From 08ebc9e535d4351b70b6d7b2edde3bb332be9614 Mon Sep 17 00:00:00 2001
From: John Cupitt <jcupitt@gmail.com>
Date: Fri, 1 Oct 2010 15:45:55 +0000
Subject: [PATCH] im_blend() can take non-uchar conditions

---
 ChangeLog                        |  1 +
 TODO                             |  8 --------
 libvips/inplace/im_draw_smudge.c |  4 ++--
 libvips/relational/im_blend.c    | 15 ++++++++++++---
 4 files changed, 15 insertions(+), 13 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 5837d7ee..a5ac1046 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -31,6 +31,7 @@
 - added im_read_point(), now partial, moved im_readpoint() to deprecated
 - added im_draw_smudge(), moved im_smudge() / im_smear() to deprecated
 - convolution functions support complex images
+- im_blend() can have any format condition image and it's converted to uchar
 
 12/5/10 started 7.22.2
 - the conditional image of ifthenelse can be any format, a (!=0) is added if
diff --git a/TODO b/TODO
index 08c56f5a..d7a640ab 100644
--- a/TODO
+++ b/TODO
@@ -5,14 +5,6 @@
 
   make a region, prepare to that, copy back over the image?
 
-- smudge is too strong ... tone it down a bit
-
-- can we make more use of im__draw_pel()? eg. im_draw_rect() etc.
-
-- im_blend() is rather fussy about formats, argh
-
-  cf. im_ifthenelse() and the extra !=0 it adds?
-
 
 
 
diff --git a/libvips/inplace/im_draw_smudge.c b/libvips/inplace/im_draw_smudge.c
index 62d5306d..a9d34bad 100644
--- a/libvips/inplace/im_draw_smudge.c
+++ b/libvips/inplace/im_draw_smudge.c
@@ -100,8 +100,8 @@ im_draw_smudge( VipsImage *im, int left, int top, int width, int height )
 		return( 0 );
 
 	if( !blur ) {
-		blur = im_create_imaskv( "im_draw_smudge", 3, 1, 1, 2, 1 );
-		blur->scale = 4;
+		blur = im_create_imaskv( "im_draw_smudge", 3, 1, 1, 4, 1 );
+		blur->scale = 6;
 	}
 
 	if( !(t[0] = im_open( "im_draw_smudge", "p" )) )
diff --git a/libvips/relational/im_blend.c b/libvips/relational/im_blend.c
index f7dcab13..f38ccfeb 100644
--- a/libvips/relational/im_blend.c
+++ b/libvips/relational/im_blend.c
@@ -323,7 +323,7 @@ blend( 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 blend pixels from either the then image @a or the else
  * image @b. 255 means @a only, 0 means @b only, and intermediate values are a
  * mixture.
@@ -348,9 +348,9 @@ im_blend( IMAGE *c, IMAGE *a, IMAGE *b, IMAGE *out )
 	const int repack = a->Coding == IM_CODING_LABQ && 
 		b->Coding == IM_CODING_LABQ;
 
-	IMAGE *t[7];
+	IMAGE *t[8];
 
-	if( im_open_local_array( out, t, 7, "im_blend", "p" ) )
+	if( im_open_local_array( out, t, 8, "im_blend", "p" ) )
 		return( -1 );
 
 	/* Unpack LABPACK as a courtesy.
@@ -366,6 +366,15 @@ im_blend( IMAGE *c, IMAGE *a, IMAGE *b, IMAGE *out )
 		b = t[1];
 	}
 
+	/* c must be uchar.
+	 */
+	if( c->BandFmt != IM_BANDFMT_UCHAR ) {
+		if( im_clip2fmt( c, t[7], IM_BANDFMT_UCHAR ) )
+			return( -1 );
+
+		c = t[7];
+	}
+
 	/* Make a and b match in bands and format.
 	 */
 	if( im__formatalike( a, b, t[2], t[3] ) ||