sys/src/cmd/lens.c

   1 #include <u.h>
   2 #include <libc.h>
   3 #include <draw.h>
   4 #include <event.h>
   5 #include <keyboard.h>
   6
   7 enum {
   8         Edge = 5,
   9         Maxmag = 16
  10 };
  11
  12 enum {
  13         Mzoom,
  14         Munzoom,
  15         Mgrid,
  16         Mredraw,
  17         Mexit
  18 };
  19
  20 char *menustr[] = {
  21         "zoom",
  22         "unzoom",
  23         "grid",
  24         "redraw",
  25         "exit",
  26         nil
  27 };
  28
  29 Menu menu = {
  30         menustr,
  31         nil,
  32         -1
  33 };
  34
  35 Point lastp;
  36 Image *red;
  37 Image *tmp;
  38 Image *grid;
  39 Image *chequer;
  40 int     screenfd;
  41 int     mag = 4;
  42 int     showgrid = 0;
  43 Rectangle       screenr;
  44 uchar   *screenbuf;
  45
  46 void    magnify(void);
  47 void makegrid(void);
  48
  49 void
  50 drawit(void)
  51 {
  52         Rectangle r;
  53         border(screen, screen->r, Edge, red, ZP);
  54         magnify();
  55         r = insetrect(screen->r, Edge);
  56         draw(screen, r, tmp, nil, tmp->r.min);
  57         flushimage(display, 1);
  58 }
  59
  60 int bypp;
  61
  62 void
  63 main(int argc, char *argv[])
  64 {
  65         Event e;
  66         char buf[5*12];
  67         ulong chan;
  68         int d;
  69
  70         USED(argc, argv);
  71         if(initdraw(nil, nil, "lens") < 0){
  72                 fprint(2, "lens: initdraw failed: %r\n");
  73                 exits("initdraw");
  74         }
  75         einit(Emouse|Ekeyboard);
  76         red = allocimage(display, Rect(0, 0, 1, 1), CMAP8, 1, DRed);
  77         chequer = allocimage(display, Rect(0, 0, 2, 2), GREY1, 1, DBlack);
  78         draw(chequer, Rect(0, 0, 1, 1), display->white, nil, ZP);
  79         draw(chequer, Rect(1, 1, 2, 2), display->white, nil, ZP);
  80         lastp = divpt(addpt(screen->r.min, screen->r.max), 2);
  81         screenfd = open("/dev/screen", OREAD);
  82         if(screenfd < 0){
  83                 fprint(2, "lens: can't open /dev/screen: %r\n");
  84                 exits("screen");
  85         }
  86         if(read(screenfd, buf, sizeof buf) != sizeof buf){
  87                 fprint(2, "lens: can't read /dev/screen: %r\n");
  88                 exits("screen");
  89         }
  90         chan = strtochan(buf);
  91         d = chantodepth(chan);
  92         if(d < 8){
  93                 fprint(2, "lens: can't handle screen format %11.11s\n", buf);
  94                 exits("screen");
  95         }
  96         bypp = d/8;
  97         screenr.min.x = atoi(buf+1*12);
  98         screenr.min.y = atoi(buf+2*12);
  99         screenr.max.x = atoi(buf+3*12);
 100         screenr.max.y = atoi(buf+4*12);
 101         screenbuf = malloc(bypp*Dx(screenr)*Dy(screenr));
 102         if(screenbuf == nil){
 103                 fprint(2, "lens: buffer malloc failed: %r\n");
 104                 exits("malloc");
 105         }
 106         eresized(0);
 107
 108         for(;;)
 109                 switch(event(&e)){
 110                 case Ekeyboard:
 111                         switch(e.kbdc){
 112                         case 'q':
 113                         case Kdel:
 114                         case Keof:
 115                         caseexit:
 116                                 exits(nil);
 117                         case '=':
 118                         case '+':
 119                         casezoom:
 120                                 if(mag < Maxmag){
 121                                         mag++;
 122                                         makegrid();
 123                                         drawit();
 124                                 }
 125                                 break;
 126                         case 'g':
 127                         casegrid:
 128                                 showgrid = !showgrid;
 129                                 makegrid();
 130                                 drawit();
 131                                 break;
 132                         case '-':
 133                         case '_':
 134                         caseunzoom:
 135                                 if(mag > 1){
 136                                         mag--;
 137                                         makegrid();
 138                                         drawit();
 139                                 }
 140                                 break;
 141                         case '.':
 142                         case ' ':
 143                         caseredraw:
 144                                 drawit();
 145                                 break;
 146                         case '1': case '2': case '3': case '4': case '5': case '6': case '7': case '8': case '9': case'0':
 147                                 mag = e.kbdc-'0';
 148                                 if(mag == 0)
 149                                         mag = 10;
 150                                 makegrid();
 151                                 drawit();
 152                                 break;
 153                         }
 154                         break;
 155                 case Emouse:
 156                         if(e.mouse.buttons & 1){
 157                                 lastp = e.mouse.xy;
 158                                 drawit();
 159                         }
 160                         if(e.mouse.buttons & 4)
 161                                 switch(emenuhit(3, &e.mouse, &menu)){
 162                                 case Mzoom:
 163                                         goto casezoom;
 164                                 case Munzoom:
 165                                         goto caseunzoom;
 166                                 case Mgrid:
 167                                         goto casegrid;
 168                                 case Mredraw:
 169                                         goto caseredraw;
 170                                 case Mexit:
 171                                         goto caseexit;
 172                                 }
 173                         break;
 174                 }
 175 }
 176
 177 void
 178 makegrid(void)
 179 {
 180         int m;
 181         if (grid != nil) {
 182                 freeimage(grid);
 183                 grid = nil;
 184         }
 185         if (showgrid) {
 186                 m = mag;
 187                 if (m < 5)
 188                         m *= 10;
 189                 grid = allocimage(display, Rect(0, 0, m, m),
 190                         CHAN2(CGrey, 8, CAlpha, 8), 1, DTransparent);
 191                 if (grid != nil){
 192                         draw(grid, Rect(0, 0, m, 1), chequer, nil, ZP);
 193                         draw(grid, Rect(0, 1, 1, m), chequer, nil, ZP);
 194                 }
 195         }
 196 }
 197
 198 void
 199 eresized(int new)
 200 {
 201         if(new && getwindow(display, Refnone) < 0){
 202                 fprint(2, "lens: can't reattach to window: %r\n");
 203                 exits("attach");
 204         }
 205         freeimage(tmp);
 206         tmp = allocimage(display, Rect(0, 0, Dx(screen->r)-Edge, Dy(screen->r)-Edge+Maxmag), screen->chan, 0, DNofill);
 207         if(tmp == nil){
 208                 fprint(2, "lens: allocimage failed: %r\n");
 209                 exits("allocimage");
 210         }
 211         drawit();
 212 }
 213
 214 void
 215 magnify(void)
 216 {
 217         int x, y, xx, yy, dd, i;
 218         int dx, dy;
 219         int xoff, yoff;
 220         uchar out[8192];
 221         uchar sp[4];
 222
 223         dx = (Dx(tmp->r)+mag-1)/mag;
 224         dy = (Dy(tmp->r)+mag-1)/mag;
 225         xoff = lastp.x-Dx(tmp->r)/(mag*2);
 226         yoff  = lastp.y-Dy(tmp->r)/(mag*2);
 227
 228         yy = yoff;
 229         dd = dy;
 230         if(yy < 0){
 231                 dd += dy;
 232                 yy = 0;
 233         }
 234         if(yy+dd > Dy(screenr))
 235                 dd = Dy(screenr)-yy;
 236         seek(screenfd, 5*12+bypp*yy*Dx(screenr), 0);
 237         if(readn(screenfd, screenbuf+bypp*yy*Dx(screenr), bypp*Dx(screenr)*dd) != bypp*Dx(screenr)*dd){
 238                 fprint(2, "lens: can't read screen: %r\n");
 239                 return;
 240         }
 241
 242         for(y=0; y<dy; y++){
 243                 yy = yoff+y;
 244                 if(yy>=0 && yy<Dy(screenr))
 245                         for(x=0; x<dx; x++){
 246                                 xx = xoff+x;
 247                                 if(xx>=0 && xx<Dx(screenr))     /* snarf pixel at xx, yy */
 248                                         for(i=0; i<bypp; i++)
 249                                                 sp[i] = screenbuf[bypp*(yy*Dx(screenr)+xx)+i];
 250                                 else
 251                                         sp[0] = sp[1] = sp[2] = sp[3] = 0;
 252
 253                                 for(xx=0; xx<mag; xx++)
 254                                         if(x*mag+xx < tmp->r.max.x)
 255                                                 for(i=0; i<bypp; i++)
 256                                                         out[(x*mag+xx)*bypp+i] = sp[i];
 257                         }
 258                 else
 259                         memset(out, 0, bypp*Dx(tmp->r));
 260                 for(yy=0; yy<mag && y*mag+yy<Dy(tmp->r); yy++){
 261                         werrstr("no error");
 262                         if(loadimage(tmp, Rect(0, y*mag+yy, Dx(tmp->r), y*mag+yy+1), out, bypp*Dx(tmp->r)) != bypp*Dx(tmp->r)){
 263                                 exits("load");
 264                         }
 265                 }
 266         }
 267         if (showgrid && mag && grid)
 268                 draw(tmp, tmp->r, grid, nil, mulpt(Pt(xoff, yoff), mag));
 269 }