colormap doesnt change to rgbv after the first image
when doing png *.png, for example.

torgbv now understands about crgb24 &c.

Reference: /n/sources/patch/applied/jpgpngtorgbv
Date: Sun Feb 20 20:54:44 CET 2005

--- /sys/src/cmd/jpg/jpg.c	Sun Feb 20 20:52:20 2005
+++ /sys/src/cmd/jpg/jpg.c	Sun Feb 20 20:52:18 2005
@@ -259,16 +259,18 @@
 	c = nil;
 	if(jflag)
 		goto Return;
-	if(!dflag && !inited){
-		if(initdraw(0, 0, 0) < 0){
-			fprint(2, "jpg: initdraw failed: %r\n");
-			return "initdraw";
+	if(!dflag){
+		if (!inited) {
+			if(initdraw(0, 0, 0) < 0){
+				fprint(2, "jpg: initdraw failed: %r\n");
+				return "initdraw";
+			}
+			if(Fflag == 0)
+				einit(Ekeyboard|Emouse);
+			inited++;
 		}
-		if(Fflag == 0)
-			einit(Ekeyboard|Emouse);
 		if(defaultcolor && screen->depth>8 && outchan==CMAP8)
 			outchan = RGB24;
-		inited++;
 	}
 	if(outchan == CMAP8)
 		c = torgbv(r, !eflag);
--- /sys/src/cmd/jpg/png.c	Sun Feb 20 20:52:33 2005
+++ /sys/src/cmd/jpg/png.c	Sun Feb 20 20:52:31 2005
@@ -154,15 +154,17 @@
 	Bterm(&b);
 
 	r = array[0];
-	if(!dflag && !inited){
-		if(initdraw(0, 0, 0) < 0){
-			fprint(2, "png: initdraw failed: %r\n");
-			return "initdraw";
+	if(!dflag){
+		if (!inited) {
+			if(initdraw(0, 0, 0) < 0){
+				fprint(2, "png: initdraw failed: %r\n");
+				return "initdraw";
+			}
+			einit(Ekeyboard|Emouse);
+			inited++;
 		}
-		einit(Ekeyboard|Emouse);
 		if(defaultcolor && screen->depth>8 && outchan==CMAP8)
 			outchan = RGB24;
-		inited++;
 	}
 	if(outchan == CMAP8)
 		c = torgbv(r, !eflag);
--- /sys/src/cmd/jpg/torgbv.c	Sun Feb 20 20:52:49 2005
+++ /sys/src/cmd/jpg/torgbv.c	Sun Feb 20 20:52:46 2005
@@ -32,6 +32,7 @@
 	int j, k, rgb, x, y, er, eg, eb, col, t;
 	int r, g, b, r1, g1, b1;
 	int *ered, *egrn, *eblu, *rp, *gp, *bp;
+	int bpc;
 	uint *map3;
 	uchar *closest;
 	Rawimage *im;
@@ -173,26 +174,52 @@
 		break;
 
 	case CYCbCr:
+		bpc = 1;
+		rpic = i->chans[0];
+		gpic = i->chans[1];
+		bpic = i->chans[2];
 		closest = closestycbcr;
 		map3 = ycbcrmap;
+		if(i->nchans != 3)
+			return _remaperror("remap: RGB image has %d channels", i->nchans);
 		goto Threecolor;
 
 	case CRGB:
+		bpc = 1;
+		rpic = i->chans[0];
+		gpic = i->chans[1];
+		bpic = i->chans[2];
+		if(i->nchans != 3)
+			return _remaperror("remap: RGB image has %d channels", i->nchans);
+		goto rgbgen;
+
+	case CRGB24:
+		bpc = 3;
+		bpic = i->chans[0];
+		gpic = i->chans[0] + 1;
+		rpic = i->chans[0] + 2;
+		goto rgbgen;
+
+	case CRGBA32:
+		bpc = 4;
+		/* i->chans[0]+0 is alpha */
+		bpic = i->chans[0] + 1;
+		gpic = i->chans[0] + 2;
+		rpic = i->chans[0] + 3;
+
+	rgbgen:
 		closest = closestrgb;
 		map3 = rgbmap;
 
 	Threecolor:
-		if(i->nchans != 3)
-			return _remaperror("remap: RGB image has %d channels", i->nchans);
-		rpic = i->chans[0];
-		gpic = i->chans[1];
-		bpic = i->chans[2];
+
 		if(errdiff == 0){
-			for(j=0; j<i->chanlen; j++){
+			outp = out;
+			for(j=0; j<i->chanlen; j+=bpc){
 				r = rpic[j]>>4;
 				g = gpic[j]>>4;
 				b = bpic[j]>>4;
-				out[j] = closest[b+16*(g+16*r)];
+				*outp++ = closest[b+16*(g+16*r)];
 			}
 		}else{
 			/* modified floyd steinberg, coefficients (1 0) 3/16, (0, 1) 3/16, (1, 1) 7/16 */
@@ -204,9 +231,12 @@
 				gp = egrn;
 				bp = eblu;
 				for(x=0; x<dx; x++){
-					r = *rpic++ + *rp;
-					g = *gpic++ + *gp;
-					b = *bpic++ + *bp;
+					r = *rpic + *rp;
+					g = *gpic + *gp;
+					b = *bpic + *bp;
+					rpic += bpc;
+					gpic += bpc;
+					bpic += bpc;
 					/*
 					 * Errors can be uncorrectable if converting from YCbCr,
 					 * since we can't guarantee that an extremal value of one of
@@ -261,12 +291,21 @@
 		}
 		break;
 
+	case CYA16:
+		bpc = 2;
+		/* i->chans[0] + 0 is alpha */
+		rpic = i->chans[0] + 1;
+		goto greygen;
+
 	case CY:
+		bpc = 1;
+		rpic = i->chans[0];
 		if(i->nchans != 1)
 			return _remaperror("remap: Y image has %d chans", i->nchans);
-		rpic = i->chans[0];
+
+	greygen:
 		if(errdiff == 0){
-			for(j=0; j<i->chanlen; j++){
+			for(j=0; j<i->chanlen; j+=bpc){
 				r = rpic[j]>>4;
 				*outp++ = closestrgb[r+16*(r+16*r)];
 			}
@@ -276,7 +315,8 @@
 				er = 0;
 				rp = ered;
 				for(x=0; x<dx; x++){
-					r = *inp++ + *rp;
+					r = *rpic + *rp;
+					rpic += bpc;
 					r1 = clamp[r+CLAMPOFF];
 					col = closestrgb[r1+16*(r1+16*r1)];
 					*outp++ = col;