feat: add vips rotate

Reference images diffs:
- plasma-rotated-90 - MAE (Mean Average Error): 0.00802462
- plasma-rotated-180 - MAE: 0.0080234
- plasma-rotated-270 - MAE: 0.00750394

CHANGELOG.md

@@ -9,6 +9,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 - Vips image processor (resizing)
 - Vips colour filters
 - Vips crop
+- Vips rotate
 
 ### Removed
 - [BREAKING] dropped support for a broken 'dominant' border colour

lib/morandi/vips_image_processor.rb

@@ -60,6 +60,7 @@ def process!
         @scale = 1.0
       end
 
+      apply_rotate!
       apply_crop!
       apply_filters!
 
@@ -83,6 +84,23 @@ def write_to_jpeg(write_to, quality = nil)
 
     private
 
+    def angle
+      @options['angle'].to_i % 360
+    end
+
+    def apply_rotate!
+      @img = case angle
+             when 0 then @img
+             when 90 then @img.rot90
+             when 180 then @img.rot180
+             when 270 then @img.rot270
+             else raise('"angle" option only accepts multiples of 90')
+             end
+
+      @image_width = @img.width
+      @image_height = @img.height
+    end
+
     def apply_crop!
       crop = @options['crop']
 

spec/morandi_spec.rb

@@ -111,30 +111,30 @@
     describe 'when given an angle of rotation' do
       let(:options) { { 'angle' => angle } }
 
-      context '90 degress', vips_wip: processor_name == 'vips' do
+      context '90 degress' do
         let(:angle) { 90 }
 
         it 'rotates the image' do
           process_image
-          expect(file_out).to match_reference_image('plasma-rotated-90')
+          expect(file_out).to match_reference_image(reference_image_prefix, 'plasma-rotated-90')
         end
       end
 
-      context '180 degress', vips_wip: processor_name == 'vips' do
+      context '180 degress' do
         let(:angle) { 180 }
 
         it 'rotates the image' do
           process_image
-          expect(file_out).to match_reference_image('plasma-rotated-180')
+          expect(file_out).to match_reference_image(reference_image_prefix, 'plasma-rotated-180')
         end
       end
 
-      context '270 degress', vips_wip: processor_name == 'vips' do
+      context '270 degress' do
         let(:angle) { 270 }
 
         it 'rotates the image' do
           process_image
-          expect(file_out).to match_reference_image('plasma-rotated-270')
+          expect(file_out).to match_reference_image(reference_image_prefix, 'plasma-rotated-270')
         end
       end