Fix computation of end of run indices.

2000-01-05  Owen Taylor  <otaylor@redhat.com>

	* gdk-pixbuf/pixops/pixops.c (pixops_process): Fix computation of end of run indices.

	* gdk-pixbuf/pixops/pixops.c: Fix double increments when dest_channels == 4.
	  (Pointed out by Tomas Ogren)

diff --git a/gdk-pixbuf/ChangeLog b/gdk-pixbuf/ChangeLog
index 8d6792224a8f84e73602588cc30d74192160931c..a70ac3822a0dd514dcc9d04290267f9120d91819 100644 (file)
--- a/gdk-pixbuf/ChangeLog
+++ b/gdk-pixbuf/ChangeLog
@@ -1,3 +1,10 @@
+2000-01-05  Owen Taylor  <otaylor@redhat.com>
+
+       * gdk-pixbuf/pixops/pixops.c (pixops_process): Fix computation of end of run indices.
+         
+       * gdk-pixbuf/pixops/pixops.c: Fix double increments when dest_channels == 4.
+         (Pointed out by Tomas Ogren)
+
 2000-01-05  Mark Crichton  <crichton@gimp.org>
 
        * gdk-pixbuf/gdk-pixbuf-loader.c (gdk_pixbuf_loader_eat_header_write): 

diff --git a/gdk-pixbuf/pixops/pixops.c b/gdk-pixbuf/pixops/pixops.c
index bfc7c7b51ae6cc81b6883421ac62874735f1ffbe..347dfef3d7b57b4b2dd5e956f754e724f8f2ea8b 100644 (file)
--- a/gdk-pixbuf/pixops/pixops.c
+++ b/gdk-pixbuf/pixops/pixops.c
@@ -82,9 +82,9 @@ pixops_scale_nearest (art_u8        *dest_buf,
          if (DEST_CHANNELS == 4)                               \
            {                                                   \
              if (SRC_CHANNELS == 4)                            \
-               *(dest++) = p[3];                               \
+               dest[3] = p[3];                                 \
              else                                              \
-               *(dest++) = 0xff;                               \
+               dest[3] = 0xff;                                 \
            }                                                   \
                                                                \
          dest += DEST_CHANNELS;                                \
@@ -200,7 +200,7 @@ pixops_composite_nearest (art_u8        *dest_buf,
              dest[2] = dest[2] + ((a0 * (p[2] - dest[2]) + 0xff) >> 8);
 
              if (dest_channels == 4)
-               *(dest++) = 0xff;
+               dest[3] = 0xff;
            }
 
          dest += dest_channels;
@@ -292,7 +292,7 @@ pixops_composite_color_nearest (art_u8        *dest_buf,
            }
          
          if (dest_channels == 4)
-           *(dest++) = 0xff;
+           dest[3] = 0xff;
 
          dest += dest_channels;
          x += x_step;
@@ -931,12 +931,12 @@ pixops_process (art_u8         *dest_buf,
   int y_step = (1 << SCALE_SHIFT) / scale_y;
 
   int dest_x;
+  int scaled_x_offset = floor (filter->x_offset * (1 << SCALE_SHIFT));
 
-  /* FIXME, this computation of run_end_index is not correct */
-  int run_end_index = ((src_width << SCALE_SHIFT) + (filter->n_x - 1) / 2 - filter->n_x) / x_step - render_x0;
+  int run_end_index = ((src_width - filter->n_x + 1 << SCALE_SHIFT) - scaled_x_offset - 1) / x_step + 1 - render_x0;
   int check_shift = check_size ? get_check_shift (check_size) : 0;
 
-  y = render_y0 * y_step + filter->y_offset * (1 << SCALE_SHIFT);
+  y = render_y0 * y_step + floor (filter->y_offset * (1 << SCALE_SHIFT));
   for (i = 0; i < (render_y1 - render_y0); i++)
     {
       int y_start = y >> SCALE_SHIFT;
@@ -972,7 +972,7 @@ pixops_process (art_u8         *dest_buf,
        }
 
       dest_x = check_x;
-      x = render_x0 * x_step + filter->x_offset * (1 << SCALE_SHIFT);
+      x = render_x0 * x_step + scaled_x_offset;
       x_start = x >> SCALE_SHIFT;
 
       while (x_start < 0 && outbuf < outbuf_end)
@@ -991,14 +991,14 @@ pixops_process (art_u8         *dest_buf,
 
       new_outbuf = (*line_func)(run_weights, filter->n_x, filter->n_y,
                                outbuf, dest_x,
-                               MIN (outbuf_end, outbuf + run_end_index * dest_channels),
+                               MIN (outbuf_end, dest_buf + dest_rowstride * i + run_end_index * dest_channels),
                                dest_channels, dest_has_alpha,
                                line_bufs, src_channels, src_has_alpha,
                                x, x_step, src_width, check_size, tcolor1, tcolor2);
 
       dest_x += (new_outbuf - outbuf) / dest_channels;
-      
-      x = dest_x * x_step + filter->x_offset * (1 << SCALE_SHIFT);
+
+      x = dest_x * x_step + scaled_x_offset;
       outbuf = new_outbuf;
 
       while (outbuf < outbuf_end)