Proxy canvas instead of DrawFilter for Android DM

dm/DMSrcSinkAndroid.cpp

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "DMSrcSink.h"
 #include "DMSrcSinkAndroid.h"
 
 #include "AnimationContext.h"
 #include "DisplayListRenderer.h"
 #include "IContextFactory.h"
 #include "RenderNode.h"
-#include "SkDrawFilter.h"
+#include "SkCanvas.h"
 #include "SkiaCanvasProxy.h"
+#include "SkTLazy.h"
 #include "SkMaskFilter.h"
 #include "SkPictureRecorder.h"
 #include "SkStream.h"
 #include "android/rect.h"
 #include "android/native_window.h"
 #include "gui/BufferQueue.h"
 #include "gui/CpuConsumer.h"
 #include "gui/IGraphicBufferConsumer.h"
 #include "gui/IGraphicBufferProducer.h"
 #include "gui/Surface.h"
@@ skipping 20 matching lines @@
     }
     SkShader::GradientType gtype = shader->asAGradient(NULL);
     if (gtype == SkShader::kLinear_GradientType ||
         gtype == SkShader::kRadial_GradientType ||
         gtype == SkShader::kSweep_GradientType) {
         return;
     }
     paint->setShader(NULL);
 }
 
-/**
- * An SkDrawFilter implementation which removes all flags and features
- * not exposed by the Android SDK.
- */
-class ViaAndroidSDKFilter : public SkDrawFilter {
+/** Simplify a paint.  */
 
-    bool filter(SkPaint* paint, Type drawType) SK_OVERRIDE {
+void Filter(SkPaint* paint) {
 
-        uint32_t flags = paint->getFlags();
-        flags &= ~SkPaint::kLCDRenderText_Flag;
-        paint->setFlags(flags);
+    uint32_t flags = paint->getFlags();
+    flags &= ~SkPaint::kLCDRenderText_Flag;
+    paint->setFlags(flags);
 
-        // Force bilinear scaling or none
-        if (paint->getFilterQuality() != kNone_SkFilterQuality) {
-            paint->setFilterQuality(kLow_SkFilterQuality);
+    // Android doesn't support Xfermodes above kLighten_Mode
+    SkXfermode::Mode mode;
+    SkXfermode::AsMode(paint->getXfermode(), &mode);
+    if (mode > SkXfermode::kLighten_Mode) {
+        paint->setXfermode(NULL);
+    }
+
+    // Force bilinear scaling or none
+    if (paint->getFilterQuality() != kNone_SkFilterQuality) {
+        paint->setFilterQuality(kLow_SkFilterQuality);
+    }
+
+    CheckShader(paint);
+
+    // Android SDK only supports mode & matrix color filters
+    // (and, again, no modes above kLighten_Mode).
+    SkColorFilter* cf = paint->getColorFilter();
+    if (cf) {
+        SkColor color;
+        SkXfermode::Mode mode;
+        SkScalar srcColorMatrix[20];
+        bool isMode = cf->asColorMode(&color, &mode);
+        if (isMode && mode > SkXfermode::kLighten_Mode) {
+            paint->setColorFilter(
+                SkColorFilter::CreateModeFilter(color, SkXfermode::kSrcOver_Mode));
+        } else if (!isMode && !cf->asColorMatrix(srcColorMatrix)) {
+            paint->setColorFilter(NULL);
         }
+    }
 
-        CheckShader(paint);
+    SkPathEffect* pe = paint->getPathEffect();
+    if (pe && !pe->exposedInAndroidJavaAPI()) {
+        paint->setPathEffect(NULL);
+    }
 
-        // Android SDK only supports mode & matrix color filters
-        SkColorFilter* cf = paint->getColorFilter();
-        if (cf) {
-            SkColor color;
-            SkXfermode::Mode mode;
-            SkScalar srcColorMatrix[20];
-            if (!cf->asColorMode(&color, &mode) && !cf->asColorMatrix(srcColorMatrix)) {
-                paint->setColorFilter(NULL);
-            }
-        }
+    // TODO: Android doesn't support all the flags that can be passed to
+    // blur filters; we need plumbing to get them out.
 
-        SkPathEffect* pe = paint->getPathEffect();
-        if (pe && !pe->exposedInAndroidJavaAPI()) {
-            paint->setPathEffect(NULL);
-        }
+    paint->setImageFilter(NULL);
+    paint->setLooper(NULL);
+};
 
-        // TODO: Android doesn't support all the flags that can be passed to
-        // blur filters; we need plumbing to get them out.
+/** SkDrawFilter is likely to be deprecated; this is a proxy
+    canvas that does the same thing: alter SkPaint fields.
 
-        paint->setImageFilter(NULL);
-        paint->setLooper(NULL);
+    onDraw*() functions may have their SkPaint modified, and are then
+    passed on to the same function on proxyTarget.
 
-        return true;
-    };
+    This still suffers one of the same architectural flaws as SkDrawFilter:
+    TextBlob paints are incomplete when filter is called.
+*/
+
+#define FILTER(p)             \
+    SkPaint filteredPaint(p); \
+    Filter(&filteredPaint);
+
+#define FILTER_PTR(p)                          \
+    SkTLazy<SkPaint> lazyPaint;                \
+    SkPaint* filteredPaint = (SkPaint*) p;     \
+    if (p) {                                   \
+        filteredPaint = lazyPaint.set(*p);     \
+        Filter(filteredPaint);                 \
+    }
+
+
+class FilteringCanvas : public SkCanvas {
+public:
+    FilteringCanvas(SkCanvas* proxyTarget) : fProxyTarget(proxyTarget) { }
+
+protected:
+    void onDrawPaint(const SkPaint& paint) SK_OVERRIDE {
+        FILTER(paint);
+        fProxyTarget->drawPaint(filteredPaint);
+    }
+    void onDrawPoints(PointMode pMode, size_t count, const SkPoint pts[],
+                      const SkPaint& paint) SK_OVERRIDE {
+        FILTER(paint);
+        fProxyTarget->drawPoints(pMode, count, pts, filteredPaint);
+    }
+    void onDrawOval(const SkRect& r, const SkPaint& paint) SK_OVERRIDE {
+        FILTER(paint);
+        fProxyTarget->drawOval(r, filteredPaint);
+    }
+    void onDrawRect(const SkRect& r, const SkPaint& paint) SK_OVERRIDE {
+        FILTER(paint);
+        fProxyTarget->drawRect(r, filteredPaint);
+    }
+    void onDrawRRect(const SkRRect& r, const SkPaint& paint) SK_OVERRIDE {
+        FILTER(paint);
+        fProxyTarget->drawRRect(r, filteredPaint);
+    }
+    void onDrawPath(const SkPath& path, const SkPaint& paint) SK_OVERRIDE {
+        FILTER(paint);
+        fProxyTarget->drawPath(path, filteredPaint);
+    }
+    void onDrawBitmap(const SkBitmap& bitmap, SkScalar left, SkScalar top,
+                      const SkPaint* paint) SK_OVERRIDE {
+        FILTER_PTR(paint);
+        fProxyTarget->drawBitmap(bitmap, left, top, filteredPaint);
+    }
+    void onDrawBitmapRect(const SkBitmap& bitmap, const SkRect* src, const SkRect& dst,
+                          const SkPaint* paint, DrawBitmapRectFlags flags) SK_OVERRIDE {
+        FILTER_PTR(paint);
+        fProxyTarget->drawBitmapRectToRect(bitmap, src, dst, filteredPaint, flags);
+    }
+    void onDrawBitmapNine(const SkBitmap& bitmap, const SkIRect& center,
+                          const SkRect& dst, const SkPaint* paint) SK_OVERRIDE {
+        FILTER_PTR(paint);
+        fProxyTarget->drawBitmapNine(bitmap, center, dst, filteredPaint);
+    }
+    void onDrawSprite(const SkBitmap& bitmap, int left, int top,
+                      const SkPaint* paint) SK_OVERRIDE {
+        FILTER_PTR(paint);
+        fProxyTarget->drawSprite(bitmap, left, top, filteredPaint);
+    }
+    void onDrawVertices(VertexMode vMode, int vertexCount, const SkPoint vertices[],
+                        const SkPoint texs[], const SkColor colors[], SkXfermode* xMode,
+                        const uint16_t indices[], int indexCount,
+                        const SkPaint& paint) SK_OVERRIDE {
+        FILTER(paint);
+        fProxyTarget->drawVertices(vMode, vertexCount, vertices, texs, colors,
+                                   xMode, indices, indexCount, filteredPaint);
+    }
+
+    void onDrawDRRect(const SkRRect& outer, const SkRRect& inner,
+                      const SkPaint& paint) SK_OVERRIDE {
+        FILTER(paint);
+        fProxyTarget->drawDRRect(outer, inner, filteredPaint);
+    }
+
+    void onDrawText(const void* text, size_t byteLength, SkScalar x, SkScalar y,
+                    const SkPaint& paint) SK_OVERRIDE {
+        FILTER(paint);
+        fProxyTarget->drawText(text, byteLength, x, y, filteredPaint);
+    }
+    void onDrawPosText(const void* text, size_t byteLength, const SkPoint pos[],
+                       const SkPaint& paint) SK_OVERRIDE {
+        FILTER(paint);
+        fProxyTarget->drawPosText(text, byteLength, pos, filteredPaint);
+    }
+    void onDrawPosTextH(const void* text, size_t byteLength, const SkScalar xpos[],
+                        SkScalar constY, const SkPaint& paint) SK_OVERRIDE {
+        FILTER(paint);
+        fProxyTarget->drawPosTextH(text, byteLength, xpos, constY, filteredPaint);
+    }
+    void onDrawTextOnPath(const void* text, size_t byteLength, const SkPath& path,
+                          const SkMatrix* matrix, const SkPaint& paint) SK_OVERRIDE {
+        FILTER(paint);
+        fProxyTarget->drawTextOnPath(text, byteLength, path, matrix, filteredPaint);
+    }
+    void onDrawTextBlob(const SkTextBlob* blob, SkScalar x, SkScalar y,
+                        const SkPaint& paint) SK_OVERRIDE {
+        FILTER(paint);
+        fProxyTarget->drawTextBlob(blob, x, y, filteredPaint);
+    }
+
+    void onDrawPatch(const SkPoint cubics[12], const SkColor colors[4],
+                     const SkPoint texCoords[4], SkXfermode* xmode,
+                     const SkPaint& paint) SK_OVERRIDE {
+        FILTER(paint);
+        fProxyTarget->drawPatch(cubics, colors, texCoords, xmode, filteredPaint);
+    }
+
+protected:
+    SkCanvas* fProxyTarget;
 };
 
 /**
  * Helper class for setting up android::uirenderer::renderthread::RenderProxy.
  */
 class ContextFactory : public android::uirenderer::IContextFactory {
 public:
     android::uirenderer::AnimationContext* createAnimationContext
         (android::uirenderer::renderthread::TimeLord& clock) SK_OVERRIDE {
         return new android::uirenderer::AnimationContext(clock);
@@ skipping 132 matching lines @@
 Error ViaAndroidSDK::draw(const Src& src,
                           SkBitmap* bitmap,
                           SkWStream* stream,
                           SkString* log) const {
     struct ProxySrc : public Src {
         const Src& fSrc;
         ProxySrc(const Src& src)
             : fSrc(src) {}
 
         Error draw(SkCanvas* canvas) const SK_OVERRIDE {
-            // Route through HWUI's upper layers to get operational transforms
+            // Pass through HWUI's upper layers to get operational transforms
             SkAutoTDelete<android::Canvas> ac (android::Canvas::create_canvas(canvas));
             SkAutoTUnref<android::uirenderer::SkiaCanvasProxy> scProxy
                 (new android::uirenderer::SkiaCanvasProxy(ac));
-            ViaAndroidSDKFilter filter;
 
-            // Route through a draw filter to get paint transforms
-            scProxy->setDrawFilter(&filter);
+            // Pass through another proxy to get paint transforms
+            FilteringCanvas fc(scProxy);
 
-            fSrc.draw(scProxy);
+            fSrc.draw(&fc);
 
             return "";
         }
         SkISize size() const SK_OVERRIDE { return fSrc.size(); }
         Name name() const SK_OVERRIDE { sk_throw(); return ""; }
     } proxy(src);
 
     return fSink->draw(proxy, bitmap, stream, log);
 }
 
 }  // namespace DM