From 68f83ebade1c29fa3b3fddd732305ddba10facce Mon Sep 17 00:00:00 2001
From: Lee Salzman <lsalzman@mozilla.com>
Date: Mon, 24 Jul 2017 14:12:26 -0400
Subject: [PATCH] Bug 1383817 - clamp gamma/contrast for ScaledFontDWrite when
 creating SkTypeface. r=mchang

MozReview-Commit-ID: LSSffVooDCI
---
 gfx/2d/ScaledFontDWrite.cpp       | 14 +++++++++++++-
 gfx/thebes/gfxWindowsPlatform.cpp |  8 --------
 2 files changed, 13 insertions(+), 9 deletions(-)

diff --git a/gfx/2d/ScaledFontDWrite.cpp b/gfx/2d/ScaledFontDWrite.cpp
index 7d2e6901efde..a1d91b17f871 100644
--- a/gfx/2d/ScaledFontDWrite.cpp
+++ b/gfx/2d/ScaledFontDWrite.cpp
@@ -156,7 +156,19 @@ ScaledFontDWrite::GetSkTypeface()
       return nullptr;
     }
 
-    mTypeface = SkCreateTypefaceFromDWriteFont(factory, mFontFace, mStyle, mForceGDIMode, mGamma, mContrast);
+    Float gamma = mGamma;
+    // Skia doesn't support a gamma value outside of 0-4, so default to 2.2
+    if (gamma < 0.0f || gamma > 4.0f) {
+      gamma = 2.2f;
+    }
+
+    Float contrast = mContrast;
+    // Skia doesn't support a contrast value outside of 0-1, so default to 1.0
+    if (contrast < 0.0f || contrast > 1.0f) {
+      contrast = 1.0f;
+    }
+
+    mTypeface = SkCreateTypefaceFromDWriteFont(factory, mFontFace, mStyle, mForceGDIMode, gamma, contrast);
   }
   return mTypeface;
 }
diff --git a/gfx/thebes/gfxWindowsPlatform.cpp b/gfx/thebes/gfxWindowsPlatform.cpp
index 57c5a18ea075..b0d00b103dd8 100755
--- a/gfx/thebes/gfxWindowsPlatform.cpp
+++ b/gfx/thebes/gfxWindowsPlatform.cpp
@@ -1193,14 +1193,6 @@ gfxWindowsPlatform::SetupClearTypeParams()
             }
         }
 
-        if (GetDefaultContentBackend() == BackendType::SKIA) {
-          // Skia doesn't support a contrast value outside of 0-1, so default to 1.0
-          if (contrast < 0.0 || contrast > 1.0) {
-            NS_WARNING("Custom dwrite contrast not supported in Skia. Defaulting to 1.0.");
-            contrast = 1.0;
-          }
-        }
-
         // For parameters that have not been explicitly set,
         // we copy values from default params (or our overridden value for contrast)
         if (gamma < 1.0 || gamma > 2.2) {