SkDevice.h

/*
 * Copyright 2010 The Android Open Source Project
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

#ifndef SkDevice_DEFINED
#define SkDevice_DEFINED

#include "SkRefCnt.h"
#include "SkCanvas.h"
#include "SkColor.h"
#include "SkSurfaceProps.h"

class SkBitmap;
class SkClipStack;
class SkDraw;
class SkDrawFilter;
class SkImageFilterCache;
struct SkIRect;
class SkMatrix;
class SkMetaData;
class SkRegion;
class SkSpecialImage;
class GrRenderTarget;

class SK_API SkBaseDevice : public SkRefCnt {
public:
    explicit SkBaseDevice(const SkImageInfo&, const SkSurfaceProps&);
    virtual ~SkBaseDevice();

    SkMetaData& getMetaData();

    const SkImageInfo& imageInfo() const { return fInfo; }

    const SkSurfaceProps& surfaceProps() const {
        return fSurfaceProps;
    }

    void getGlobalBounds(SkIRect* bounds) const {
        SkASSERT(bounds);
        const SkIPoint& origin = this->getOrigin();
        bounds->setXYWH(origin.x(), origin.y(), this->width(), this->height());
    }

    SkIRect getGlobalBounds() const {
        SkIRect bounds;
        this->getGlobalBounds(&bounds);
        return bounds;
    }

    int width() const {
        return this->imageInfo().width();
    }

    int height() const {
        return this->imageInfo().height();
    }

    bool isOpaque() const {
        return this->imageInfo().isOpaque();
    }

#ifdef SK_SUPPORT_LEGACY_ACCESSBITMAP

    const SkBitmap& accessBitmap(bool changePixels);
#endif

    bool writePixels(const SkImageInfo&, const void*, size_t rowBytes, int x, int y);

    bool accessPixels(SkPixmap* pmap);

    bool peekPixels(SkPixmap*);

    const SkIPoint& getOrigin() const { return fOrigin; }

protected:
    enum TileUsage {
        kPossible_TileUsage,    
        kNever_TileUsage,       
    };

    struct TextFlags {
        uint32_t    fFlags;     // SkPaint::getFlags()
    };

    uint32_t filterTextFlags(const SkPaint&) const;

    virtual bool onShouldDisableLCD(const SkPaint&) const { return false; }

     virtual void setMatrixClip(const SkMatrix&, const SkRegion&,
                                const SkClipStack&) {};

    virtual void drawPaint(const SkDraw&, const SkPaint& paint) = 0;
    virtual void drawPoints(const SkDraw&, SkCanvas::PointMode mode, size_t count,
                            const SkPoint[], const SkPaint& paint) = 0;
    virtual void drawRect(const SkDraw&, const SkRect& r,
                          const SkPaint& paint) = 0;
    virtual void drawOval(const SkDraw&, const SkRect& oval,
                          const SkPaint& paint) = 0;
    virtual void drawArc(const SkDraw&, const SkRect& oval, SkScalar startAngle,
                         SkScalar sweepAngle, bool useCenter, const SkPaint& paint);
    virtual void drawRRect(const SkDraw&, const SkRRect& rr,
                           const SkPaint& paint) = 0;

    // Default impl calls drawPath()
    virtual void drawDRRect(const SkDraw&, const SkRRect& outer,
                            const SkRRect& inner, const SkPaint&);

    virtual void drawPath(const SkDraw&, const SkPath& path,
                          const SkPaint& paint,
                          const SkMatrix* prePathMatrix = NULL,
                          bool pathIsMutable = false) = 0;
    virtual void drawBitmap(const SkDraw&, const SkBitmap& bitmap,
                            const SkMatrix& matrix, const SkPaint& paint) = 0;
    virtual void drawSprite(const SkDraw&, const SkBitmap& bitmap,
                            int x, int y, const SkPaint& paint) = 0;

    virtual void drawBitmapRect(const SkDraw&, const SkBitmap&,
                                const SkRect* srcOrNull, const SkRect& dst,
                                const SkPaint& paint,
                                SkCanvas::SrcRectConstraint) = 0;
    virtual void drawBitmapNine(const SkDraw&, const SkBitmap&, const SkIRect& center,
                                const SkRect& dst, const SkPaint&);
    virtual void drawBitmapLattice(const SkDraw&, const SkBitmap&, const SkCanvas::Lattice&,
                                   const SkRect& dst, const SkPaint&);

    virtual void drawImage(const SkDraw&, const SkImage*, SkScalar x, SkScalar y, const SkPaint&);
    virtual void drawImageRect(const SkDraw&, const SkImage*, const SkRect* src, const SkRect& dst,
                               const SkPaint&, SkCanvas::SrcRectConstraint);
    virtual void drawImageNine(const SkDraw&, const SkImage*, const SkIRect& center,
                               const SkRect& dst, const SkPaint&);
    virtual void drawImageLattice(const SkDraw&, const SkImage*, const SkCanvas::Lattice&,
                                  const SkRect& dst, const SkPaint&);

    virtual void drawText(const SkDraw&, const void* text, size_t len,
                          SkScalar x, SkScalar y, const SkPaint& paint) = 0;
    virtual void drawPosText(const SkDraw&, const void* text, size_t len,
                             const SkScalar pos[], int scalarsPerPos,
                             const SkPoint& offset, const SkPaint& paint) = 0;
    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& paint) = 0;
    // default implementation unrolls the blob runs.
    virtual void drawTextBlob(const SkDraw&, const SkTextBlob*, SkScalar x, SkScalar y,
                              const SkPaint& paint, SkDrawFilter* drawFilter);
    // default implementation calls drawVertices
    virtual void drawPatch(const SkDraw&, const SkPoint cubics[12], const SkColor colors[4],
                           const SkPoint texCoords[4], SkXfermode* xmode, const SkPaint& paint);

    // default implementation calls drawPath
    virtual void drawAtlas(const SkDraw&, const SkImage* atlas, const SkRSXform[], const SkRect[],
                           const SkColor[], int count, SkXfermode::Mode, const SkPaint&);

    virtual void drawAnnotation(const SkDraw&, const SkRect&, const char[], SkData*) {}

    virtual void drawDevice(const SkDraw&, SkBaseDevice*, int x, int y,
                            const SkPaint&) = 0;

    virtual void drawTextOnPath(const SkDraw&, const void* text, size_t len, const SkPath&,
                                const SkMatrix*, const SkPaint&);
    virtual void drawTextRSXform(const SkDraw&, const void* text, size_t len, const SkRSXform[],
                                 const SkPaint&);

    virtual void drawSpecial(const SkDraw&, SkSpecialImage*, int x, int y, const SkPaint&);
    virtual sk_sp<SkSpecialImage> makeSpecial(const SkBitmap&);
    virtual sk_sp<SkSpecialImage> makeSpecial(const SkImage*);
    virtual sk_sp<SkSpecialImage> snapSpecial();

    bool readPixels(const SkImageInfo&, void* dst, size_t rowBytes, int x, int y);


#ifdef SK_SUPPORT_LEGACY_ACCESSBITMAP

    virtual const SkBitmap& onAccessBitmap() {
        SkASSERT(0);
        return fLegacyBitmap;
    }
#endif

    virtual GrContext* context() const { return nullptr; }

protected:
    virtual sk_sp<SkSurface> makeSurface(const SkImageInfo&, const SkSurfaceProps&);
    virtual bool onPeekPixels(SkPixmap*) { return false; }

    virtual bool onReadPixels(const SkImageInfo&, void*, size_t, int x, int y);

    virtual bool onWritePixels(const SkImageInfo&, const void*, size_t, int x, int y);

    virtual bool onAccessPixels(SkPixmap*) { return false; }

    struct CreateInfo {
        static SkPixelGeometry AdjustGeometry(const SkImageInfo&, TileUsage, SkPixelGeometry,
                                              bool preserveLCDText);

        // The constructor may change the pixel geometry based on other parameters.
        CreateInfo(const SkImageInfo& info,
                   TileUsage tileUsage,
                   SkPixelGeometry geo)
            : fInfo(info)
            , fTileUsage(tileUsage)
            , fPixelGeometry(AdjustGeometry(info, tileUsage, geo, false))
        {}

        CreateInfo(const SkImageInfo& info,
                   TileUsage tileUsage,
                   SkPixelGeometry geo,
                   bool preserveLCDText)
            : fInfo(info)
            , fTileUsage(tileUsage)
            , fPixelGeometry(AdjustGeometry(info, tileUsage, geo, preserveLCDText))
        {}

        const SkImageInfo       fInfo;
        const TileUsage         fTileUsage;
        const SkPixelGeometry   fPixelGeometry;
    };

    virtual SkBaseDevice* onCreateDevice(const CreateInfo&, const SkPaint*) {
        return NULL;
    }

    // A helper function used by derived classes to log the scale factor of a bitmap or image draw.
    static void LogDrawScaleFactor(const SkMatrix&, SkFilterQuality);

private:
    friend class SkCanvas;
    friend struct DeviceCM; //for setMatrixClip
    friend class SkDraw;
    friend class SkDrawIter;
    friend class SkDeviceFilteredPaint;
    friend class SkNoPixelsBitmapDevice;
    friend class SkSurface_Raster;
    friend class DeviceTestingAccess;

    // used to change the backend's pixels (and possibly config/rowbytes)
    // but cannot change the width/height, so there should be no change to
    // any clip information.
    // TODO: move to SkBitmapDevice
    virtual void replaceBitmapBackendForRasterSurface(const SkBitmap&) {}

    virtual bool forceConservativeRasterClip() const { return false; }

    virtual GrDrawContext* accessDrawContext() { return nullptr; }

    // just called by SkCanvas when built as a layer
    void setOrigin(int x, int y) { fOrigin.set(x, y); }

    virtual void flush() {}

    virtual SkImageFilterCache* getImageFilterCache() { return NULL; }

    friend class SkBitmapDevice;
    void privateResize(int w, int h) {
        *const_cast<SkImageInfo*>(&fInfo) = fInfo.makeWH(w, h);
    }

    SkIPoint    fOrigin;
    SkMetaData* fMetaData;
    const SkImageInfo    fInfo;
    const SkSurfaceProps fSurfaceProps;

#ifdef SK_SUPPORT_LEGACY_ACCESSBITMAP
    SkBitmap    fLegacyBitmap;
#endif

    typedef SkRefCnt INHERITED;
};

#endif