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, 23 insertions, 0 deletions

diff --git a/core/fxge/dib/fx_dib_main.cpp b/core/fxge/dib/fx_dib_main.cpp
index 8df1322e97..dfdf7ec909 100644
--- a/core/fxge/dib/fx_dib_main.cpp
+++ b/core/fxge/dib/fx_dib_main.cpp
@@ -54,6 +54,29 @@ const int16_t SDP_Table[513] = {
     0,   0,   0,
 };
 
+FXDIB_ResampleOptions::FXDIB_ResampleOptions() = default;
+
+FXDIB_ResampleOptions::FXDIB_ResampleOptions(bool downsample,
+                                             bool bilinear,
+                                             bool bicubic,
+                                             bool halftone,
+                                             bool no_smoothing,
+                                             bool lossy)
+    : bInterpolateDownsample(downsample),
+      bInterpolateBilinear(bilinear),
+      bInterpolateBicubic(bicubic),
+      bHalftone(halftone),
+      bNoSmoothing(no_smoothing),
+      bLossy(lossy) {}
+
+bool FXDIB_ResampleOptions::HasAnyOptions() const {
+  return bInterpolateDownsample || bInterpolateBilinear ||
+         bInterpolateBicubic || bHalftone || bNoSmoothing || bLossy;
+}
+
+const FXDIB_ResampleOptions kBilinearInterpolation = {
+    false, /*bilinear=*/true, false, false, false, false};
+
 FX_RECT FXDIB_SwapClipBox(const FX_RECT& clip,
                           int width,
                           int height,