Decouple contrast boost from fake gamma.

src/core/SkPaint.cpp

Index: src/core/SkPaint.cpp
diff --git a/src/core/SkPaint.cpp b/src/core/SkPaint.cpp
index 8bd386a762a201d4e9adb4121a272e220ddbcc45..650bfa47eec17a2f1fdf8f938fb66351519770a5 100644
--- a/src/core/SkPaint.cpp
+++ b/src/core/SkPaint.cpp
@@ -959,7 +959,7 @@ SkScalar SkPaint::getFontMetrics(FontMetrics* metrics, SkScalar zoom) const {
         metrics = &storage;
     }
 
-    paint.descriptorProc(nullptr, FakeGamma::Off, zoomPtr, FontMetricsDescProc, metrics);
+    paint.descriptorProc(nullptr, kNone_FontWeightFlag, zoomPtr, FontMetricsDescProc, metrics);
 
     if (scale) {
         metrics->fTop = SkScalarMul(metrics->fTop, scale);
@@ -1516,8 +1516,8 @@ void SkScalerContext::PostMakeRec(const SkPaint&, SkScalerContext::Rec* rec) {
             break;
         }
         case SkMask::kBW_Format:
-            // No need to differentiate gamma if we're BW
-            rec->ignorePreBlend();
+            // No need to differentiate gamma or apply contrast if we're BW
+            rec->ignorePreBlend(false);
             break;
     }
 }
@@ -1551,14 +1551,14 @@ static void write_out_descriptor(SkDescriptor* desc, const SkScalerContext::Rec&
 
 static size_t fill_out_rec(const SkPaint& paint, SkScalerContext::Rec* rec,
                            const SkSurfaceProps* surfaceProps,
-                           bool fakeGamma,
+                           bool fakeGamma, bool boostContrast,
                            const SkMatrix* deviceMatrix,
                            const SkPathEffect* pe, SkWriteBuffer* peBuffer,
                            const SkMaskFilter* mf, SkWriteBuffer* mfBuffer,
                            const SkRasterizer* ra, SkWriteBuffer* raBuffer) {
     SkScalerContext::MakeRec(paint, surfaceProps, deviceMatrix, rec);
     if (!fakeGamma) {
-        rec->ignorePreBlend();
+        rec->ignorePreBlend(boostContrast);
     }
 
     int entryCount = 1;
@@ -1580,7 +1580,7 @@ static size_t fill_out_rec(const SkPaint& paint, SkScalerContext::Rec* rec,
            The primary filter is blur, for which contrast makes no sense,
            and for which the destination guess error is more visible.
            Also, all existing users of blur have calibrated for linear. */
-        rec->ignorePreBlend();
+        rec->ignorePreBlend(false);
     }
     if (ra) {
         raBuffer->writeFlattenable(ra);
@@ -1647,7 +1647,7 @@ static void test_desc(const SkScalerContext::Rec& rec,
 /* see the note on ignoreGamma on descriptorProc */
 void SkPaint::getScalerContextDescriptor(SkAutoDescriptor* ad,
                                          const SkSurfaceProps& surfaceProps,
-                                         FakeGamma fakeGamma,
+                                         uint32_t fontWeightFlags,
                                          const SkMatrix* deviceMatrix) const {
     SkScalerContext::Rec    rec;
 
@@ -1656,9 +1656,10 @@ void SkPaint::getScalerContextDescriptor(SkAutoDescriptor* ad,
     SkRasterizer*   ra = this->getRasterizer();
 
     SkWriteBuffer   peBuffer, mfBuffer, raBuffer;
-    size_t descSize = fill_out_rec(*this, &rec,
-                                   &surfaceProps, FakeGamma::On == fakeGamma, deviceMatrix,
-                                   pe, &peBuffer, mf, &mfBuffer, ra, &raBuffer);
+    size_t descSize = fill_out_rec(*this, &rec, &surfaceProps,
+                                   SkToBool(fontWeightFlags & kFakeGamma_FontWeightFlag),
+                                   SkToBool(fontWeightFlags & kBoostContrast_FontWeightFlag),
+                                   deviceMatrix, pe, &peBuffer, mf, &mfBuffer, ra, &raBuffer);
 
     ad->reset(descSize);
     SkDescriptor* desc = ad->getDesc();
@@ -1678,7 +1679,7 @@ void SkPaint::getScalerContextDescriptor(SkAutoDescriptor* ad,
  *  contrast = 0, luminanceColor = transparent black.
  */
 void SkPaint::descriptorProc(const SkSurfaceProps* surfaceProps,
-                             FakeGamma fakeGamma,
+                             uint32_t fontWeightFlags,
                              const SkMatrix* deviceMatrix,
                              void (*proc)(SkTypeface*, const SkDescriptor*, void*),
                              void* context) const {
@@ -1689,9 +1690,10 @@ void SkPaint::descriptorProc(const SkSurfaceProps* surfaceProps,
     SkRasterizer*   ra = this->getRasterizer();
 
     SkWriteBuffer   peBuffer, mfBuffer, raBuffer;
-    size_t descSize = fill_out_rec(*this, &rec,
-                                   surfaceProps, FakeGamma::On == fakeGamma, deviceMatrix,
-                                   pe, &peBuffer, mf, &mfBuffer, ra, &raBuffer);
+    size_t descSize = fill_out_rec(*this, &rec, surfaceProps,
+                                   SkToBool(fontWeightFlags & kFakeGamma_FontWeightFlag),
+                                   SkToBool(fontWeightFlags & kBoostContrast_FontWeightFlag),
+                                   deviceMatrix, pe, &peBuffer, mf, &mfBuffer, ra, &raBuffer);
 
     SkAutoDescriptor    ad(descSize);
     SkDescriptor*       desc = ad.getDesc();
@@ -1708,10 +1710,10 @@ void SkPaint::descriptorProc(const SkSurfaceProps* surfaceProps,
 }
 
 SkGlyphCache* SkPaint::detachCache(const SkSurfaceProps* surfaceProps,
-                                   FakeGamma fakeGamma,
+                                   uint32_t fontWeightFlags,
                                    const SkMatrix* deviceMatrix) const {
     SkGlyphCache* cache;
-    this->descriptorProc(surfaceProps, fakeGamma, deviceMatrix, DetachDescProc, &cache);
+    this->descriptorProc(surfaceProps, fontWeightFlags, deviceMatrix, DetachDescProc, &cache);
     return cache;
 }
 
@@ -2246,7 +2248,8 @@ SkTextBaseIter::SkTextBaseIter(const char text[], size_t length,
         fPaint.setPathEffect(nullptr);
     }
 
-    fCache = fPaint.detachCache(nullptr, SkPaint::FakeGamma::On, nullptr);
+    // SRGBTODO: Is this correct?
+    fCache = fPaint.detachCache(nullptr, SkPaint::kFakeGammaAndContrast_FontWeightFlag, nullptr);

[Brian Osman, 2016/04/07 17:08:32]

It seems like the choice of flags here may be arbitrary? SkTextInterceptsIter
looks like it just relies on the font metrics, and SkTextToPathIter just gets
the pathified version of glyphs. It doesn't look like either of those care about
the mask?

 
     SkPaint::Style  style = SkPaint::kFill_Style;
     sk_sp<SkPathEffect> pe;