rename gamma to table, since it is more general than just gamma

git-svn-id: http://skia.googlecode.com/svn/trunk@412 2bbb7eff-a529-9590-31e7-b0007b416f81

1 files changed, 76 insertions, 0 deletions

diff --git a/include/effects/SkTableMaskFilter.h b/include/effects/SkTableMaskFilter.h
new file mode 100644
index 0000000000..a57053d6f3
--- /dev/null
+++ b/include/effects/SkTableMaskFilter.h
@@ -0,0 +1,76 @@
+/*
+ * Copyright (C) 2006 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef SkTableMaskFilter_DEFINED
+#define SkTableMaskFilter_DEFINED
+
+#include "SkMaskFilter.h"
+#include "SkScalar.h"
+
+/** \class SkTableMaskFilter
+ 
+    Applies a table lookup on each of the alpha values in the mask.
+    Helper methods create some common tables (e.g. gamma, clipping)
+ */
+class SkTableMaskFilter : public SkMaskFilter {
+public:
+    SkTableMaskFilter();
+    SkTableMaskFilter(const uint8_t table[256]);
+    virtual ~SkTableMaskFilter();
+
+    void setTable(const uint8_t table[256]);
+
+    /** Utility that sets the gamma table
+     */
+    static void MakeGammaTable(uint8_t table[256], SkScalar gamma);
+
+    /** Utility that creates a clipping table: clamps values below min to 0
+        and above max to 255, and rescales the remaining into 0..255
+     */
+    static void MakeClipTable(uint8_t table[256], uint8_t min, uint8_t max);
+
+    static SkTableMaskFilter* CreateGamma(SkScalar gamma) {
+        uint8_t table[256];
+        MakeGammaTable(table, gamma);
+        return SkNEW_ARGS(SkTableMaskFilter, (table));
+    }
+
+    static SkTableMaskFilter* CreateClip(uint8_t min, uint8_t max) {
+        uint8_t table[256];
+        MakeClipTable(table, min, max);
+        return SkNEW_ARGS(SkTableMaskFilter, (table));
+    }
+
+    // overrides from SkMaskFilter
+    virtual SkMask::Format getFormat();
+    virtual bool filterMask(SkMask*, const SkMask&, const SkMatrix&, SkIPoint*);
+    
+    // overrides from SkFlattenable
+    virtual void flatten(SkFlattenableWriteBuffer& wb);
+    virtual Factory getFactory();
+
+protected:
+    SkTableMaskFilter(SkFlattenableReadBuffer& rb);
+    static SkFlattenable* Factory(SkFlattenableReadBuffer&);
+
+private:
+    uint8_t fTable[256];
+    
+    typedef SkMaskFilter INHERITED;
+};
+
+#endif
+