By order of jrb: const patch for various bits, io-gif.c fixup for

By order of jrb:
	const patch for various bits,
	io-gif.c fixup for animations.

7 files changed, 183 insertions, 159 deletions

diff --git a/gdk-pixbuf/ChangeLog b/gdk-pixbuf/ChangeLog
index 481bb3236..2fe762d87 100644
--- a/gdk-pixbuf/ChangeLog
+++ b/gdk-pixbuf/ChangeLog
@@ -1,3 +1,23 @@
+2000-02-04  Michael Meeks  <mmeeks@gnu.org>
+
+	* gdk-pixbuf/io-gif.c (struct _GifContext): add x,y_offset.
+	(gif_get_frame_info): put the offsets on the context.
+	(gif_get_lzw): copy them off into the frame.
+	(new_context): no change required; will 0 offsets by default.
+
+2000-01-28  Michael Meeks  <michael@mejm2.dow.cam.ac.uk>
+
+	* gdk-pixbuf/pixops/pixops.c (pixops_process): const + nasty
+	un-consting cast.
+
+	* gdk-pixbuf/pixops/pixops.h: const.
+
+	* gdk-pixbuf/gdk-pixbuf-util.c: const.
+	
+	* gdk-pixbuf/gdk-pixbuf-scale.c: const.
+
+	* gdk-pixbuf/gdk-pixbuf.h: constify lots of things.
+
 2000-02-03  Federico Mena Quintero  <federico@helixcode.com>
 
 	* gdk-pixbuf/gdk-pixbuf-render.c
diff --git a/gdk-pixbuf/gdk-pixbuf-scale.c b/gdk-pixbuf/gdk-pixbuf-scale.c
index a3e7859ed..0f621d1d6 100644
--- a/gdk-pixbuf/gdk-pixbuf-scale.c
+++ b/gdk-pixbuf/gdk-pixbuf-scale.c
@@ -22,20 +22,20 @@
  * destination drawable replacing the previous contents.
  **/
 void
-gdk_pixbuf_scale (GdkPixbuf      *src,
-		  GdkPixbuf      *dest,
-		  int             dest_x,
-		  int             dest_y,
-		  int             dest_width,
-		  int             dest_height,
-		  double          offset_x,
-		  double          offset_y,
-		  double          scale_x,
-		  double          scale_y,
-		  ArtFilterLevel  filter_level)
+gdk_pixbuf_scale (const GdkPixbuf *src,
+		  GdkPixbuf       *dest,
+		  int              dest_x,
+		  int              dest_y,
+		  int              dest_width,
+		  int              dest_height,
+		  double           offset_x,
+		  double           offset_y,
+		  double           scale_x,
+		  double           scale_y,
+		  ArtFilterLevel   filter_level)
 {
-  offset_x = floor(offset_x + 0.5);
-  offset_y = floor(offset_y + 0.5);
+  offset_x = floor (offset_x + 0.5);
+  offset_y = floor (offset_y + 0.5);
   
   pixops_scale (dest->art_pixbuf->pixels + dest_y * dest->art_pixbuf->rowstride + dest_x * dest->art_pixbuf->n_channels,
 		-offset_x, -offset_y, dest_width - offset_x, dest_height - offset_y,
@@ -66,21 +66,21 @@ gdk_pixbuf_scale (GdkPixbuf      *src,
  * destination drawable.
  **/
 void
-gdk_pixbuf_composite (GdkPixbuf      *src,
-		      GdkPixbuf      *dest,
-		      int             dest_x,
-		      int             dest_y,
-		      int             dest_width,
-		      int             dest_height,
-		      double          offset_x,
-		      double          offset_y,
-		      double          scale_x,
-		      double          scale_y,
-		      ArtFilterLevel  filter_level,
-		      int             overall_alpha)
+gdk_pixbuf_composite (const GdkPixbuf *src,
+		      GdkPixbuf       *dest,
+		      int              dest_x,
+		      int              dest_y,
+		      int              dest_width,
+		      int              dest_height,
+		      double           offset_x,
+		      double           offset_y,
+		      double           scale_x,
+		      double           scale_y,
+		      ArtFilterLevel   filter_level,
+		      int              overall_alpha)
 {
-  offset_x = floor(offset_x + 0.5);
-  offset_y = floor(offset_y + 0.5);
+  offset_x = floor (offset_x + 0.5);
+  offset_y = floor (offset_y + 0.5);
   pixops_composite (dest->art_pixbuf->pixels + dest_y * dest->art_pixbuf->rowstride + dest_x * dest->art_pixbuf->n_channels,
 		    -offset_x, -offset_y, dest_width - offset_x, dest_height - offset_y,
 		    dest->art_pixbuf->rowstride, dest->art_pixbuf->n_channels, dest->art_pixbuf->has_alpha,
@@ -116,26 +116,26 @@ gdk_pixbuf_composite (GdkPixbuf      *src,
  * destination drawable.
  **/
 void
-gdk_pixbuf_composite_color (GdkPixbuf      *src,
-			    GdkPixbuf      *dest,
-			    int             dest_x,
-			    int             dest_y,
-			    int             dest_width,
-			    int             dest_height,
-			    double          offset_x,
-			    double          offset_y,
-			    double          scale_x,
-			    double          scale_y,
-			    ArtFilterLevel  filter_level,
-			    int             overall_alpha,
-			    int             check_x,
-			    int             check_y,
-			    int             check_size,
-			    art_u32         color1,
-			    art_u32         color2)
+gdk_pixbuf_composite_color (const GdkPixbuf *src,
+			    GdkPixbuf       *dest,
+			    int              dest_x,
+			    int              dest_y,
+			    int              dest_width,
+			    int              dest_height,
+			    double           offset_x,
+			    double           offset_y,
+			    double           scale_x,
+			    double           scale_y,
+			    ArtFilterLevel   filter_level,
+			    int              overall_alpha,
+			    int              check_x,
+			    int              check_y,
+			    int              check_size,
+			    art_u32          color1,
+			    art_u32          color2)
 {
-  offset_x = floor(offset_x + 0.5);
-  offset_y = floor(offset_y + 0.5);
+  offset_x = floor (offset_x + 0.5);
+  offset_y = floor (offset_y + 0.5);
   
   pixops_composite_color (dest->art_pixbuf->pixels + dest_y * dest->art_pixbuf->rowstride + dest_x * dest->art_pixbuf->n_channels,
 			  -offset_x, -offset_y, dest_width - offset_x, dest_height - offset_y,
@@ -158,10 +158,10 @@ gdk_pixbuf_composite_color (GdkPixbuf      *src,
  * Return value: the new #GdkPixbuf
  **/
 GdkPixbuf *
-gdk_pixbuf_scale_simple (GdkPixbuf      *src,
-			 int             dest_width,
-			 int             dest_height,
-			 ArtFilterLevel  filter_level)
+gdk_pixbuf_scale_simple (const GdkPixbuf *src,
+			 int              dest_width,
+			 int              dest_height,
+			 ArtFilterLevel   filter_level)
 {
   GdkPixbuf *dest = gdk_pixbuf_new (ART_PIX_RGB, src->art_pixbuf->has_alpha, 8, dest_width, dest_height);
 
@@ -191,14 +191,14 @@ gdk_pixbuf_scale_simple (GdkPixbuf      *src,
  * Return value: the new #GdkPixbuf
  **/
 GdkPixbuf *
-gdk_pixbuf_composite_color_simple (GdkPixbuf      *src,
-				   int             dest_width,
-				   int             dest_height,
-				   ArtFilterLevel  filter_level,
-				   int             overall_alpha,
-				   int             check_size,
-				   art_u32         color1,
-				   art_u32         color2)
+gdk_pixbuf_composite_color_simple (const GdkPixbuf *src,
+				   int              dest_width,
+				   int              dest_height,
+				   ArtFilterLevel   filter_level,
+				   int              overall_alpha,
+				   int              check_size,
+				   art_u32          color1,
+				   art_u32          color2)
 {
   GdkPixbuf *dest = gdk_pixbuf_new (ART_PIX_RGB, src->art_pixbuf->has_alpha, 8, dest_width, dest_height);
 
diff --git a/gdk-pixbuf/gdk-pixbuf-util.c b/gdk-pixbuf/gdk-pixbuf-util.c
index 36dbed13c..96a8ca49b 100644
--- a/gdk-pixbuf/gdk-pixbuf-util.c
+++ b/gdk-pixbuf/gdk-pixbuf-util.c
@@ -110,13 +110,14 @@ gdk_pixbuf_add_alpha (GdkPixbuf *pixbuf, gboolean substitute_color, guchar r, gu
  * pixbuf formats is done automatically.
  **/
 void
-gdk_pixbuf_copy_area (GdkPixbuf *src_pixbuf,
+gdk_pixbuf_copy_area (const GdkPixbuf *src_pixbuf,
 		      int src_x, int src_y,
 		      int width, int height,
 		      GdkPixbuf *dest_pixbuf,
 		      int dest_x, int dest_y)
 {
-	ArtPixBuf *src_apb, *dest_apb;
+	const ArtPixBuf *src_apb;
+	ArtPixBuf       *dest_apb;
 
 	g_return_if_fail (src_pixbuf != NULL);
 	g_return_if_fail (dest_pixbuf != NULL);
diff --git a/gdk-pixbuf/gdk-pixbuf.h b/gdk-pixbuf/gdk-pixbuf.h
index ad94e445c..c3d053cf4 100644
--- a/gdk-pixbuf/gdk-pixbuf.h
+++ b/gdk-pixbuf/gdk-pixbuf.h
@@ -97,8 +97,8 @@ int          gdk_pixbuf_get_rowstride       (GdkPixbuf *pixbuf);
 
 /* Reference counting */
 
-GdkPixbuf *gdk_pixbuf_ref (GdkPixbuf *pixbuf);
-void gdk_pixbuf_unref (GdkPixbuf *pixbuf);
+GdkPixbuf *gdk_pixbuf_ref   (GdkPixbuf *pixbuf);
+void       gdk_pixbuf_unref (GdkPixbuf *pixbuf);
 
 /* Wrap a libart pixbuf */
 GdkPixbuf *gdk_pixbuf_new_from_art_pixbuf (ArtPixBuf *art_pixbuf);
@@ -156,19 +156,19 @@ void gdk_pixbuf_render_to_drawable_alpha (GdkPixbuf *pixbuf, GdkDrawable *drawab
 					  GdkRgbDither dither,
 					  int x_dither, int y_dither);
 
-void gdk_pixbuf_render_pixmap_and_mask (GdkPixbuf *pixbuf,
-					GdkPixmap **pixmap_return, GdkBitmap **mask_return,
-					int alpha_threshold);
+void gdk_pixbuf_render_pixmap_and_mask   (GdkPixbuf *pixbuf,
+					  GdkPixmap **pixmap_return, GdkBitmap **mask_return,
+					  int alpha_threshold);
 
 /* Fetching a region from a drawable */
-GdkPixbuf *gdk_pixbuf_get_from_drawable (GdkPixbuf *dest,
-					 GdkDrawable *src, GdkColormap *cmap,
-					 int src_x, int src_y,
-					 int dest_x, int dest_y,
-					 int width, int height);
+GdkPixbuf *gdk_pixbuf_get_from_drawable  (GdkPixbuf *dest,
+					  GdkDrawable *src, GdkColormap *cmap,
+					  int src_x, int src_y,
+					  int dest_x, int dest_y,
+					  int width, int height);
 
 /* Copy an area of a pixbuf onto another one */
-void gdk_pixbuf_copy_area (GdkPixbuf *src_pixbuf,
+void gdk_pixbuf_copy_area (const GdkPixbuf *src_pixbuf,
 			   int src_x, int src_y,
 			   int width, int height,
 			   GdkPixbuf *dest_pixbuf,
@@ -176,70 +176,70 @@ void gdk_pixbuf_copy_area (GdkPixbuf *src_pixbuf,
 
 /* Scaling */
 
-void gdk_pixbuf_scale           (GdkPixbuf      *src,
-				 GdkPixbuf      *dest,
-				 int             dest_x,
-				 int             dest_y,
-				 int             dest_width,
-				 int             dest_height,
-				 double          offset_x,
-				 double          offset_y,
-				 double          scale_x,
-				 double          scale_y,
-				 ArtFilterLevel  filter_level);
-void gdk_pixbuf_composite       (GdkPixbuf      *src,
-				 GdkPixbuf      *dest,
-				 int             dest_x,
-				 int             dest_y,
-				 int             dest_width,
-				 int             dest_height,
-				 double          offset_x,
-				 double          offset_y,
-				 double          scale_x,
-				 double          scale_y,
-				 ArtFilterLevel  filter_level,
-				 int             overall_alpha);
-void gdk_pixbuf_composite_color (GdkPixbuf      *src,
-				 GdkPixbuf      *dest,
-				 int             dest_x,
-				 int             dest_y,
-				 int             dest_width,
-				 int             dest_height,
-				 double          offset_x,
-				 double          offset_y,
-				 double          scale_x,
-				 double          scale_y,
-				 ArtFilterLevel  filter_level,
-				 int             overall_alpha,
-				 int             check_x,
-				 int             check_y,
-				 int             check_size,
-				 art_u32         color1,
-				 art_u32         color2);
-
-GdkPixbuf *gdk_pixbuf_scale_simple           (GdkPixbuf      *src,
-					      int             dest_width,
-					      int             dest_height,
-					      ArtFilterLevel  filter_level);
-GdkPixbuf *gdk_pixbuf_composite_color_simple (GdkPixbuf      *src,
-					      int             dest_width,
-					      int             dest_height,
-					      ArtFilterLevel  filter_level,
-					      int             overall_alpha,
-					      int             check_size,
-					      art_u32         color1,
-					      art_u32         color2);
+void gdk_pixbuf_scale           (const GdkPixbuf *src,
+				 GdkPixbuf       *dest,
+				 int              dest_x,
+				 int              dest_y,
+				 int              dest_width,
+				 int              dest_height,
+				 double           offset_x,
+				 double           offset_y,
+				 double           scale_x,
+				 double           scale_y,
+				 ArtFilterLevel   filter_level);
+void gdk_pixbuf_composite       (const GdkPixbuf *src,
+				 GdkPixbuf       *dest,
+				 int              dest_x,
+				 int              dest_y,
+				 int              dest_width,
+				 int              dest_height,
+				 double           offset_x,
+				 double           offset_y,
+				 double           scale_x,
+				 double           scale_y,
+				 ArtFilterLevel   filter_level,
+				 int              overall_alpha);
+void gdk_pixbuf_composite_color (const GdkPixbuf *src,
+				 GdkPixbuf       *dest,
+				 int              dest_x,
+				 int              dest_y,
+				 int              dest_width,
+				 int              dest_height,
+				 double           offset_x,
+				 double           offset_y,
+				 double           scale_x,
+				 double           scale_y,
+				 ArtFilterLevel   filter_level,
+				 int              overall_alpha,
+				 int              check_x,
+				 int              check_y,
+				 int              check_size,
+				 art_u32          color1,
+				 art_u32          color2);
+
+GdkPixbuf *gdk_pixbuf_scale_simple           (const GdkPixbuf *src,
+					      int              dest_width,
+					      int              dest_height,
+					      ArtFilterLevel   filter_level);
+GdkPixbuf *gdk_pixbuf_composite_color_simple (const GdkPixbuf *src,
+					      int              dest_width,
+					      int              dest_height,
+					      ArtFilterLevel   filter_level,
+					      int              overall_alpha,
+					      int              check_size,
+					      art_u32          color1,
+					      art_u32          color2);
 
 /* Animation support */
 
 GdkPixbufAnimation *gdk_pixbuf_animation_new_from_file (const char *filename);
 
-GdkPixbufAnimation *gdk_pixbuf_animation_ref (GdkPixbufAnimation *animation);
-void gdk_pixbuf_animation_unref (GdkPixbufAnimation *animation);
+GdkPixbufAnimation *gdk_pixbuf_animation_ref   (GdkPixbufAnimation *animation);
+void                gdk_pixbuf_animation_unref (GdkPixbufAnimation *animation);
 
 /* General (presently empty) initialization hooks, primarily for gnome-libs */
-void gdk_pixbuf_preinit(gpointer app, gpointer modinfo);
-void gdk_pixbuf_postinit(gpointer app, gpointer modinfo);
+void gdk_pixbuf_preinit  (gpointer app, gpointer modinfo);
+void gdk_pixbuf_postinit (gpointer app, gpointer modinfo);
 
 
 
diff --git a/gdk-pixbuf/io-gif.c b/gdk-pixbuf/io-gif.c
index fede1baf6..d566af1bb 100644
--- a/gdk-pixbuf/io-gif.c
+++ b/gdk-pixbuf/io-gif.c
@@ -123,6 +123,8 @@ struct _GifContext
 	int frame_len;
 	int frame_height;
 	int frame_interlace;
+	int x_offset;
+	int y_offset;
 
 	/* Static read only */
 	FILE *file;
@@ -674,8 +676,8 @@ gif_get_lzw (GifContext *context)
 			(* context->prepare_func) (context->pixbuf, context->user_data);
 		if (context->animation || context->frame_done_func) {
 			context->frame = g_new (GdkPixbufFrame, 1);
-			context->frame->x_offset = 0;
-			context->frame->y_offset = 0;
+			context->frame->x_offset = context->x_offset;
+			context->frame->y_offset = context->y_offset;;
 			context->frame->delay_time = context->gif89.delay_time;
 			switch (context->gif89.disposal) {
 			case 0:
@@ -934,10 +936,9 @@ gif_get_frame_info (GifContext *context)
 	/* Okay, we got all the info we need.  Lets record it */
 	context->frame_len = LM_to_uint (buf[4], buf[5]);
 	context->frame_height = LM_to_uint (buf[6], buf[7]);
-	if (context->frame) {
-		context->frame->x_offset = LM_to_uint (buf[0], buf[1]);
-		context->frame->y_offset = LM_to_uint (buf[2], buf[3]);
-	}
+	context->x_offset = LM_to_uint (buf[0], buf[1]);
+	context->y_offset = LM_to_uint (buf[2], buf[3]);
+
 	if (context->frame_height > context->height) {
 		/* we don't want to resize things.  So we exit */
 		context->state = GIF_DONE;
@@ -1063,6 +1064,7 @@ new_context (void)
 	GifContext *context;
 
 	context = g_new0 (GifContext, 1);
+
 	context->pixbuf = NULL;
 	context->file = NULL;
 	context->state = GIF_START;
@@ -1077,6 +1079,7 @@ new_context (void)
 	context->gif89.delay_time = -1;
 	context->gif89.input_flag = -1;
 	context->gif89.disposal = -1;
+
 	return context;
 }
 /* Shared library entry point */
diff --git a/gdk-pixbuf/pixops/pixops.c b/gdk-pixbuf/pixops/pixops.c
index 5834a26a3..d6646cfcd 100644
--- a/gdk-pixbuf/pixops/pixops.c
+++ b/gdk-pixbuf/pixops/pixops.c
@@ -56,7 +56,7 @@ pixops_scale_nearest (art_u8        *dest_buf,
 		      int            dest_rowstride,
 		      int            dest_channels,
 		      art_boolean    dest_has_alpha,
-		      art_u8        *src_buf,
+		      const art_u8  *src_buf,
 		      int            src_width,
 		      int            src_height,
 		      int            src_rowstride,
@@ -73,7 +73,7 @@ pixops_scale_nearest (art_u8        *dest_buf,
 #define INNER_LOOP(SRC_CHANNELS,DEST_CHANNELS) 			\
       for (j=0; j < (render_x1 - render_x0); j++)		\
 	{							\
-	  art_u8 *p = src + (x >> SCALE_SHIFT) * SRC_CHANNELS;	\
+	  const art_u8 *p = src + (x >> SCALE_SHIFT) * SRC_CHANNELS;	\
 								\
 	  dest[0] = p[0];					\
 	  dest[1] = p[1];					\
@@ -93,8 +93,8 @@ pixops_scale_nearest (art_u8        *dest_buf,
 
   for (i = 0; i < (render_y1 - render_y0); i++)
     {
-      art_u8 *src = src_buf + ((i * y_step + y_step / 2) >> SCALE_SHIFT) * src_rowstride;
-      art_u8 *dest = dest_buf + i * dest_rowstride;
+      const art_u8 *src  = src_buf + ((i * y_step + y_step / 2) >> SCALE_SHIFT) * src_rowstride;
+      art_u8       *dest = dest_buf + i * dest_rowstride;
 
       x = render_x0 * x_step + x_step / 2;
 
@@ -119,7 +119,7 @@ pixops_scale_nearest (art_u8        *dest_buf,
 	    {
 	      for (j=0; j < (render_x1 - render_x0); j++)
 		{
-		  art_u8 *p = src + (x >> SCALE_SHIFT) * 4;
+		  const art_u8 *p = src + (x >> SCALE_SHIFT) * 4;
 
 		  *(art_u32 *)dest = *(art_u32 *)p;
 		  
@@ -141,7 +141,7 @@ pixops_composite_nearest (art_u8        *dest_buf,
 			  int            dest_rowstride,
 			  int            dest_channels,
 			  art_boolean    dest_has_alpha,
-			  art_u8        *src_buf,
+			  const art_u8  *src_buf,
 			  int            src_width,
 			  int            src_height,
 			  int            src_rowstride,
@@ -158,15 +158,15 @@ pixops_composite_nearest (art_u8        *dest_buf,
 
   for (i = 0; i < (render_y1 - render_y0); i++)
     {
-      art_u8 *src = src_buf + (((i + render_y0) * y_step + y_step / 2) >> SCALE_SHIFT) * src_rowstride;
-      art_u8 *dest = dest_buf + i * dest_rowstride + render_x0 * dest_channels;
+      const art_u8 *src  = src_buf + (((i + render_y0) * y_step + y_step / 2) >> SCALE_SHIFT) * src_rowstride;
+      art_u8       *dest = dest_buf + i * dest_rowstride + render_x0 * dest_channels;
 
       x = render_x0 * x_step + x_step / 2;
       
       for (j=0; j < (render_x1 - render_x0); j++)
 	{
-	  art_u8 *p = src + (x >> SCALE_SHIFT) * src_channels;
-          unsigned int a0;
+	  const art_u8 *p = src + (x >> SCALE_SHIFT) * src_channels;
+          unsigned int  a0;
 
 	  if (src_has_alpha)
 	    a0 = (p[3] * overall_alpha + 0xff) >> 8;
@@ -218,7 +218,7 @@ pixops_composite_color_nearest (art_u8        *dest_buf,
 				int            dest_rowstride,
 				int            dest_channels,
 				art_boolean    dest_has_alpha,
-				art_u8        *src_buf,
+				const art_u8  *src_buf,
 				int            src_width,
 				int            src_height,
 				int            src_rowstride,
@@ -242,8 +242,8 @@ pixops_composite_color_nearest (art_u8        *dest_buf,
 
   for (i = 0; i < (render_y1 - render_y0); i++)
     {
-      art_u8 *src = src_buf + (((i + render_y0) * y_step + y_step/2) >> SCALE_SHIFT) * src_rowstride;
-      art_u8 *dest = dest_buf + i * dest_rowstride;
+      const art_u8 *src  = src_buf + (((i + render_y0) * y_step + y_step/2) >> SCALE_SHIFT) * src_rowstride;
+      art_u8       *dest = dest_buf + i * dest_rowstride;
 
       x = render_x0 * x_step + x_step / 2;
       
@@ -270,8 +270,8 @@ pixops_composite_color_nearest (art_u8        *dest_buf,
 
       for (j=0 ; j < (render_x1 - render_x0); j++)
 	{
-	  art_u8 *p = src + (x >> SCALE_SHIFT) * src_channels;
-          unsigned int a0;
+	  const art_u8 *p = src + (x >> SCALE_SHIFT) * src_channels;
+          unsigned int  a0;
 
 	  if (src_has_alpha)
 	    a0 = (p[3] * overall_alpha + 0xff) >> 8;
@@ -906,7 +906,7 @@ pixops_process (art_u8         *dest_buf,
 		int             dest_rowstride,
 		int             dest_channels,
 		art_boolean     dest_has_alpha,
-		art_u8         *src_buf,
+		const art_u8   *src_buf,
 		int             src_width,
 		int             src_height,
 		int             src_rowstride,
@@ -962,11 +962,11 @@ pixops_process (art_u8         *dest_buf,
       for (j=0; j<filter->n_y; j++)
 	{
 	  if (y_start <  0)
-	    line_bufs[j] = src_buf;
+	    line_bufs[j] = (art_u8 *)src_buf;
 	  else if (y_start < src_height)
-	    line_bufs[j] = src_buf + src_rowstride * y_start;
+	    line_bufs[j] = (art_u8 *)src_buf + src_rowstride * y_start;
 	  else
-	    line_bufs[j] = src_buf + src_rowstride * (src_height - 1);
+	    line_bufs[j] = (art_u8 *)src_buf + src_rowstride * (src_height - 1);
 
 	  y_start++;
 	}
@@ -1296,7 +1296,7 @@ pixops_composite_color (art_u8         *dest_buf,
 			int             dest_rowstride,
 			int             dest_channels,
 			art_boolean     dest_has_alpha,
-			art_u8         *src_buf,
+			const art_u8   *src_buf,
 			int             src_width,
 			int             src_height,
 			int             src_rowstride,
@@ -1380,7 +1380,7 @@ pixops_composite (art_u8        *dest_buf,
 		  int            dest_rowstride,
 		  int            dest_channels,
 		  art_boolean    dest_has_alpha,
-		  art_u8        *src_buf,
+		  const art_u8  *src_buf,
 		  int            src_width,
 		  int            src_height,
 		  int            src_rowstride,
@@ -1463,7 +1463,7 @@ pixops_scale (art_u8        *dest_buf,
 	      int            dest_rowstride,
 	      int            dest_channels,
 	      art_boolean    dest_has_alpha,
-	      art_u8        *src_buf,
+	      const art_u8  *src_buf,
 	      int            src_width,
 	      int            src_height,
 	      int            src_rowstride,
diff --git a/gdk-pixbuf/pixops/pixops.h b/gdk-pixbuf/pixops/pixops.h
index 387b46bc1..193d65918 100644
--- a/gdk-pixbuf/pixops/pixops.h
+++ b/gdk-pixbuf/pixops/pixops.h
@@ -14,7 +14,7 @@ void pixops_composite (art_u8         *dest_buf,
 		       int             dest_rowstride,
 		       int             dest_channels,
 		       int             dest_has_alpha,
-		       art_u8         *src_buf,
+		       const art_u8   *src_buf,
 		       int             src_width,
 		       int             src_height,
 		       int             src_rowstride,
@@ -39,7 +39,7 @@ void pixops_composite_color (art_u8         *dest_buf,
 			     int             dest_rowstride,
 			     int             dest_channels,
 			     int             dest_has_alpha,
-			     art_u8         *src_buf,
+			     const art_u8   *src_buf,
 			     int             src_width,
 			     int             src_height,
 			     int             src_rowstride,
@@ -68,7 +68,7 @@ void pixops_scale     (art_u8         *dest_buf,
 		       int             dest_rowstride,
 		       int             dest_channels,
 		       int             dest_has_alpha,
-		       art_u8         *src_buf,
+		       const art_u8   *src_buf,
 		       int             src_width,
 		       int             src_height,
 		       int             src_rowstride,