Introduce new "fixed" thumbnail crop mode

This mode retains given aspect ratio and crops the area from inside of the
source image.

6 files changed, 74 insertions, 23 deletions

diff --git a/src/generators.c b/src/generators.c
index 2e8cca6..f627839 100644
--- a/src/generators.c
+++ b/src/generators.c
@@ -300,7 +300,7 @@ metadata_apply_overrides (ExifData *exif_data,
   if (setup->write_supplied_exif && item->metadata_external_exif)
     exif_data->external_exif_data = g_path_is_absolute (item->metadata_external_exif) ? g_strdup (item->metadata_external_exif) : g_build_filename (path_info->src_dir, item->metadata_external_exif, NULL);
 
-  exif_data->squared_thumbnail = image_size->is_thumbnail && image_size->squared_thumb;
+  exif_data->thumbnail_crop_style = image_size->is_thumbnail ? image_size->thumb_crop_style : CROP_STYLE_NORMAL;
   exif_data->thumbnail_crop_hint = get_prop_int (items, item, PROP_THUMB_CROP_HINT, CROP_HINT_UNDEFINED);
 }
 
@@ -403,8 +403,19 @@ generate_image (TGallerySetup *setup,
         if (img_w > 0 && img_h > 0) {
           stats_images_inc ();
 
-          if (image_size->is_thumbnail && image_size->squared_thumb)
-            img_w = img_h = image_size->square_size;
+          if (image_size->is_thumbnail && image_size->thumb_crop_style != CROP_STYLE_NORMAL) {
+            switch (image_size->thumb_crop_style) {
+              case CROP_STYLE_SQUARED:
+                img_w = img_h = image_size->square_size;
+                break;
+              case CROP_STYLE_FIXED:
+                img_w = image_size->crop_width;
+                img_h = image_size->crop_height;
+                break;
+              default:
+                g_assert_not_reached ();
+            }
+          }
           else {
             /*  Only the "preview" size is affected by deprecated item and album overrides  */
             if (is_preview) {
@@ -795,7 +806,7 @@ process_img_item (TGallerySetup *setup,
     if (s2 != NULL)
       get_image_sizes (s2, &img_thumb_w, &img_thumb_h, setup->autorotate);
 
-    if (thumb_image_size->squared_thumb || img_thumb_w == img_thumb_h)
+    if (img_thumb_w == img_thumb_h)
       replace_table_add_key (replace_table, "THUMB_ORIENTATION", "squared");
     else
       replace_table_add_key (replace_table, "THUMB_ORIENTATION", (img_thumb_h > img_thumb_w) ? "portrait" : "landscape");
diff --git a/src/jpeg-utils.cpp b/src/jpeg-utils.cpp
index a552e69..e714778 100644
--- a/src/jpeg-utils.cpp
+++ b/src/jpeg-utils.cpp
@@ -458,9 +458,9 @@ resize_image (const gchar *src, const gchar *dst,
 {
   MagickWand *magick_wand;
   ExceptionType severity;
-  unsigned long w;
-  unsigned long h;
-  unsigned long amount;
+  unsigned long w, h;
+  unsigned long new_w, new_h;
+  double source_aspect, target_aspect;
   gchar *description;
 
   /*  Read an image.  */
@@ -481,27 +481,45 @@ resize_image (const gchar *src, const gchar *dst,
   {
     /*  Process thumbnail if required  */
     if (thumbnail) {
-      if (exif->squared_thumbnail) {
+      if (exif->thumbnail_crop_style != CROP_STYLE_NORMAL) {
         w = MagickGetImageWidth (magick_wand);
         h = MagickGetImageHeight (magick_wand);
-        amount = MAX (w, h) * SQUARED_SIMPLE_SHAVE_AMOUNT / 100;
-        amount = MIN (w - 2*amount, h - 2*amount);
+        new_w = w;
+        new_h = h;
+        if (exif->thumbnail_crop_style == CROP_STYLE_SQUARED) {
+          new_w = MAX (w, h) * CROP_SIMPLE_SHAVE_AMOUNT / 100;
+          new_w = MIN (w - 2*new_w, h - 2*new_w);
+          new_h = new_w;
+        }
+        if (exif->thumbnail_crop_style == CROP_STYLE_FIXED) {
+          source_aspect = (double) w / (double) h;
+          target_aspect = (double) size_x / (double) size_y;
+          if (target_aspect >= source_aspect) {
+            new_w = w;
+            new_h = (int) ((double) w / target_aspect);
+          } else {
+            new_w = (int) ((double) h * target_aspect);
+            new_h = h;
+          }
+          new_w = (int) ((double) new_w * (double) (100 - CROP_SIMPLE_SHAVE_AMOUNT) / 100);
+          new_h = (int) ((double) new_h * (double) (100 - CROP_SIMPLE_SHAVE_AMOUNT) / 100);
+        }
         switch (exif->thumbnail_crop_hint) {
           case CROP_HINT_UNDEFINED:
           case CROP_HINT_CENTER:
-            MagickCropImage (magick_wand, amount, amount, (w - amount) / 2, (h - amount) / 2);
+            MagickCropImage (magick_wand, new_w, new_h, (w - new_w) / 2, (h - new_h) / 2);
             break;
           case CROP_HINT_LEFT:
-            MagickCropImage (magick_wand, amount, amount, 0, (h - amount) / 2);
+            MagickCropImage (magick_wand, new_w, new_h, 0, (h - new_h) / 2);
             break;
           case CROP_HINT_RIGHT:
-            MagickCropImage (magick_wand, amount, amount, w - amount, (h - amount) / 2);
+            MagickCropImage (magick_wand, new_w, new_h, w - new_w, (h - new_h) / 2);
             break;
           case CROP_HINT_TOP:
-            MagickCropImage (magick_wand, amount, amount, (w - amount) / 2, 0);
+            MagickCropImage (magick_wand, new_w, new_h, (w - new_w) / 2, 0);
             break;
           case CROP_HINT_BOTTOM:
-            MagickCropImage (magick_wand, amount, amount, (w - amount) / 2, h - amount);
+            MagickCropImage (magick_wand, new_w, new_h, (w - new_w) / 2, h - new_h);
             break;
         }
       }
diff --git a/src/jpeg-utils.h b/src/jpeg-utils.h
index 3700d66..9e4c729 100644
--- a/src/jpeg-utils.h
+++ b/src/jpeg-utils.h
@@ -25,7 +25,7 @@
 G_BEGIN_DECLS
 
 
-#define SQUARED_SIMPLE_SHAVE_AMOUNT 0  /* percent */
+#define CROP_SIMPLE_SHAVE_AMOUNT 0  /* percent */
 
 /*  EXIF data known keys  */
 #define EXIF_APERTURE           "Exif.Photo.FNumber"
@@ -57,7 +57,7 @@ typedef struct {
   double override_aperture;
   double override_focal_length;
   gchar *external_exif_data;
-  gboolean squared_thumbnail;
+  TCropStyle thumbnail_crop_style;
   TCropHint thumbnail_crop_hint;
 } ExifData;
 
diff --git a/src/setup.c b/src/setup.c
index d945021..5cfc255 100644
--- a/src/setup.c
+++ b/src/setup.c
@@ -193,10 +193,14 @@ parse_design_setup_xml (const gchar *filename)
     if (s2 && g_ascii_strcasecmp (s2, "thumbnail") == 0)
       image_size->is_thumbnail = TRUE;
     g_free (s2);
+    image_size->thumb_crop_style = CROP_STYLE_NORMAL;
     if (image_size->is_thumbnail) {
       s2 = xml_file_get_node_attribute (xml, s, "style");
       if (s2 && g_ascii_strcasecmp (s2, "squared") == 0)
-        image_size->squared_thumb = TRUE;
+        image_size->thumb_crop_style = CROP_STYLE_SQUARED;
+      else
+      if (s2 && g_ascii_strcasecmp (s2, "fixed") == 0)
+        image_size->thumb_crop_style = CROP_STYLE_FIXED;
       g_free (s2);
     }
     g_free (s);
@@ -219,6 +223,11 @@ parse_design_setup_xml (const gchar *filename)
     image_size->square_size = xml_file_get_node_attribute_long_with_default (xml, s, "size", 0);
     g_free (s);
 
+    s = g_strdup_printf ("/design_setup/image_sizes/size[%d]/crop", i + 1);
+    image_size->crop_width = xml_file_get_node_attribute_long_with_default (xml, s, "w", 0);
+    image_size->crop_height = xml_file_get_node_attribute_long_with_default (xml, s, "h", 0);
+    g_free (s);
+
     s = g_strdup_printf ("/design_setup/image_sizes/size[%d]/quality", i + 1);
     image_size->quality = xml_file_get_node_attribute_long_with_default (xml, s, "value", -1);
     g_free (s);
@@ -347,7 +356,7 @@ makeup_legacy_design (const gchar *filename)
     image_size->quality = xml_file_get_node_attribute_long_with_default (xml, s, "quality", -1);
     image_size->no_resize = (i != 0);
     image_size->is_thumbnail = (i == 0);
-    image_size->squared_thumb = (i == 0) && squared_thumbs;
+    image_size->thumb_crop_style = ((i == 0) && squared_thumbs) ? CROP_STYLE_SQUARED : CROP_STYLE_NORMAL;
     g_free (s);
     design->image_sizes = g_list_append (design->image_sizes, image_size);
   }
diff --git a/src/setup.h b/src/setup.h
index 4678423..f49eb9a 100644
--- a/src/setup.h
+++ b/src/setup.h
@@ -86,6 +86,11 @@ typedef struct {
   gchar *footer;
 } TGallerySetup;
 
+typedef enum {
+  CROP_STYLE_NORMAL = 0,
+  CROP_STYLE_SQUARED,
+  CROP_STYLE_FIXED
+} TCropStyle;
 
 typedef struct {
   gchar *name;
@@ -95,9 +100,11 @@ typedef struct {
   int portrait_width;
   int portrait_height;
   int square_size;
+  int crop_width;
+  int crop_height;
   int quality;
   gboolean no_resize;
-  gboolean squared_thumb;
+  TCropStyle thumb_crop_style;
 } TImageSize;
 
 typedef struct {
diff --git a/templates/default.xml b/templates/default.xml
index c903a4b..3948538 100644
--- a/templates/default.xml
+++ b/templates/default.xml
@@ -46,13 +46,19 @@
     <!-- Thumbnail section is mandatory. -->
     <!-- Corresponds with optional <item thumbnail> tag in album source file.
          Note that thumbnail images are always resized even for custom supplied files.  -->
-    <!-- The "type" attribute has to be set to "thumbnail" to be treated as such.
-         An optional "style" attribute set to "squared" indicates the need of squared
-         thumbnails as opposed to original aspect ratio. -->
+    <!-- The "type" attribute has to be set to "thumbnail" to be treated as such. -->
+    <!-- An optional "style" attribute affects cropping:
+           * normal  - image is resized to fit the dimension limits, maintaining
+                       aspect ratio without any crop (default)
+           * squared - image is cropped to a squared size and resized to fit
+           * fixed   - image is cropped to a specified dimension and cropped to
+                       fit the specified aspect ratio
+         An optional album item <thumbnail crop> tags may affect crop area.  -->
     <size name="thumbnail" type="thumbnail" style="normal">
       <landscape w="180" h="120" />
       <portrait w="120" h="180" />
       <square size="180" />
+      <crop w="180" h="120" />   <!--  valid only for the "fixed" crop style  -->
       <quality value="80" />
     </size>