Implement a generic matrix transform image filter.

include/effects/SkMatrixImageFilter.h

 /*
- * Copyright 2013 The Android Open Source Project
+ * Copyright 2014 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
-#ifndef SkResizeImageFilter_DEFINED
-#define SkResizeImageFilter_DEFINED
+#ifndef SkMatrixImageFilter_DEFINED
+#define SkMatrixImageFilter_DEFINED
 
 #include "SkImageFilter.h"
 #include "SkScalar.h"
-#include "SkRect.h"
+#include "SkSize.h"
 #include "SkPoint.h"
 #include "SkPaint.h"
 
-/*! \class SkResizeImageFilter
-    Resampling image filter. This filter draws its source image resampled using the given scale
-    values.
+/*! \class SkMatrixImageFilter
+    Matrix transformation image filter.  This filter draws its source
+    input transformed by the given matrix.
  */
 
-class SK_API SkResizeImageFilter : public SkImageFilter {
+class SK_API SkMatrixImageFilter : public SkImageFilter {
 public:
-    virtual ~SkResizeImageFilter();
-
-    /** Construct a (scaling-only) resampling image filter.
-     *  @param sx           The x scale parameter to apply when resizing.
-     *  @param sy           The y scale parameter to apply when resizing.
+    /** Construct a 2D transformation image filter.
+     *  @param transform    The matrix to apply when drawing the src bitmap
      *  @param filterLevel  The quality of filtering to apply when scaling.
      *  @param input        The input image filter.  If NULL, the src bitmap
      *                      passed to filterImage() is used instead.
      */
-    static SkResizeImageFilter* Create(SkScalar sx, SkScalar sy, SkPaint::FilterLevel filterLevel,
-                                       SkImageFilter* input = NULL) {
-        return SkNEW_ARGS(SkResizeImageFilter, (sx, sy, filterLevel, input));
-    }
+
+    static SkMatrixImageFilter* Create(const SkMatrix& transform,
+                                       SkPaint::FilterLevel,
+                                       SkImageFilter* input = NULL);
+    virtual ~SkMatrixImageFilter();
 
     virtual void computeFastBounds(const SkRect&, SkRect*) const SK_OVERRIDE;
 
-    SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkResizeImageFilter)
+    SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkMatrixImageFilter)
 
 protected:
-    SkResizeImageFilter(SkReadBuffer& buffer);
+    SkMatrixImageFilter(const SkMatrix& transform,
+                        SkPaint::FilterLevel,
+                        SkImageFilter* input = NULL);
+    SkMatrixImageFilter(SkReadBuffer& buffer);
     virtual void flatten(SkWriteBuffer&) const SK_OVERRIDE;
 
     virtual bool onFilterImage(Proxy*, const SkBitmap& src, const Context&,
                                SkBitmap* result, SkIPoint* loc) const SK_OVERRIDE;
     virtual bool onFilterBounds(const SkIRect& src, const SkMatrix&,
                                 SkIRect* dst) const SK_OVERRIDE;
 
-#ifdef SK_SUPPORT_LEGACY_PUBLICEFFECTCONSTRUCTORS
-public:
-#endif
-    SkResizeImageFilter(SkScalar sx, SkScalar sy, SkPaint::FilterLevel filterLevel,
-                        SkImageFilter* input = NULL);
-
 private:
-    SkScalar              fSx, fSy;
+    SkMatrix              fTransform;
     SkPaint::FilterLevel  fFilterLevel;
     typedef SkImageFilter INHERITED;
 };
 
 #endif