189     SL_SWAP(x1, y1);
190     SL_SWAP(x2, y2);
191     SL_SWAP(dx, dy);
192     reverse = 1;
193   } else
194     reverse = 0;
195   /* note error check for dx==0 should be included here */
196   if (x1 > x2) {      /* start from the smaller coordinate */
197     x = x2;
198     y = y2;
199 /*  x1 = x1;
200     y1 = y1; */
201   } else {
202     x = x1;
203     y = y1;
204     x1 = x2;
205     y1 = y2;
206   }
207 
208 
209   /* Note dx=n implies 0 - n or (dx+1) pixels to be set */
210   /* Go round loop dx/4 times then plot last 0,1,2 or 3 pixels */
211   /* In fact (dx-1)/4 as 2 pixels are already plotted */
212   xend = (dx - 1) / 4;
213   pixels_left = (dx - 1) % 4;  /* number of pixels left over at the
214            * end */
215   plot(object, x, y, reverse, color);
216   if (pixels_left < 0)
217     return;      /* plot only one pixel for zero length
218            * vectors */
219   plot(object, x1, y1, reverse, color);  /* plot first two points */
220   incr2 = 4 * dy - 2 * dx;
221   if (incr2 < 0) {    /* slope less than 1/2 */
222     c = 2 * dy;
223     incr1 = 2 * c;
224     D = incr1 - dx;
225 
226     for (i = 0; i < xend; i++) {  /* plotting loop */
227       ++x;
228       --x1;
229       if (D < 0) {
230         /* pattern 1 forwards */
231         plot(object, x, y, reverse, color);
232         plot(object, ++x, y, reverse, color);
233         /* pattern 1 backwards */
234         plot(object, x1, y1, reverse, color);
235         plot(object, --x1, y1, reverse, color);
236         D += incr1;
237       } else {
238         if (D < c) {
239           /* pattern 2 forwards */
240           plot(object, x, y, reverse, color);
241           plot(object, ++x, y += step, reverse,
242               color);
243           /* pattern 2 backwards */
244           plot(object, x1, y1, reverse, color);
245           plot(object, --x1, y1 -= step, reverse,
246               color);
247         } else {
248           /* pattern 3 forwards */
249           plot(object, x, y += step, reverse, color);
250           plot(object, ++x, y, reverse, color);
251           /* pattern 3 backwards */
252           plot(object, x1, y1 -= step, reverse,
253               color);
254           plot(object, --x1, y1, reverse, color);
255         }
256         D += incr2;
257       }
258     }      /* end for */
259 
260     /* plot last pattern */
261     if (pixels_left) {
262       if (D < 0) {
263         plot(object, ++x, y, reverse, color);  /* pattern 1 */
264         if (pixels_left > 1)
265           plot(object, ++x, y, reverse, color);
266         if (pixels_left > 2)
267           plot(object, --x1, y1, reverse, color);
268       } else {
269         if (D < c) {
270           plot(object, ++x, y, reverse, color);  /* pattern 2  */
271           if (pixels_left > 1)
272             plot(object, ++x, y += step, reverse, color);
273           if (pixels_left > 2)
274             plot(object, --x1, y1, reverse, color);
275         } else {
276           /* pattern 3 */
277           plot(object, ++x, y += step, reverse, color);
278           if (pixels_left > 1)
279             plot(object, ++x, y, reverse, color);
280           if (pixels_left > 2)
281             plot(object, --x1, y1 -= step, reverse, color);
282         }
283       }
284     }      /* end if pixels_left */
285   }
286   /* end slope < 1/2 */
287   else {        /* slope greater than 1/2 */
288     c = 2 * (dy - dx);
289     incr1 = 2 * c;
290     D = incr1 + dx;
291     for (i = 0; i < xend; i++) {
292       ++x;
293       --x1;
294       if (D > 0) {
295         /* pattern 4 forwards */
296         plot(object, x, y += step, reverse, color);
297         plot(object, ++x, y += step, reverse, color);
298         /* pattern 4 backwards */
299         plot(object, x1, y1 -= step, reverse, color);
300         plot(object, --x1, y1 -= step, reverse, color);
301         D += incr1;
302       } else {
303         if (D < c) {
304           /* pattern 2 forwards */
305           plot(object, x, y, reverse, color);
306           plot(object, ++x, y += step, reverse,
307               color);
308 
309           /* pattern 2 backwards */
310           plot(object, x1, y1, reverse, color);
311           plot(object, --x1, y1 -= step, reverse,
312               color);
313         } else {
314           /* pattern 3 forwards */
315           plot(object, x, y += step, reverse, color);
316           plot(object, ++x, y, reverse, color);
317           /* pattern 3 backwards */
318           plot(object, x1, y1 -= step, reverse, color);
319           plot(object, --x1, y1, reverse, color);
320         }
321         D += incr2;
322       }
323     }      /* end for */
324     /* plot last pattern */
325     if (pixels_left) {
326       if (D > 0) {
327         plot(object, ++x, y += step, reverse, color);  /* pattern 4 */
328         if (pixels_left > 1)
329           plot(object, ++x, y += step, reverse,
330               color);
331         if (pixels_left > 2)
332           plot(object, --x1, y1 -= step, reverse,
333               color);
334       } else {
335         if (D < c) {
336           plot(object, ++x, y, reverse, color);  /* pattern 2  */
337           if (pixels_left > 1)
338             plot(object, ++x, y += step, reverse, color);
339           if (pixels_left > 2)
340             plot(object, --x1, y1, reverse, color);
341         } else {
342           /* pattern 3 */
343           plot(object, ++x, y += step, reverse, color);
344           if (pixels_left > 1)
345             plot(object, ++x, y, reverse, color);
346           if (pixels_left > 2) {
347             if (D > c)  /* step 3 */
348               plot(object, --x1, y1 -= step, reverse, color);
349             else  /* step 2 */
350               plot(object, --x1, y1, reverse, color);
351           }
352         }
353       }
354     }
355   }
356 }
357 
358 void
359 VGLBox(VGLBitmap *object, int x1, int y1, int x2, int y2, u_long color)
360 {
361   VGLLine(object, x1, y1, x2, y1, color);
362   VGLLine(object, x2, y1, x2, y2, color);
363   VGLLine(object, x2, y2, x1, y2, color);
364   VGLLine(object, x1, y2, x1, y1, color);
365 }
366 
367 void
368 VGLFilledBox(VGLBitmap *object, int x1, int y1, int x2, int y2, u_long color)
369 {
370   int y;
371 
372   for (y=y1; y<=y2; y++) VGLLine(object, x1, y, x2, y, color);
373 }
374 
375 static inline void
376 set4pixels(VGLBitmap *object, int x, int y, int xc, int yc, u_long color)
377 {
378   if (x!=0) {
379     VGLSetXY(object, xc+x, yc+y, color);
380     VGLSetXY(object, xc-x, yc+y, color);
381     if (y!=0) {
382       VGLSetXY(object, xc+x, yc-y, color);
383       VGLSetXY(object, xc-x, yc-y, color);
384     }
385   }
386   else {
387     VGLSetXY(object, xc, yc+y, color);
388     if (y!=0)
389       VGLSetXY(object, xc, yc-y, color);
390   }
391 }
392 
393 void
394 VGLEllipse(VGLBitmap *object, int xc, int yc, int a, int b, u_long color)
395 {
396   int x = 0, y = b, asq = a*a, asq2 = a*a*2, bsq = b*b;
397   int bsq2 = b*b*2, d = bsq-asq*b+asq/4, dx = 0, dy = asq2*b;
398 
399   while (dx<dy) {
400     set4pixels(object, x, y, xc, yc, color);
401     if (d>0) {
402       y--; dy-=asq2; d-=dy;
403     }
404     x++; dx+=bsq2; d+=bsq+dx;
405   }
406   d+=(3*(asq-bsq)/2-(dx+dy))/2;
407   while (y>=0) {
408     set4pixels(object, x, y, xc, yc, color);
409     if (d<0) {
410       x++; dx+=bsq2; d+=dx;
411     }
412     y--; dy-=asq2; d+=asq-dy;
413   }
414 }
415 
416 static inline void
417 set2lines(VGLBitmap *object, int x, int y, int xc, int yc, u_long color)
418 {
419   if (x!=0) {
420     VGLLine(object, xc+x, yc+y, xc-x, yc+y, color);
421     if (y!=0)
422       VGLLine(object, xc+x, yc-y, xc-x, yc-y, color);
423   }
424   else {
425     VGLLine(object, xc, yc+y, xc, yc-y, color);
426   }
427 }
428 
429 void
430 VGLFilledEllipse(VGLBitmap *object, int xc, int yc, int a, int b, u_long color)
431 {
432   int x = 0, y = b, asq = a*a, asq2 = a*a*2, bsq = b*b;
433   int bsq2 = b*b*2, d = bsq-asq*b+asq/4, dx = 0, dy = asq2*b;
434 
435   while (dx<dy) {
436     set2lines(object, x, y, xc, yc, color);
437     if (d>0) {
438       y--; dy-=asq2; d-=dy;
439     }
440     x++; dx+=bsq2; d+=bsq+dx;
441   }
442   d+=(3*(asq-bsq)/2-(dx+dy))/2;
443   while (y>=0) {
444     set2lines(object, x, y, xc, yc, color);
445     if (d<0) {
446       x++; dx+=bsq2; d+=dx;
447     }
448     y--; dy-=asq2; d+=asq-dy;
449   }
450 }
451 
452 void
453 VGLClear(VGLBitmap *object, u_long color)
454 {
455   VGLBitmap src;
456   int i, len, mouseoverlap, offset;
457 
458   VGLCheckSwitch();
459   if (object == VGLDisplay) {
460     VGLMouseFreeze();
461     mouseoverlap = VGLMouseOverlap(0, 0, object->Xsize, object->Ysize);
462     if (mouseoverlap)
463       VGLMousePointerHide();
464     VGLClear(&VGLVDisplay, color);
465   } else if (object->Type != MEMBUF)
466     return;		/* invalid */
467   switch (object->Type) {
468   case MEMBUF:
469   case VIDBUF8:
470   case VIDBUF8S:
471   case VIDBUF16:
472   case VIDBUF16S:
473   case VIDBUF24:
474   case VIDBUF24S:
475   case VIDBUF32:
476   case VIDBUF32S:
477     src.Type = MEMBUF;
478     src.Xsize = object->Xsize;
479     src.VXsize = object->VXsize;
480     src.Ysize = 1;
481     src.VYsize = 1;
482     src.Xorigin = 0;
483     src.Yorigin = 0;
484     src.Bitmap = alloca(object->VXsize * object->PixelBytes);
485     src.PixelBytes = object->PixelBytes;
486     color = htole32(color);
487     for (i = 0; i < object->VXsize; i++)
488       bcopy(&color, src.Bitmap + i * object->PixelBytes, object->PixelBytes);
489     for (i = 0; i < object->VYsize; i++)
490       __VGLBitmapCopy(&src, 0, 0, object, 0, i, object->VXsize, 1);
491     break;
492 
493   case VIDBUF8X:
494     /* XXX works only for Xsize % 4 = 0 */
495     outb(0x3c6, 0xff);
496     outb(0x3c4, 0x02); outb(0x3c5, 0x0f);
497     memset(object->Bitmap, (byte)color, VGLAdpInfo.va_line_width*object->VYsize);
498     break;
499 
500   case VIDBUF4:
501   case VIDBUF4S:
502     /* XXX works only for Xsize % 8 = 0 */
503     outb(0x3c4, 0x02); outb(0x3c5, 0x0f);
504     outb(0x3ce, 0x05); outb(0x3cf, 0x02);		/* mode 2 */
505     outb(0x3ce, 0x01); outb(0x3cf, 0x00);		/* set/reset enable */
506     outb(0x3ce, 0x08); outb(0x3cf, 0xff);		/* bit mask */
507     for (offset = 0; offset < VGLAdpInfo.va_line_width*object->VYsize; ) {
508       VGLSetSegment(offset);
509       len = min(object->VXsize*object->VYsize - offset,
510 		VGLAdpInfo.va_window_size);
511       memset(object->Bitmap, (byte)color, len);
512       offset += len;
513     }
514     outb(0x3ce, 0x05); outb(0x3cf, 0x00);
515     break;
516   }
517   if (object == VGLDisplay) {
518     if (mouseoverlap)
519       VGLMousePointerShow();
520     VGLMouseUnFreeze();
521   }
522 }
523 
524 static inline u_long
525 VGLrgbToNative(uint16_t r, uint16_t g, uint16_t b)
526 {
527   int nr, ng, nb;
528 
529   nr = VGLModeInfo.vi_pixel_fsizes[2];
530   ng = VGLModeInfo.vi_pixel_fsizes[1];
531   nb = VGLModeInfo.vi_pixel_fsizes[0];
532   return (r >> (16 - nr) << (ng + nb)) | (g >> (16 - ng) << nb) |
533 	 (b >> (16 - nb) << 0);
534 }
535 
536 u_long
537 VGLrgb332ToNative(byte c)
538 {
539   uint16_t r, g, b;
540 
541   /* 3:3:2 to 16:16:16 */
542   r = ((c & 0xe0) >> 5) * 0xffff / 7;
543   g = ((c & 0x1c) >> 2) * 0xffff / 7;
544   b = ((c & 0x03) >> 0) * 0xffff / 3;
545 
546   return VGLrgbToNative(r, g, b);
547 }
548 
549 void
550 VGLRestorePalette()
551 {
552   int i;
553 
554   if (VGLModeInfo.vi_mem_model == V_INFO_MM_DIRECT)
555     return;
556   outb(0x3C6, 0xFF);
557   inb(0x3DA);
558   outb(0x3C8, 0x00);
559   for (i=0; i<256; i++) {
560     outb(0x3C9, VGLSavePaletteRed[i]);
561     inb(0x84);
562     outb(0x3C9, VGLSavePaletteGreen[i]);
563     inb(0x84);
564     outb(0x3C9, VGLSavePaletteBlue[i]);
565     inb(0x84);
566   }
567   inb(0x3DA);
568   outb(0x3C0, 0x20);
569 }
570 
571 void
572 VGLSavePalette()
573 {
574   int i;
575 
576   if (VGLModeInfo.vi_mem_model == V_INFO_MM_DIRECT)
577     return;
578   outb(0x3C6, 0xFF);
579   inb(0x3DA);
580   outb(0x3C7, 0x00);
581   for (i=0; i<256; i++) {
582     VGLSavePaletteRed[i] = inb(0x3C9);
583     inb(0x84);
584     VGLSavePaletteGreen[i] = inb(0x3C9);
585     inb(0x84);
586     VGLSavePaletteBlue[i] = inb(0x3C9);
587     inb(0x84);
588   }
589   inb(0x3DA);
590   outb(0x3C0, 0x20);
591 }
592 
593 void
594 VGLSetPalette(byte *red, byte *green, byte *blue)
595 {
596   int i;
597 
598   if (VGLModeInfo.vi_mem_model == V_INFO_MM_DIRECT)
599     return;
600   for (i=0; i<256; i++) {
601     VGLSavePaletteRed[i] = red[i];
602     VGLSavePaletteGreen[i] = green[i];
603     VGLSavePaletteBlue[i] = blue[i];
604   }
605   VGLCheckSwitch();
606   outb(0x3C6, 0xFF);
607   inb(0x3DA);
608   outb(0x3C8, 0x00);
609   for (i=0; i<256; i++) {
610     outb(0x3C9, VGLSavePaletteRed[i]);
611     inb(0x84);
612     outb(0x3C9, VGLSavePaletteGreen[i]);
613     inb(0x84);
614     outb(0x3C9, VGLSavePaletteBlue[i]);
615     inb(0x84);
616   }
617   inb(0x3DA);
618   outb(0x3C0, 0x20);
619 }
620 
621 void
622 VGLSetPaletteIndex(byte color, byte red, byte green, byte blue)
623 {
624   if (VGLModeInfo.vi_mem_model == V_INFO_MM_DIRECT)
625     return;
626   VGLSavePaletteRed[color] = red;
627   VGLSavePaletteGreen[color] = green;
628   VGLSavePaletteBlue[color] = blue;
629   VGLCheckSwitch();
630   outb(0x3C6, 0xFF);
631   inb(0x3DA);
632   outb(0x3C8, color);
633   outb(0x3C9, red); outb(0x3C9, green); outb(0x3C9, blue);
634   inb(0x3DA);
635   outb(0x3C0, 0x20);
636 }
637 
638 void
639 VGLRestoreBorder(void)
640 {
641   VGLSetBorder(VGLBorderColor);
642 }
643 
644 void
645 VGLSetBorder(byte color)
646 {
647   if (VGLModeInfo.vi_mem_model == V_INFO_MM_DIRECT && ioctl(0, KDENABIO, 0))
648     return;
649   VGLCheckSwitch();
650   inb(0x3DA);
651   outb(0x3C0,0x11); outb(0x3C0, color);
652   inb(0x3DA);
653   outb(0x3C0, 0x20);
654   VGLBorderColor = color;
655   if (VGLModeInfo.vi_mem_model == V_INFO_MM_DIRECT)
656     ioctl(0, KDDISABIO, 0);
657 }
658 
659 void
660 VGLRestoreBlank(void)
661 {
662   VGLBlankDisplay(VGLBlank);
663 }
664 
665 void
666 VGLBlankDisplay(int blank)
667 {
668   byte val;
669 
670   if (VGLModeInfo.vi_mem_model == V_INFO_MM_DIRECT && ioctl(0, KDENABIO, 0))
671     return;
672   VGLCheckSwitch();
673   outb(0x3C4, 0x01); val = inb(0x3C5); outb(0x3C4, 0x01);
674   outb(0x3C5, ((blank) ? (val |= 0x20) : (val &= 0xDF)));
675   VGLBlank = blank;
676   if (VGLModeInfo.vi_mem_model == V_INFO_MM_DIRECT)
677     ioctl(0, KDDISABIO, 0);
678 }
679