Added Image#draw

lib/dxruby_sdl/image.rb

@@ -114,6 +114,10 @@ def box_fill(x1, y1, x2, y2, color)
       return self
     end
 
+    def draw(x, y, image, x1 = 0, y1 = 0, width = image.width, height = image.height)
+      SDL.blitSurface(image, x1, y1, width, height, self, x, y)
+    end
+
     def draw_font(x, y, string, font, color = [255, 255, 255])
       if string.empty?
         return

spec/lib/dxruby_sdl/image_spec.rb

@@ -196,6 +196,43 @@
     end
   end
 
+  shared_context 'Source and Destination Images' do
+    let(:source_image) { DXRubySDL::Image.new(640, 480) }
+    let(:dest_image) { DXRubySDL::Image.new(640, 480) }
+  end
+
+  describe '#draw' do
+    context 'nothing argumet' do
+      include_context 'Source and Destination Images'
+
+      subject { source_image.draw(0, 0, dest_image) }
+
+      before do
+        allow(SDL).to receive(:blitSurface)
+        subject
+      end
+
+      describe SDL do
+        it { expect(SDL).to have_received(:blitSurface).with( dest_image, 0, 0, dest_image.width, dest_image.height, source_image, 0, 0).once }
+      end
+    end
+
+    context 'Specify argument' do
+      include_context 'Source and Destination Images'
+
+      subject { source_image.draw(0, 0, dest_image, 100, 200, 300, 400) }
+
+      before do
+        allow(SDL).to receive(:blitSurface)
+        subject
+      end
+
+      describe SDL do
+        it { expect(SDL).to have_received(:blitSurface).with(dest_image, 100, 200, 300, 400, source_image, 0, 0).once }
+      end
+    end
+  end
+
   shared_context '#draw_font' do
     let!(:font) { DXRubySDL::Font.new(32) }
     let(:args) { [0, 0, 'やあ', font] }