ifthenelse allows non-uchar conditional images

ChangeLog

@@ -1,3 +1,7 @@
+12/5/10 started 7.22.2
+- the conditional image of ifthenelse can be any format, a (!=0) is added if
+  necessary
+
 12/5/10 started 7.22.1
 - fix a problem with tiff pyramid write and >1cpu, thanks Ruven
 - constant ops clip to target range

configure.in

@@ -6,7 +6,7 @@ AC_CONFIG_MACRO_DIR(m4)
 # user-visible library versioning
 m4_define([vips_major_version], [7])
 m4_define([vips_minor_version], [22])
-m4_define([vips_micro_version], [1])
+m4_define([vips_micro_version], [2])
 m4_define([vips_version],
           [vips_major_version.vips_minor_version.vips_micro_version])
 
@@ -29,7 +29,7 @@ PACKAGE=vips
 #   interface changes not backwards compatible?: reset age to 0
 
 LIBRARY_CURRENT=29
-LIBRARY_REVISION=2
+LIBRARY_REVISION=3
 LIBRARY_AGE=14
 
 AM_INIT_AUTOMAKE($PACKAGE,$VERSION)

libvips/relational/im_ifthenelse.c

@@ -15,6 +15,9 @@
  * 	- use im_check*()
  * 	- allow many-band conditional and single-band a/b
  * 	- allow a/b to differ in format and bands
+ * 25/6/10
+ * 	- let the conditional image be any format by adding a (!=0) if
+ * 	  necessary
  */
 
 /*
@@ -185,7 +188,7 @@ ifthenelse( IMAGE *c, IMAGE *a, IMAGE *b, IMAGE *out )
  * @b: else #IMAGE
  * @out: output #IMAGE
  *
- * This operation scans the condition image @c (which must be unsigned char) 
+ * This operation scans the condition image @c 
  * and uses it to select pixels from either the then image @a or the else
  * image @b. Non-zero means @a, 0 means @b.
  *
@@ -216,6 +219,15 @@ im_ifthenelse( IMAGE *c, IMAGE *a, IMAGE *b, IMAGE *out )
 		im__bandalike( t[0], t[1], t[2], t[3] ) )
 		return( -1 );
 
+	/* If c is not uchar, do (!=0) to make a uchar image.
+	 */
+	if( c->BandFmt != IM_BANDFMT_UCHAR ) {
+		if( im_notequalconst( c, t[4], 0 ) )
+			return( -1 );
+
+		c = t[4];
+	}
+
 	if( ifthenelse( c, t[2], t[3], out ) )
 		return( -1 );