GrDrawContext.h

/*
 * Copyright 2015 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

#ifndef GrDrawContext_DEFINED
#define GrDrawContext_DEFINED

#include "GrColor.h"
#include "GrPaint.h"
#include "GrRenderTarget.h"
#include "SkRefCnt.h"
#include "SkRegion.h"
#include "SkSurfaceProps.h"
#include "../private/GrInstancedPipelineInfo.h"
#include "../private/GrSingleOwner.h"

class GrAuditTrail;
class GrClip;
class GrContext;
class GrDrawBatch;
class GrDrawContextPriv;
class GrDrawPathBatchBase;
class GrDrawingManager;
class GrDrawTarget;
class GrPaint;
class GrPathProcessor;
class GrPipelineBuilder;
class GrRenderTarget;
class GrStyle;
class GrSurface;
struct GrUserStencilSettings;
class SkDrawFilter;
struct SkIPoint;
struct SkIRect;
class SkLatticeIter;
class SkMatrix;
class SkPaint;
class SkPath;
struct SkPoint;
struct SkRect;
class SkRRect;
struct SkRSXform;
class SkTextBlob;

/*
 * A helper object to orchestrate draws
 */
class SK_API GrDrawContext : public SkRefCnt {
public:
    ~GrDrawContext() override;

    bool copySurface(GrSurface* src, const SkIRect& srcRect, const SkIPoint& dstPoint);

    // TODO: it is odd that we need both the SkPaint in the following 3 methods.
    // We should extract the text parameters from SkPaint and pass them separately
    // akin to GrStyle (GrTextInfo?)
    virtual void drawText(const GrClip&,  const GrPaint&, const SkPaint&,
                          const SkMatrix& viewMatrix, const char text[], size_t byteLength,
                          SkScalar x, SkScalar y, const SkIRect& clipBounds);
    virtual void drawPosText(const GrClip&, const GrPaint&, const SkPaint&,
                             const SkMatrix& viewMatrix, const char text[], size_t byteLength,
                             const SkScalar pos[], int scalarsPerPosition,
                             const SkPoint& offset, const SkIRect& clipBounds);
    virtual void drawTextBlob(const GrClip&, const SkPaint&,
                              const SkMatrix& viewMatrix, const SkTextBlob*,
                              SkScalar x, SkScalar y,
                              SkDrawFilter*, const SkIRect& clipBounds);

    void discard();

    void clear(const SkIRect* rect, GrColor color, bool canIgnoreRect);

    void drawPaint(const GrClip&, const GrPaint&, const SkMatrix& viewMatrix);

    void drawRect(const GrClip&,
                  const GrPaint& paint,
                  const SkMatrix& viewMatrix,
                  const SkRect&,
                  const GrStyle* style  = nullptr);

    void fillRectToRect(const GrClip&,
                        const GrPaint& paint,
                        const SkMatrix& viewMatrix,
                        const SkRect& rectToDraw,
                        const SkRect& localRect);

    void fillRectWithLocalMatrix(const GrClip& clip,
                                 const GrPaint& paint,
                                 const SkMatrix& viewMatrix,
                                 const SkRect& rect,
                                 const SkMatrix& localMatrix);

    void drawRRect(const GrClip&,
                   const GrPaint&,
                   const SkMatrix& viewMatrix,
                   const SkRRect& rrect,
                   const GrStyle& style);

    void drawDRRect(const GrClip&,
                    const GrPaint&,
                    const SkMatrix& viewMatrix,
                    const SkRRect& outer,
                    const SkRRect& inner);

    void drawPath(const GrClip&,
                  const GrPaint&,
                  const SkMatrix& viewMatrix,
                  const SkPath&,
                  const GrStyle& style);

    void drawVertices(const GrClip&,
                      const GrPaint& paint,
                      const SkMatrix& viewMatrix,
                      GrPrimitiveType primitiveType,
                      int vertexCount,
                      const SkPoint positions[],
                      const SkPoint texs[],
                      const GrColor colors[],
                      const uint16_t indices[],
                      int indexCount);

    void drawAtlas(const GrClip&,
                   const GrPaint& paint,
                   const SkMatrix& viewMatrix,
                   int spriteCount,
                   const SkRSXform xform[],
                   const SkRect texRect[],
                   const SkColor colors[]);
    
    void drawOval(const GrClip&,
                  const GrPaint& paint,
                  const SkMatrix& viewMatrix,
                  const SkRect& oval,
                  const GrStyle& style);
    void drawArc(const GrClip&,
                 const GrPaint& paint,
                 const SkMatrix& viewMatrix,
                 const SkRect& oval,
                 SkScalar startAngle,
                 SkScalar sweepAngle,
                 bool useCenter,
                 const GrStyle& style);

    void drawImageLattice(const GrClip&,
                          const GrPaint& paint,
                          const SkMatrix& viewMatrix,
                          int imageWidth,
                          int imageHeight,
                          std::unique_ptr<SkLatticeIter> iter,
                          const SkRect& dst);

    void prepareForExternalIO();

    bool isStencilBufferMultisampled() const {
        return fRenderTarget->isStencilBufferMultisampled();
    }
    bool isUnifiedMultisampled() const { return fRenderTarget->isUnifiedMultisampled(); }
    bool hasMixedSamples() const { return fRenderTarget->isMixedSampled(); }

    bool mustUseHWAA(const GrPaint& paint) const {
        return paint.isAntiAlias() && fRenderTarget->isUnifiedMultisampled();
    }

    const GrSurfaceDesc& desc() const { return fRenderTarget->desc(); }
    int width() const { return fRenderTarget->width(); }
    int height() const { return fRenderTarget->height(); }
    GrPixelConfig config() const { return fRenderTarget->config(); }
    int numColorSamples() const { return fRenderTarget->numColorSamples(); }
    bool isGammaCorrect() const { return SkToBool(fColorSpace.get()); }
    SkSourceGammaTreatment sourceGammaTreatment() const {
        return this->isGammaCorrect() ? SkSourceGammaTreatment::kRespect
                                      : SkSourceGammaTreatment::kIgnore;
    }
    const SkSurfaceProps& surfaceProps() const { return fSurfaceProps; }
    SkColorSpace* getColorSpace() const { return fColorSpace.get(); }
    GrSurfaceOrigin origin() const { return fRenderTarget->origin(); }

    bool wasAbandoned() const;

    GrRenderTarget* accessRenderTarget() { return fRenderTarget.get(); }

    sk_sp<GrRenderTarget> renderTarget() { return fRenderTarget; }

    sk_sp<GrTexture> asTexture() { return sk_ref_sp(fRenderTarget->asTexture()); }

    // Provides access to functions that aren't part of the public API.
    GrDrawContextPriv drawContextPriv();
    const GrDrawContextPriv drawContextPriv() const;

    GrAuditTrail* auditTrail() { return fAuditTrail; }

protected:
    GrDrawContext(GrContext*, GrDrawingManager*, sk_sp<GrRenderTarget>, sk_sp<SkColorSpace>,
                  const SkSurfaceProps* surfaceProps, GrAuditTrail*, GrSingleOwner*);

    GrDrawingManager* drawingManager() { return fDrawingManager; }

    SkDEBUGCODE(GrSingleOwner* singleOwner() { return fSingleOwner; })
    SkDEBUGCODE(void validate() const;)

private:
    friend class GrAtlasTextBlob; // for access to drawBatch
    friend class GrStencilAndCoverTextContext; // for access to drawBatch

    friend class GrDrawingManager; // for ctor
    friend class GrDrawContextPriv;
    friend class GrTestTarget;  // for access to getDrawTarget
    friend class GrSWMaskHelper;                 // for access to drawBatch

    // All the path renderers currently make their own batches
    friend class GrSoftwarePathRenderer;         // for access to drawBatch
    friend class GrAAConvexPathRenderer;         // for access to drawBatch
    friend class GrDashLinePathRenderer;         // for access to drawBatch
    friend class GrAAHairLinePathRenderer;       // for access to drawBatch
    friend class GrAALinearizingConvexPathRenderer;  // for access to drawBatch
    friend class GrAADistanceFieldPathRenderer;  // for access to drawBatch
    friend class GrDefaultPathRenderer;          // for access to drawBatch
    friend class GrPLSPathRenderer;              // for access to drawBatch
    friend class GrMSAAPathRenderer;             // for access to drawBatch
    friend class GrStencilAndCoverPathRenderer;  // for access to drawBatch
    friend class GrTessellatingPathRenderer;     // for access to drawBatch

    bool drawFilledDRRect(const GrClip& clip,
                          const GrPaint& paint,
                          const SkMatrix& viewMatrix,
                          const SkRRect& origOuter,
                          const SkRRect& origInner);

    bool drawFilledRect(const GrClip& clip,
                        const GrPaint& paint,
                        const SkMatrix& viewMatrix,
                        const SkRect& rect,
                        const GrUserStencilSettings* ss);

    void drawNonAAFilledRect(const GrClip&,
                             const GrPaint&,
                             const SkMatrix& viewMatrix,
                             const SkRect& rect,
                             const SkRect* localRect,
                             const SkMatrix* localMatrix,
                             const GrUserStencilSettings* ss,
                             bool useHWAA);

    void internalDrawPath(const GrClip& clip,
                          const GrPaint& paint,
                          const SkMatrix& viewMatrix,
                          const SkPath& path,
                          const GrStyle& style);

    // This entry point allows the GrTextContext-derived classes to add their batches to
    // the drawTarget.
    void drawBatch(const GrPipelineBuilder& pipelineBuilder, const GrClip&, GrDrawBatch* batch);

    GrDrawTarget* getDrawTarget();

    GrDrawingManager*                 fDrawingManager;
    sk_sp<GrRenderTarget>             fRenderTarget;

    // In MDB-mode the drawTarget can be closed by some other drawContext that has picked
    // it up. For this reason, the drawTarget should only ever be accessed via 'getDrawTarget'.
    GrDrawTarget*                     fDrawTarget;
    GrContext*                        fContext;
    GrInstancedPipelineInfo           fInstancedPipelineInfo;

    sk_sp<SkColorSpace>               fColorSpace;
    SkSurfaceProps                    fSurfaceProps;
    GrAuditTrail*                     fAuditTrail;

    // In debug builds we guard against improper thread handling
    SkDEBUGCODE(mutable GrSingleOwner* fSingleOwner;)
};

#endif