| |
| /* |
| * 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 "SkScalarCompare.h" |
| #include "SkXfermode.h" |
| |
| class SkBounder; |
| class SkDevice; |
| class SkDraw; |
| class SkDrawFilter; |
| class SkPicture; |
| |
| /** \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: |
| SkCanvas(); |
| |
| /** Construct a canvas with the specified device to draw into. |
| |
| @param device Specifies a device for the canvas to draw into. |
| */ |
| explicit SkCanvas(SkDevice* device); |
| |
| /** Deprecated - 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(); |
| |
| /////////////////////////////////////////////////////////////////////////// |
| |
| /** |
| * Trigger the immediate execution of all pending draw operations. |
| */ |
| void flush(); |
| |
| /** |
| * Return the width/height of the underlying device. The current drawable |
| * area may be small (due to clipping or saveLayer). For a canvas with |
| * no device, 0,0 will be returned. |
| */ |
| SkISize getDeviceSize() const; |
| |
| /** 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. |
| */ |
| SkDevice* getDevice() const; |
| |
| /** 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. |
| */ |
| virtual SkDevice* setDevice(SkDevice* device); |
| |
| /** |
| * 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. |
| */ |
| SkDevice* getTopDevice() const; |
| |
| /** |
| * Create a new raster device and make it current. This also returns |
| * the new device. |
| */ |
| SkDevice* setBitmapDevice(const SkBitmap& bitmap); |
| |
| /** |
| * Shortcut for getDevice()->createCompatibleDevice(...). |
| * If getDevice() == NULL, this method does nothing, and returns NULL. |
| */ |
| SkDevice* createCompatibleDevice(SkBitmap::Config config, |
| int width, int height, |
| bool isOpaque); |
| |
| /////////////////////////////////////////////////////////////////////////// |
| |
| /** |
| * 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); |
| |
| /** |
| * 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 = kNative_Premul_Config8888); |
| |
| /////////////////////////////////////////////////////////////////////////// |
| |
| 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 */ |
| kClipToLayer_SaveFlag = 0x10, |
| |
| // helper masks for common choices |
| kMatrixClip_SaveFlag = 0x03, |
| kARGB_NoClipLayer_SaveFlag = 0x0F, |
| 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. |
| @return The value to pass to restoreToCount() to balance this save() |
| */ |
| virtual 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() |
| */ |
| virtual 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. |
| */ |
| virtual void restore(); |
| |
| /** Returns the number of matrix/clip states on the SkCanvas' private stack. |
| This will equal # save() calls - # restore() calls. |
| */ |
| 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 less than |
| getSaveCount() |
| @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) |
| */ |
| virtual 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) |
| */ |
| virtual 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) |
| */ |
| virtual 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) |
| */ |
| virtual 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) |
| */ |
| virtual 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. |
| */ |
| virtual 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 intersect with the current clip |
| @param op The region op to apply to the current clip |
| @return true if the canvas' clip is non-empty |
| */ |
| virtual bool clipRect(const SkRect& rect, |
| SkRegion::Op op = SkRegion::kIntersect_Op, |
| bool doAntiAlias = false); |
| |
| /** Modify the current clip with the specified path. |
| @param path The path to apply to the current clip |
| @param op The region op to apply to the current clip |
| @return true if the canvas' new clip is non-empty |
| */ |
| virtual bool clipPath(const SkPath& path, |
| SkRegion::Op op = SkRegion::kIntersect_Op, |
| bool doAntiAlias = false); |
| |
| /** 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 |
| @return true if the canvas' new clip is non-empty |
| */ |
| virtual bool 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. |
| @return true if the new clip region is non-empty |
| */ |
| bool setClipRegion(const SkRegion& deviceRgn) { |
| return this->clipRegion(deviceRgn, SkRegion::kReplace_Op); |
| } |
| |
| /** Enum describing how to treat edges when performing quick-reject tests |
| of a geometry against the current clip. Treating them as antialiased |
| (kAA_EdgeType) will take into account the extra pixels that may be drawn |
| if the edge does not lie exactly on a device pixel boundary (after being |
| transformed by the current matrix). |
| */ |
| enum EdgeType { |
| /** Treat the edges as B&W (not antialiased) for the purposes of testing |
| against the current clip |
| */ |
| kBW_EdgeType, |
| /** Treat the edges as antialiased for the purposes of testing |
| against the current clip |
| */ |
| kAA_EdgeType |
| }; |
| |
| /** 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 |
| @param et specifies how to treat the edges (see EdgeType) |
| @return true if the rect (transformed by the canvas' matrix) does not |
| intersect with the canvas' clip |
| */ |
| bool quickReject(const SkRect& rect, EdgeType et) 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 |
| @param et specifies how to treat the edges (see EdgeType) |
| @return true if the path (transformed by the canvas' matrix) does not |
| intersect with the canvas' clip |
| */ |
| bool quickReject(const SkPath& path, EdgeType et) 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, EdgeType et) const { |
| SkASSERT(SkScalarToCompareType(top) <= SkScalarToCompareType(bottom)); |
| const SkRectCompareType& clipR = this->getLocalClipBoundsCompareType(et); |
| // 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 SkScalarToCompareType(top) >= clipR.fBottom |
| || SkScalarToCompareType(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. |
| */ |
| bool getClipBounds(SkRect* bounds, EdgeType et = kAA_EdgeType) 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. |
| */ |
| 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 |
| */ |
| void drawOval(const SkRect& oval, 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. |
| @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); |
| |
| /** 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 drawBitmapRect(const SkBitmap& bitmap, const SkIRect* src, |
| const SkRect& dst, const SkPaint* paint = NULL); |
| |
| 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 stretch at all. |
| * - The sides are stretch in only one axis. |
| * - The center is stretch 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); |
| |
| #ifdef SK_BUILD_FOR_ANDROID |
| /** Draw the text on path, 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) |
| @param path The path to draw on |
| @param matrix The canvas matrix |
| */ |
| void drawPosTextOnPath(const void* text, size_t byteLength, |
| const SkPoint pos[], const SkPaint& paint, |
| const SkPath& path, const SkMatrix* matrix); |
| #endif |
| |
| /** 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. This contrasts with |
| the more immediate method SkPicture::draw(), which does not bracket |
| the canvas with save/restore, thus the canvas may be left in a changed |
| state after the 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 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 |
| kMultiply_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); |
| |
| ////////////////////////////////////////////////////////////////////////// |
| |
| /** 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 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; |
| |
| 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. |
| */ |
| ClipType getClipType() const; |
| |
| /** 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; |
| |
| /** |
| * Return true if the current clip is non-empty. |
| * |
| * If bounds is not NULL, set it to the bounds of the current clip |
| * in global coordinates. |
| */ |
| bool getTotalClipBounds(SkIRect* bounds) const; |
| |
| /** |
| * Return the current clipstack. This mirrors the result in getTotalClip() |
| * but is represented as a stack of geometric clips + region-ops. |
| */ |
| const SkClipStack& getTotalClipStack() const; |
| |
| void setExternalMatrix(const SkMatrix* = NULL); |
| |
| /////////////////////////////////////////////////////////////////////////// |
| |
| /** 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 |
| |
| SkDevice* 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; |
| }; |
| |
| protected: |
| // 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(); |
| |
| // all of the drawBitmap variants call this guy |
| virtual void commonDrawBitmap(const SkBitmap&, const SkIRect*, |
| const SkMatrix&, const SkPaint& paint); |
| |
| // Clip rectangle bounds. Called internally by saveLayer. |
| // returns false if the entire rectangle is entirely clipped out |
| bool clipRectBounds(const SkRect* bounds, SaveFlags flags, |
| SkIRect* intersection); |
| |
| 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; |
| SkDevice* fLastDeviceToGainFocus; |
| int fLayerCount; // number of successful saveLayer calls |
| |
| void prepareForDeviceDraw(SkDevice*, const SkMatrix&, const SkRegion&, |
| const SkClipStack& clipStack); |
| |
| bool fDeviceCMDirty; // cleared by updateDeviceCMCache() |
| void updateDeviceCMCache(); |
| |
| friend class SkDrawIter; // needs setupDrawForLayerDevice() |
| |
| SkDevice* createLayerDevice(SkBitmap::Config, int width, int height, |
| bool isOpaque); |
| |
| SkDevice* init(SkDevice*); |
| |
| // 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 SkIRect*, const SkMatrix& m, |
| const SkPaint* paint); |
| void internalDrawBitmapRect(const SkBitmap& bitmap, const SkIRect* src, |
| const SkRect& dst, const SkPaint* paint); |
| void internalDrawBitmapNine(const SkBitmap& bitmap, const SkIRect& center, |
| const SkRect& dst, const SkPaint* paint); |
| void internalDrawPaint(const SkPaint& paint); |
| |
| |
| void drawDevice(SkDevice*, 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 SkRectCompareType fLocalBoundsCompareType; |
| mutable bool fLocalBoundsCompareTypeDirty; |
| |
| mutable SkRectCompareType fLocalBoundsCompareTypeBW; |
| mutable bool fLocalBoundsCompareTypeDirtyBW; |
| |
| /* Get the local clip bounds with an anti-aliased edge. |
| */ |
| const SkRectCompareType& getLocalClipBoundsCompareType() const { |
| return getLocalClipBoundsCompareType(kAA_EdgeType); |
| } |
| |
| const SkRectCompareType& getLocalClipBoundsCompareType(EdgeType et) const { |
| if (et == kAA_EdgeType) { |
| if (fLocalBoundsCompareTypeDirty) { |
| this->computeLocalClipBoundsCompareType(et); |
| fLocalBoundsCompareTypeDirty = false; |
| } |
| return fLocalBoundsCompareType; |
| } else { |
| if (fLocalBoundsCompareTypeDirtyBW) { |
| this->computeLocalClipBoundsCompareType(et); |
| fLocalBoundsCompareTypeDirtyBW = false; |
| } |
| return fLocalBoundsCompareTypeBW; |
| } |
| } |
| void computeLocalClipBoundsCompareType(EdgeType et) const; |
| |
| SkMatrix fExternalMatrix, fExternalInverse; |
| bool fUseExternalMatrix; |
| |
| 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 |
| }; |
| |
| /** 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) { |
| SkASSERT(canvas); |
| fSaveCount = canvas->getSaveCount(); |
| if (doSave) { |
| canvas->save(); |
| } |
| } |
| ~SkAutoCanvasRestore() { |
| fCanvas->restoreToCount(fSaveCount); |
| } |
| |
| private: |
| SkCanvas* fCanvas; |
| int fSaveCount; |
| }; |
| |
| #endif |
