src/gpu/SkGpuDevice.h

/*
 * Copyright 2010 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */



#ifndef SkGpuDevice_DEFINED
#define SkGpuDevice_DEFINED

#include "SkGr.h"
#include "SkBitmap.h"
#include "SkDevice.h"
#include "SkPicture.h"
#include "SkRegion.h"
#include "GrContext.h"
#include "GrSurfacePriv.h"

struct SkDrawProcs;
struct GrSkDrawProcs;

class GrAccelData;
struct GrCachedLayer;
class GrTextContext;

/**
 *  Subclass of SkBaseDevice, which directs all drawing to the GrGpu owned by the
 *  canvas.
 */
class SK_API SkGpuDevice : public SkBaseDevice {
public:
    enum Flags {
        kNeedClear_Flag = 1 << 0,  //!< Surface requires an initial clear
        kDFText_Flag   = 1 << 1,  //!< Surface should render text using signed distance fields
    };

    /**
     * Creates an SkGpuDevice from a GrSurface. This will fail if the surface is not a render
     * target. The caller owns a ref on the returned device. If the surface is cached,
     * the kCached_Flag should be specified to make the device responsible for unlocking
     * the surface when it is released.
     */
    static SkGpuDevice* Create(GrSurface* surface, const SkSurfaceProps&, unsigned flags = 0);

    /**
     *  New device that will create an offscreen renderTarget based on the
     *  ImageInfo and sampleCount. The device's storage will not
     *  count against the GrContext's texture cache budget. The device's pixels
     *  will be uninitialized. On failure, returns NULL.
     */
    static SkGpuDevice* Create(GrContext*, const SkImageInfo&, const SkSurfaceProps&,
                               int sampleCount);

    virtual ~SkGpuDevice();

    SkGpuDevice* cloneDevice(const SkSurfaceProps& props) {
        SkBaseDevice* dev = this->onCreateCompatibleDevice(CreateInfo(this->imageInfo(),
                                                                      kGeneral_Usage,
                                                                      props.pixelGeometry()));
        return static_cast<SkGpuDevice*>(dev);
    }

    GrContext* context() const { return fContext; }

    virtual GrRenderTarget* accessRenderTarget() SK_OVERRIDE;

    virtual SkImageInfo imageInfo() const SK_OVERRIDE {
        return fRenderTarget ? fRenderTarget->surfacePriv().info() : SkImageInfo::MakeUnknown();
    }

    virtual void clear(SkColor color) SK_OVERRIDE;
    virtual void drawPaint(const SkDraw&, const SkPaint& paint) SK_OVERRIDE;
    virtual void drawPoints(const SkDraw&, SkCanvas::PointMode mode, size_t count,
                            const SkPoint[], const SkPaint& paint) SK_OVERRIDE;
    virtual void drawRect(const SkDraw&, const SkRect& r,
                          const SkPaint& paint) SK_OVERRIDE;
    virtual void drawRRect(const SkDraw&, const SkRRect& r,
                           const SkPaint& paint) SK_OVERRIDE;
    virtual void drawDRRect(const SkDraw& draw, const SkRRect& outer,
                            const SkRRect& inner, const SkPaint& paint) SK_OVERRIDE;
    virtual void drawOval(const SkDraw&, const SkRect& oval,
                          const SkPaint& paint) SK_OVERRIDE;
    virtual void drawPath(const SkDraw&, const SkPath& path,
                          const SkPaint& paint, const SkMatrix* prePathMatrix,
                          bool pathIsMutable) SK_OVERRIDE;
    virtual void drawBitmap(const SkDraw&, const SkBitmap& bitmap,
                            const SkMatrix&, const SkPaint&) SK_OVERRIDE;
    virtual void drawBitmapRect(const SkDraw&, const SkBitmap&,
                                const SkRect* srcOrNull, const SkRect& dst,
                                const SkPaint& paint,
                                SkCanvas::DrawBitmapRectFlags flags) SK_OVERRIDE;
    virtual void drawSprite(const SkDraw&, const SkBitmap& bitmap,
                            int x, int y, const SkPaint& paint);
    virtual void drawText(const SkDraw&, const void* text, size_t len,
                          SkScalar x, SkScalar y, const SkPaint&) SK_OVERRIDE;
    virtual void drawPosText(const SkDraw&, const void* text, size_t len,
                             const SkScalar pos[], int scalarsPerPos,
                             const SkPoint& offset, const SkPaint&) SK_OVERRIDE;
    virtual void drawTextOnPath(const SkDraw&, const void* text, size_t len,
                                const SkPath& path, const SkMatrix* matrix,
                                const SkPaint&) SK_OVERRIDE;
    virtual void drawVertices(const SkDraw&, SkCanvas::VertexMode, int vertexCount,
                              const SkPoint verts[], const SkPoint texs[],
                              const SkColor colors[], SkXfermode* xmode,
                              const uint16_t indices[], int indexCount,
                              const SkPaint&) SK_OVERRIDE;
    virtual void drawDevice(const SkDraw&, SkBaseDevice*, int x, int y,
                            const SkPaint&) SK_OVERRIDE;

    virtual void flush() SK_OVERRIDE;

    virtual void onAttachToCanvas(SkCanvas* canvas) SK_OVERRIDE;
    virtual void onDetachFromCanvas() SK_OVERRIDE;

    virtual const SkBitmap& onAccessBitmap() SK_OVERRIDE;

    virtual bool canHandleImageFilter(const SkImageFilter*) SK_OVERRIDE;
    virtual bool filterImage(const SkImageFilter*, const SkBitmap&,
                             const SkImageFilter::Context&,
                             SkBitmap*, SkIPoint*) SK_OVERRIDE;

protected:
    virtual bool onReadPixels(const SkImageInfo&, void*, size_t, int, int) SK_OVERRIDE;
    virtual bool onWritePixels(const SkImageInfo&, const void*, size_t, int, int) SK_OVERRIDE;
    bool onShouldDisableLCD(const SkPaint&) const SK_OVERRIDE;

    /**  PRIVATE / EXPERIMENTAL -- do not call */
    virtual bool EXPERIMENTAL_drawPicture(SkCanvas* canvas, const SkPicture* picture,
                                          const SkMatrix*, const SkPaint*) SK_OVERRIDE;

private:
    GrContext*      fContext;

    GrSkDrawProcs*  fDrawProcs;

    GrClipData      fClipData;

    GrTextContext*  fTextContext;

    // state for our render-target
    GrRenderTarget* fRenderTarget;
    uint32_t        fFlags;

    // remove when our clients don't rely on accessBitmap()
    SkBitmap fLegacyBitmap;

    SkGpuDevice(GrSurface*, const SkSurfaceProps&, unsigned flags = 0);

    virtual SkBaseDevice* onCreateCompatibleDevice(const CreateInfo&) SK_OVERRIDE;

    virtual SkSurface* newSurface(const SkImageInfo&, const SkSurfaceProps&) SK_OVERRIDE;

    virtual SkImageFilter::Cache* getImageFilterCache() SK_OVERRIDE;

    virtual bool forceConservativeRasterClip() const SK_OVERRIDE { return true; }

    // sets the render target, clip, and matrix on GrContext. Use forceIdenity to override
    // SkDraw's matrix and draw in device coords.
    void prepareDraw(const SkDraw&, bool forceIdentity);

    /**
     * Implementation for both drawBitmap and drawBitmapRect.
     */
    void drawBitmapCommon(const SkDraw&,
                          const SkBitmap& bitmap,
                          const SkRect* srcRectPtr,
                          const SkSize* dstSizePtr,      // ignored iff srcRectPtr == NULL
                          const SkPaint&,
                          SkCanvas::DrawBitmapRectFlags flags);

    /**
     * Helper functions called by drawBitmapCommon. By the time these are called the SkDraw's
     * matrix, clip, and the device's render target has already been set on GrContext.
     */

    // The tileSize and clippedSrcRect will be valid only if true is returned.
    bool shouldTileBitmap(const SkBitmap& bitmap,
                          const GrTextureParams& sampler,
                          const SkRect* srcRectPtr,
                          int maxTileSize,
                          int* tileSize,
                          SkIRect* clippedSrcRect) const;
    void internalDrawBitmap(const SkBitmap&,
                            const SkRect&,
                            const GrTextureParams& params,
                            const SkPaint& paint,
                            SkCanvas::DrawBitmapRectFlags flags,
                            bool bicubic,
                            bool needsTextureDomain);
    void drawTiledBitmap(const SkBitmap& bitmap,
                         const SkRect& srcRect,
                         const SkIRect& clippedSrcRect,
                         const GrTextureParams& params,
                         const SkPaint& paint,
                         SkCanvas::DrawBitmapRectFlags flags,
                         int tileSize,
                         bool bicubic);

    bool drawDashLine(const SkPoint pts[2], const SkPaint& paint);

    bool filterTexture(GrContext*, GrTexture*, const SkImageFilter*,
                       const SkImageFilter::Context&,
                       SkBitmap* result, SkIPoint* offset);

    static SkPicture::AccelData::Key ComputeAccelDataKey();

    typedef SkBaseDevice INHERITED;
};

#endif