[gs-cvs] gs/src

[Ray Johnston]

Update of /cvs/ghostscript/gs/src
In directory casper:/tmp/cvs-serv22342/src

Modified Files:
      Tag: GS_8_1X
	gdevmem.c gsdevmem.c 
Log Message:
Fix problems with the "image" device when the palette is an 8-bit gray
palette (uses the image8 device with num_components == 1). Since the
DeviceN changes, changing num_components requires also setting the
gray_index value appropriately. Also the rgb to color mapping function
did not allow for num_components == 1 and used uninitialized values for
the green and blue comonents. Fixes bugs 458261, 686909 and 687204.
Corresponds to rev 1.7 gdevmem.c and rev 1.5 gsdevmem.c on main branch.


Index: gdevmem.c
===================================================================
RCS file: /cvs/ghostscript/gs/src/gdevmem.c,v
retrieving revision 1.6
retrieving revision 1.6.2.1
diff -u -d -r1.6 -r1.6.2.1
--- gdevmem.c	16 Sep 2002 22:04:43 -0000	1.6
+++ gdevmem.c	13 Feb 2004 18:45:00 -0000	1.6.2.1
@@ -529,13 +529,21 @@
 {
     gx_device_memory * const mdev = (gx_device_memory *)dev;
     byte br = gx_color_value_to_byte(cv[0]);
-    byte bg = gx_color_value_to_byte(cv[1]);
-    byte bb = gx_color_value_to_byte(cv[2]);
+    
     register const byte *pptr = mdev->palette.data;
     int cnt = mdev->palette.size;
     const byte *which = 0;	/* initialized only to pacify gcc */
     int best = 256 * 3;
 
+    if (mdev->color_info.num_components != 1) {
+	/* not 1 component, assume three */
+	/* The comparison is rather simplistic, treating differences in	*/
+	/* all components as equal. Better choices would be 'distance'	*/
+	/* in HLS space or other, but these would be much slower.	*/
+	/* At least exact matches will be found.			*/
+	byte bg = gx_color_value_to_byte(cv[1]);
+	byte bb = gx_color_value_to_byte(cv[2]);
+
     while ((cnt -= 3) >= 0) {
 	register int diff = *pptr - br;
 
@@ -555,7 +563,25 @@
 		    which = pptr, best = diff;
 	    }
 	}
+	    if (diff == 0)	/* can't get any better than 0 diff */
+		break;
 	pptr += 3;
+	}
+    } else {
+	/* Gray scale conversion. The palette is made of three equal	*/
+	/* components, so this case is simpler.				*/
+	while ((cnt -= 3) >= 0) {
+	    register int diff = *pptr - br;
+
+	    if (diff < 0)
+		diff = -diff;
+	    if (diff < best) {	/* quick rejection */
+		which = pptr, best = diff;
+	    }
+	    if (diff == 0)
+		break;
+	    pptr += 3;
+	}
     }
     return (gx_color_index) ((which - mdev->palette.data) / 3);
 }

Index: gsdevmem.c
===================================================================
RCS file: /cvs/ghostscript/gs/src/gsdevmem.c,v
retrieving revision 1.4
retrieving revision 1.4.2.1
diff -u -d -r1.4 -r1.4.2.1
--- gsdevmem.c	21 Feb 2002 22:24:52 -0000	1.4
+++ gsdevmem.c	13 Feb 2004 18:45:00 -0000	1.4.2.1
@@ -177,6 +177,7 @@
 	    new_dev->color_info.num_components = 1;
 	    new_dev->color_info.max_color = 0;
 	    new_dev->color_info.dither_colors = 0;
+	    new_dev->color_info.gray_index = 0;
 	}
     }
     new_dev->initial_matrix = *pmat;