Fix #772: Huge image display issue

https://github.com/BestImageViewer/geeqie/issues/772
Patch by terrancewong, expanded by CAC.
There is a problem with the GdkPixbuf library when the image width is > 32767.
The problem shows in gdk_pixbuf_copy_area() and GDK_INTERP_NEAREST.
The easiest way to solve the problems is to work around them.

diff --git a/src/renderer-tiles.c b/src/renderer-tiles.c
index 893a424..e828f4b 100644 (file)
--- a/src/renderer-tiles.c
+++ b/src/renderer-tiles.c
@@ -1291,33 +1291,81 @@ static gboolean rt_source_tile_render(RendererTiles *rt, ImageTile *it,
        return draw;
 }
 
+/**
+ * @brief 
+ * @param has_alpha 
+ * @param ignore_alpha 
+ * @param src 
+ * @param dest 
+ * @param pb_x 
+ * @param pb_y 
+ * @param pb_w 
+ * @param pb_h 
+ * @param offset_x 
+ * @param offset_y 
+ * @param scale_x 
+ * @param scale_y 
+ * @param interp_type 
+ * @param check_x 
+ * @param check_y 
+ * @param wide_image Used as a work-around for a GdkPixbuf problem. Set when image width is > 32767. Problem exhibited with gdk_pixbuf_copy_area() and GDK_INTERP_NEAREST. See #772 on GitHub Geeqie
+ * 
+ * 
+ */
 static void rt_tile_get_region(gboolean has_alpha, gboolean ignore_alpha,
                                const GdkPixbuf *src, GdkPixbuf *dest,
                                int pb_x, int pb_y, int pb_w, int pb_h,
                                double offset_x, double offset_y, double scale_x, double scale_y,
                                GdkInterpType interp_type,
-                               int check_x, int check_y)
+                               int check_x, int check_y, gboolean wide_image)
 {
        GdkPixbuf* tmppixbuf;
+       gint srs;
+       gint drs;
+       gint x;
+       gint y;
+       gint c;
+       guchar *psrc;
+       guchar *pdst;
 
        if (!has_alpha)
                {
                if (scale_x == 1.0 && scale_y == 1.0)
                        {
-                       gdk_pixbuf_copy_area(src,
-                                            -offset_x + pb_x, -offset_y + pb_y,
-                                            pb_w, pb_h,
-                                            dest,
-                                            pb_x, pb_y);
+                       if (wide_image)
+                               {
+                               srs = gdk_pixbuf_get_rowstride(src);
+                               drs = gdk_pixbuf_get_rowstride(dest);
+                               psrc = gdk_pixbuf_get_pixels(src);
+                               pdst = gdk_pixbuf_get_pixels(dest);
+                               for (y = 0; y < pb_h; y++)
+                                       {
+                                       for (x = 0; x < pb_w; x++)
+                                               {
+                                               for (c = 0; c < 3; c++)
+                                                       {
+                                                       pdst[(y * drs) + x*3 + c] = psrc[(-(int)offset_y + pb_y + y) * srs + (-(int)offset_x + pb_x+x)*3 + c];
+                                                       }
+                                               }
+                                       }
+                               }
+                       else
+                               {
+                               gdk_pixbuf_copy_area(src,
+                                                                       -offset_x + pb_x, -offset_y + pb_y,
+                                                                       pb_w, pb_h,
+                                                                       dest,
+                                                                       pb_x, pb_y);
+                                       }
                        }
                else
                        {
                        gdk_pixbuf_scale(src, dest,
-                                        pb_x, pb_y, pb_w, pb_h,
-                                        offset_x,
-                                        offset_y,
-                                        scale_x, scale_y,
-                                        interp_type);
+                                                       pb_x, pb_y, pb_w, pb_h,
+                                                       offset_x,
+                                                       offset_y,
+                                                       scale_x, scale_y,
+                                                       (wide_image && interp_type == GDK_INTERP_NEAREST) ? GDK_INTERP_TILES : interp_type);
                        }
                }
        else
@@ -1387,6 +1435,7 @@ static void rt_tile_render(RendererTiles *rt, ImageTile *it,
        gboolean has_alpha;
        gboolean draw = FALSE;
        gint orientation = rt_get_orientation(rt);
+       gboolean wide_image = FALSE;
 
        if (it->render_todo == TILE_RENDER_NONE && it->surface && !new_data) return;
 
@@ -1478,6 +1527,7 @@ static void rt_tile_render(RendererTiles *rt, ImageTile *it,
                 * small sizes for anything but GDK_INTERP_NEAREST
                 */
                if (pr->width < PR_MIN_SCALE_SIZE || pr->height < PR_MIN_SCALE_SIZE) fast = TRUE;
+               if (pr->image_width > 32767) wide_image = TRUE;
 
                rt_tile_get_region(has_alpha, pr->ignore_alpha,
                                   pr->pixbuf, it->pixbuf, pb_x, pb_y, pb_w, pb_h,
@@ -1485,7 +1535,7 @@ static void rt_tile_render(RendererTiles *rt, ImageTile *it,
                                   (gdouble) 0.0 - src_y,
                                   scale_x, scale_y,
                                   (fast) ? GDK_INTERP_NEAREST : pr->zoom_quality,
-                                  it->x + pb_x, it->y + pb_y);
+                                  it->x + pb_x, it->y + pb_y, wide_image);
                if (rt->stereo_mode & PR_STEREO_ANAGLYPH &&
                    (pr->stereo_pixbuf_offset_right > 0 || pr->stereo_pixbuf_offset_left > 0))
                        {
@@ -1496,7 +1546,7 @@ static void rt_tile_render(RendererTiles *rt, ImageTile *it,
                                           (gdouble) 0.0 - src_y,
                                           scale_x, scale_y,
                                           (fast) ? GDK_INTERP_NEAREST : pr->zoom_quality,
-                                          it->x + pb_x, it->y + pb_y);
+                                          it->x + pb_x, it->y + pb_y, wide_image);
                        pr_create_anaglyph(rt->stereo_mode, it->pixbuf, right_pb, pb_x, pb_y, pb_w, pb_h);
                        /* do not care about freeing spare_tile, it will be reused */
                        }