Move SkAvoidXferMode into frameworks/base.

We are removing it from Skia, so we need it here to support Android.

Add some small cleanups (remove comment that doesn't apply, convert
SK_OVERRIDE to override, remove 'virtual' keyword from methods with
'override' on them).

BUG:skbug.com/3329
Change-Id: I1f883082d6fb9d49b9c9ba9e1f50bd713eabf915

5 files changed, 252 insertions, 4 deletions

diff --git a/core/jni/Android.mk b/core/jni/Android.mk
index cb9b421..f41cd15 100644
--- a/core/jni/Android.mk
+++ b/core/jni/Android.mk
@@ -87,6 +87,7 @@ LOCAL_SRC_FILES:= \
     android_graphics_Canvas.cpp \
     android_graphics_Picture.cpp \
     android/graphics/AutoDecodeCancel.cpp \
+    android/graphics/AvoidXferMode.cpp \
     android/graphics/Bitmap.cpp \
     android/graphics/BitmapFactory.cpp \
     android/graphics/Camera.cpp \
diff --git a/core/jni/android/graphics/AvoidXferMode.cpp b/core/jni/android/graphics/AvoidXferMode.cpp
new file mode 100644
index 0000000..89c1006
--- /dev/null
+++ b/core/jni/android/graphics/AvoidXferMode.cpp
@@ -0,0 +1,177 @@
+/*
+ * Copyright 2006 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.
+ */
+
+#include "AvoidXferMode.h"
+#include "SkColorPriv.h"
+#include "SkReadBuffer.h"
+#include "SkWriteBuffer.h"
+#include "SkString.h"
+
+AvoidXferMode::AvoidXferMode(SkColor opColor, U8CPU tolerance, Mode mode) {
+    if (tolerance > 255) {
+        tolerance = 255;
+    }
+    fTolerance = SkToU8(tolerance);
+    fOpColor = opColor;
+    fDistMul = (256 << 14) / (tolerance + 1);
+    fMode = mode;
+}
+
+SkFlattenable* AvoidXferMode::CreateProc(SkReadBuffer& buffer) {
+    const SkColor color = buffer.readColor();
+    const unsigned tolerance = buffer.readUInt();
+    const unsigned mode = buffer.readUInt();
+    return Create(color, tolerance, (Mode)mode);
+}
+
+void AvoidXferMode::flatten(SkWriteBuffer& buffer) const {
+    buffer.writeColor(fOpColor);
+    buffer.writeUInt(fTolerance);
+    buffer.writeUInt(fMode);
+}
+
+// returns 0..31
+static unsigned color_dist16(uint16_t c, unsigned r, unsigned g, unsigned b) {
+    SkASSERT(r <= SK_R16_MASK);
+    SkASSERT(g <= SK_G16_MASK);
+    SkASSERT(b <= SK_B16_MASK);
+
+    unsigned dr = SkAbs32(SkGetPackedR16(c) - r);
+    unsigned dg = SkAbs32(SkGetPackedG16(c) - g) >> (SK_G16_BITS - SK_R16_BITS);
+    unsigned db = SkAbs32(SkGetPackedB16(c) - b);
+
+    return SkMax32(dr, SkMax32(dg, db));
+}
+
+// returns 0..255
+static unsigned color_dist32(SkPMColor c, U8CPU r, U8CPU g, U8CPU b) {
+    SkASSERT(r <= 0xFF);
+    SkASSERT(g <= 0xFF);
+    SkASSERT(b <= 0xFF);
+
+    unsigned dr = SkAbs32(SkGetPackedR32(c) - r);
+    unsigned dg = SkAbs32(SkGetPackedG32(c) - g);
+    unsigned db = SkAbs32(SkGetPackedB32(c) - b);
+
+    return SkMax32(dr, SkMax32(dg, db));
+}
+
+static int scale_dist_14(int dist, uint32_t mul, uint32_t sub) {
+    int tmp = dist * mul - sub;
+    int result = (tmp + (1 << 13)) >> 14;
+
+    return result;
+}
+
+static inline unsigned Accurate255To256(unsigned x) {
+    return x + (x >> 7);
+}
+
+void AvoidXferMode::xfer32(SkPMColor dst[], const SkPMColor src[], int count,
+                             const SkAlpha aa[]) const {
+    unsigned    opR = SkColorGetR(fOpColor);
+    unsigned    opG = SkColorGetG(fOpColor);
+    unsigned    opB = SkColorGetB(fOpColor);
+    uint32_t    mul = fDistMul;
+    uint32_t    sub = (fDistMul - (1 << 14)) << 8;
+
+    int MAX, mask;
+
+    if (kTargetColor_Mode == fMode) {
+        mask = -1;
+        MAX = 255;
+    } else {
+        mask = 0;
+        MAX = 0;
+    }
+
+    for (int i = 0; i < count; i++) {
+        int d = color_dist32(dst[i], opR, opG, opB);
+        // now reverse d if we need to
+        d = MAX + (d ^ mask) - mask;
+        SkASSERT((unsigned)d <= 255);
+        d = Accurate255To256(d);
+
+        d = scale_dist_14(d, mul, sub);
+        SkASSERT(d <= 256);
+
+        if (d > 0) {
+            if (aa) {
+                d = SkAlphaMul(d, Accurate255To256(*aa++));
+                if (0 == d) {
+                    continue;
+                }
+            }
+            dst[i] = SkFourByteInterp256(src[i], dst[i], d);
+        }
+    }
+}
+
+static inline U16CPU SkBlend3216(SkPMColor src, U16CPU dst, unsigned scale) {
+    SkASSERT(scale <= 32);
+    scale <<= 3;
+
+    return SkPackRGB16( SkAlphaBlend(SkPacked32ToR16(src), SkGetPackedR16(dst), scale),
+                        SkAlphaBlend(SkPacked32ToG16(src), SkGetPackedG16(dst), scale),
+                        SkAlphaBlend(SkPacked32ToB16(src), SkGetPackedB16(dst), scale));
+}
+
+void AvoidXferMode::xfer16(uint16_t dst[], const SkPMColor src[], int count,
+                             const SkAlpha aa[]) const {
+    unsigned    opR = SkColorGetR(fOpColor) >> (8 - SK_R16_BITS);
+    unsigned    opG = SkColorGetG(fOpColor) >> (8 - SK_G16_BITS);
+    unsigned    opB = SkColorGetB(fOpColor) >> (8 - SK_R16_BITS);
+    uint32_t    mul = fDistMul;
+    uint32_t    sub = (fDistMul - (1 << 14)) << SK_R16_BITS;
+
+    int MAX, mask;
+
+    if (kTargetColor_Mode == fMode) {
+        mask = -1;
+        MAX = 31;
+    } else {
+        mask = 0;
+        MAX = 0;
+    }
+
+    for (int i = 0; i < count; i++) {
+        int d = color_dist16(dst[i], opR, opG, opB);
+        // now reverse d if we need to
+        d = MAX + (d ^ mask) - mask;
+        SkASSERT((unsigned)d <= 31);
+        // convert from 0..31 to 0..32
+        d += d >> 4;
+        d = scale_dist_14(d, mul, sub);
+        SkASSERT(d <= 32);
+
+        if (d > 0) {
+            if (aa) {
+                d = SkAlphaMul(d, Accurate255To256(*aa++));
+                if (0 == d) {
+                    continue;
+                }
+            }
+            dst[i] = SkBlend3216(src[i], dst[i], d);
+        }
+    }
+}
+
+void AvoidXferMode::xferA8(SkAlpha dst[], const SkPMColor src[], int count,
+                             const SkAlpha aa[]) const {
+}
+
+#ifndef SK_IGNORE_TO_STRING
+void AvoidXferMode::toString(SkString* str) const {
+    str->append("AvoidXferMode: opColor: ");
+    str->appendHex(fOpColor);
+    str->appendf("distMul: %d ", fDistMul);
+
+    static const char* gModeStrings[] = { "Avoid", "Target" };
+
+    str->appendf("mode: %s", gModeStrings[fMode]);
+}
+#endif
diff --git a/core/jni/android/graphics/AvoidXferMode.h b/core/jni/android/graphics/AvoidXferMode.h
new file mode 100644
index 0000000..6e45c0a
--- /dev/null
+++ b/core/jni/android/graphics/AvoidXferMode.h
@@ -0,0 +1,70 @@
+/*
+ * Copyright 2006 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 AvoidXferMode_DEFINED
+#define AvoidXferMode_DEFINED
+
+#include "SkColor.h"
+#include "SkTypes.h"
+#include "SkXfermode.h"
+
+/** \class AvoidXferMode
+
+    This xfermode will draw the src everywhere except on top of the specified
+    color.
+*/
+class AvoidXferMode : public SkXfermode {
+public:
+    enum Mode {
+        kAvoidColor_Mode,   //!< draw everywhere except on the opColor
+        kTargetColor_Mode   //!< draw only on top of the opColor
+    };
+
+    /** This xfermode draws, or doesn't draw, based on the destination's
+        distance from an op-color.
+
+        There are two modes, and each mode interprets a tolerance value.
+
+        Avoid: In this mode, drawing is allowed only on destination pixels that
+               are different from the op-color.
+               Tolerance near 0: avoid any colors even remotely similar to the op-color
+               Tolerance near 255: avoid only colors nearly identical to the op-color
+
+        Target: In this mode, drawing only occurs on destination pixels that
+                are similar to the op-color
+                Tolerance near 0: draw only on colors that are nearly identical to the op-color
+                Tolerance near 255: draw on any colors even remotely similar to the op-color
+     */
+    static AvoidXferMode* Create(SkColor opColor, U8CPU tolerance, Mode mode) {
+        return SkNEW_ARGS(AvoidXferMode, (opColor, tolerance, mode));
+    }
+
+    // overrides from SkXfermode
+    void xfer32(SkPMColor dst[], const SkPMColor src[], int count,
+            const SkAlpha aa[]) const override;
+    void xfer16(uint16_t dst[], const SkPMColor src[], int count,
+            const SkAlpha aa[]) const override;
+    void xferA8(SkAlpha dst[], const SkPMColor src[], int count,
+            const SkAlpha aa[]) const override;
+
+    SK_TO_STRING_OVERRIDE()
+    SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(AvoidXferMode)
+
+protected:
+    AvoidXferMode(SkColor opColor, U8CPU tolerance, Mode mode);
+    void flatten(SkWriteBuffer&) const override;
+
+private:
+    SkColor     fOpColor;
+    uint32_t    fDistMul;   // x.14 cached from fTolerance
+    uint8_t     fTolerance;
+    Mode        fMode;
+
+    typedef SkXfermode INHERITED;
+};
+
+#endif
diff --git a/core/jni/android/graphics/Xfermode.cpp b/core/jni/android/graphics/Xfermode.cpp
index 5a3883a..e3efc52 100644
--- a/core/jni/android/graphics/Xfermode.cpp
+++ b/core/jni/android/graphics/Xfermode.cpp
@@ -18,7 +18,7 @@
 #include "GraphicsJNI.h"
 #include "core_jni_helpers.h"
 
-#include "SkAvoidXfermode.h"
+#include "AvoidXferMode.h"
 #include "SkPixelXorXfermode.h"
 
 namespace android {
@@ -35,8 +35,8 @@ public:
     static jlong avoid_create(JNIEnv* env, jobject, jint opColor,
                                 jint tolerance, jint modeHandle)
     {
-        SkAvoidXfermode::Mode mode = static_cast<SkAvoidXfermode::Mode>(modeHandle);
-        return reinterpret_cast<jlong>(SkAvoidXfermode::Create(opColor, tolerance, mode));
+        AvoidXferMode::Mode mode = static_cast<AvoidXferMode::Mode>(modeHandle);
+        return reinterpret_cast<jlong>(AvoidXferMode::Create(opColor, tolerance, mode));
     }
 
     static jlong pixelxor_create(JNIEnv* env, jobject, jint opColor)
diff --git a/graphics/java/android/graphics/AvoidXfermode.java b/graphics/java/android/graphics/AvoidXfermode.java
index 206c959..48ee6fa 100644
--- a/graphics/java/android/graphics/AvoidXfermode.java
+++ b/graphics/java/android/graphics/AvoidXfermode.java
@@ -23,7 +23,7 @@ package android.graphics;
 @Deprecated
 public class AvoidXfermode extends Xfermode {
 
-    // these need to match the enum in SkAvoidXfermode.h on the native side
+    // these need to match the enum in AvoidXfermode.h on the native side
     public enum Mode {
         AVOID   (0),    //!< draw everywhere except on the opColor
         TARGET  (1);    //!< draw only on top of the opColor