scale afterwards

lib/squib/graphics/save_images.rb

@@ -4,66 +4,62 @@ class Card
     # :nodoc:
     # @api private
     def save_png(batch, scale_box)
-      surface = if preprocess_save?(batch, scale_box)
-                  w, h = compute_dimensions(scale_box, batch.rotate, batch.trim)
-                  preprocessed_save(w, h, batch, scale_box)
+      surface = if preprocess_save?(batch)
+                  w, h = compute_dimensions(batch.rotate, batch.trim)
+                  preprocessed_save(w, h, batch)
                 else
                   @cairo_surface
                 end
+      surface = scaled_surface(surface, scale_box) if scaling?(scale_box)
       write_png(surface, index, batch.dir, batch.prefix, batch.count_format)
     end
 
     # :nodoc:
     # @api private
-    def preprocess_save?(batch, box)
-        box.width != @width ||
-        box.height != @height ||
-        batch.rotate != false ||
-        batch.trim > 0
+    def preprocess_save?(batch)
+      batch.rotate != false || batch.trim > 0
     end
 
-    def compute_dimensions(box, rotate, trim)
+    def scaling?(box)
+      box.width != @width || box.height != @height
+    end
+
+    def compute_dimensions(rotate, trim)
       if rotate
          [ @height - 2 * trim, @width - 2 * trim ]
        else
          [ @width - 2 * trim, @height - 2 * trim ]
        end
     end
 
-    def preprocessed_save(trimmed_w, trimmed_h, batch, scale_box)
-      scale_w = scale_box.width.to_f / trimmed_w
-      scale_h = scale_box.height.to_f / trimmed_h
-      w = if scale_box.width == @width
-            trimmed_w
-          else # user specified a width
-            scale_box.width
-          end
-      h = if scale_box.height == @height # specified height
-            trimmed_h
-          else # user specified a width
-            scale_box.height
-          end
+    def preprocessed_save(w, h, batch)
       new_cc = Cairo::Context.new(Cairo::ImageSurface.new(w, h))
-      new_cc.scale(scale_w, scale_h) # scale back
       trim_radius = batch.trim_radius
       if batch.rotate != false
         new_cc.translate(w * 0.5, h * 0.5)
         new_cc.rotate(batch.angle)
         new_cc.translate(h * -0.5, w * -0.5)
-        new_cc.rounded_rectangle(0, 0,
-                                 trimmed_h, trimmed_w,
-                                 trim_radius, trim_radius)
+        new_cc.rounded_rectangle(0, 0, h, w, trim_radius, trim_radius)
       else
-        new_cc.rounded_rectangle(0, 0,
-                                 trimmed_w, trimmed_h,
-                                 trim_radius, trim_radius)
+        new_cc.rounded_rectangle(0, 0, w, h, trim_radius, trim_radius)
       end
       new_cc.clip
       new_cc.set_source(@cairo_surface, -batch.trim, -batch.trim)
       new_cc.paint
       return new_cc.target
     end
 
+    def scaled_surface(surface, box)
+      new_cc = Cairo::Context.new(Cairo::ImageSurface.new(box.width, box.height))
+      new_cc.scale(
+        box.width.to_f / surface.width,
+        box.height.to_f / surface.height
+      )
+      new_cc.set_source(surface)
+      new_cc.paint
+      return new_cc.target
+    end
+
     def write_png(surface, i, dir, prefix, count_format)
       surface.write_to_png("#{dir}/#{prefix}#{count_format % i}.png")
     end

samples/saves/_save_scaled.rb

@@ -3,14 +3,16 @@
 
 Squib::Deck.new(width: 50, height: 20) do
   background color: :gray
-  text str: 'Text!', font: 'Sans 6'
+  text str: 'Text!', font: 'Sans 5'
 
   save_png prefix: 'save_png_no_scaled_'
   save_png prefix: 'save_png_no_scaled_trimmed_', trim: 5, trim_radius: 5
   # save_png supports scaling to a different size
   save_png width: 100, height: 40, prefix: 'save_png_scaled_'
   save_png width: 100, height: 40, trim: 5, trim_radius: 5,
            prefix: 'save_png_scaled_trimmed_'
-  save_png width: 100, height: 40, trim: 5, trim_radius: 5,
+  save_png width: 40, height: 100, trim: 5, trim_radius: 5,
            rotate: :clockwise, prefix: 'save_png_scaled_trimmed_rotated_'
+  save_png width: 40, height: 100,
+           rotate: :clockwise, prefix: 'save_png_scaled_rotated_'
 end