commit 9fa4c12a40fe32c193c16acf0ad5c4bf1056aa36
author Lei Zhang <thestig@chromium.org> Fri Mar 28 22:23:37 2025 -0700
committer Pdfium LUCI CQ <pdfium-scoped@luci-project-accounts.iam.gserviceaccount.com> Fri Mar 28 22:23:37 2025 -0700
tree 6b6bddde2b3b9fd236aae39b31f9b312a136ff7b
parent 1b73b02127fd59ac9f869adb6fe24870aa565061

Remove do_premultiply parameter for CFX_DIBitmap::ScopedPremultiplier

All the places that instantiate ScopedPremultiplier use the same logic
for determining the do_premultiply value. Remove the parameter and
determine the do_premultiply value in NeedToPremultiplyBitmap() inside
cfx_dibitmap.cpp. This make it easier to change the logic later.

Bug: 42271033
Change-Id: I4811d36a398d8ae6044162f44bda3a61b55c1866
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/129011
Commit-Queue: Lei Zhang <thestig@chromium.org>
Reviewed-by: Tom Sepez <tsepez@chromium.org>
Reviewed-by: Thomas Sepez <tsepez@google.com>

core/fxge/dib/cfx_dibitmap.cpp

diff --git a/core/fxge/dib/cfx_dibitmap.cpp b/core/fxge/dib/cfx_dibitmap.cpp
index e37626c..6b9b1ca 100644
--- a/core/fxge/dib/cfx_dibitmap.cpp
+++ b/core/fxge/dib/cfx_dibitmap.cpp
@@ -961,9 +961,8 @@
 
 #if defined(PDF_USE_SKIA)
 CFX_DIBitmap::ScopedPremultiplier::ScopedPremultiplier(
-    RetainPtr<CFX_DIBitmap> bitmap,
-    bool do_premultiply)
-    : bitmap_(std::move(bitmap)), do_premultiply_(do_premultiply) {
+    RetainPtr<CFX_DIBitmap> bitmap)
+    : bitmap_(std::move(bitmap)), do_premultiply_(NeedToPremultiplyBitmap()) {
   CHECK(!bitmap_->IsPremultiplied());
   if (do_premultiply_) {
     bitmap_->PreMultiply();
@@ -976,4 +975,9 @@
   }
   CHECK(!bitmap_->IsPremultiplied());
 }
+
+bool CFX_DIBitmap::ScopedPremultiplier::NeedToPremultiplyBitmap() const {
+  return CFX_DefaultRenderDevice::UseSkiaRenderer();
+}
+
 #endif  // defined(PDF_USE_SKIA)

core/fxge/dib/cfx_dibitmap.h

diff --git a/core/fxge/dib/cfx_dibitmap.h b/core/fxge/dib/cfx_dibitmap.h
index 752765e..b097936 100644
--- a/core/fxge/dib/cfx_dibitmap.h
+++ b/core/fxge/dib/cfx_dibitmap.h
@@ -34,11 +34,15 @@
   class ScopedPremultiplier {
    public:
     // `bitmap` must start out un-premultiplied.
-    // ScopedPremultiplier is a no-op if `do_premultiply` is false.
-    ScopedPremultiplier(RetainPtr<CFX_DIBitmap> bitmap, bool do_premultiply);
+    // ScopedPremultiplier is a no-op if `bitmap` does not need to be
+    // pre-multiplied, as determined by NeedToPremultiplyBitmap().
+    explicit ScopedPremultiplier(RetainPtr<CFX_DIBitmap> bitmap);
     ~ScopedPremultiplier();
 
    private:
+    // Returns true if Skia is enabled at runtime.
+    bool NeedToPremultiplyBitmap() const;
+
     RetainPtr<CFX_DIBitmap> const bitmap_;
     const bool do_premultiply_;
   };

fpdfsdk/fpdf_formfill.cpp

diff --git a/fpdfsdk/fpdf_formfill.cpp b/fpdfsdk/fpdf_formfill.cpp
index 2ad5fcc..5b7bc30 100644
--- a/fpdfsdk/fpdf_formfill.cpp
+++ b/fpdfsdk/fpdf_formfill.cpp
@@ -734,7 +734,7 @@
 
 #if defined(PDF_USE_SKIA)
   CFX_DIBitmap::ScopedPremultiplier scoped_premultiplier(
-      pdfium::WrapRetain(cbitmap), CFX_DefaultRenderDevice::UseSkiaRenderer());
+      pdfium::WrapRetain(cbitmap));
 #endif
   FFLCommon(hHandle, page, cbitmap, start_x, start_y, size_x, size_y, rotate,
             flags);

fpdfsdk/fpdf_view.cpp

diff --git a/fpdfsdk/fpdf_view.cpp b/fpdfsdk/fpdf_view.cpp
index 316f205..da464bc 100644
--- a/fpdfsdk/fpdf_view.cpp
+++ b/fpdfsdk/fpdf_view.cpp
@@ -718,8 +718,7 @@
   pPage->SetRenderContext(std::move(owned_context));
 
 #if defined(PDF_USE_SKIA)
-  CFX_DIBitmap::ScopedPremultiplier scoped_premultiplier(
-      pBitmap, CFX_DefaultRenderDevice::UseSkiaRenderer());
+  CFX_DIBitmap::ScopedPremultiplier scoped_premultiplier(pBitmap);
 #endif
   auto device = std::make_unique<CFX_DefaultRenderDevice>();
   device->AttachWithRgbByteOrder(std::move(pBitmap),
@@ -755,8 +754,7 @@
   pPage->SetRenderContext(std::move(owned_context));
 
 #if defined(PDF_USE_SKIA)
-  CFX_DIBitmap::ScopedPremultiplier scoped_premultiplier(
-      pBitmap, CFX_DefaultRenderDevice::UseSkiaRenderer());
+  CFX_DIBitmap::ScopedPremultiplier scoped_premultiplier(pBitmap);
 #endif
   auto device = std::make_unique<CFX_DefaultRenderDevice>();
   device->AttachWithRgbByteOrder(std::move(pBitmap),