add FilterLevel API to SkPaint, replacing various Flag bits

BUG=
R=bsalomon@google.com

Review URL: https://codereview.chromium.org/19769005

git-svn-id: http://skia.googlecode.com/svn/trunk@10138 2bbb7eff-a529-9590-31e7-b0007b416f81

include/core/SkPaint.h

@@ -98,7 +98,10 @@ public:
     */
     enum Flags {
         kAntiAlias_Flag       = 0x01,   //!< mask to enable antialiasing
-        kFilterBitmap_Flag    = 0x02,   //!< mask to enable bitmap filtering
+
+        // DEPRECATED -- use setFilterLevel instead
+        kFilterBitmap_Flag    = 0x02, // temporary flag
+
         kDither_Flag          = 0x04,   //!< mask to enable dithering
         kUnderlineText_Flag   = 0x08,   //!< mask to enable underline text
         kStrikeThruText_Flag  = 0x10,   //!< mask to enable strike-thru text
@@ -111,7 +114,10 @@ public:
         kAutoHinting_Flag     = 0x800,  //!< mask to force Freetype's autohinter
         kVerticalText_Flag    = 0x1000,
         kGenA8FromLCD_Flag    = 0x2000, // hack for GDI -- do not use if you can help it
+        
+        // DEPRECATED -- use setFilterLevel instead
         kHighQualityFilterBitmap_Flag = 0x4000, // temporary flag
+        // DEPRECATED -- use setFilterLevel instead
         kHighQualityDownsampleBitmap_Flag = 0x8000, // temporary flag
 
         // when adding extra flags, note that the fFlags member is specified
@@ -280,11 +286,41 @@ public:
     */
     void setDevKernText(bool devKernText);
 
-    bool isFilterBitmap() const {
+    enum FilterLevel {
-        return SkToBool(this->getFlags() & kFilterBitmap_Flag);
+        kNone_FilterLevel,
+        kLow_FilterLevel,
+        kMedium_FilterLevel,
+        kHigh_FilterLevel
+    };
+
+    /**
+     *  Return the filter level. This affects the quality (and performance) of
+     *  drawing scaled images.
+     */
+    FilterLevel getFilterLevel() const;
+
+    /**
+     *  Set the filter level. This affects the quality (and performance) of
+     *  drawing scaled images.
+     */
+    void setFilterLevel(FilterLevel);
+
+    /**
+     *  DEPRECATED: use setFilterLevel instead.
+     *  If the predicate is true, set the filterLevel to Low, else set it to
+     *  None.
+     */
+    void setFilterBitmap(bool doFilter) {
+        this->setFilterLevel(doFilter ? kLow_FilterLevel : kNone_FilterLevel);
     }
 
-    void setFilterBitmap(bool filterBitmap);
+    /**
+     *  DEPRECATED: call getFilterLevel() instead.
+     *  Returns true if getFilterLevel() returns anything other than None.
+     */
+    bool isFilterBitmap() const {
+        return kNone_FilterLevel != this->getFilterLevel();
+    }
 
     /** Styles apply to rect, oval, path, and text.
         Bitmaps are always drawn in "fill", and lines are always drawn in

src/core/SkPaint.cpp

@@ -205,6 +205,29 @@ void SkPaint::setPaintOptionsAndroid(const SkPaintOptionsAndroid& options) {
 }
 #endif
 
+SkPaint::FilterLevel SkPaint::getFilterLevel() const {
+    int level = 0;
+    if (fFlags & kFilterBitmap_Flag) {
+        level |= 1;
+    }
+    if (fFlags & kHighQualityFilterBitmap_Flag) {
+        level |= 2;
+    }
+    return (FilterLevel)level;
+}
+
+void SkPaint::setFilterLevel(FilterLevel level) {
+    unsigned mask = kFilterBitmap_Flag | kHighQualityFilterBitmap_Flag;
+    unsigned flags = 0;
+    if (level & 1) {
+        flags |= kFilterBitmap_Flag;
+    }
+    if (level & 2) {
+        flags |= kHighQualityFilterBitmap_Flag;
+    }
+    this->setFlags((fFlags & ~mask) | flags);
+}
+
 void SkPaint::setHinting(Hinting hintingLevel) {
     GEN_ID_INC_EVAL((unsigned) hintingLevel != fHinting);
     fHinting = hintingLevel;
@@ -263,10 +286,6 @@ void SkPaint::setDevKernText(bool doDevKern) {
     this->setFlags(SkSetClearMask(fFlags, doDevKern, kDevKernText_Flag));
 }
 
-void SkPaint::setFilterBitmap(bool doFilter) {
-    this->setFlags(SkSetClearMask(fFlags, doFilter, kFilterBitmap_Flag));
-}
-
 void SkPaint::setStyle(Style style) {
     if ((unsigned)style < kStyleCount) {
         GEN_ID_INC_EVAL((unsigned)style != fStyle);