Gamma correction for distance field text.

Handles both non-LCD and LCD text. Uses a texture to look up the gamma correction values for a given text color or luminance.

BUG=skia:
R=reed@google.com, bungeman@google.com, robertphillips@google.com, bsalomon@google.com

Author: jvanverth@google.com

Review URL: https://codereview.chromium.org/258883002

1 files changed, 50 insertions, 15 deletions

diff --git a/src/core/SkGlyphCache.h b/src/core/SkGlyphCache.h
index 8b404dcc09..d18b61a0a9 100644
--- a/src/core/SkGlyphCache.h
+++ b/src/core/SkGlyphCache.h
@@ -244,37 +244,72 @@ private:
     friend class SkGlyphCache_Globals;
 };
 
-class SkAutoGlyphCache {
+class SkAutoGlyphCacheBase {
 public:
-    SkAutoGlyphCache(SkGlyphCache* cache) : fCache(cache) {}
-    SkAutoGlyphCache(SkTypeface* typeface, const SkDescriptor* desc) {
+    SkGlyphCache* getCache() const { return fCache; }
+
+    void release() {
+        if (fCache) {
+            SkGlyphCache::AttachCache(fCache);
+            fCache = NULL;
+        }
+    }
+
+protected:
+    // Hide the constructors so we can't create one of these directly.
+    // Create SkAutoGlyphCache or SkAutoGlyphCacheNoCache instead.
+    SkAutoGlyphCacheBase(SkGlyphCache* cache) : fCache(cache) {}
+    SkAutoGlyphCacheBase(SkTypeface* typeface, const SkDescriptor* desc) {
         fCache = SkGlyphCache::DetachCache(typeface, desc);
     }
+    SkAutoGlyphCacheBase(const SkPaint& paint,
+                         const SkDeviceProperties* deviceProperties,
+                         const SkMatrix* matrix) {
+        fCache = NULL;
+    }
+    SkAutoGlyphCacheBase() {}
+
+    SkGlyphCache*   fCache;
+
+private:
+    static bool DetachProc(const SkGlyphCache*, void*);
+};
+
+class SkAutoGlyphCache : public SkAutoGlyphCacheBase {
+public:
+    SkAutoGlyphCache(SkGlyphCache* cache) : SkAutoGlyphCacheBase(cache) {}
+    SkAutoGlyphCache(SkTypeface* typeface, const SkDescriptor* desc) :
+        SkAutoGlyphCacheBase(typeface, desc) {}
     SkAutoGlyphCache(const SkPaint& paint,
                      const SkDeviceProperties* deviceProperties,
                      const SkMatrix* matrix) {
-        fCache = paint.detachCache(deviceProperties, matrix);
+        fCache = paint.detachCache(deviceProperties, matrix, false);
     }
-    ~SkAutoGlyphCache() {
+    SkAutoGlyphCache() : SkAutoGlyphCacheBase() {
         if (fCache) {
             SkGlyphCache::AttachCache(fCache);
         }
     }
+};
+#define SkAutoGlyphCache(...) SK_REQUIRE_LOCAL_VAR(SkAutoGlyphCache)
 
-    SkGlyphCache* getCache() const { return fCache; }
-
-    void release() {
+class SkAutoGlyphCacheNoGamma : public SkAutoGlyphCacheBase {
+public:
+    SkAutoGlyphCacheNoGamma(SkGlyphCache* cache) : SkAutoGlyphCacheBase(cache) {}
+    SkAutoGlyphCacheNoGamma(SkTypeface* typeface, const SkDescriptor* desc) :
+        SkAutoGlyphCacheBase(typeface, desc) {}
+    SkAutoGlyphCacheNoGamma(const SkPaint& paint,
+                            const SkDeviceProperties* deviceProperties,
+                            const SkMatrix* matrix) {
+        fCache = paint.detachCache(deviceProperties, matrix, true);
+    }
+    SkAutoGlyphCacheNoGamma() : SkAutoGlyphCacheBase() {
         if (fCache) {
             SkGlyphCache::AttachCache(fCache);
-            fCache = NULL;
         }
     }
-
-private:
-    SkGlyphCache*   fCache;
-
-    static bool DetachProc(const SkGlyphCache*, void*);
 };
-#define SkAutoGlyphCache(...) SK_REQUIRE_LOCAL_VAR(SkAutoGlyphCache)
+#define SkAutoGlyphCacheNoGamma(...) SK_REQUIRE_LOCAL_VAR(SkAutoGlyphCacheNoGamma)
+
 
 #endif