skia2/include/utils/SkNoDrawCanvas.h
Mike Reed d567408362 Add secret draw-behind method
This is a variant of drawPaint but is automatically clipped
to the bounds of the most recent saveBehind buffer (axis-aligned bounds).

No public exposure.

Impl is pretty simple (its a variant of drawPaint)
- find the most recent saveBehind device bounds
- if there is none, draw nothing, else
  - temporarily intersect the device's clip with that bounds
  - drawPaint
  - restore the clip

See https://buganizer.corp.google.com/issues/129117085

Change-Id: I7c532e63a80b118fb2416c572b8e0d2abf8cf59a
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/209166
Commit-Queue: Mike Reed <reed@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
2019-04-19 20:50:22 +00:00

90 lines
4.1 KiB
C++

/*
* Copyright 2016 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#ifndef SkNoDrawCanvas_DEFINED
#define SkNoDrawCanvas_DEFINED
#include "SkCanvas.h"
#include "SkCanvasVirtualEnforcer.h"
#include "SkVertices.h"
struct SkIRect;
// SkNoDrawCanvas is a helper for SkCanvas subclasses which do not need to
// actually rasterize (e.g., analysis of the draw calls).
//
// It provides the following simplifications:
//
// * not backed by any device/pixels
// * conservative clipping (clipping calls only use rectangles)
//
class SK_API SkNoDrawCanvas : public SkCanvasVirtualEnforcer<SkCanvas> {
public:
SkNoDrawCanvas(int width, int height);
// TODO: investigate the users of this ctor.
SkNoDrawCanvas(const SkIRect&);
explicit SkNoDrawCanvas(sk_sp<SkBaseDevice> device);
// Optimization to reset state to be the same as after construction.
void resetCanvas(int width, int height) {
resetForNextPicture(SkIRect::MakeWH(width, height));
}
protected:
SaveLayerStrategy getSaveLayerStrategy(const SaveLayerRec& rec) override;
bool onDoSaveBehind(const SkRect*) override;
// No-op overrides for aborting rasterization earlier than SkNullBlitter.
void onDrawAnnotation(const SkRect&, const char[], SkData*) override {}
void onDrawDRRect(const SkRRect&, const SkRRect&, const SkPaint&) override {}
void onDrawDrawable(SkDrawable*, const SkMatrix*) override {}
void onDrawTextBlob(const SkTextBlob*, SkScalar, SkScalar, const SkPaint&) override {}
void onDrawPatch(const SkPoint[12], const SkColor[4], const SkPoint[4], SkBlendMode,
const SkPaint&) override {}
void onDrawPaint(const SkPaint&) override {}
void onDrawBehind(const SkPaint&) override {}
void onDrawPoints(PointMode, size_t, const SkPoint[], const SkPaint&) override {}
void onDrawRect(const SkRect&, const SkPaint&) override {}
void onDrawRegion(const SkRegion&, const SkPaint&) override {}
void onDrawOval(const SkRect&, const SkPaint&) override {}
void onDrawArc(const SkRect&, SkScalar, SkScalar, bool, const SkPaint&) override {}
void onDrawRRect(const SkRRect&, const SkPaint&) override {}
void onDrawPath(const SkPath&, const SkPaint&) override {}
void onDrawBitmap(const SkBitmap&, SkScalar, SkScalar, const SkPaint*) override {}
void onDrawBitmapRect(const SkBitmap&, const SkRect*, const SkRect&, const SkPaint*,
SrcRectConstraint) override {}
void onDrawImage(const SkImage*, SkScalar, SkScalar, const SkPaint*) override {}
void onDrawImageRect(const SkImage*, const SkRect*, const SkRect&, const SkPaint*,
SrcRectConstraint) override {}
void onDrawImageNine(const SkImage*, const SkIRect&, const SkRect&, const SkPaint*) override {}
void onDrawBitmapNine(const SkBitmap&, const SkIRect&, const SkRect&,
const SkPaint*) override {}
void onDrawImageLattice(const SkImage*, const Lattice&, const SkRect&,
const SkPaint*) override {}
void onDrawBitmapLattice(const SkBitmap&, const Lattice&, const SkRect&,
const SkPaint*) override {}
void onDrawVerticesObject(const SkVertices*, const SkVertices::Bone[], int, SkBlendMode,
const SkPaint&) override {}
void onDrawAtlas(const SkImage*, const SkRSXform[], const SkRect[], const SkColor[],
int, SkBlendMode, const SkRect*, const SkPaint*) override {}
void onDrawShadowRec(const SkPath&, const SkDrawShadowRec&) override {}
void onDrawPicture(const SkPicture*, const SkMatrix*, const SkPaint*) override {}
void onDrawEdgeAAQuad(const SkRect&, const SkPoint[4], QuadAAFlags, SkColor,
SkBlendMode) override {}
void onDrawEdgeAAImageSet(const ImageSetEntry[], int, const SkPoint[],
const SkMatrix[], const SkPaint*, SrcRectConstraint) override {}
private:
typedef SkCanvasVirtualEnforcer<SkCanvas> INHERITED;
};
#endif // SkNoDrawCanvas_DEFINED