Revert "replace Arithmetic xfermode with imagefilter"

This reverts commit Ia3f3b721854c516f3b7f8c44f71f40a8a2eeb9b4.

Reason for revert: need to guard the no-gpu codepath

Original issue's description:
> replace Arithmetic xfermode with imagefilter
> 
> chrome pre-cl: https://codereview.chromium.org/2369023002/
> 
> BUG=skia:
> 
> GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2595
> 
> Change-Id: Ia3f3b721854c516f3b7f8c44f71f40a8a2eeb9b4
> Reviewed-on: https://skia-review.googlesource.com/2595
> Commit-Queue: Mike Reed <reed@google.com>
> Reviewed-by: Florin Malita <fmalita@chromium.org>
> Reviewed-by: Robert Phillips <robertphillips@google.com>
> 

TBR=robertphillips@google.com,fmalita@chromium.org,fmalita@google.com,reed@google.com
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true

Change-Id: I761799b594a0379c6bf356e6abc73552c3d19480
Reviewed-on: https://skia-review.googlesource.com/2661
Reviewed-by: Florin Malita <fmalita@chromium.org>
Commit-Queue: Florin Malita <fmalita@chromium.org>

5 files changed, 65 insertions, 18 deletions

diff --git a/gm/aaxfermodes.cpp b/gm/aaxfermodes.cpp
index 678a8379e3..78f7d3e324 100644
--- a/gm/aaxfermodes.cpp
+++ b/gm/aaxfermodes.cpp
@@ -39,11 +39,13 @@ enum Shape {
     kLast_Shape = kConcave_Shape
 };
 
+namespace skiagm {
+
 /**
  * Verifies AA works properly on all Xfermodes, including arithmetic, with both opaque and unknown
  * src colors.
  */
-class AAXfermodesGM : public skiagm::GM {
+class AAXfermodesGM : public GM {
 public:
     AAXfermodesGM() {}
 
@@ -118,9 +120,6 @@ protected:
             canvas->translate(0, kSubtitleSpacing + kShapeSpacing/2);
 
             for (size_t m = 0; m <= SkXfermode::kLastCoeffMode; m++) {
-                if (firstMode + m > SkXfermode::kLastMode) {
-                    break;
-                }
                 SkXfermode::Mode mode = static_cast<SkXfermode::Mode>(firstMode + m);
                 canvas->save();
 
@@ -211,7 +210,7 @@ protected:
             if (maxSum > 255) {
                 SkPaint dimPaint;
                 dimPaint.setAntiAlias(false);
-                dimPaint.setXfermodeMode(SkXfermode::kDstIn_Mode);
+                dimPaint.setXfermode(SkXfermode::Make(SkXfermode::kDstIn_Mode));
                 if (255 != paint->getAlpha()) {
                     // Dim the src and dst colors.
                     dimPaint.setARGB(255 * 255 / maxSum, 0, 0, 0);
@@ -228,10 +227,16 @@ protected:
     }
 
     void drawShape(SkCanvas* canvas, Shape shape, const SkPaint& paint, SkXfermode::Mode mode) {
-        SkASSERT(mode <= SkXfermode::kLastMode);
         SkPaint shapePaint(paint);
         shapePaint.setAntiAlias(kSquare_Shape != shape);
-        shapePaint.setXfermodeMode(mode);
+
+        sk_sp<SkXfermode> xfermode;
+        if (mode <= SkXfermode::kLastMode) {
+            xfermode = SkXfermode::Make(mode);
+        } else {
+            xfermode = SkArithmeticMode::Make(+1.0f, +0.25f, -0.5f, +0.1f);
+        }
+        shapePaint.setXfermode(std::move(xfermode));
 
         switch (shape) {
             case kSquare_Shape:
@@ -268,6 +273,12 @@ private:
     SkPath    fOval;
     SkPath    fConcave;
 
-    typedef skiagm::GM INHERITED;
+    typedef GM INHERITED;
 };
-DEF_GM( return new AAXfermodesGM; )
+
+//////////////////////////////////////////////////////////////////////////////
+
+static GM* MyFactory(void*) { return new AAXfermodesGM; }
+static GMRegistry reg(MyFactory);
+
+}
diff --git a/gm/arithmode.cpp b/gm/arithmode.cpp
index f98fbf7057..70661a0fba 100644
--- a/gm/arithmode.cpp
+++ b/gm/arithmode.cpp
@@ -15,7 +15,6 @@
 #define WW  100
 #define HH  32
 
-#ifdef SK_SUPPORT_LEGACY_ARITHMETICMODE
 static SkBitmap make_bm() {
     SkBitmap bm;
     bm.allocN32Pixels(WW, HH);
@@ -161,4 +160,3 @@ private:
 ///////////////////////////////////////////////////////////////////////////////
 
 DEF_GM( return new ArithmodeGM; )
-#endif
diff --git a/gm/imagefiltersgraph.cpp b/gm/imagefiltersgraph.cpp
index 980398967a..0f3dcd10c9 100644
--- a/gm/imagefiltersgraph.cpp
+++ b/gm/imagefiltersgraph.cpp
@@ -7,6 +7,7 @@
 
 #include "gm.h"
 
+#include "SkArithmeticMode.h"
 #include "SkBlurImageFilter.h"
 #include "SkColorFilter.h"
 #include "SkColorFilterImageFilter.h"
@@ -89,7 +90,7 @@ protected:
 
             SkPaint paint;
             paint.setImageFilter(
-                SkXfermodeImageFilter::MakeArithmetic(0, 1, 1, 0, true,
+                SkXfermodeImageFilter::Make(SkArithmeticMode::Make(0, SK_Scalar1, SK_Scalar1, 0),
                                             std::move(matrixFilter),
                                             std::move(offsetFilter),
                                             nullptr));
diff --git a/gm/xfermodeimagefilter.cpp b/gm/xfermodeimagefilter.cpp
index a0677c796a..0ff0ea9dd1 100644
--- a/gm/xfermodeimagefilter.cpp
+++ b/gm/xfermodeimagefilter.cpp
@@ -7,6 +7,7 @@
 
 #include "gm.h"
 #include "sk_tool_utils.h"
+#include "SkArithmeticMode.h"
 #include "SkImage.h"
 #include "SkImageSource.h"
 #include "SkOffsetImageFilter.h"
@@ -96,7 +97,9 @@ protected:
             }
         }
         // Test arithmetic mode as image filter
-        paint.setImageFilter(SkXfermodeImageFilter::MakeArithmetic(0, 1, 1, 0, true, background));
+        paint.setImageFilter(SkXfermodeImageFilter::Make(
+                         SkArithmeticMode::Make(0, SK_Scalar1, SK_Scalar1, 0),
+                         background));
         DrawClippedBitmap(canvas, fBitmap, paint, x, y);
         x += fBitmap.width() + MARGIN;
         if (x + fBitmap.width() > WIDTH) {
diff --git a/gm/xfermodes.cpp b/gm/xfermodes.cpp
index 8fbbdbec6a..68d267bd22 100644
--- a/gm/xfermodes.cpp
+++ b/gm/xfermodes.cpp
@@ -11,6 +11,31 @@
 #include "SkXfermode.h"
 #include "SkPM4f.h"
 
+#include "SkArithmeticMode.h"
+
+#define kCustomShift    16
+#define kCustomMask     (~0xFFFF)
+
+enum CustomModes {
+    kArithmetic_CustomMode  = 1 << kCustomShift,
+};
+
+static sk_sp<SkXfermode> make_custom(int customMode) {
+    switch (customMode) {
+        case kArithmetic_CustomMode: {
+            const SkScalar k1 = 0.25;
+            const SkScalar k2 = 0.75;
+            const SkScalar k3 = 0.75;
+            const SkScalar k4 = -0.25;
+            return SkArithmeticMode::Make(k1, k2, k3, k4);
+        }
+        default:
+            break;
+    }
+    SkASSERT(false);
+    return nullptr;
+}
+
 enum SrcType {
     //! A WxH image with a rectangle in the lower right.
     kRectangleImage_SrcType               = 0x01,
@@ -73,6 +98,8 @@ const struct {
     { SkXfermode::kSaturation_Mode,   "Saturation",   kBasic_SrcType },
     { SkXfermode::kColor_Mode,        "Color",        kBasic_SrcType },
     { SkXfermode::kLuminosity_Mode,   "Luminosity",   kBasic_SrcType },
+
+    { SkXfermode::Mode(0xFFFF),       "Arithmetic",   kBasic_SrcType + kArithmetic_CustomMode   },
 };
 
 static void make_bitmaps(int w, int h, SkBitmap* src, SkBitmap* dst,
@@ -118,7 +145,7 @@ class XfermodesGM : public skiagm::GM {
      * uses the implied shape of the drawing command and these modes
      * demonstrate that.
      */
-    void draw_mode(SkCanvas* canvas, SkXfermode::Mode mode, SrcType srcType,
+    void draw_mode(SkCanvas* canvas, sk_sp<SkXfermode> mode, SrcType srcType,
                    SkScalar x, SkScalar y) {
         SkPaint p;
         SkMatrix m;
@@ -126,7 +153,7 @@ class XfermodesGM : public skiagm::GM {
         m.setTranslate(x, y);
 
         canvas->drawBitmap(fSrcB, x, y, &p);
-        p.setXfermodeMode(mode);
+        p.setXfermode(std::move(mode));
         switch (srcType) {
             case kSmallTransparentImage_SrcType: {
                 m.postScale(SK_ScalarHalf, SK_ScalarHalf, x, y);
@@ -214,7 +241,7 @@ protected:
     }
 
     SkISize onISize() override {
-        return SkISize::Make(1990, 570);
+        return SkISize::Make(1990, 660);
     }
 
     void onDraw(SkCanvas* canvas) override {
@@ -242,7 +269,14 @@ protected:
                 if ((gModes[i].fSourceTypeMask & sourceType) == 0) {
                     continue;
                 }
-                SkRect r{ x, y, x+w, y+h };
+                sk_sp<SkXfermode> mode;
+                if (gModes[i].fSourceTypeMask & kCustomMask) {
+                    mode = make_custom(gModes[i].fSourceTypeMask & kCustomMask);
+                } else {
+                    mode = SkXfermode::Make(gModes[i].fMode);
+                }
+                SkRect r;
+                r.set(x, y, x+w, y+h);
 
                 SkPaint p;
                 p.setStyle(SkPaint::kFill_Style);
@@ -250,7 +284,7 @@ protected:
                 canvas->drawRect(r, p);
 
                 canvas->saveLayer(&r, nullptr);
-                draw_mode(canvas, gModes[i].fMode, static_cast<SrcType>(sourceType),
+                draw_mode(canvas, std::move(mode), static_cast<SrcType>(sourceType),
                           r.fLeft, r.fTop);
                 canvas->restore();