paint(1) color picker

paint(1) color picker

[qwx]

Hello,

I wrote a patch for paint(1) allowing one to change a palette color by
clicking on it with mouse button 3.

I know it's sacrilegious to touch the c64 palette, but it's been useful.

I'd like to push this.  What do you think?

Thanks,

qwx

diff -r eb26bc92b777 sys/src/cmd/paint.c
--- a/sys/src/cmd/paint.c	Sun Jan 13 17:17:11 2019 +0100
+++ b/sys/src/cmd/paint.c	Sun Jan 20 07:54:13 2019 +0100
@@ -523,9 +523,12 @@
 		return 1;
 	}
 	if(ptinrect(m.xy, palr)){
+		int i, n;
+		char buf[32];
 		Image *col;
 
-		col = pal[(m.xy.x - palr.min.x) * nelem(pal) / Dx(palr)];
+		i = (m.xy.x - palr.min.x) * nelem(pal) / Dx(palr);
+		col = pal[i];
 		switch(m.buttons & 7){
 		case 1:
 			ink = col;
@@ -536,6 +539,17 @@
 			drawpal();
 			update(nil);
 			break;
+		case 4:
+			buf[0] = 0;
+			if(eenter("Color", buf, sizeof(buf), &m) <= 0)
+				break;
+			n = strtol(buf, nil, 0);
+			freeimage(pal[i]);
+			pal[i] = allocimage(display, Rect(0, 0, 1, 1), RGB24, 1, n << 8 | 0xFF);
+			if(pal[i] == nil)
+				sysfatal("allocimage: %r");
+			drawpal();
+			break;
 		}
 		return 1;
 	}