Fix FILTER_BITMAP_FLAG regression in DrawFilter.

Skia removed the corresponding kFilterBitmapFlag, replacing it with a
separate function: setFilterLevel. If the flag is set, turn it into a
call to setFilterLevel.

Corresponds to changes in I2736f3f68683651574d79a169ff0ab563e0a469e to
fix Paint.setFlags().

BUG:15112859
Change-Id: I269cbd7a624e5dde5688305e1ba97075ba73f4fd

diff --git a/core/jni/android/graphics/DrawFilter.cpp b/core/jni/android/graphics/DrawFilter.cpp
index fbfa2ec..3275875 100644 (file)
--- a/core/jni/android/graphics/DrawFilter.cpp
+++ b/core/jni/android/graphics/DrawFilter.cpp
@@ -30,6 +30,35 @@
 
 namespace android {
 
+// Custom version of SkPaintFlagsDrawFilter that also calls setFilterLevel.
+class CompatFlagsDrawFilter : public SkPaintFlagsDrawFilter {
+public:
+    CompatFlagsDrawFilter(uint32_t clearFlags, uint32_t setFlags,
+            SkPaint::FilterLevel desiredLevel)
+    : SkPaintFlagsDrawFilter(clearFlags, setFlags)
+    , fDesiredLevel(desiredLevel) {
+    }
+
+    virtual bool filter(SkPaint* paint, Type type) {
+        SkPaintFlagsDrawFilter::filter(paint, type);
+        paint->setFilterLevel(fDesiredLevel);
+        return true;
+    }
+
+private:
+    const SkPaint::FilterLevel fDesiredLevel;
+};
+
+// Returns whether flags contains FILTER_BITMAP_FLAG. If flags does, remove it.
+static inline bool hadFiltering(jint& flags) {
+    // Equivalent to the Java Paint's FILTER_BITMAP_FLAG.
+    static const uint32_t sFilterBitmapFlag = 0x02;
+
+    const bool result = (flags & sFilterBitmapFlag) != 0;
+    flags &= ~sFilterBitmapFlag;
+    return result;
+}
+
 class SkDrawFilterGlue {
 public:
 
@@ -40,12 +69,25 @@ public:
 
     static jlong CreatePaintFlagsDF(JNIEnv* env, jobject clazz,
                                     jint clearFlags, jint setFlags) {
-        // trim off any out-of-range bits
-        clearFlags &= SkPaint::kAllFlags;
-        setFlags &= SkPaint::kAllFlags;
-
         if (clearFlags | setFlags) {
-            SkDrawFilter* filter = new SkPaintFlagsDrawFilter(clearFlags, setFlags);
+            // Mask both groups of flags to remove FILTER_BITMAP_FLAG, which no
+            // longer has a Skia equivalent flag (instead it corresponds to
+            // calling setFilterLevel), and keep track of which group(s), if
+            // any, had the flag set.
+            const bool turnFilteringOn = hadFiltering(setFlags);
+            const bool turnFilteringOff = hadFiltering(clearFlags);
+
+            SkDrawFilter* filter;
+            if (turnFilteringOn) {
+                // Turning filtering on overrides turning it off.
+                filter = new CompatFlagsDrawFilter(clearFlags, setFlags,
+                        SkPaint::kLow_FilterLevel);
+            } else if (turnFilteringOff) {
+                filter = new CompatFlagsDrawFilter(clearFlags, setFlags,
+                        SkPaint::kNone_FilterLevel);
+            } else {
+                filter = new SkPaintFlagsDrawFilter(clearFlags, setFlags);
+            }
             return reinterpret_cast<jlong>(filter);
         } else {
             return NULL;