...

3 files changed, 29 insertions, 5 deletions

diff --git a/include/cru/osx/graphics/quartz/ImageFactory.h b/include/cru/osx/graphics/quartz/ImageFactory.h
index e9854738..19e9c8c1 100644
--- a/include/cru/osx/graphics/quartz/ImageFactory.h
+++ b/include/cru/osx/graphics/quartz/ImageFactory.h
@@ -15,5 +15,6 @@ class QuartzImageFactory : public OsxQuartzResource,
 
  public:
   std::unique_ptr<IImage> DecodeFromStream(io::Stream* stream) override;
+  std::unique_ptr<IImage> CreateBitmap(int width, int height) override;
 };
 }  // namespace cru::platform::graphics::osx::quartz
diff --git a/include/cru/platform/graphics/ImageFactory.h b/include/cru/platform/graphics/ImageFactory.h
index 2a7902b2..e74f57e0 100644
--- a/include/cru/platform/graphics/ImageFactory.h
+++ b/include/cru/platform/graphics/ImageFactory.h
@@ -7,5 +7,12 @@ namespace cru::platform::graphics {
 struct CRU_PLATFORM_GRAPHICS_API IImageFactory
     : public virtual IGraphicsResource {
   virtual std::unique_ptr<IImage> DecodeFromStream(io::Stream* stream) = 0;
+
+  /**
+   * \brief Create an empty bitmap with given width and height.
+   * \remarks Implementation should ensure that the bitmap supports alpha
+   * channel. It had better be in 32-bit rgba format.
+   */
+  virtual std::unique_ptr<IImage> CreateBitmap(int width, int height) = 0;
 };
 }  // namespace cru::platform::graphics
diff --git a/src/osx/graphics/quartz/ImageFactory.cpp b/src/osx/graphics/quartz/ImageFactory.cpp
index 7796ef3a..95315e1a 100644
--- a/src/osx/graphics/quartz/ImageFactory.cpp
+++ b/src/osx/graphics/quartz/ImageFactory.cpp
@@ -1,4 +1,5 @@
 #include "cru/osx/graphics/quartz/ImageFactory.h"
+#include "cru/common/Exception.h"
 #include "cru/osx/graphics/quartz/Convert.h"
 #include "cru/osx/graphics/quartz/Image.h"
 #include "cru/platform/graphics/Image.h"
@@ -20,12 +21,27 @@ std::unique_ptr<IImage> QuartzImageFactory::DecodeFromStream(
   CGImageRef cg_image =
       CGImageSourceCreateImageAtIndex(image_source, 0, nullptr);
 
-  QuartzImage* image =
-      new QuartzImage(GetGraphicsFactory(), this, cg_image, true);
-
-  CFRelease(cg_image);
+  CFRelease(image_source);
   CGDataProviderRelease(data_provider);
 
-  return std::unique_ptr<IImage>(image);
+  return std::unique_ptr<IImage>(
+      new QuartzImage(GetGraphicsFactory(), this, cg_image, true));
+}
+
+std::unique_ptr<IImage> QuartzImageFactory::CreateBitmap(int width,
+                                                         int height) {
+  if (width <= 0) throw Exception(u"Image width should be greater than 0.");
+  if (height <= 0) throw Exception(u"Image height should be greater than 0.");
+
+  CGColorSpaceRef color_space = CGColorSpaceCreateDeviceRGB();
+
+  auto cg_image = CGImageCreate(width, height, 8, 32, 4 * width, color_space,
+                                kCGImageAlphaLast, nullptr, nullptr, true,
+                                kCGRenderingIntentDefault);
+
+  CGColorSpaceRelease(color_space);
+
+  return std::unique_ptr<IImage>(
+      new QuartzImage(GetGraphicsFactory(), this, cg_image, true));
 }
 }  // namespace cru::platform::graphics::osx::quartz