SkPaintFilterCanvas skip-draw support

At the time SkPaintFilterCanvas was introduced as a SkDrawFilter replacement,
no clients were relying on the draw veto logic.  Now Chromium does.

To facilitate migrating off SkDrawFilter, let's augment SkPaintFilterCanvas
with skip-draw semantics.

A side effect of the CL is that now we call the filter virtual even for null
paints.

BUG=skia:4782
R=reed@google.com,robertphillips@google.com
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1577933002

Review URL: https://codereview.chromium.org/1577933002

1 files changed, 83 insertions, 31 deletions

diff --git a/src/utils/SkPaintFilterCanvas.cpp b/src/utils/SkPaintFilterCanvas.cpp
index ce1e4b7dbf..0a5b7e6629 100644
--- a/src/utils/SkPaintFilterCanvas.cpp
+++ b/src/utils/SkPaintFilterCanvas.cpp
@@ -12,20 +12,24 @@
 
 class SkPaintFilterCanvas::AutoPaintFilter {
 public:
-    AutoPaintFilter(const SkPaintFilterCanvas* canvas, Type type, const SkPaint* paint) {
-        if (paint) {
-            canvas->onFilterPaint(fLazyPaint.set(*paint), type);
-        }
+    AutoPaintFilter(const SkPaintFilterCanvas* canvas, Type type, const SkPaint* paint)
+        : fOrigPaint(paint) {
+        fShouldDraw = canvas->onFilter(fOrigPaint, type, &fFilteredPaint);
     }
 
-    AutoPaintFilter(const SkPaintFilterCanvas* canvas, Type type, const SkPaint& paint) {
-        canvas->onFilterPaint(fLazyPaint.set(paint), type);
+    AutoPaintFilter(const SkPaintFilterCanvas* canvas, Type type, const SkPaint& paint)
+        : AutoPaintFilter(canvas, type, &paint) { }
+
+    const SkPaint* paint() const {
+        return fFilteredPaint.isValid() ? fFilteredPaint.get() : fOrigPaint;
     }
 
-    const SkPaint* paint() const { return fLazyPaint.getMaybeNull(); }
+    bool shouldDraw() const { return fShouldDraw; }
 
 private:
-    SkTLazy<SkPaint> fLazyPaint;
+    const SkPaint*   fOrigPaint;
+    SkTLazy<SkPaint> fFilteredPaint;
+    bool             fShouldDraw;
 };
 
 SkPaintFilterCanvas::SkPaintFilterCanvas(int width, int height) : INHERITED(width, height) { }
@@ -44,70 +48,102 @@ SkPaintFilterCanvas::SkPaintFilterCanvas(SkCanvas *canvas)
 
 void SkPaintFilterCanvas::onDrawPaint(const SkPaint& paint) {
     AutoPaintFilter apf(this, kPaint_Type, paint);
-    this->INHERITED::onDrawPaint(*apf.paint());
+    if (apf.shouldDraw()) {
+        this->INHERITED::onDrawPaint(*apf.paint());
+    }
 }
 
 void SkPaintFilterCanvas::onDrawPoints(PointMode mode, size_t count, const SkPoint pts[],
                                        const SkPaint& paint) {
     AutoPaintFilter apf(this, kPoint_Type, paint);
-    this->INHERITED::onDrawPoints(mode, count, pts, *apf.paint());
+    if (apf.shouldDraw()) {
+        this->INHERITED::onDrawPoints(mode, count, pts, *apf.paint());
+    }
 }
 
 void SkPaintFilterCanvas::onDrawRect(const SkRect& rect, const SkPaint& paint) {
     AutoPaintFilter apf(this, kRect_Type, paint);
-    this->INHERITED::onDrawRect(rect, *apf.paint());
+    if (apf.shouldDraw()) {
+        this->INHERITED::onDrawRect(rect, *apf.paint());
+    }
 }
 
 void SkPaintFilterCanvas::onDrawRRect(const SkRRect& rrect, const SkPaint& paint) {
     AutoPaintFilter apf(this, kRRect_Type, paint);
-    this->INHERITED::onDrawRRect(rrect, *apf.paint());
+    if (apf.shouldDraw()) {
+        this->INHERITED::onDrawRRect(rrect, *apf.paint());
+    }
 }
 
 void SkPaintFilterCanvas::onDrawDRRect(const SkRRect& outer, const SkRRect& inner,
                                        const SkPaint& paint) {
     AutoPaintFilter apf(this, kDRRect_Type, paint);
-    this->INHERITED::onDrawDRRect(outer, inner, *apf.paint());
+    if (apf.shouldDraw()) {
+        this->INHERITED::onDrawDRRect(outer, inner, *apf.paint());
+    }
 }
 
 void SkPaintFilterCanvas::onDrawOval(const SkRect& rect, const SkPaint& paint) {
     AutoPaintFilter apf(this, kOval_Type, paint);
-    this->INHERITED::onDrawOval(rect, *apf.paint());
+    if (apf.shouldDraw()) {
+        this->INHERITED::onDrawOval(rect, *apf.paint());
+    }
 }
 
 void SkPaintFilterCanvas::onDrawPath(const SkPath& path, const SkPaint& paint) {
     AutoPaintFilter apf(this, kPath_Type, paint);
-    this->INHERITED::onDrawPath(path, *apf.paint());
+    if (apf.shouldDraw()) {
+        this->INHERITED::onDrawPath(path, *apf.paint());
+    }
 }
 
 void SkPaintFilterCanvas::onDrawBitmap(const SkBitmap& bm, SkScalar left, SkScalar top,
                                        const SkPaint* paint) {
     AutoPaintFilter apf(this, kBitmap_Type, paint);
-    this->INHERITED::onDrawBitmap(bm, left, top, apf.paint());
+    if (apf.shouldDraw()) {
+        this->INHERITED::onDrawBitmap(bm, left, top, apf.paint());
+    }
 }
 
 void SkPaintFilterCanvas::onDrawBitmapRect(const SkBitmap& bm, const SkRect* src, const SkRect& dst,
                                            const SkPaint* paint, SrcRectConstraint constraint) {
     AutoPaintFilter apf(this, kBitmap_Type, paint);
-    this->INHERITED::onDrawBitmapRect(bm, src, dst, apf.paint(), constraint);
+    if (apf.shouldDraw()) {
+        this->INHERITED::onDrawBitmapRect(bm, src, dst, apf.paint(), constraint);
+    }
+}
+
+void SkPaintFilterCanvas::onDrawBitmapNine(const SkBitmap& bm, const SkIRect& center,
+                                           const SkRect& dst, const SkPaint* paint) {
+    AutoPaintFilter apf(this, kBitmap_Type, paint);
+    if (apf.shouldDraw()) {
+        this->INHERITED::onDrawBitmapNine(bm, center, dst, apf.paint());
+    }
 }
 
 void SkPaintFilterCanvas::onDrawImage(const SkImage* image, SkScalar left, SkScalar top,
                                       const SkPaint* paint) {
     AutoPaintFilter apf(this, kBitmap_Type, paint);
-    this->INHERITED::onDrawImage(image, left, top, apf.paint());
+    if (apf.shouldDraw()) {
+        this->INHERITED::onDrawImage(image, left, top, apf.paint());
+    }
 }
 
 void SkPaintFilterCanvas::onDrawImageRect(const SkImage* image, const SkRect* src,
                                           const SkRect& dst, const SkPaint* paint,
                                           SrcRectConstraint constraint) {
     AutoPaintFilter apf(this, kBitmap_Type, paint);
-    this->INHERITED::onDrawImageRect(image, src, dst, apf.paint(), constraint);
+    if (apf.shouldDraw()) {
+        this->INHERITED::onDrawImageRect(image, src, dst, apf.paint(), constraint);
+    }
 }
 
-void SkPaintFilterCanvas::onDrawBitmapNine(const SkBitmap& bm, const SkIRect& center,
-                                           const SkRect& dst, const SkPaint* paint) {
+void SkPaintFilterCanvas::onDrawImageNine(const SkImage* image, const SkIRect& center,
+                                               const SkRect& dst, const SkPaint* paint) {
     AutoPaintFilter apf(this, kBitmap_Type, paint);
-    this->INHERITED::onDrawBitmapNine(bm, center, dst, apf.paint());
+    if (apf.shouldDraw()) {
+        this->INHERITED::onDrawImageNine(image, center, dst, apf.paint());
+    }
 }
 
 void SkPaintFilterCanvas::onDrawVertices(VertexMode vmode, int vertexCount,
@@ -116,49 +152,65 @@ void SkPaintFilterCanvas::onDrawVertices(VertexMode vmode, int vertexCount,
                                          const uint16_t indices[], int indexCount,
                                          const SkPaint& paint) {
     AutoPaintFilter apf(this, kVertices_Type, paint);
-    this->INHERITED::onDrawVertices(vmode, vertexCount, vertices, texs, colors, xmode, indices,
-                                    indexCount, *apf.paint());
+    if (apf.shouldDraw()) {
+        this->INHERITED::onDrawVertices(vmode, vertexCount, vertices, texs, colors, xmode, indices,
+                                        indexCount, *apf.paint());
+    }
 }
 
 void SkPaintFilterCanvas::onDrawPatch(const SkPoint cubics[], const SkColor colors[],
                                       const SkPoint texCoords[], SkXfermode* xmode,
                                       const SkPaint& paint) {
     AutoPaintFilter apf(this, kPatch_Type, paint);
-    this->INHERITED::onDrawPatch(cubics, colors, texCoords, xmode, *apf.paint());
+    if (apf.shouldDraw()) {
+        this->INHERITED::onDrawPatch(cubics, colors, texCoords, xmode, *apf.paint());
+    }
 }
 
 void SkPaintFilterCanvas::onDrawPicture(const SkPicture* picture, const SkMatrix* m,
                                         const SkPaint* paint) {
     AutoPaintFilter apf(this, kPicture_Type, paint);
-    this->INHERITED::onDrawPicture(picture, m, apf.paint());
+    if (apf.shouldDraw()) {
+        this->INHERITED::onDrawPicture(picture, m, apf.paint());
+    }
 }
 
 void SkPaintFilterCanvas::onDrawText(const void* text, size_t byteLength, SkScalar x, SkScalar y,
                                      const SkPaint& paint) {
     AutoPaintFilter apf(this, kText_Type, paint);
-    this->INHERITED::onDrawText(text, byteLength, x, y, *apf.paint());
+    if (apf.shouldDraw()) {
+        this->INHERITED::onDrawText(text, byteLength, x, y, *apf.paint());
+    }
 }
 
 void SkPaintFilterCanvas::onDrawPosText(const void* text, size_t byteLength, const SkPoint pos[],
                                         const SkPaint& paint) {
     AutoPaintFilter apf(this, kText_Type, paint);
-    this->INHERITED::onDrawPosText(text, byteLength, pos, *apf.paint());
+    if (apf.shouldDraw()) {
+        this->INHERITED::onDrawPosText(text, byteLength, pos, *apf.paint());
+    }
 }
 
 void SkPaintFilterCanvas::onDrawPosTextH(const void* text, size_t byteLength, const SkScalar xpos[],
                                          SkScalar constY, const SkPaint& paint) {
     AutoPaintFilter apf(this, kText_Type, paint);
-    this->INHERITED::onDrawPosTextH(text, byteLength, xpos, constY, *apf.paint());
+    if (apf.shouldDraw()) {
+        this->INHERITED::onDrawPosTextH(text, byteLength, xpos, constY, *apf.paint());
+    }
 }
 
 void SkPaintFilterCanvas::onDrawTextOnPath(const void* text, size_t byteLength, const SkPath& path,
                                            const SkMatrix* matrix, const SkPaint& paint) {
     AutoPaintFilter apf(this, kText_Type, paint);
-    this->INHERITED::onDrawTextOnPath(text, byteLength, path, matrix, *apf.paint());
+    if (apf.shouldDraw()) {
+        this->INHERITED::onDrawTextOnPath(text, byteLength, path, matrix, *apf.paint());
+    }
 }
 
 void SkPaintFilterCanvas::onDrawTextBlob(const SkTextBlob* blob, SkScalar x, SkScalar y,
                                          const SkPaint& paint) {
     AutoPaintFilter apf(this, kTextBlob_Type, paint);
-    this->INHERITED::onDrawTextBlob(blob, x, y, *apf.paint());
+    if (apf.shouldDraw()) {
+        this->INHERITED::onDrawTextBlob(blob, x, y, *apf.paint());
+    }
 }