diff -r 000000000000 -r 6474c204b198 gfx/skia/trunk/include/core/SkCanvas.h --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/gfx/skia/trunk/include/core/SkCanvas.h Wed Dec 31 06:09:35 2014 +0100 @@ -0,0 +1,1503 @@ +/* + * Copyright 2006 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 SkCanvas_DEFINED +#define SkCanvas_DEFINED + +#include "SkTypes.h" +#include "SkBitmap.h" +#include "SkDeque.h" +#include "SkClipStack.h" +#include "SkPaint.h" +#include "SkRefCnt.h" +#include "SkPath.h" +#include "SkRegion.h" +#include "SkXfermode.h" + +// if not defined, we always assume ClipToLayer for saveLayer() +//#define SK_SUPPORT_LEGACY_CLIPTOLAYERFLAG + + +//#define SK_SUPPORT_LEGACY_WRITEPIXELSCONFIG +//#define SK_SUPPORT_LEGACY_GETCLIPTYPE +//#define SK_SUPPORT_LEGACY_GETTOTALCLIP +//#define SK_SUPPORT_LEGACY_GETTOPDEVICE + +class SkBounder; +class SkBaseDevice; +class SkDraw; +class SkDrawFilter; +class SkMetaData; +class SkPicture; +class SkRRect; +class SkSurface; +class SkSurface_Base; +class GrContext; +class GrRenderTarget; + +/** \class SkCanvas + + A Canvas encapsulates all of the state about drawing into a device (bitmap). + This includes a reference to the device itself, and a stack of matrix/clip + values. For any given draw call (e.g. drawRect), the geometry of the object + being drawn is transformed by the concatenation of all the matrices in the + stack. The transformed geometry is clipped by the intersection of all of + the clips in the stack. + + While the Canvas holds the state of the drawing device, the state (style) + of the object being drawn is held by the Paint, which is provided as a + parameter to each of the draw() methods. The Paint holds attributes such as + color, typeface, textSize, strokeWidth, shader (e.g. gradients, patterns), + etc. +*/ +class SK_API SkCanvas : public SkRefCnt { +public: + SK_DECLARE_INST_COUNT(SkCanvas) + + /** + * Attempt to allocate an offscreen raster canvas, matching the ImageInfo. + * On success, return a new canvas that will draw into that offscreen. + * + * The caller can access the pixels after drawing into this canvas by + * calling readPixels() or peekPixels(). + * + * If the requested ImageInfo is opaque (either the colortype is + * intrinsically opaque like RGB_565, or the info's alphatype is kOpaque) + * then the pixel memory may be uninitialized. Otherwise, the pixel memory + * will be initialized to 0, which is interpreted as transparent. + * + * On failure, return NULL. This can fail for several reasons: + * 1. the memory allocation failed (e.g. request is too large) + * 2. invalid ImageInfo (e.g. negative dimensions) + * 3. unsupported ImageInfo for a canvas + * - kUnknown_SkColorType, kIndex_8_SkColorType + * - kIgnore_SkAlphaType + * - this list is not complete, so others may also be unsupported + * + * Note: it is valid to request a supported ImageInfo, but with zero + * dimensions. + */ + static SkCanvas* NewRaster(const SkImageInfo&); + + static SkCanvas* NewRasterN32(int width, int height) { + return NewRaster(SkImageInfo::MakeN32Premul(width, height)); + } + + /** + * Attempt to allocate raster canvas, matching the ImageInfo, that will draw directly into the + * specified pixels. To access the pixels after drawing to them, the caller should call + * flush() or call peekPixels(...). + * + * On failure, return NULL. This can fail for several reasons: + * 1. invalid ImageInfo (e.g. negative dimensions) + * 2. unsupported ImageInfo for a canvas + * - kUnknown_SkColorType, kIndex_8_SkColorType + * - kIgnore_SkAlphaType + * - this list is not complete, so others may also be unsupported + * + * Note: it is valid to request a supported ImageInfo, but with zero + * dimensions. + */ + static SkCanvas* NewRasterDirect(const SkImageInfo&, void*, size_t); + + static SkCanvas* NewRasterDirectN32(int width, int height, SkPMColor* pixels, size_t rowBytes) { + return NewRasterDirect(SkImageInfo::MakeN32Premul(width, height), pixels, rowBytes); + } + + /** + * Creates an empty canvas with no backing device/pixels, and zero + * dimensions. + */ + SkCanvas(); + + /** + * Creates a canvas of the specified dimensions, but explicitly not backed + * by any device/pixels. Typically this use used by subclasses who handle + * the draw calls in some other way. + */ + SkCanvas(int width, int height); + + /** Construct a canvas with the specified device to draw into. + + @param device Specifies a device for the canvas to draw into. + */ + explicit SkCanvas(SkBaseDevice* device); + + /** Construct a canvas with the specified bitmap to draw into. + @param bitmap Specifies a bitmap for the canvas to draw into. Its + structure are copied to the canvas. + */ + explicit SkCanvas(const SkBitmap& bitmap); + virtual ~SkCanvas(); + + SkMetaData& getMetaData(); + + /** + * Return ImageInfo for this canvas. If the canvas is not backed by pixels + * (cpu or gpu), then the info's ColorType will be kUnknown_SkColorType. + */ + SkImageInfo imageInfo() const; + + /////////////////////////////////////////////////////////////////////////// + + /** + * Trigger the immediate execution of all pending draw operations. + */ + void flush(); + + /** + * Gets the size of the base or root layer in global canvas coordinates. The + * origin of the base layer is always (0,0). The current drawable area may be + * smaller (due to clipping or saveLayer). + */ + SkISize getBaseLayerSize() const; + + /** + * DEPRECATED: call getBaseLayerSize + */ + SkISize getDeviceSize() const { return this->getBaseLayerSize(); } + + /** + * DEPRECATED. + * Return the canvas' device object, which may be null. The device holds + * the bitmap of the pixels that the canvas draws into. The reference count + * of the returned device is not changed by this call. + */ + SkBaseDevice* getDevice() const; + + /** + * saveLayer() can create another device (which is later drawn onto + * the previous device). getTopDevice() returns the top-most device current + * installed. Note that this can change on other calls like save/restore, + * so do not access this device after subsequent canvas calls. + * The reference count of the device is not changed. + * + * @param updateMatrixClip If this is true, then before the device is + * returned, we ensure that its has been notified about the current + * matrix and clip. Note: this happens automatically when the device + * is drawn to, but is optional here, as there is a small perf hit + * sometimes. + */ +#ifndef SK_SUPPORT_LEGACY_GETTOPDEVICE +private: +#endif + SkBaseDevice* getTopDevice(bool updateMatrixClip = false) const; +public: + + /** + * Create a new surface matching the specified info, one that attempts to + * be maximally compatible when used with this canvas. + */ + SkSurface* newSurface(const SkImageInfo&); + + /** + * Return the GPU context of the device that is associated with the canvas. + * For a canvas with non-GPU device, NULL is returned. + */ + GrContext* getGrContext(); + + /////////////////////////////////////////////////////////////////////////// + + /** + * If the canvas has writable pixels in its top layer (and is not recording to a picture + * or other non-raster target) and has direct access to its pixels (i.e. they are in + * local RAM) return the address of those pixels, and if not null, + * return the ImageInfo and rowBytes. The returned address is only valid + * while the canvas object is in scope and unchanged. Any API calls made on + * canvas (or its parent surface if any) will invalidate the + * returned address (and associated information). + * + * On failure, returns NULL and the info and rowBytes parameters are + * ignored. + */ + void* accessTopLayerPixels(SkImageInfo* info, size_t* rowBytes); + + /** + * If the canvas has readable pixels in its base layer (and is not recording to a picture + * or other non-raster target) and has direct access to its pixels (i.e. they are in + * local RAM) return the const-address of those pixels, and if not null, + * return the ImageInfo and rowBytes. The returned address is only valid + * while the canvas object is in scope and unchanged. Any API calls made on + * canvas (or its parent surface if any) will invalidate the + * returned address (and associated information). + * + * On failure, returns NULL and the info and rowBytes parameters are + * ignored. + */ + const void* peekPixels(SkImageInfo* info, size_t* rowBytes); + + /** + * This enum can be used with read/writePixels to perform a pixel ops to or + * from an 8888 config other than Skia's native config (SkPMColor). There + * are three byte orders supported: native, BGRA, and RGBA. Each has a + * premultiplied and unpremultiplied variant. + * + * Components of a 8888 pixel can be packed/unpacked from a 32bit word using + * either byte offsets or shift values. Byte offsets are endian-invariant + * while shifts are not. BGRA and RGBA configs are defined by byte + * orderings. The native config is defined by shift values (SK_A32_SHIFT, + * ..., SK_B32_SHIFT). + */ + enum Config8888 { + /** + * Skia's native order specified by: + * SK_A32_SHIFT, SK_R32_SHIFT, SK_G32_SHIFT, and SK_B32_SHIFT + * + * kNative_Premul_Config8888 is equivalent to SkPMColor + * kNative_Unpremul_Config8888 has the same component order as SkPMColor + * but is not premultiplied. + */ + kNative_Premul_Config8888, + kNative_Unpremul_Config8888, + /** + * low byte to high byte: B, G, R, A. + */ + kBGRA_Premul_Config8888, + kBGRA_Unpremul_Config8888, + /** + * low byte to high byte: R, G, B, A. + */ + kRGBA_Premul_Config8888, + kRGBA_Unpremul_Config8888 + }; + + /** + * On success (returns true), copy the canvas pixels into the bitmap. + * On failure, the bitmap parameter is left unchanged and false is + * returned. + * + * The canvas' pixels are converted to the bitmap's config. The only + * supported config is kARGB_8888_Config, though this is likely to be + * relaxed in the future. The meaning of config kARGB_8888_Config is + * modified by the enum param config8888. The default value interprets + * kARGB_8888_Config as SkPMColor + * + * If the bitmap has pixels already allocated, the canvas pixels will be + * written there. If not, bitmap->allocPixels() will be called + * automatically. If the bitmap is backed by a texture readPixels will + * fail. + * + * The actual pixels written is the intersection of the canvas' bounds, and + * the rectangle formed by the bitmap's width,height and the specified x,y. + * If bitmap pixels extend outside of that intersection, they will not be + * modified. + * + * Other failure conditions: + * * If the canvas is backed by a non-raster device (e.g. PDF) then + * readPixels will fail. + * * If bitmap is texture-backed then readPixels will fail. (This may be + * relaxed in the future.) + * + * Example that reads the entire canvas into a bitmap using the native + * SkPMColor: + * SkISize size = canvas->getDeviceSize(); + * bitmap->setConfig(SkBitmap::kARGB_8888_Config, size.fWidth, + * size.fHeight); + * if (canvas->readPixels(bitmap, 0, 0)) { + * // use the pixels + * } + */ + bool readPixels(SkBitmap* bitmap, + int x, int y, + Config8888 config8888 = kNative_Premul_Config8888); + + /** + * DEPRECATED: This will be removed as soon as webkit is no longer relying + * on it. The bitmap is resized to the intersection of srcRect and the + * canvas bounds. New pixels are always allocated on success. Bitmap is + * unmodified on failure. + */ + bool readPixels(const SkIRect& srcRect, SkBitmap* bitmap); + +#ifdef SK_SUPPORT_LEGACY_WRITEPIXELSCONFIG + /** + * DEPRECATED + * Similar to draw sprite, this method will copy the pixels in bitmap onto + * the canvas, with the top/left corner specified by (x, y). The canvas' + * pixel values are completely replaced: there is no blending. + * + * Currently if bitmap is backed by a texture this is a no-op. This may be + * relaxed in the future. + * + * If the bitmap has config kARGB_8888_Config then the config8888 param + * will determines how the pixel valuess are intepreted. If the bitmap is + * not kARGB_8888_Config then this parameter is ignored. + * + * Note: If you are recording drawing commands on this canvas to + * SkPicture, writePixels() is ignored! + */ + void writePixels(const SkBitmap& bitmap, int x, int y, Config8888 config8888); +#endif + + /** + * This method affects the pixels in the base-layer, and operates in pixel coordinates, + * ignoring the matrix and clip. + * + * The specified ImageInfo and (x,y) offset specifies a rectangle: target. + * + * target.setXYWH(x, y, info.width(), info.height()); + * + * Target is intersected with the bounds of the base-layer. If this intersection is not empty, + * then we have two sets of pixels (of equal size), the "src" specified by info+pixels+rowBytes + * and the "dst" by the canvas' backend. Replace the dst pixels with the corresponding src + * pixels, performing any colortype/alphatype transformations needed (in the case where the + * src and dst have different colortypes or alphatypes). + * + * This call can fail, returning false, for several reasons: + * - If the src colortype/alphatype cannot be converted to the canvas' types + * - If this canvas is not backed by pixels (e.g. picture or PDF) + */ + bool writePixels(const SkImageInfo&, const void* pixels, size_t rowBytes, int x, int y); + + /** + * Helper for calling writePixels(info, ...) by passing its pixels and rowbytes. If the bitmap + * is just wrapping a texture, returns false and does nothing. + */ + bool writePixels(const SkBitmap& bitmap, int x, int y); + + /////////////////////////////////////////////////////////////////////////// + + enum SaveFlags { + /** save the matrix state, restoring it on restore() */ + kMatrix_SaveFlag = 0x01, + /** save the clip state, restoring it on restore() */ + kClip_SaveFlag = 0x02, + /** the layer needs to support per-pixel alpha */ + kHasAlphaLayer_SaveFlag = 0x04, + /** the layer needs to support 8-bits per color component */ + kFullColorLayer_SaveFlag = 0x08, + /** + * the layer should clip against the bounds argument + * + * if SK_SUPPORT_LEGACY_CLIPTOLAYERFLAG is undefined, this is treated as always on. + */ + kClipToLayer_SaveFlag = 0x10, + + // helper masks for common choices + kMatrixClip_SaveFlag = 0x03, +#ifdef SK_SUPPORT_LEGACY_CLIPTOLAYERFLAG + kARGB_NoClipLayer_SaveFlag = 0x0F, +#endif + kARGB_ClipLayer_SaveFlag = 0x1F + }; + + /** This call saves the current matrix, clip, and drawFilter, and pushes a + copy onto a private stack. Subsequent calls to translate, scale, + rotate, skew, concat or clipRect, clipPath, and setDrawFilter all + operate on this copy. + When the balancing call to restore() is made, the previous matrix, clip, + and drawFilter are restored. + @param flags The flags govern what portion of the Matrix/Clip/drawFilter + state the save (and matching restore) effect. For example, + if only kMatrix is specified, then only the matrix state + will be pushed and popped. Likewise for the clip if kClip + is specified. However, the drawFilter is always affected + by calls to save/restore. + @return The value to pass to restoreToCount() to balance this save() + */ + int save(SaveFlags flags = kMatrixClip_SaveFlag); + + /** This behaves the same as save(), but in addition it allocates an + offscreen bitmap. All drawing calls are directed there, and only when + the balancing call to restore() is made is that offscreen transfered to + the canvas (or the previous layer). + @param bounds (may be null) This rect, if non-null, is used as a hint to + limit the size of the offscreen, and thus drawing may be + clipped to it, though that clipping is not guaranteed to + happen. If exact clipping is desired, use clipRect(). + @param paint (may be null) This is copied, and is applied to the + offscreen when restore() is called + @param flags LayerFlags + @return The value to pass to restoreToCount() to balance this save() + */ + int saveLayer(const SkRect* bounds, const SkPaint* paint, + SaveFlags flags = kARGB_ClipLayer_SaveFlag); + + /** This behaves the same as save(), but in addition it allocates an + offscreen bitmap. All drawing calls are directed there, and only when + the balancing call to restore() is made is that offscreen transfered to + the canvas (or the previous layer). + @param bounds (may be null) This rect, if non-null, is used as a hint to + limit the size of the offscreen, and thus drawing may be + clipped to it, though that clipping is not guaranteed to + happen. If exact clipping is desired, use clipRect(). + @param alpha This is applied to the offscreen when restore() is called. + @param flags LayerFlags + @return The value to pass to restoreToCount() to balance this save() + */ + int saveLayerAlpha(const SkRect* bounds, U8CPU alpha, + SaveFlags flags = kARGB_ClipLayer_SaveFlag); + + /** This call balances a previous call to save(), and is used to remove all + modifications to the matrix/clip/drawFilter state since the last save + call. + It is an error to call restore() more times than save() was called. + */ + void restore(); + + /** Returns the number of matrix/clip states on the SkCanvas' private stack. + This will equal # save() calls - # restore() calls + 1. The save count on + a new canvas is 1. + */ + int getSaveCount() const; + + /** Efficient way to pop any calls to save() that happened after the save + count reached saveCount. It is an error for saveCount to be greater than + getSaveCount(). To pop all the way back to the initial matrix/clip context + pass saveCount == 1. + @param saveCount The number of save() levels to restore from + */ + void restoreToCount(int saveCount); + + /** Returns true if drawing is currently going to a layer (from saveLayer) + * rather than to the root device. + */ + virtual bool isDrawingToLayer() const; + + /** Preconcat the current matrix with the specified translation + @param dx The distance to translate in X + @param dy The distance to translate in Y + returns true if the operation succeeded (e.g. did not overflow) + */ + bool translate(SkScalar dx, SkScalar dy); + + /** Preconcat the current matrix with the specified scale. + @param sx The amount to scale in X + @param sy The amount to scale in Y + returns true if the operation succeeded (e.g. did not overflow) + */ + bool scale(SkScalar sx, SkScalar sy); + + /** Preconcat the current matrix with the specified rotation. + @param degrees The amount to rotate, in degrees + returns true if the operation succeeded (e.g. did not overflow) + */ + bool rotate(SkScalar degrees); + + /** Preconcat the current matrix with the specified skew. + @param sx The amount to skew in X + @param sy The amount to skew in Y + returns true if the operation succeeded (e.g. did not overflow) + */ + bool skew(SkScalar sx, SkScalar sy); + + /** Preconcat the current matrix with the specified matrix. + @param matrix The matrix to preconcatenate with the current matrix + @return true if the operation succeeded (e.g. did not overflow) + */ + bool concat(const SkMatrix& matrix); + + /** Replace the current matrix with a copy of the specified matrix. + @param matrix The matrix that will be copied into the current matrix. + */ + void setMatrix(const SkMatrix& matrix); + + /** Helper for setMatrix(identity). Sets the current matrix to identity. + */ + void resetMatrix(); + + /** + * Modify the current clip with the specified rectangle. + * @param rect The rect to combine with the current clip + * @param op The region op to apply to the current clip + * @param doAntiAlias true if the clip should be antialiased + */ + void clipRect(const SkRect& rect, + SkRegion::Op op = SkRegion::kIntersect_Op, + bool doAntiAlias = false); + + /** + * Modify the current clip with the specified SkRRect. + * @param rrect The rrect to combine with the current clip + * @param op The region op to apply to the current clip + * @param doAntiAlias true if the clip should be antialiased + */ + void clipRRect(const SkRRect& rrect, + SkRegion::Op op = SkRegion::kIntersect_Op, + bool doAntiAlias = false); + + /** + * Modify the current clip with the specified path. + * @param path The path to combine with the current clip + * @param op The region op to apply to the current clip + * @param doAntiAlias true if the clip should be antialiased + */ + void clipPath(const SkPath& path, + SkRegion::Op op = SkRegion::kIntersect_Op, + bool doAntiAlias = false); + + /** EXPERIMENTAL -- only used for testing + Set to false to force clips to be hard, even if doAntiAlias=true is + passed to clipRect or clipPath. + */ + void setAllowSoftClip(bool allow) { + fAllowSoftClip = allow; + } + + /** EXPERIMENTAL -- only used for testing + Set to simplify clip stack using path ops. + */ + void setAllowSimplifyClip(bool allow) { + fAllowSimplifyClip = allow; + } + + /** Modify the current clip with the specified region. Note that unlike + clipRect() and clipPath() which transform their arguments by the current + matrix, clipRegion() assumes its argument is already in device + coordinates, and so no transformation is performed. + @param deviceRgn The region to apply to the current clip + @param op The region op to apply to the current clip + */ + void clipRegion(const SkRegion& deviceRgn, + SkRegion::Op op = SkRegion::kIntersect_Op); + + /** Helper for clipRegion(rgn, kReplace_Op). Sets the current clip to the + specified region. This does not intersect or in any other way account + for the existing clip region. + @param deviceRgn The region to copy into the current clip. + */ + void setClipRegion(const SkRegion& deviceRgn) { + this->clipRegion(deviceRgn, SkRegion::kReplace_Op); + } + + /** Return true if the specified rectangle, after being transformed by the + current matrix, would lie completely outside of the current clip. Call + this to check if an area you intend to draw into is clipped out (and + therefore you can skip making the draw calls). + @param rect the rect to compare with the current clip + @return true if the rect (transformed by the canvas' matrix) does not + intersect with the canvas' clip + */ + bool quickReject(const SkRect& rect) const; + + /** Return true if the specified path, after being transformed by the + current matrix, would lie completely outside of the current clip. Call + this to check if an area you intend to draw into is clipped out (and + therefore you can skip making the draw calls). Note, for speed it may + return false even if the path itself might not intersect the clip + (i.e. the bounds of the path intersects, but the path does not). + @param path The path to compare with the current clip + @return true if the path (transformed by the canvas' matrix) does not + intersect with the canvas' clip + */ + bool quickReject(const SkPath& path) const; + + /** Return true if the horizontal band specified by top and bottom is + completely clipped out. This is a conservative calculation, meaning + that it is possible that if the method returns false, the band may still + in fact be clipped out, but the converse is not true. If this method + returns true, then the band is guaranteed to be clipped out. + @param top The top of the horizontal band to compare with the clip + @param bottom The bottom of the horizontal and to compare with the clip + @return true if the horizontal band is completely clipped out (i.e. does + not intersect the current clip) + */ + bool quickRejectY(SkScalar top, SkScalar bottom) const { + SkASSERT(top <= bottom); + +#ifndef SK_WILL_NEVER_DRAW_PERSPECTIVE_TEXT + // TODO: add a hasPerspective method similar to getLocalClipBounds. This + // would cache the SkMatrix::hasPerspective result. Alternatively, have + // the MC stack just set a hasPerspective boolean as it is updated. + if (this->getTotalMatrix().hasPerspective()) { + // TODO: consider implementing some half-plane test between the + // two Y planes and the device-bounds (i.e., project the top and + // bottom Y planes and then determine if the clip bounds is completely + // outside either one). + return false; + } +#endif + + const SkRect& clipR = this->getLocalClipBounds(); + // In the case where the clip is empty and we are provided with a + // negative top and positive bottom parameter then this test will return + // false even though it will be clipped. We have chosen to exclude that + // check as it is rare and would result double the comparisons. + return top >= clipR.fBottom || bottom <= clipR.fTop; + } + + /** Return the bounds of the current clip (in local coordinates) in the + bounds parameter, and return true if it is non-empty. This can be useful + in a way similar to quickReject, in that it tells you that drawing + outside of these bounds will be clipped out. + */ + virtual bool getClipBounds(SkRect* bounds) const; + + /** Return the bounds of the current clip, in device coordinates; returns + true if non-empty. Maybe faster than getting the clip explicitly and + then taking its bounds. + */ + virtual bool getClipDeviceBounds(SkIRect* bounds) const; + + + /** Fill the entire canvas' bitmap (restricted to the current clip) with the + specified ARGB color, using the specified mode. + @param a the alpha component (0..255) of the color to fill the canvas + @param r the red component (0..255) of the color to fill the canvas + @param g the green component (0..255) of the color to fill the canvas + @param b the blue component (0..255) of the color to fill the canvas + @param mode the mode to apply the color in (defaults to SrcOver) + */ + void drawARGB(U8CPU a, U8CPU r, U8CPU g, U8CPU b, + SkXfermode::Mode mode = SkXfermode::kSrcOver_Mode); + + /** Fill the entire canvas' bitmap (restricted to the current clip) with the + specified color and mode. + @param color the color to draw with + @param mode the mode to apply the color in (defaults to SrcOver) + */ + void drawColor(SkColor color, + SkXfermode::Mode mode = SkXfermode::kSrcOver_Mode); + + /** + * This erases the entire drawing surface to the specified color, + * irrespective of the clip. It does not blend with the previous pixels, + * but always overwrites them. + * + * It is roughly equivalent to the following: + * canvas.save(); + * canvas.clipRect(hugeRect, kReplace_Op); + * paint.setColor(color); + * paint.setXfermodeMode(kSrc_Mode); + * canvas.drawPaint(paint); + * canvas.restore(); + * though it is almost always much more efficient. + */ + virtual void clear(SkColor); + + /** + * Fill the entire canvas' bitmap (restricted to the current clip) with the + * specified paint. + * @param paint The paint used to fill the canvas + */ + virtual void drawPaint(const SkPaint& paint); + + enum PointMode { + /** drawPoints draws each point separately */ + kPoints_PointMode, + /** drawPoints draws each pair of points as a line segment */ + kLines_PointMode, + /** drawPoints draws the array of points as a polygon */ + kPolygon_PointMode + }; + + /** Draw a series of points, interpreted based on the PointMode mode. For + all modes, the count parameter is interpreted as the total number of + points. For kLine mode, count/2 line segments are drawn. + For kPoint mode, each point is drawn centered at its coordinate, and its + size is specified by the paint's stroke-width. It draws as a square, + unless the paint's cap-type is round, in which the points are drawn as + circles. + For kLine mode, each pair of points is drawn as a line segment, + respecting the paint's settings for cap/join/width. + For kPolygon mode, the entire array is drawn as a series of connected + line segments. + Note that, while similar, kLine and kPolygon modes draw slightly + differently than the equivalent path built with a series of moveto, + lineto calls, in that the path will draw all of its contours at once, + with no interactions if contours intersect each other (think XOR + xfermode). drawPoints always draws each element one at a time. + @param mode PointMode specifying how to draw the array of points. + @param count The number of points in the array + @param pts Array of points to draw + @param paint The paint used to draw the points + */ + virtual void drawPoints(PointMode mode, size_t count, const SkPoint pts[], + const SkPaint& paint); + + /** Helper method for drawing a single point. See drawPoints() for a more + details. + */ + void drawPoint(SkScalar x, SkScalar y, const SkPaint& paint); + + /** Draws a single pixel in the specified color. + @param x The X coordinate of which pixel to draw + @param y The Y coordiante of which pixel to draw + @param color The color to draw + */ + void drawPoint(SkScalar x, SkScalar y, SkColor color); + + /** Draw a line segment with the specified start and stop x,y coordinates, + using the specified paint. NOTE: since a line is always "framed", the + paint's Style is ignored. + @param x0 The x-coordinate of the start point of the line + @param y0 The y-coordinate of the start point of the line + @param x1 The x-coordinate of the end point of the line + @param y1 The y-coordinate of the end point of the line + @param paint The paint used to draw the line + */ + void drawLine(SkScalar x0, SkScalar y0, SkScalar x1, SkScalar y1, + const SkPaint& paint); + + /** Draw the specified rectangle using the specified paint. The rectangle + will be filled or stroked based on the Style in the paint. + @param rect The rect to be drawn + @param paint The paint used to draw the rect + */ + virtual void drawRect(const SkRect& rect, const SkPaint& paint); + + /** Draw the specified rectangle using the specified paint. The rectangle + will be filled or framed based on the Style in the paint. + @param rect The rect to be drawn + @param paint The paint used to draw the rect + */ + void drawIRect(const SkIRect& rect, const SkPaint& paint) { + SkRect r; + r.set(rect); // promotes the ints to scalars + this->drawRect(r, paint); + } + + /** Draw the specified rectangle using the specified paint. The rectangle + will be filled or framed based on the Style in the paint. + @param left The left side of the rectangle to be drawn + @param top The top side of the rectangle to be drawn + @param right The right side of the rectangle to be drawn + @param bottom The bottom side of the rectangle to be drawn + @param paint The paint used to draw the rect + */ + void drawRectCoords(SkScalar left, SkScalar top, SkScalar right, + SkScalar bottom, const SkPaint& paint); + + /** Draw the specified oval using the specified paint. The oval will be + filled or framed based on the Style in the paint. + @param oval The rectangle bounds of the oval to be drawn + @param paint The paint used to draw the oval + */ + virtual void drawOval(const SkRect& oval, const SkPaint&); + + /** + * Draw the specified RRect using the specified paint The rrect will be filled or stroked + * based on the Style in the paint. + * + * @param rrect The round-rect to draw + * @param paint The paint used to draw the round-rect + */ + virtual void drawRRect(const SkRRect& rrect, const SkPaint& paint); + + /** + * Draw the annulus formed by the outer and inner rrects. The results + * are undefined if the outer does not contain the inner. + */ + void drawDRRect(const SkRRect& outer, const SkRRect& inner, const SkPaint&); + + /** Draw the specified circle using the specified paint. If radius is <= 0, + then nothing will be drawn. The circle will be filled + or framed based on the Style in the paint. + @param cx The x-coordinate of the center of the cirle to be drawn + @param cy The y-coordinate of the center of the cirle to be drawn + @param radius The radius of the cirle to be drawn + @param paint The paint used to draw the circle + */ + void drawCircle(SkScalar cx, SkScalar cy, SkScalar radius, + const SkPaint& paint); + + /** Draw the specified arc, which will be scaled to fit inside the + specified oval. If the sweep angle is >= 360, then the oval is drawn + completely. Note that this differs slightly from SkPath::arcTo, which + treats the sweep angle mod 360. + @param oval The bounds of oval used to define the shape of the arc + @param startAngle Starting angle (in degrees) where the arc begins + @param sweepAngle Sweep angle (in degrees) measured clockwise + @param useCenter true means include the center of the oval. For filling + this will draw a wedge. False means just use the arc. + @param paint The paint used to draw the arc + */ + void drawArc(const SkRect& oval, SkScalar startAngle, SkScalar sweepAngle, + bool useCenter, const SkPaint& paint); + + /** Draw the specified round-rect using the specified paint. The round-rect + will be filled or framed based on the Style in the paint. + @param rect The rectangular bounds of the roundRect to be drawn + @param rx The x-radius of the oval used to round the corners + @param ry The y-radius of the oval used to round the corners + @param paint The paint used to draw the roundRect + */ + void drawRoundRect(const SkRect& rect, SkScalar rx, SkScalar ry, + const SkPaint& paint); + + /** Draw the specified path using the specified paint. The path will be + filled or framed based on the Style in the paint. + @param path The path to be drawn + @param paint The paint used to draw the path + */ + virtual void drawPath(const SkPath& path, const SkPaint& paint); + + /** Draw the specified bitmap, with its top/left corner at (x,y), using the + specified paint, transformed by the current matrix. Note: if the paint + contains a maskfilter that generates a mask which extends beyond the + bitmap's original width/height, then the bitmap will be drawn as if it + were in a Shader with CLAMP mode. Thus the color outside of the original + width/height will be the edge color replicated. + + If a shader is present on the paint it will be ignored, except in the + case where the bitmap is kA8_Config. In that case, the color is + generated by the shader. + + @param bitmap The bitmap to be drawn + @param left The position of the left side of the bitmap being drawn + @param top The position of the top side of the bitmap being drawn + @param paint The paint used to draw the bitmap, or NULL + */ + virtual void drawBitmap(const SkBitmap& bitmap, SkScalar left, SkScalar top, + const SkPaint* paint = NULL); + + enum DrawBitmapRectFlags { + kNone_DrawBitmapRectFlag = 0x0, + /** + * When filtering is enabled, allow the color samples outside of + * the src rect (but still in the src bitmap) to bleed into the + * drawn portion + */ + kBleed_DrawBitmapRectFlag = 0x1, + }; + + /** Draw the specified bitmap, with the specified matrix applied (before the + canvas' matrix is applied). + @param bitmap The bitmap to be drawn + @param src Optional: specify the subset of the bitmap to be drawn + @param dst The destination rectangle where the scaled/translated + image will be drawn + @param paint The paint used to draw the bitmap, or NULL + */ + virtual void drawBitmapRectToRect(const SkBitmap& bitmap, const SkRect* src, + const SkRect& dst, + const SkPaint* paint = NULL, + DrawBitmapRectFlags flags = kNone_DrawBitmapRectFlag); + + void drawBitmapRect(const SkBitmap& bitmap, const SkRect& dst, + const SkPaint* paint = NULL) { + this->drawBitmapRectToRect(bitmap, NULL, dst, paint, kNone_DrawBitmapRectFlag); + } + + void drawBitmapRect(const SkBitmap& bitmap, const SkIRect* isrc, + const SkRect& dst, const SkPaint* paint = NULL, + DrawBitmapRectFlags flags = kNone_DrawBitmapRectFlag) { + SkRect realSrcStorage; + SkRect* realSrcPtr = NULL; + if (isrc) { + realSrcStorage.set(*isrc); + realSrcPtr = &realSrcStorage; + } + this->drawBitmapRectToRect(bitmap, realSrcPtr, dst, paint, flags); + } + + virtual void drawBitmapMatrix(const SkBitmap& bitmap, const SkMatrix& m, + const SkPaint* paint = NULL); + + /** + * Draw the bitmap stretched differentially to fit into dst. + * center is a rect within the bitmap, and logically divides the bitmap + * into 9 sections (3x3). For example, if the middle pixel of a [5x5] + * bitmap is the "center", then the center-rect should be [2, 2, 3, 3]. + * + * If the dst is >= the bitmap size, then... + * - The 4 corners are not stretched at all. + * - The sides are stretched in only one axis. + * - The center is stretched in both axes. + * Else, for each axis where dst < bitmap, + * - The corners shrink proportionally + * - The sides (along the shrink axis) and center are not drawn + */ + virtual void drawBitmapNine(const SkBitmap& bitmap, const SkIRect& center, + const SkRect& dst, const SkPaint* paint = NULL); + + /** Draw the specified bitmap, with its top/left corner at (x,y), + NOT transformed by the current matrix. Note: if the paint + contains a maskfilter that generates a mask which extends beyond the + bitmap's original width/height, then the bitmap will be drawn as if it + were in a Shader with CLAMP mode. Thus the color outside of the original + width/height will be the edge color replicated. + @param bitmap The bitmap to be drawn + @param left The position of the left side of the bitmap being drawn + @param top The position of the top side of the bitmap being drawn + @param paint The paint used to draw the bitmap, or NULL + */ + virtual void drawSprite(const SkBitmap& bitmap, int left, int top, + const SkPaint* paint = NULL); + + /** Draw the text, with origin at (x,y), using the specified paint. + The origin is interpreted based on the Align setting in the paint. + @param text The text to be drawn + @param byteLength The number of bytes to read from the text parameter + @param x The x-coordinate of the origin of the text being drawn + @param y The y-coordinate of the origin of the text being drawn + @param paint The paint used for the text (e.g. color, size, style) + */ + virtual void drawText(const void* text, size_t byteLength, SkScalar x, + SkScalar y, const SkPaint& paint); + + /** Draw the text, with each character/glyph origin specified by the pos[] + array. The origin is interpreted by the Align setting in the paint. + @param text The text to be drawn + @param byteLength The number of bytes to read from the text parameter + @param pos Array of positions, used to position each character + @param paint The paint used for the text (e.g. color, size, style) + */ + virtual void drawPosText(const void* text, size_t byteLength, + const SkPoint pos[], const SkPaint& paint); + + /** Draw the text, with each character/glyph origin specified by the x + coordinate taken from the xpos[] array, and the y from the constY param. + The origin is interpreted by the Align setting in the paint. + @param text The text to be drawn + @param byteLength The number of bytes to read from the text parameter + @param xpos Array of x-positions, used to position each character + @param constY The shared Y coordinate for all of the positions + @param paint The paint used for the text (e.g. color, size, style) + */ + virtual void drawPosTextH(const void* text, size_t byteLength, + const SkScalar xpos[], SkScalar constY, + const SkPaint& paint); + + /** Draw the text, with origin at (x,y), using the specified paint, along + the specified path. The paint's Align setting determins where along the + path to start the text. + @param text The text to be drawn + @param byteLength The number of bytes to read from the text parameter + @param path The path the text should follow for its baseline + @param hOffset The distance along the path to add to the text's + starting position + @param vOffset The distance above(-) or below(+) the path to + position the text + @param paint The paint used for the text + */ + void drawTextOnPathHV(const void* text, size_t byteLength, + const SkPath& path, SkScalar hOffset, + SkScalar vOffset, const SkPaint& paint); + + /** Draw the text, with origin at (x,y), using the specified paint, along + the specified path. The paint's Align setting determins where along the + path to start the text. + @param text The text to be drawn + @param byteLength The number of bytes to read from the text parameter + @param path The path the text should follow for its baseline + @param matrix (may be null) Applied to the text before it is + mapped onto the path + @param paint The paint used for the text + */ + virtual void drawTextOnPath(const void* text, size_t byteLength, + const SkPath& path, const SkMatrix* matrix, + const SkPaint& paint); + + /** PRIVATE / EXPERIMENTAL -- do not call + Perform back-end analysis/optimization of a picture. This may attach + optimization data to the picture which can be used by a later + drawPicture call. + @param picture The recorded drawing commands to analyze/optimize + */ + void EXPERIMENTAL_optimize(SkPicture* picture); + + /** Draw the picture into this canvas. This method effective brackets the + playback of the picture's draw calls with save/restore, so the state + of this canvas will be unchanged after this call. + @param picture The recorded drawing commands to playback into this + canvas. + */ + virtual void drawPicture(SkPicture& picture); + + enum VertexMode { + kTriangles_VertexMode, + kTriangleStrip_VertexMode, + kTriangleFan_VertexMode + }; + + /** Draw the array of vertices, interpreted as triangles (based on mode). + @param vmode How to interpret the array of vertices + @param vertexCount The number of points in the vertices array (and + corresponding texs and colors arrays if non-null) + @param vertices Array of vertices for the mesh + @param texs May be null. If not null, specifies the coordinate + in _texture_ space (not uv space) for each vertex. + @param colors May be null. If not null, specifies a color for each + vertex, to be interpolated across the triangle. + @param xmode Used if both texs and colors are present. In this + case the colors are combined with the texture using mode, + before being drawn using the paint. If mode is null, then + kModulate_Mode is used. + @param indices If not null, array of indices to reference into the + vertex (texs, colors) array. + @param indexCount number of entries in the indices array (if not null) + @param paint Specifies the shader/texture if present. + */ + virtual void drawVertices(VertexMode vmode, int vertexCount, + const SkPoint vertices[], const SkPoint texs[], + const SkColor colors[], SkXfermode* xmode, + const uint16_t indices[], int indexCount, + const SkPaint& paint); + + /** Send a blob of data to the canvas. + For canvases that draw, this call is effectively a no-op, as the data + is not parsed, but just ignored. However, this call exists for + subclasses like SkPicture's recording canvas, that can store the data + and then play it back later (via another call to drawData). + */ + virtual void drawData(const void* data, size_t length) { + // do nothing. Subclasses may do something with the data + } + + /** Add comments. beginCommentGroup/endCommentGroup open/close a new group. + Each comment added via addComment is notionally attached to its + enclosing group. Top-level comments simply belong to no group. + */ + virtual void beginCommentGroup(const char* description) { + // do nothing. Subclasses may do something + } + virtual void addComment(const char* kywd, const char* value) { + // do nothing. Subclasses may do something + } + virtual void endCommentGroup() { + // do nothing. Subclasses may do something + } + + /** + * With this call the client asserts that subsequent draw operations (up to the + * matching popCull()) are fully contained within the given bounding box. The assertion + * is not enforced, but the information might be used to quick-reject command blocks, + * so an incorrect bounding box may result in incomplete rendering. + */ + void pushCull(const SkRect& cullRect) { + ++fCullCount; + this->onPushCull(cullRect); + } + + /** + * Terminates the current culling block, and restores the previous one (if any). + */ + void popCull() { + if (fCullCount > 0) { + --fCullCount; + this->onPopCull(); + } + } + ////////////////////////////////////////////////////////////////////////// + + /** Get the current bounder object. + The bounder's reference count is unchaged. + @return the canva's bounder (or NULL). + */ + SkBounder* getBounder() const { return fBounder; } + + /** Set a new bounder (or NULL). + Pass NULL to clear any previous bounder. + As a convenience, the parameter passed is also returned. + If a previous bounder exists, its reference count is decremented. + If bounder is not NULL, its reference count is incremented. + @param bounder the new bounder (or NULL) to be installed in the canvas + @return the set bounder object + */ + virtual SkBounder* setBounder(SkBounder* bounder); + + /** Get the current filter object. The filter's reference count is not + affected. The filter is saved/restored, just like the matrix and clip. + @return the canvas' filter (or NULL). + */ + SkDrawFilter* getDrawFilter() const; + + /** Set the new filter (or NULL). Pass NULL to clear any existing filter. + As a convenience, the parameter is returned. If an existing filter + exists, its refcnt is decrement. If the new filter is not null, its + refcnt is incremented. The filter is saved/restored, just like the + matrix and clip. + @param filter the new filter (or NULL) + @return the new filter + */ + virtual SkDrawFilter* setDrawFilter(SkDrawFilter* filter); + + ////////////////////////////////////////////////////////////////////////// + + /** + * Return true if the current clip is empty (i.e. nothing will draw). + * Note: this is not always a free call, so it should not be used + * more often than necessary. However, once the canvas has computed this + * result, subsequent calls will be cheap (until the clip state changes, + * which can happen on any clip..() or restore() call. + */ + virtual bool isClipEmpty() const; + + /** + * Returns true if the current clip is just a (non-empty) rectangle. + * Returns false if the clip is empty, or if it is complex. + */ + virtual bool isClipRect() const; + + /** Return the current matrix on the canvas. + This does not account for the translate in any of the devices. + @return The current matrix on the canvas. + */ + const SkMatrix& getTotalMatrix() const; + +#ifdef SK_SUPPORT_LEGACY_GETCLIPTYPE + enum ClipType { + kEmpty_ClipType = 0, + kRect_ClipType, + kComplex_ClipType + }; + /** Returns a description of the total clip; may be cheaper than + getting the clip and querying it directly. + */ + virtual ClipType getClipType() const; +#endif + +#ifdef SK_SUPPORT_LEGACY_GETTOTALCLIP + /** DEPRECATED -- need to move this guy to private/friend + * Return the current device clip (concatenation of all clip calls). + * This does not account for the translate in any of the devices. + * @return the current device clip (concatenation of all clip calls). + */ + const SkRegion& getTotalClip() const; +#endif + + /** Return the clip stack. The clip stack stores all the individual + * clips organized by the save/restore frame in which they were + * added. + * @return the current clip stack ("list" of individual clip elements) + */ + const SkClipStack* getClipStack() const { + return &fClipStack; + } + + class ClipVisitor { + public: + virtual ~ClipVisitor(); + virtual void clipRect(const SkRect&, SkRegion::Op, bool antialias) = 0; + virtual void clipRRect(const SkRRect&, SkRegion::Op, bool antialias) = 0; + virtual void clipPath(const SkPath&, SkRegion::Op, bool antialias) = 0; + }; + + /** + * Replays the clip operations, back to front, that have been applied to + * the canvas, calling the appropriate method on the visitor for each + * clip. All clips have already been transformed into device space. + */ + void replayClips(ClipVisitor*) const; + + /////////////////////////////////////////////////////////////////////////// + + /** After calling saveLayer(), there can be any number of devices that make + up the top-most drawing area. LayerIter can be used to iterate through + those devices. Note that the iterator is only valid until the next API + call made on the canvas. Ownership of all pointers in the iterator stays + with the canvas, so none of them should be modified or deleted. + */ + class SK_API LayerIter /*: SkNoncopyable*/ { + public: + /** Initialize iterator with canvas, and set values for 1st device */ + LayerIter(SkCanvas*, bool skipEmptyClips); + ~LayerIter(); + + /** Return true if the iterator is done */ + bool done() const { return fDone; } + /** Cycle to the next device */ + void next(); + + // These reflect the current device in the iterator + + SkBaseDevice* device() const; + const SkMatrix& matrix() const; + const SkRegion& clip() const; + const SkPaint& paint() const; + int x() const; + int y() const; + + private: + // used to embed the SkDrawIter object directly in our instance, w/o + // having to expose that class def to the public. There is an assert + // in our constructor to ensure that fStorage is large enough + // (though needs to be a compile-time-assert!). We use intptr_t to work + // safely with 32 and 64 bit machines (to ensure the storage is enough) + intptr_t fStorage[32]; + class SkDrawIter* fImpl; // this points at fStorage + SkPaint fDefaultPaint; + bool fDone; + }; + + // don't call + const SkRegion& internal_private_getTotalClip() const; + // don't call + void internal_private_getTotalClipAsPath(SkPath*) const; + // don't call + GrRenderTarget* internal_private_accessTopLayerRenderTarget(); + +protected: + // default impl defers to getDevice()->newSurface(info) + virtual SkSurface* onNewSurface(const SkImageInfo&); + + // default impl defers to its device + virtual const void* onPeekPixels(SkImageInfo*, size_t* rowBytes); + virtual void* onAccessTopLayerPixels(SkImageInfo*, size_t* rowBytes); + + // Subclass save/restore notifiers. + // Overriders should call the corresponding INHERITED method up the inheritance chain. + // willSaveLayer()'s return value may suppress full layer allocation. + enum SaveLayerStrategy { + kFullLayer_SaveLayerStrategy, + kNoLayer_SaveLayerStrategy + }; + virtual void willSave(SaveFlags); + virtual SaveLayerStrategy willSaveLayer(const SkRect*, const SkPaint*, SaveFlags); + virtual void willRestore(); + + virtual void didTranslate(SkScalar, SkScalar); + virtual void didScale(SkScalar, SkScalar); + virtual void didRotate(SkScalar); + virtual void didSkew(SkScalar, SkScalar); + virtual void didConcat(const SkMatrix&); + virtual void didSetMatrix(const SkMatrix&); + + virtual void onDrawDRRect(const SkRRect&, const SkRRect&, const SkPaint&); + + enum ClipEdgeStyle { + kHard_ClipEdgeStyle, + kSoft_ClipEdgeStyle + }; + + virtual void onClipRect(const SkRect& rect, SkRegion::Op op, ClipEdgeStyle edgeStyle); + virtual void onClipRRect(const SkRRect& rrect, SkRegion::Op op, ClipEdgeStyle edgeStyle); + virtual void onClipPath(const SkPath& path, SkRegion::Op op, ClipEdgeStyle edgeStyle); + virtual void onClipRegion(const SkRegion& deviceRgn, SkRegion::Op op); + + // Returns the canvas to be used by DrawIter. Default implementation + // returns this. Subclasses that encapsulate an indirect canvas may + // need to overload this method. The impl must keep track of this, as it + // is not released or deleted by the caller. + virtual SkCanvas* canvasForDrawIter(); + + // Clip rectangle bounds. Called internally by saveLayer. + // returns false if the entire rectangle is entirely clipped out + // If non-NULL, The imageFilter parameter will be used to expand the clip + // and offscreen bounds for any margin required by the filter DAG. + bool clipRectBounds(const SkRect* bounds, SaveFlags flags, + SkIRect* intersection, + const SkImageFilter* imageFilter = NULL); + + // Called by child classes that override clipPath and clipRRect to only + // track fast conservative clip bounds, rather than exact clips. + void updateClipConservativelyUsingBounds(const SkRect&, SkRegion::Op, + bool inverseFilled); + + // notify our surface (if we have one) that we are about to draw, so it + // can perform copy-on-write or invalidate any cached images + void predrawNotify(); + + virtual void onPushCull(const SkRect& cullRect); + virtual void onPopCull(); + +private: + class MCRec; + + SkClipStack fClipStack; + SkDeque fMCStack; + // points to top of stack + MCRec* fMCRec; + // the first N recs that can fit here mean we won't call malloc + uint32_t fMCRecStorage[32]; + + SkBounder* fBounder; + int fSaveLayerCount; // number of successful saveLayer calls + int fCullCount; // number of active culls + + SkMetaData* fMetaData; + + SkSurface_Base* fSurfaceBase; + SkSurface_Base* getSurfaceBase() const { return fSurfaceBase; } + void setSurfaceBase(SkSurface_Base* sb) { + fSurfaceBase = sb; + } + friend class SkSurface_Base; + friend class SkSurface_Gpu; + + bool fDeviceCMDirty; // cleared by updateDeviceCMCache() + void updateDeviceCMCache(); + + friend class SkDrawIter; // needs setupDrawForLayerDevice() + friend class AutoDrawLooper; + friend class SkLua; // needs top layer size and offset + friend class SkDeferredDevice; // needs getTopDevice() + + SkBaseDevice* createLayerDevice(const SkImageInfo&); + + SkBaseDevice* init(SkBaseDevice*); + + /** + * DEPRECATED + * + * Specify a device for this canvas to draw into. If it is not null, its + * reference count is incremented. If the canvas was already holding a + * device, its reference count is decremented. The new device is returned. + */ + SkBaseDevice* setRootDevice(SkBaseDevice* device); + + /** + * Gets the size/origin of the top level layer in global canvas coordinates. We don't want this + * to be public because it exposes decisions about layer sizes that are internal to the canvas. + */ + SkISize getTopLayerSize() const; + SkIPoint getTopLayerOrigin() const; + + // internal methods are not virtual, so they can safely be called by other + // canvas apis, without confusing subclasses (like SkPictureRecording) + void internalDrawBitmap(const SkBitmap&, const SkMatrix& m, const SkPaint* paint); + void internalDrawBitmapRect(const SkBitmap& bitmap, const SkRect* src, + const SkRect& dst, const SkPaint* paint, + DrawBitmapRectFlags flags); + void internalDrawBitmapNine(const SkBitmap& bitmap, const SkIRect& center, + const SkRect& dst, const SkPaint* paint); + void internalDrawPaint(const SkPaint& paint); + int internalSaveLayer(const SkRect* bounds, const SkPaint* paint, + SaveFlags, bool justForImageFilter, SaveLayerStrategy strategy); + void internalDrawDevice(SkBaseDevice*, int x, int y, const SkPaint*); + + // shared by save() and saveLayer() + int internalSave(SaveFlags flags); + void internalRestore(); + static void DrawRect(const SkDraw& draw, const SkPaint& paint, + const SkRect& r, SkScalar textSize); + static void DrawTextDecorations(const SkDraw& draw, const SkPaint& paint, + const char text[], size_t byteLength, + SkScalar x, SkScalar y); + + /* These maintain a cache of the clip bounds in local coordinates, + (converted to 2s-compliment if floats are slow). + */ + mutable SkRect fCachedLocalClipBounds; + mutable bool fCachedLocalClipBoundsDirty; + bool fAllowSoftClip; + bool fAllowSimplifyClip; + + const SkRect& getLocalClipBounds() const { + if (fCachedLocalClipBoundsDirty) { + if (!this->getClipBounds(&fCachedLocalClipBounds)) { + fCachedLocalClipBounds.setEmpty(); + } + fCachedLocalClipBoundsDirty = false; + } + return fCachedLocalClipBounds; + } + + class AutoValidateClip : ::SkNoncopyable { + public: + explicit AutoValidateClip(SkCanvas* canvas) : fCanvas(canvas) { + fCanvas->validateClip(); + } + ~AutoValidateClip() { fCanvas->validateClip(); } + + private: + const SkCanvas* fCanvas; + }; + +#ifdef SK_DEBUG + void validateClip() const; +#else + void validateClip() const {} +#endif + + typedef SkRefCnt INHERITED; +}; + +/** Stack helper class to automatically call restoreToCount() on the canvas + when this object goes out of scope. Use this to guarantee that the canvas + is restored to a known state. +*/ +class SkAutoCanvasRestore : SkNoncopyable { +public: + SkAutoCanvasRestore(SkCanvas* canvas, bool doSave) : fCanvas(canvas), fSaveCount(0) { + if (fCanvas) { + fSaveCount = canvas->getSaveCount(); + if (doSave) { + canvas->save(); + } + } + } + ~SkAutoCanvasRestore() { + if (fCanvas) { + fCanvas->restoreToCount(fSaveCount); + } + } + + /** + * Perform the restore now, instead of waiting for the destructor. Will + * only do this once. + */ + void restore() { + if (fCanvas) { + fCanvas->restoreToCount(fSaveCount); + fCanvas = NULL; + } + } + +private: + SkCanvas* fCanvas; + int fSaveCount; +}; +#define SkAutoCanvasRestore(...) SK_REQUIRE_LOCAL_VAR(SkAutoCanvasRestore) + +/** Stack helper class to automatically open and close a comment block + */ +class SkAutoCommentBlock : SkNoncopyable { +public: + SkAutoCommentBlock(SkCanvas* canvas, const char* description) { + fCanvas = canvas; + if (NULL != fCanvas) { + fCanvas->beginCommentGroup(description); + } + } + + ~SkAutoCommentBlock() { + if (NULL != fCanvas) { + fCanvas->endCommentGroup(); + } + } + +private: + SkCanvas* fCanvas; +}; +#define SkAutoCommentBlock(...) SK_REQUIRE_LOCAL_VAR(SkAutoCommentBlock) + +/** + * If the caller wants read-only access to the pixels in a canvas, it can just + * call canvas->peekPixels(), since that is the fastest way to "peek" at the + * pixels on a raster-backed canvas. + * + * If the canvas has pixels, but they are not readily available to the CPU + * (e.g. gpu-backed), then peekPixels() will fail, but readPixels() will + * succeed (though be slower, since it will return a copy of the pixels). + * + * SkAutoROCanvasPixels encapsulates these two techniques, trying first to call + * peekPixels() (for performance), but if that fails, calling readPixels() and + * storing the copy locally. + * + * The caller must respect the restrictions associated with peekPixels(), since + * that may have been called: The returned information is invalidated if... + * - any API is called on the canvas (or its parent surface if present) + * - the canvas goes out of scope + */ +class SkAutoROCanvasPixels : SkNoncopyable { +public: + SkAutoROCanvasPixels(SkCanvas* canvas); + + // returns NULL on failure + const void* addr() const { return fAddr; } + + // undefined if addr() == NULL + size_t rowBytes() const { return fRowBytes; } + + // undefined if addr() == NULL + const SkImageInfo& info() const { return fInfo; } + + // helper that, if returns true, installs the pixels into the bitmap. Note + // that the bitmap may reference the address returned by peekPixels(), so + // the caller must respect the restrictions associated with peekPixels(). + bool asROBitmap(SkBitmap*) const; + +private: + SkBitmap fBitmap; // used if peekPixels() fails + const void* fAddr; // NULL on failure + SkImageInfo fInfo; + size_t fRowBytes; +}; + +#endif