move erase into SkPixmap

harvested from https://codereview.chromium.org/1148793007

BUG=skia:
TBR=

Review URL: https://codereview.chromium.org/1161033005

2 files changed, 44 insertions, 10 deletions

diff --git a/include/core/SkBitmap.h b/include/core/SkBitmap.h
index c070203d04..b13b6f7451 100644
--- a/include/core/SkBitmap.h
+++ b/include/core/SkBitmap.h
@@ -473,10 +473,7 @@ public:
      *  of the color is ignored (treated as opaque). If the colortype only supports
      *  alpha (e.g. A1 or A8) then the color's r,g,b components are ignored.
      */
-    void eraseColor(SkColor c) const {
-        this->eraseARGB(SkColorGetA(c), SkColorGetR(c), SkColorGetG(c),
-                        SkColorGetB(c));
-    }
+    void eraseColor(SkColor c) const;
 
     /**
      *  Fill the entire bitmap with the specified color.
@@ -484,7 +481,9 @@ public:
      *  of the color is ignored (treated as opaque). If the colortype only supports
      *  alpha (e.g. A1 or A8) then the color's r,g,b components are ignored.
      */
-    void eraseARGB(U8CPU a, U8CPU r, U8CPU g, U8CPU b) const;
+    void eraseARGB(U8CPU a, U8CPU r, U8CPU g, U8CPU b) const {
+        this->eraseColor(SkColorSetARGB(a, r, g, b));
+    }
 
     SK_ATTR_DEPRECATED("use eraseARGB or eraseColor")
     void eraseRGB(U8CPU r, U8CPU g, U8CPU b) const {
@@ -497,7 +496,12 @@ public:
      *  of the color is ignored (treated as opaque). If the colortype only supports
      *  alpha (e.g. A1 or A8) then the color's r,g,b components are ignored.
      */
-    void eraseArea(const SkIRect& area, SkColor c) const;
+    void erase(SkColor c, const SkIRect& area) const;
+
+    // DEPRECATED
+    void eraseArea(const SkIRect& area, SkColor c) const {
+        this->erase(c, area);
+    }
 
     /**
      *  Return the SkColor of the specified pixel.  In most cases this will
@@ -736,13 +740,9 @@ private:
     };
 
     SkImageInfo fInfo;
-
     uint32_t    fRowBytes;
-
     uint8_t     fFlags;
 
-    void internalErase(const SkIRect&, U8CPU a, U8CPU r, U8CPU g, U8CPU b)const;
-
     /*  Unreference any pixelrefs or colortables
     */
     void freePixels();
diff --git a/include/core/SkPixmap.h b/include/core/SkPixmap.h
index 913d007c4d..a32b40c58d 100644
--- a/include/core/SkPixmap.h
+++ b/include/core/SkPixmap.h
@@ -133,6 +133,14 @@ public:
         return this->readPixels(dst.info(), dst.writable_addr(), dst.rowBytes(), 0, 0);
     }
 
+    /**
+     *  Returns true if pixels were written to (e.g. if colorType is kUnknown_SkColorType, this
+     *  will return false). If subset does not intersect the bounds of this pixmap, returns false.
+     */
+    bool erase(SkColor, const SkIRect& subset) const;
+
+    bool erase(SkColor color) const { return this->erase(color, this->bounds()); }
+
 private:
     const void*     fPixels;
     SkColorTable*   fCTable;
@@ -165,8 +173,34 @@ public:
      */
     void alloc(const SkImageInfo&);
 
+    // We wrap these so we can clear our internal storage
+
+    void reset() {
+        this->freeStorage();
+        this->INHERITED::reset();
+    }
+    void reset(const SkImageInfo& info, const void* addr, size_t rb, SkColorTable* ctable = NULL) {
+        this->freeStorage();
+        this->INHERITED::reset(info, addr, rb, ctable);
+    }
+    void reset(const SkImageInfo& info) {
+        this->freeStorage();
+        this->INHERITED::reset(info);
+    }
+    bool SK_WARN_UNUSED_RESULT reset(const SkMask& mask) {
+        this->freeStorage();
+        return this->INHERITED::reset(mask);
+    }
+
 private:
     void*   fStorage;
+
+    void freeStorage() {
+        sk_free(fStorage);
+        fStorage = NULL;
+    }
+
+    typedef SkPixmap INHERITED;
 };
 
 /////////////////////////////////////////////////////////////////////////////////////////////