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/*
* Copyright 2018 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#ifndef GrCCStroker_DEFINED
#define GrCCStroker_DEFINED
#include "GrAllocator.h"
#include "GrMesh.h"
#include "SkNx.h"
#include "ccpr/GrCCStrokeGeometry.h"
class GrBuffer;
class GrCCCoverageProcessor;
class GrOnFlushResourceProvider;
class GrOpFlushState;
class GrPipeline;
class GrPrimitiveProcessor;
class SkMatrix;
class SkPath;
class SkStrokeRec;
/**
* This class parses stroked SkPaths into a GPU instance buffer, then issues calls to draw their
* coverage counts.
*/
class GrCCStroker {
public:
GrCCStroker(int numPaths, int numSkPoints, int numSkVerbs)
: fGeometry(numSkPoints, numSkVerbs), fPathInfos(numPaths) {}
// Parses a device-space SkPath into the current batch, using the SkPath's original verbs with
// 'deviceSpacePts', and the SkStrokeRec's original settings with 'strokeDevWidth'. Accepts an
// optional post-device-space translate for placement in an atlas.
//
// Strokes intended as hairlines must have a strokeDevWidth of 1. Non-hairline strokes can only
// be drawn with rigid body transforms; affine transformation of the stroke lines themselves is
// not yet supported.
void parseDeviceSpaceStroke(const SkPath&, const SkPoint* deviceSpacePts, const SkStrokeRec&,
float strokeDevWidth, GrScissorTest,
const SkIRect& clippedDevIBounds,
const SkIVector& devToAtlasOffset);
using BatchID = int;
// Compiles the outstanding parsed paths into a batch, and returns an ID that can be used to
// draw their strokes in the future.
BatchID closeCurrentBatch();
// Builds an internal GPU buffer and prepares for calls to drawStrokes(). Caller must close the
// current batch before calling this method, and cannot parse new paths afer.
bool prepareToDraw(GrOnFlushResourceProvider*);
// Called after prepareToDraw(). Draws the given batch of path strokes.
void drawStrokes(GrOpFlushState*, BatchID, const SkIRect& drawBounds) const;
private:
static constexpr int kNumScissorModes = 2;
static constexpr BatchID kEmptyBatchID = -1;
using Verb = GrCCStrokeGeometry::Verb;
using InstanceTallies = GrCCStrokeGeometry::InstanceTallies;
// Every kBeginPath verb has a corresponding PathInfo entry.
struct PathInfo {
SkIVector fDevToAtlasOffset;
float fStrokeRadius;
GrScissorTest fScissorTest;
};
// Defines a sub-batch of stroke instances that have a scissor test and the same scissor rect.
// Start indices are deduced by looking at the previous ScissorSubBatch.
struct ScissorSubBatch {
ScissorSubBatch(GrTAllocator<InstanceTallies>* alloc, const InstanceTallies& startIndices,
const SkIRect& scissor)
: fEndInstances(&alloc->emplace_back(startIndices)), fScissor(scissor) {}
InstanceTallies* fEndInstances;
SkIRect fScissor;
};
// Defines a batch of stroke instances that can be drawn with drawStrokes(). Start indices are
// deduced by looking at the previous Batch in the list.
struct Batch {
Batch(GrTAllocator<InstanceTallies>* alloc, const InstanceTallies& startNonScissorIndices,
int startScissorSubBatch)
: fNonScissorEndInstances(&alloc->emplace_back(startNonScissorIndices))
, fEndScissorSubBatch(startScissorSubBatch) {}
InstanceTallies* fNonScissorEndInstances;
int fEndScissorSubBatch;
};
class InstanceBufferBuilder;
void appendStrokeMeshesToBuffers(int numSegmentsLog2, const Batch&,
const InstanceTallies* startIndices[2],
int startScissorSubBatch, const SkIRect& drawBounds) const;
void flushBufferedMeshesAsStrokes(const GrPrimitiveProcessor&, GrOpFlushState*, const
GrPipeline&, const SkIRect& drawBounds) const;
template<int GrCCStrokeGeometry::InstanceTallies::* InstanceType>
void drawConnectingGeometry(GrOpFlushState*, const GrPipeline&,
const GrCCCoverageProcessor&, const Batch&,
const InstanceTallies* startIndices[2], int startScissorSubBatch,
const SkIRect& drawBounds) const;
GrCCStrokeGeometry fGeometry;
SkSTArray<32, PathInfo> fPathInfos;
SkSTArray<32, Batch> fBatches;
SkSTArray<32, ScissorSubBatch> fScissorSubBatches;
int fMaxNumScissorSubBatches = 0;
bool fHasOpenBatch = false;
const InstanceTallies fZeroTallies = InstanceTallies();
GrSTAllocator<128, InstanceTallies> fTalliesAllocator;
const InstanceTallies* fInstanceCounts[kNumScissorModes] = {&fZeroTallies, &fZeroTallies};
sk_sp<GrBuffer> fInstanceBuffer;
// The indices stored in batches are relative to these base instances.
InstanceTallies fBaseInstances[kNumScissorModes];
mutable SkSTArray<32, GrMesh> fMeshesBuffer;
mutable SkSTArray<32, SkIRect> fScissorsBuffer;
};
#endif