grab from latest android

git-svn-id: http://skia.googlecode.com/svn/trunk@27 2bbb7eff-a529-9590-31e7-b0007b416f81

1 files changed, 125 insertions, 0 deletions

diff --git a/include/core/SkColorFilter.h b/include/core/SkColorFilter.h
new file mode 100644
index 0000000000..a1b3171fdd
--- /dev/null
+++ b/include/core/SkColorFilter.h
@@ -0,0 +1,125 @@
+/*
+ * 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 SkColorFilter_DEFINED
+#define SkColorFilter_DEFINED
+
+#include "SkColor.h"
+#include "SkFlattenable.h"
+#include "SkPorterDuff.h"
+
+class SkColorFilter : public SkFlattenable {
+public:
+    /** Called with a scanline of colors, as if there was a shader installed.
+        The implementation writes out its filtered version into result[].
+        Note: shader and result may be the same buffer.
+        @param src      array of colors, possibly generated by a shader
+        @param count    the number of entries in the src[] and result[] arrays
+        @param result   written by the filter
+    */
+    virtual void filterSpan(const SkPMColor src[], int count,
+                            SkPMColor result[]) = 0;
+    /** Called with a scanline of colors, as if there was a shader installed.
+        The implementation writes out its filtered version into result[].
+        Note: shader and result may be the same buffer.
+        @param src      array of colors, possibly generated by a shader
+        @param count    the number of entries in the src[] and result[] arrays
+        @param result   written by the filter
+    */
+    virtual void filterSpan16(const uint16_t shader[], int count,
+                              uint16_t result[]);
+
+    enum Flags {
+        /** If set the filter methods will not change the alpha channel of the
+            colors.
+        */
+        kAlphaUnchanged_Flag = 0x01,
+        /** If set, this subclass implements filterSpan16(). If this flag is
+            set, then kAlphaUnchanged_Flag must also be set.
+        */
+        kHasFilter16_Flag    = 0x02
+    };
+
+    /** Returns the flags for this filter. Override in subclasses to return
+        custom flags.
+    */
+    virtual uint32_t getFlags() { return 0; }
+
+    /** Create a colorfilter that uses the specified color and porter-duff mode.
+        If porterDuffMode is DST, this function will return NULL (since that
+        mode will have no effect on the result).
+        @param srcColor The source color used with the specified mode
+        @param mode     The porter-duff mode that is applied to each color in
+                        the colorfilter's filterSpan[16,32] methods
+        @return colorfilter object that applies the src color and porter-duff
+                mode, or NULL if the mode will have no effect.
+    */
+    static SkColorFilter* CreatePorterDuffFilter(SkColor srcColor,
+                                                 SkPorterDuff::Mode mode);
+
+    /** Create a colorfilter that calls through to the specified procs to
+        filter the colors. The SkXfermodeProc parameter must be non-null, but
+        the SkXfermodeProc16 is optional, and may be null.
+    */
+    static SkColorFilter* CreatXfermodeProcFilter(SkColor srcColor,
+                                              SkXfermodeProc proc,
+                                              SkXfermodeProc16 proc16 = NULL);
+
+    /** Create a colorfilter that multiplies the RGB channels by one color, and
+        then adds a second color, pinning the result for each component to
+        [0..255]. The alpha components of the mul and add arguments
+        are ignored.
+    */
+    static SkColorFilter* CreateLightingFilter(SkColor mul, SkColor add);
+    
+protected:
+    SkColorFilter() {}
+    SkColorFilter(SkFlattenableReadBuffer& rb) : INHERITED(rb) {}
+    
+private:
+    typedef SkFlattenable INHERITED;
+};
+
+#include "SkShader.h"
+
+class SkFilterShader : public SkShader {
+public:
+    SkFilterShader(SkShader* shader, SkColorFilter* filter);
+    virtual ~SkFilterShader();
+
+    // override
+    virtual uint32_t getFlags();
+    virtual bool setContext(const SkBitmap& device, const SkPaint& paint,
+                            const SkMatrix& matrix);
+    virtual void shadeSpan(int x, int y, SkPMColor result[], int count);
+    virtual void shadeSpan16(int x, int y, uint16_t result[], int count);
+    virtual void beginSession();
+    virtual void endSession();
+    
+protected:
+    SkFilterShader(SkFlattenableReadBuffer& );
+    virtual void flatten(SkFlattenableWriteBuffer& );
+    virtual Factory getFactory() { return CreateProc; }
+private:
+    static SkFlattenable* CreateProc(SkFlattenableReadBuffer& buffer) { 
+        return SkNEW_ARGS(SkFilterShader, (buffer)); }
+    SkShader*       fShader;
+    SkColorFilter*  fFilter;
+    
+    typedef SkShader INHERITED;
+};
+
+#endif