Replace int flags with struct FXDIB_ResampleOptions.

Using bit values in an int may not be reliable, since different parts of
the code can interpret the bits differently. e.g. FXDIB_DOWNSAMPLE and
RENDER_FORCE_DOWNSAMPLE are defined in different places, but can be used
interchangeably because they just happen to have the same value. It
works but is rather fragile.

Instead, use a struct of bools to explicitly define what different bits
mean. Remove FXDIB_DOWNSAMPLE and friends.

Change-Id: I9cf0c8f94d1ed27edf8dba22b0ab0ee67f2722cc
Reviewed-on: https://pdfium-review.googlesource.com/c/44650
Commit-Queue: Lei Zhang <thestig@chromium.org>
Reviewed-by: Tom Sepez <tsepez@chromium.org>

1 files changed, 8 insertions, 6 deletions

diff --git a/core/fxge/dib/cfx_dibbase.cpp b/core/fxge/dib/cfx_dibbase.cpp
index 7fc9bef9cb..1dcbcf9e17 100644
--- a/core/fxge/dib/cfx_dibbase.cpp
+++ b/core/fxge/dib/cfx_dibbase.cpp
@@ -1171,17 +1171,19 @@ RetainPtr<CFX_DIBitmap> CFX_DIBBase::TransformTo(const CFX_Matrix& mtDest,
                                                  int* result_left,
                                                  int* result_top) {
   RetainPtr<CFX_DIBBase> holder(this);
-  CFX_ImageTransformer transformer(holder, mtDest, 0, nullptr);
+  CFX_ImageTransformer transformer(holder, mtDest, FXDIB_ResampleOptions(),
+                                   nullptr);
   transformer.Continue(nullptr);
   *result_left = transformer.result().left;
   *result_top = transformer.result().top;
   return transformer.DetachBitmap();
 }
 
-RetainPtr<CFX_DIBitmap> CFX_DIBBase::StretchTo(int dest_width,
-                                               int dest_height,
-                                               uint32_t flags,
-                                               const FX_RECT* pClip) {
+RetainPtr<CFX_DIBitmap> CFX_DIBBase::StretchTo(
+    int dest_width,
+    int dest_height,
+    const FXDIB_ResampleOptions& options,
+    const FX_RECT* pClip) {
   RetainPtr<CFX_DIBBase> holder(this);
   FX_RECT clip_rect(0, 0, abs(dest_width), abs(dest_height));
   if (pClip)
@@ -1195,7 +1197,7 @@ RetainPtr<CFX_DIBitmap> CFX_DIBBase::StretchTo(int dest_width,
 
   CFX_BitmapStorer storer;
   CFX_ImageStretcher stretcher(&storer, holder, dest_width, dest_height,
-                               clip_rect, flags);
+                               clip_rect, options);
   if (stretcher.Start())
     stretcher.Continue(nullptr);