add crop
diff --git a/src/cmd/draw/crop.c b/src/cmd/draw/crop.c
new file mode 100644
index 0000000..e397a31
--- /dev/null
+++ b/src/cmd/draw/crop.c
@@ -0,0 +1,211 @@
+#include <u.h>
+#include <libc.h>
+#include <draw.h>
+#include <memdraw.h>
+
+enum
+{
+ None,
+ Inset, /* move border in or out uniformly */
+ Insetxy, /* move border in or out; different parameters for x and y */
+ Set, /* set rectangle to absolute values */
+ Blank, /* cut off blank region according to color value */
+ /* Blank is not actually set as a mode; it can be combined with others */
+};
+
+void
+usage(void)
+{
+ fprint(2, "usage: crop [-c rgb] [-i ±inset | -r R | -x ±inset | -y ±inset] [-t tx ty] [-b rgb ] [imagefile]\n");
+ fprint(2, "\twhere R is a rectangle minx miny maxx maxy\n");
+ fprint(2, "\twhere rgb is a color red green blue\n");
+ exits("usage");
+}
+
+int
+getint(char *s)
+{
+ if(s == nil)
+ usage();
+ if(*s == '+')
+ return atoi(s+1);
+ if(*s == '-')
+ return -atoi(s+1);
+ return atoi(s);
+}
+
+Rectangle
+crop(Memimage *m, ulong c)
+{
+ Memimage *n;
+ int x, y, bpl, wpl;
+ int left, right, top, bottom;
+ ulong *buf;
+
+ left = m->r.max.x;
+ right = m->r.min.x;
+ top = m->r.max.y;
+ bottom = m->r.min.y;
+ n = nil;
+ if(m->chan != RGBA32){
+ /* convert type for simplicity */
+ n = allocmemimage(m->r, RGBA32);
+ if(n == nil)
+ sysfatal("can't allocate temporary image: %r");
+ memimagedraw(n, n->r, m, m->r.min, nil, ZP, S);
+ m = n;
+ }
+ wpl = wordsperline(m->r, m->depth);
+ bpl = wpl*sizeof(ulong);
+ buf = malloc(bpl);
+ if(buf == nil)
+ sysfatal("can't allocate buffer: %r");
+
+ for(y=m->r.min.y; y<m->r.max.y; y++){
+ x = unloadmemimage(m, Rect(m->r.min.x, y, m->r.max.x, y+1), (uchar*)buf, bpl);
+ if(x != bpl)
+ sysfatal("unloadmemimage");
+ for(x=0; x<wpl; x++)
+ if(buf[x] != c){
+ if(x < left)
+ left = x;
+ if(x > right)
+ right = x;
+ if(y < top)
+ top = y;
+ bottom = y;
+ }
+ }
+
+ if(n != nil)
+ freememimage(n);
+ return Rect(left, top, right+1, bottom+1);
+}
+
+void
+main(int argc, char *argv[])
+{
+ int fd, mode, red, green, blue;
+ Rectangle r, rparam;
+ Point t;
+ Memimage *m, *new;
+ char *file;
+ ulong bg, cropval;
+ long dw;
+
+ memimageinit();
+ mode = None;
+ bg = 0;
+ cropval = 0;
+ t = ZP;
+ memset(&rparam, 0, sizeof rparam);
+
+ ARGBEGIN{
+ case 'b':
+ if(bg != 0)
+ usage();
+ red = getint(ARGF())&0xFF;
+ green = getint(ARGF())&0xFF;
+ blue = getint(ARGF())&0xFF;
+ bg = (red<<24)|(green<<16)|(blue<<8)|0xFF;
+ break;
+ case 'c':
+ if(cropval != 0)
+ usage();
+ red = getint(ARGF())&0xFF;
+ green = getint(ARGF())&0xFF;
+ blue = getint(ARGF())&0xFF;
+ cropval = (red<<24)|(green<<16)|(blue<<8)|0xFF;
+ break;
+ case 'i':
+ if(mode != None)
+ usage();
+ mode = Inset;
+ rparam.min.x = getint(ARGF());
+ break;
+ case 'x':
+ if(mode != None && mode != Insetxy)
+ usage();
+ mode = Insetxy;
+ rparam.min.x = getint(ARGF());
+ break;
+ case 'y':
+ if(mode != None && mode != Insetxy)
+ usage();
+ mode = Insetxy;
+ rparam.min.y = getint(ARGF());
+ break;
+ case 'r':
+ if(mode != None)
+ usage();
+ mode = Set;
+ rparam.min.x = getint(ARGF());
+ rparam.min.y = getint(ARGF());
+ rparam.max.x = getint(ARGF());
+ rparam.max.y = getint(ARGF());
+ break;
+ case 't':
+ t.x = getint(ARGF());
+ t.y = getint(ARGF());
+ break;
+ default:
+ usage();
+ }ARGEND
+
+ if(mode == None && cropval == 0 && eqpt(ZP, t))
+ usage();
+
+ file = "<stdin>";
+ fd = 0;
+ if(argc > 1)
+ usage();
+ else if(argc == 1){
+ file = argv[0];
+ fd = open(file, OREAD);
+ if(fd < 0)
+ sysfatal("can't open %s: %r", file);
+ }
+
+ m = readmemimage(fd);
+ if(m == nil)
+ sysfatal("can't read %s: %r", file);
+
+ r = m->r;
+ if(cropval != 0){
+ r = crop(m, cropval);
+ m->clipr = r;
+ }
+
+ switch(mode){
+ case None:
+ break;
+ case Inset:
+ r = insetrect(r, rparam.min.x);
+ break;
+ case Insetxy:
+ r.min.x += rparam.min.x;
+ r.max.x -= rparam.min.x;
+ r.min.y += rparam.min.y;
+ r.max.y -= rparam.min.y;
+ break;
+ case Set:
+ r = rparam;
+ break;
+ }
+
+ new = allocmemimage(r, m->chan);
+ if(new == nil)
+ sysfatal("can't allocate new image: %r");
+ if(bg != 0)
+ memfillcolor(new, bg);
+ else
+ memfillcolor(new, 0x000000FF);
+
+ memimagedraw(new, m->clipr, m, m->clipr.min, nil, ZP, S);
+ dw = byteaddr(new, ZP) - byteaddr(new, t);
+ new->r = rectaddpt(new->r, t);
+ new->zero += dw;
+ if(writememimage(1, new) < 0)
+ sysfatal("write error on output: %r");
+ exits(nil);
+}
