add native draw bitmap with alpha mask

core/fpdfapi/fpdf_render/fpdf_render_image.cpp

 // Copyright 2014 PDFium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
 #include "core/fpdfapi/fpdf_render/render_int.h"
 
 #include <memory>
 #include <utility>
@@ skipping 628 matching lines @@
       }
     }
     bitmap_device2.GetBitmap()->ConvertFormat(FXDIB_8bppMask);
     bitmap_device1.GetBitmap()->MultiplyAlpha(bitmap_device2.GetBitmap());
     bitmap_device1.GetBitmap()->MultiplyAlpha(255);
   }
   m_pRenderStatus->m_pDevice->SetDIBitsWithBlend(
       bitmap_device1.GetBitmap(), rect.left, rect.top, m_BlendType);
   return FALSE;
 }
+
 FX_BOOL CPDF_ImageRenderer::DrawMaskedImage() {
   if (m_pRenderStatus->m_bPrint &&
       !(m_pRenderStatus->m_pDevice->GetRenderCaps() & FXRC_BLEND_MODE)) {
     m_Result = FALSE;
     return FALSE;
   }
   FX_RECT rect = m_ImageMatrix.GetUnitRect().GetOuterRect();
   rect.Intersect(m_pRenderStatus->m_pDevice->GetClipBox());
   if (rect.IsEmpty()) {
     return FALSE;
   }
   CFX_Matrix new_matrix = m_ImageMatrix;
   new_matrix.TranslateI(-rect.left, -rect.top);
   int width = rect.Width();
   int height = rect.Height();
   CFX_FxgeDevice bitmap_device1;
   if (!bitmap_device1.Create(width, height, FXDIB_Rgb32, nullptr))
     return TRUE;
 
+#if defined _SKIA_SUPPORT_
+  bitmap_device1.Clear(0xffffff);
+#else
   bitmap_device1.GetBitmap()->Clear(0xffffff);
+#endif
   {
     CPDF_RenderStatus bitmap_render;
     bitmap_render.Initialize(m_pRenderStatus->m_pContext, &bitmap_device1,
                              nullptr, nullptr, nullptr, nullptr, nullptr, 0,
                              m_pRenderStatus->m_bDropObjects, nullptr, TRUE);
     CPDF_ImageRenderer image_render;
     if (image_render.Start(&bitmap_render, m_pDIBSource, 0, 255, &new_matrix,
                            m_Flags, TRUE)) {
       image_render.Continue(nullptr);
     }
   }
   {
     CFX_FxgeDevice bitmap_device2;
     if (!bitmap_device2.Create(width, height, FXDIB_8bppRgb, nullptr))
       return TRUE;
 
+#if defined _SKIA_SUPPORT_
+    bitmap_device2.Clear(0);
+#else
     bitmap_device2.GetBitmap()->Clear(0);
+#endif
     CPDF_RenderStatus bitmap_render;
     bitmap_render.Initialize(m_pRenderStatus->m_pContext, &bitmap_device2,
                              nullptr, nullptr, nullptr, nullptr, nullptr, 0,
                              m_pRenderStatus->m_bDropObjects, nullptr, TRUE);
     CPDF_ImageRenderer image_render;
     if (image_render.Start(&bitmap_render, m_Loader.m_pMask, 0xffffffff, 255,
                            &new_matrix, m_Flags, TRUE)) {
       image_render.Continue(nullptr);
     }
     if (m_Loader.m_MatteColor != 0xffffffff) {
@@ skipping 28 matching lines @@
               orig = 255;
             }
             *dest_scan++ = orig;
             dest_scan++;
           } else {
             dest_scan += 4;
           }
         }
       }
     }
+#ifdef _SKIA_SUPPORT_
+    m_pRenderStatus->m_pDevice->SetBitsWithMask(
+        bitmap_device1.GetBitmap(), bitmap_device2.GetBitmap(), rect.left,
+        rect.top, m_BitmapAlpha, m_BlendType);
+  }
+#else
     bitmap_device2.GetBitmap()->ConvertFormat(FXDIB_8bppMask);
     bitmap_device1.GetBitmap()->MultiplyAlpha(bitmap_device2.GetBitmap());
-#ifdef _SKIA_SUPPORT_
-    CFX_SkiaDeviceDriver::PreMultiply(bitmap_device1.GetBitmap());
-#endif
     if (m_BitmapAlpha < 255) {
       bitmap_device1.GetBitmap()->MultiplyAlpha(m_BitmapAlpha);
     }
   }
   m_pRenderStatus->m_pDevice->SetDIBitsWithBlend(
       bitmap_device1.GetBitmap(), rect.left, rect.top, m_BlendType);
+#endif  //  _SKIA_SUPPORT_
   return FALSE;
 }
 
 FX_BOOL CPDF_ImageRenderer::StartDIBSource() {
   if (!(m_Flags & RENDER_FORCE_DOWNSAMPLE) && m_pDIBSource->GetBPP() > 1) {
     int image_size = m_pDIBSource->GetBPP() / 8 * m_pDIBSource->GetWidth() *
                      m_pDIBSource->GetHeight();
     if (image_size > FPDF_HUGE_IMAGE_SIZE &&
         !(m_Flags & RENDER_FORCE_HALFTONE)) {
       m_Flags |= RENDER_FORCE_DOWNSAMPLE;
     }
   }
 #ifdef _SKIA_SUPPORT_
   CFX_DIBitmap* premultiplied = m_pDIBSource->Clone();
-  CFX_SkiaDeviceDriver::PreMultiply(premultiplied);
+  if (m_pDIBSource->HasAlpha())
+    CFX_SkiaDeviceDriver::PreMultiply(premultiplied);
   if (m_pRenderStatus->m_pDevice->StartDIBitsWithBlend(
           premultiplied, m_BitmapAlpha, m_FillArgb, &m_ImageMatrix, m_Flags,
           m_DeviceHandle, m_BlendType)) {
     if (m_DeviceHandle) {
       m_Status = 3;
       return TRUE;
     }
     return FALSE;
   }
 #else
@@ skipping 284 matching lines @@
   } else if (pFunc) {
     int size = dest_pitch * height;
     for (int i = 0; i < size; i++) {
       dest_buf[i] = transfers[src_buf[i]];
     }
   } else {
     FXSYS_memcpy(dest_buf, src_buf, dest_pitch * height);
   }
   return pMask.release();
 }