Add SkFontHost::FilterRect() which allows the font host to filter our request

before we turn it into a font-cache entry, for the cases where the scaler will
ignore and/or collapse certain feature requests (e.g. doesn't support all levels
of hinting)



git-svn-id: http://skia.googlecode.com/svn/trunk@283 2bbb7eff-a529-9590-31e7-b0007b416f81

4 files changed, 30 insertions, 4 deletions

diff --git a/include/config/SkUserConfig.h b/include/config/SkUserConfig.h
index 2d51204573..ccdf40fe92 100644
--- a/include/config/SkUserConfig.h
+++ b/include/config/SkUserConfig.h
@@ -115,7 +115,7 @@
 /*  To enable additional blitters (and fontscaler code) to support separate
     alpha channels for R G B channels, define SK_SUPPORT_LCDTEXT
  */
-#define SK_SUPPORT_LCDTEXT
+//#define SK_SUPPORT_LCDTEXT
 
 /*  If SK_DEBUG is defined, then you can optionally define SK_SUPPORT_UNITTEST
     which will run additional self-tests at startup. These can take a long time,
diff --git a/include/core/SkFontHost.h b/include/core/SkFontHost.h
index 12f20a0e7a..752c352069 100644
--- a/include/core/SkFontHost.h
+++ b/include/core/SkFontHost.h
@@ -131,6 +131,20 @@ public:
 
     ///////////////////////////////////////////////////////////////////////////
 
+    /** Given a filled-out rec, the fonthost may decide to modify it to reflect
+        what the host is actually capable of fulfilling. For example, if the
+        rec is requesting a level of hinting that, for this host, maps some
+        other level (e.g. kFull -> kNormal), it should update the rec to reflect
+        what will actually be done. This is an optimization so that the font
+        cache does not contain different recs (i.e. keys) that in reality map to
+        the same output.
+     
+        A lazy (but valid) fonthost can do nothing in its FilterRec routine.
+     */
+    static void FilterRec(SkScalerContext::Rec* rec);
+
+    ///////////////////////////////////////////////////////////////////////////
+    
     /** Return the number of tables in the font
      */
     static int CountTables(SkFontID);
diff --git a/include/core/SkMask.h b/include/core/SkMask.h
index 8c041e45d1..4139d0bfc5 100644
--- a/include/core/SkMask.h
+++ b/include/core/SkMask.h
@@ -126,6 +126,10 @@ struct SkMask {
         kJustRenderImage_CreateMode,        //!< render into preallocate mask
         kComputeBoundsAndRenderImage_CreateMode  //!< compute bounds, alloc image and render into it
     };
+    
+    static bool FormatIsLCD(Format fm) {
+        return kHorizontalLCD_Format == fm || kVerticalLCD_Format == fm;
+    }
 };
 
 #endif
diff --git a/include/core/SkScalerContext.h b/include/core/SkScalerContext.h
index dbe8ecb0b8..dd01bc68b7 100644
--- a/include/core/SkScalerContext.h
+++ b/include/core/SkScalerContext.h
@@ -152,8 +152,8 @@ public:
         kGammaForWhite_Flag = 0x08, // illegal to set both Gamma flags
         // together, these two flags resulting in a two bit value which matches
         // up with the SkPaint::Hinting enum.
-        kHintingBit1        = 0x10,
-        kHintingBit2        = 0x20,
+        kHintingBit1_Flag   = 0x10,
+        kHintingBit2_Flag   = 0x20,
     };
     struct Rec {
         uint32_t    fFontID;
@@ -174,9 +174,17 @@ public:
         }
 
         void setHinting(SkPaint::Hinting hinting) {
-            fFlags = (fFlags & ~(kHintingBit1 | kHintingBit2)) |
+            fFlags = (fFlags & ~(kHintingBit1_Flag | kHintingBit2_Flag)) |
                      (static_cast<int>(hinting) << 4);
         }
+
+        SkMask::Format getFormat() const {
+            return static_cast<SkMask::Format>(fMaskFormat);
+        }
+
+        bool isLCD() const {
+            return SkMask::FormatIsLCD(this->getFormat());
+        }
     };
 
     SkScalerContext(const SkDescriptor* desc);