sys/src/cmd/lens.c

   1 #include <u.h>
   2 #include <libc.h>
   3 #include <draw.h>
   4 #include <event.h>
   5
   6 enum {
   7         Edge = 5,
   8         Maxmag = 16
   9 };
  10
  11 enum {
  12         Mzoom,
  13         Munzoom,
  14         Mgrid,
  15         Mredraw,
  16         Mexit
  17 };
  18
  19 char *menustr[] = {
  20         "zoom",
  21         "unzoom",
  22         "grid",
  23         "redraw",
  24         "exit",
  25         nil
  26 };
  27
  28 Menu menu = {
  29         menustr,
  30         nil,
  31         -1
  32 };
  33
  34 Point lastp;
  35 Image *red;
  36 Image *tmp;
  37 Image *grid;
  38 Image *chequer;
  39 int     screenfd;
  40 int     mag = 4;
  41 int     showgrid = 0;
  42 Rectangle       screenr;
  43 uchar   *screenbuf;
  44
  45 void    magnify(void);
  46 void makegrid(void);
  47
  48 void
  49 drawit(void)
  50 {
  51         Rectangle r;
  52         border(screen, screen->r, Edge, red, ZP);
  53         magnify();
  54         r = insetrect(screen->r, Edge);
  55         draw(screen, r, tmp, nil, tmp->r.min);
  56         flushimage(display, 1);
  57 }
  58
  59 int bypp;
  60
  61 void
  62 main(int argc, char *argv[])
  63 {
  64         Event e;
  65         char buf[5*12];
  66         ulong chan;
  67         int d;
  68
  69         USED(argc, argv);
  70         if(initdraw(nil, nil, "lens") < 0){
  71                 fprint(2, "lens: initdraw failed: %r\n");
  72                 exits("initdraw");
  73         }
  74         einit(Emouse|Ekeyboard);
  75         red = allocimage(display, Rect(0, 0, 1, 1), CMAP8, 1, DRed);
  76         chequer = allocimage(display, Rect(0, 0, 2, 2), GREY1, 1, DBlack);
  77         draw(chequer, Rect(0, 0, 1, 1), display->white, nil, ZP);
  78         draw(chequer, Rect(1, 1, 2, 2), display->white, nil, ZP);
  79         lastp = divpt(addpt(screen->r.min, screen->r.max), 2);
  80         screenfd = open("/dev/screen", OREAD);
  81         if(screenfd < 0){
  82                 fprint(2, "lens: can't open /dev/screen: %r\n");
  83                 exits("screen");
  84         }
  85         if(read(screenfd, buf, sizeof buf) != sizeof buf){
  86                 fprint(2, "lens: can't read /dev/screen: %r\n");
  87                 exits("screen");
  88         }
  89         chan = strtochan(buf);
  90         d = chantodepth(chan);
  91         if(d < 8){
  92                 fprint(2, "lens: can't handle screen format %11.11s\n", buf);
  93                 exits("screen");
  94         }
  95         bypp = d/8;
  96         screenr.min.x = atoi(buf+1*12);
  97         screenr.min.y = atoi(buf+2*12);
  98         screenr.max.x = atoi(buf+3*12);
  99         screenr.max.y = atoi(buf+4*12);
 100         screenbuf = malloc(bypp*Dx(screenr)*Dy(screenr));
 101         if(screenbuf == nil){
 102                 fprint(2, "lens: buffer malloc failed: %r\n");
 103                 exits("malloc");
 104         }
 105         eresized(0);
 106
 107         for(;;)
 108                 switch(event(&e)){
 109                 case Ekeyboard:
 110                         switch(e.kbdc){
 111                         case 'q':
 112                         case 0x7f:
 113                         case '\04':
 114                         caseexit:
 115                                 exits(nil);
 116                         case '=':
 117                         case '+':
 118                         casezoom:
 119                                 if(mag < Maxmag){
 120                                         mag++;
 121                                         makegrid();
 122                                         drawit();
 123                                 }
 124                                 break;
 125                         case 'g':
 126                         casegrid:
 127                                 showgrid = !showgrid;
 128                                 makegrid();
 129                                 drawit();
 130                                 break;
 131                         case '-':
 132                         case '_':
 133                         caseunzoom:
 134                                 if(mag > 1){
 135                                         mag--;
 136                                         makegrid();
 137                                         drawit();
 138                                 }
 139                                 break;
 140                         case '.':
 141                         case ' ':
 142                         caseredraw:
 143                                 drawit();
 144                                 break;
 145                         case '1': case '2': case '3': case '4': case '5': case '6': case '7': case '8': case '9': case'0':
 146                                 mag = e.kbdc-'0';
 147                                 if(mag == 0)
 148                                         mag = 10;
 149                                 makegrid();
 150                                 drawit();
 151                                 break;
 152                         }
 153                         break;
 154                 case Emouse:
 155                         if(e.mouse.buttons & 1){
 156                                 lastp = e.mouse.xy;
 157                                 drawit();
 158                         }
 159                         if(e.mouse.buttons & 4)
 160                                 switch(emenuhit(3, &e.mouse, &menu)){
 161                                 case Mzoom:
 162                                         goto casezoom;
 163                                 case Munzoom:
 164                                         goto caseunzoom;
 165                                 case Mgrid:
 166                                         goto casegrid;
 167                                 case Mredraw:
 168                                         goto caseredraw;
 169                                 case Mexit:
 170                                         goto caseexit;
 171                                 }
 172                         break;
 173                 }
 174 }
 175
 176 void
 177 makegrid(void)
 178 {
 179         int m;
 180         if (grid != nil) {
 181                 freeimage(grid);
 182                 grid = nil;
 183         }
 184         if (showgrid) {
 185                 m = mag;
 186                 if (m < 5)
 187                         m *= 10;
 188                 grid = allocimage(display, Rect(0, 0, m, m),
 189                         CHAN2(CGrey, 8, CAlpha, 8), 1, DTransparent);
 190                 if (grid != nil){
 191                         draw(grid, Rect(0, 0, m, 1), chequer, nil, ZP);
 192                         draw(grid, Rect(0, 1, 1, m), chequer, nil, ZP);
 193                 }
 194         }
 195 }
 196
 197 void
 198 eresized(int new)
 199 {
 200         if(new && getwindow(display, Refnone) < 0){
 201                 fprint(2, "lens: can't reattach to window: %r\n");
 202                 exits("attach");
 203         }
 204         freeimage(tmp);
 205         tmp = allocimage(display, Rect(0, 0, Dx(screen->r)-Edge, Dy(screen->r)-Edge+Maxmag), screen->chan, 0, DNofill);
 206         if(tmp == nil){
 207                 fprint(2, "lens: allocimage failed: %r\n");
 208                 exits("allocimage");
 209         }
 210         drawit();
 211 }
 212
 213 void
 214 magnify(void)
 215 {
 216         int x, y, xx, yy, dd, i;
 217         int dx, dy;
 218         int xoff, yoff;
 219         uchar out[8192];
 220         uchar sp[4];
 221
 222         dx = (Dx(tmp->r)+mag-1)/mag;
 223         dy = (Dy(tmp->r)+mag-1)/mag;
 224         xoff = lastp.x-Dx(tmp->r)/(mag*2);
 225         yoff  = lastp.y-Dy(tmp->r)/(mag*2);
 226
 227         yy = yoff;
 228         dd = dy;
 229         if(yy < 0){
 230                 dd += dy;
 231                 yy = 0;
 232         }
 233         if(yy+dd > Dy(screenr))
 234                 dd = Dy(screenr)-yy;
 235         seek(screenfd, 5*12+bypp*yy*Dx(screenr), 0);
 236         if(readn(screenfd, screenbuf+bypp*yy*Dx(screenr), bypp*Dx(screenr)*dd) != bypp*Dx(screenr)*dd){
 237                 fprint(2, "lens: can't read screen: %r\n");
 238                 return;
 239         }
 240
 241         for(y=0; y<dy; y++){
 242                 yy = yoff+y;
 243                 if(yy>=0 && yy<Dy(screenr))
 244                         for(x=0; x<dx; x++){
 245                                 xx = xoff+x;
 246                                 if(xx>=0 && xx<Dx(screenr))     /* snarf pixel at xx, yy */
 247                                         for(i=0; i<bypp; i++)
 248                                                 sp[i] = screenbuf[bypp*(yy*Dx(screenr)+xx)+i];
 249                                 else
 250                                         sp[0] = sp[1] = sp[2] = sp[3] = 0;
 251
 252                                 for(xx=0; xx<mag; xx++)
 253                                         if(x*mag+xx < tmp->r.max.x)
 254                                                 for(i=0; i<bypp; i++)
 255                                                         out[(x*mag+xx)*bypp+i] = sp[i];
 256                         }
 257                 else
 258                         memset(out, 0, bypp*Dx(tmp->r));
 259                 for(yy=0; yy<mag && y*mag+yy<Dy(tmp->r); yy++){
 260                         werrstr("no error");
 261                         if(loadimage(tmp, Rect(0, y*mag+yy, Dx(tmp->r), y*mag+yy+1), out, bypp*Dx(tmp->r)) != bypp*Dx(tmp->r)){
 262                                 exits("load");
 263                         }
 264                 }
 265         }
 266         if (showgrid && mag && grid)
 267                 draw(tmp, tmp->r, grid, nil, mulpt(Pt(xoff, yoff), mag));
 268 }