ref: 28f3a3aad8d2d73010f1c81080e92f71903f4556
dir: /sys/src/cmd/lens.c/
#include <u.h> #include <libc.h> #include <draw.h> #include <event.h> #include <keyboard.h> enum { Edge = 5, Maxmag = 16 }; enum { Mzoom, Munzoom, Mgrid, Mredraw, Mexit }; char *menustr[] = { "zoom", "unzoom", "grid", "redraw", "exit", nil }; Menu menu = { menustr, nil, -1 }; Point lastp; Image *red; Image *tmp; Image *grid; Image *chequer; int screenfd; int mag = 4; int showgrid = 0; Rectangle screenr; uchar *screenbuf; void magnify(void); void makegrid(void); void drawit(void) { Rectangle r; border(screen, screen->r, Edge, red, ZP); magnify(); r = insetrect(screen->r, Edge); draw(screen, r, tmp, nil, tmp->r.min); flushimage(display, 1); } int bypp; void main(int argc, char *argv[]) { Event e; char buf[5*12]; ulong chan; int d; USED(argc, argv); if(initdraw(nil, nil, "lens") < 0){ fprint(2, "lens: initdraw failed: %r\n"); exits("initdraw"); } einit(Emouse|Ekeyboard); red = allocimage(display, Rect(0, 0, 1, 1), CMAP8, 1, DRed); chequer = allocimage(display, Rect(0, 0, 2, 2), GREY1, 1, DBlack); draw(chequer, Rect(0, 0, 1, 1), display->white, nil, ZP); draw(chequer, Rect(1, 1, 2, 2), display->white, nil, ZP); lastp = divpt(addpt(screen->r.min, screen->r.max), 2); screenfd = open("/dev/screen", OREAD); if(screenfd < 0){ fprint(2, "lens: can't open /dev/screen: %r\n"); exits("screen"); } if(read(screenfd, buf, sizeof buf) != sizeof buf){ fprint(2, "lens: can't read /dev/screen: %r\n"); exits("screen"); } chan = strtochan(buf); d = chantodepth(chan); if(d < 8){ fprint(2, "lens: can't handle screen format %11.11s\n", buf); exits("screen"); } bypp = d/8; screenr.min.x = atoi(buf+1*12); screenr.min.y = atoi(buf+2*12); screenr.max.x = atoi(buf+3*12); screenr.max.y = atoi(buf+4*12); screenbuf = malloc(bypp*Dx(screenr)*Dy(screenr)); if(screenbuf == nil){ fprint(2, "lens: buffer malloc failed: %r\n"); exits("malloc"); } eresized(0); for(;;) switch(event(&e)){ case Ekeyboard: switch(e.kbdc){ case 'q': case Kdel: case Keof: caseexit: exits(nil); case '=': case '+': casezoom: if(mag < Maxmag){ mag++; makegrid(); drawit(); } break; case 'g': casegrid: showgrid = !showgrid; makegrid(); drawit(); break; case '-': case '_': caseunzoom: if(mag > 1){ mag--; makegrid(); drawit(); } break; case '.': case ' ': caseredraw: drawit(); break; case '1': case '2': case '3': case '4': case '5': case '6': case '7': case '8': case '9': case'0': mag = e.kbdc-'0'; if(mag == 0) mag = 10; makegrid(); drawit(); break; } break; case Emouse: if(e.mouse.buttons & 1){ lastp = e.mouse.xy; drawit(); } if(e.mouse.buttons & 4) switch(emenuhit(3, &e.mouse, &menu)){ case Mzoom: goto casezoom; case Munzoom: goto caseunzoom; case Mgrid: goto casegrid; case Mredraw: goto caseredraw; case Mexit: goto caseexit; } break; } } void makegrid(void) { int m; if (grid != nil) { freeimage(grid); grid = nil; } if (showgrid) { m = mag; if (m < 5) m *= 10; grid = allocimage(display, Rect(0, 0, m, m), CHAN2(CGrey, 8, CAlpha, 8), 1, DTransparent); if (grid != nil){ draw(grid, Rect(0, 0, m, 1), chequer, nil, ZP); draw(grid, Rect(0, 1, 1, m), chequer, nil, ZP); } } } void eresized(int new) { if(new && getwindow(display, Refnone) < 0){ fprint(2, "lens: can't reattach to window: %r\n"); exits("attach"); } freeimage(tmp); tmp = allocimage(display, Rect(0, 0, Dx(screen->r)-Edge, Dy(screen->r)-Edge+Maxmag), screen->chan, 0, DNofill); if(tmp == nil){ fprint(2, "lens: allocimage failed: %r\n"); exits("allocimage"); } drawit(); } void magnify(void) { int x, y, xx, yy, dd, i; int dx, dy; int xoff, yoff; uchar out[8192]; uchar sp[4]; dx = (Dx(tmp->r)+mag-1)/mag; dy = (Dy(tmp->r)+mag-1)/mag; xoff = lastp.x-Dx(tmp->r)/(mag*2); yoff = lastp.y-Dy(tmp->r)/(mag*2); yy = yoff; dd = dy; if(yy < 0){ dd += dy; yy = 0; } if(yy+dd > Dy(screenr)) dd = Dy(screenr)-yy; seek(screenfd, 5*12+bypp*yy*Dx(screenr), 0); if(readn(screenfd, screenbuf+bypp*yy*Dx(screenr), bypp*Dx(screenr)*dd) != bypp*Dx(screenr)*dd){ fprint(2, "lens: can't read screen: %r\n"); return; } for(y=0; y<dy; y++){ yy = yoff+y; if(yy>=0 && yy<Dy(screenr)) for(x=0; x<dx; x++){ xx = xoff+x; if(xx>=0 && xx<Dx(screenr)) /* snarf pixel at xx, yy */ for(i=0; i<bypp; i++) sp[i] = screenbuf[bypp*(yy*Dx(screenr)+xx)+i]; else sp[0] = sp[1] = sp[2] = sp[3] = 0; for(xx=0; xx<mag; xx++) if(x*mag+xx < tmp->r.max.x) for(i=0; i<bypp; i++) out[(x*mag+xx)*bypp+i] = sp[i]; } else memset(out, 0, bypp*Dx(tmp->r)); for(yy=0; yy<mag && y*mag+yy<Dy(tmp->r); yy++){ werrstr("no error"); if(loadimage(tmp, Rect(0, y*mag+yy, Dx(tmp->r), y*mag+yy+1), out, bypp*Dx(tmp->r)) != bypp*Dx(tmp->r)){ exits("load"); } } } if (showgrid && mag && grid) draw(tmp, tmp->r, grid, nil, mulpt(Pt(xoff, yoff), mag)); }