add native draw bitmap with alpha mask

PDFs draw bitmaps with alpha by supplying an
image alpha mask along side the image color data.

The alpha mask may not be the same scale as the
image data. Skia doesn't have a direct mapping
for this draw call, but can come close by using
the internal SkCompositeShader class.

This scales the alpha mask to match the size of
the image data, then puts both in the composite
shader to draw.

There are more things to do:

- Allow Alpha8 or Gray8 to draw scaled to
  a matching device (blit doesn't work today)

Temporary code marked with
a TODO implements this functionality.

- Refactor PDFium to allow SkComposeShader's
  components to take a matrix.

The latter goal will defer drawing so that PDFium
doesn't resize the mask, discarding resolution,
before Skia has a chance to record it.

Additionally fix drawing text with a negative
font size.

R=reed@google.com,dsinclair@chromium.org,herb@chromium.org

Review-Url: https://codereview.chromium.org/2182763002

3 files changed, 19 insertions, 0 deletions

diff --git a/core/fxge/include/cfx_fxgedevice.h b/core/fxge/include/cfx_fxgedevice.h
index a5dba37c3e..7f34f1ca4a 100644
--- a/core/fxge/include/cfx_fxgedevice.h
+++ b/core/fxge/include/cfx_fxgedevice.h
@@ -28,8 +28,15 @@ class CFX_FxgeDevice : public CFX_RenderDevice {
 
 #ifdef _SKIA_SUPPORT_
   bool AttachRecorder(SkPictureRecorder* recorder);
+  void Clear(uint32_t color);
   SkPictureRecorder* CreateRecorder(int size_x, int size_y);
   void DebugVerifyBitmapIsPreMultiplied() const override;
+  bool SetBitsWithMask(const CFX_DIBSource* pBitmap,
+                       const CFX_DIBSource* pMask,
+                       int left,
+                       int top,
+                       int bitmap_alpha,
+                       int blend_type) override;
 #endif
 
  private:
diff --git a/core/fxge/include/cfx_renderdevice.h b/core/fxge/include/cfx_renderdevice.h
index fafa6260e1..390d39b69d 100644
--- a/core/fxge/include/cfx_renderdevice.h
+++ b/core/fxge/include/cfx_renderdevice.h
@@ -253,6 +253,12 @@ class CFX_RenderDevice {
 
 #ifdef _SKIA_SUPPORT_
   virtual void DebugVerifyBitmapIsPreMultiplied() const;
+  virtual bool SetBitsWithMask(const CFX_DIBSource* pBitmap,
+                               const CFX_DIBSource* pMask,
+                               int left,
+                               int top,
+                               int bitmap_alpha,
+                               int blend_type);
   void Flush();
 #endif
 
diff --git a/core/fxge/include/ifx_renderdevicedriver.h b/core/fxge/include/ifx_renderdevicedriver.h
index 572469b8c0..8b20cf0838 100644
--- a/core/fxge/include/ifx_renderdevicedriver.h
+++ b/core/fxge/include/ifx_renderdevicedriver.h
@@ -99,6 +99,12 @@ class IFX_RenderDeviceDriver {
                               const FX_RECT& clip_rect,
                               int alpha,
                               FX_BOOL bAlphaMode);
+  virtual bool SetBitsWithMask(const CFX_DIBSource* pBitmap,
+                               const CFX_DIBSource* pMask,
+                               int left,
+                               int top,
+                               int bitmap_alpha,
+                               int blend_type);
 };
 
 #endif  // CORE_FXGE_INCLUDE_IFX_RENDERDEVICEDRIVER_H_