3 * Copyright 2010 The Android Open Source Project
5 * Use of this source code is governed by a BSD-style license that can be
6 * found in the LICENSE file.
10 #ifndef SkDevice_DEFINED
11 #define SkDevice_DEFINED
17 #include "SkDeviceProperties.h"
28 class SK_API SkBaseDevice : public SkRefCnt {
30 SK_DECLARE_INST_COUNT(SkBaseDevice)
33 * Construct a new device.
38 * Construct a new device.
40 SkBaseDevice(const SkDeviceProperties& deviceProperties);
42 virtual ~SkBaseDevice();
45 * Creates a device that is of the same type as this device (e.g. SW-raster,
46 * GPU, or PDF). The backing store for this device is created automatically
47 * (e.g. offscreen pixels or FBO or whatever is appropriate).
49 * @param width width of the device to create
50 * @param height height of the device to create
51 * @param isOpaque performance hint, set to true if you know that you will
52 * draw into this device such that all of the pixels will
55 SkBaseDevice* createCompatibleDevice(SkBitmap::Config config,
56 int width, int height,
59 SkMetaData& getMetaData();
62 kVector_Capability = 0x1, //!< mask indicating a vector representation
64 virtual uint32_t getDeviceCapabilities() = 0;
66 /** Return the width of the device (in pixels).
68 virtual int width() const = 0;
69 /** Return the height of the device (in pixels).
71 virtual int height() const = 0;
73 /** Return the image properties of the device. */
74 virtual const SkDeviceProperties& getDeviceProperties() const {
75 //Currently, all the properties are leaky.
76 return fLeakyProperties;
80 * Return ImageInfo for this device. If the canvas is not backed by pixels
81 * (cpu or gpu), then the info's ColorType will be kUnknown_SkColorType.
83 virtual SkImageInfo imageInfo() const;
86 * Return the bounds of the device in the coordinate space of the root
87 * canvas. The root device will have its top-left at 0,0, but other devices
88 * such as those associated with saveLayer may have a non-zero origin.
90 void getGlobalBounds(SkIRect* bounds) const {
92 const SkIPoint& origin = this->getOrigin();
93 bounds->setXYWH(origin.x(), origin.y(), this->width(), this->height());
97 /** Returns true if the device's bitmap's config treats every pixel as
100 virtual bool isOpaque() const = 0;
102 /** Return the bitmap config of the device's pixels
104 SK_ATTR_DEPRECATED("want to hide configness of the device -- don't use")
105 virtual SkBitmap::Config config() const = 0;
107 /** Return the bitmap associated with this device. Call this each time you need
108 to access the bitmap, as it notifies the subclass to perform any flushing
109 etc. before you examine the pixels.
110 @param changePixels set to true if the caller plans to change the pixels
111 @return the device's bitmap
113 const SkBitmap& accessBitmap(bool changePixels);
116 * DEPRECATED: This will be made protected once WebKit stops using it.
117 * Instead use Canvas' writePixels method.
119 * Similar to draw sprite, this method will copy the pixels in bitmap onto
120 * the device, with the top/left corner specified by (x, y). The pixel
121 * values in the device are completely replaced: there is no blending.
123 * Currently if bitmap is backed by a texture this is a no-op. This may be
124 * relaxed in the future.
126 * If the bitmap has config kARGB_8888_Config then the config8888 param
127 * will determines how the pixel valuess are intepreted. If the bitmap is
128 * not kARGB_8888_Config then this parameter is ignored.
130 virtual void writePixels(const SkBitmap& bitmap, int x, int y,
131 SkCanvas::Config8888 config8888 = SkCanvas::kNative_Premul_Config8888) = 0;
134 * Return the device's associated gpu render target, or NULL.
136 virtual GrRenderTarget* accessRenderTarget() = 0;
140 * Return the device's origin: its offset in device coordinates from
141 * the default origin in its canvas' matrix/clip
143 const SkIPoint& getOrigin() const { return fOrigin; }
146 * onAttachToCanvas is invoked whenever a device is installed in a canvas
147 * (i.e., setDevice, saveLayer (for the new device created by the save),
148 * and SkCanvas' SkBaseDevice & SkBitmap -taking ctors). It allows the
149 * devices to prepare for drawing (e.g., locking their pixels, etc.)
151 virtual void onAttachToCanvas(SkCanvas*) {
152 SkASSERT(!fAttachedToCanvas);
155 fAttachedToCanvas = true;
160 * onDetachFromCanvas notifies a device that it will no longer be drawn to.
161 * It gives the device a chance to clean up (e.g., unlock its pixels). It
162 * is invoked from setDevice (for the displaced device), restore and
163 * possibly from SkCanvas' dtor.
165 virtual void onDetachFromCanvas() {
166 SkASSERT(fAttachedToCanvas);
167 this->unlockPixels();
169 fAttachedToCanvas = false;
176 kSaveLayer_Usage // <! internal use only
180 uint32_t fFlags; // SkPaint::getFlags()
181 SkPaint::Hinting fHinting;
185 * Device may filter the text flags for drawing text here. If it wants to
186 * make a change to the specified values, it should write them into the
187 * textflags parameter (output) and return true. If the paint is fine as
188 * is, then ignore the textflags parameter and return false.
190 * The baseclass SkBaseDevice filters based on its depth and blitters.
192 virtual bool filterTextFlags(const SkPaint& paint, TextFlags*) = 0;
196 * DEPRECATED: This will be removed in a future change. Device subclasses
197 * should use the matrix and clip from the SkDraw passed to draw functions.
199 * Called with the correct matrix and clip before this device is drawn
200 * to using those settings. If your subclass overrides this, be sure to
201 * call through to the base class as well.
203 * The clipstack is another view of the clip. It records the actual
204 * geometry that went into building the region. It is present for devices
205 * that want to parse it, but is not required: the region is a complete
206 * picture of the current clip. (i.e. if you regionize all of the geometry
207 * in the clipstack, you will arrive at an equivalent region to the one
210 virtual void setMatrixClip(const SkMatrix&, const SkRegion&,
211 const SkClipStack&) {};
213 /** Clears the entire device to the specified color (including alpha).
216 virtual void clear(SkColor color) = 0;
218 SK_ATTR_DEPRECATED("use clear() instead")
219 void eraseColor(SkColor eraseColor) { this->clear(eraseColor); }
221 /** These are called inside the per-device-layer loop for each draw call.
222 When these are called, we have already applied any saveLayer operations,
223 and are handling any looping from the paint, and any effects from the
226 virtual void drawPaint(const SkDraw&, const SkPaint& paint) = 0;
227 virtual void drawPoints(const SkDraw&, SkCanvas::PointMode mode, size_t count,
228 const SkPoint[], const SkPaint& paint) = 0;
229 virtual void drawRect(const SkDraw&, const SkRect& r,
230 const SkPaint& paint) = 0;
231 virtual void drawOval(const SkDraw&, const SkRect& oval,
232 const SkPaint& paint) = 0;
233 virtual void drawRRect(const SkDraw&, const SkRRect& rr,
234 const SkPaint& paint) = 0;
237 * If pathIsMutable, then the implementation is allowed to cast path to a
238 * non-const pointer and modify it in place (as an optimization). Canvas
239 * may do this to implement helpers such as drawOval, by placing a temp
240 * path on the stack to hold the representation of the oval.
242 * If prePathMatrix is not null, it should logically be applied before any
243 * stroking or other effects. If there are no effects on the paint that
244 * affect the geometry/rasterization, then the pre matrix can just be
245 * pre-concated with the current matrix.
247 virtual void drawPath(const SkDraw&, const SkPath& path,
248 const SkPaint& paint,
249 const SkMatrix* prePathMatrix = NULL,
250 bool pathIsMutable = false) = 0;
251 virtual void drawBitmap(const SkDraw&, const SkBitmap& bitmap,
252 const SkMatrix& matrix, const SkPaint& paint) = 0;
253 virtual void drawSprite(const SkDraw&, const SkBitmap& bitmap,
254 int x, int y, const SkPaint& paint) = 0;
257 * The default impl. will create a bitmap-shader from the bitmap,
258 * and call drawRect with it.
260 virtual void drawBitmapRect(const SkDraw&, const SkBitmap&,
261 const SkRect* srcOrNull, const SkRect& dst,
262 const SkPaint& paint,
263 SkCanvas::DrawBitmapRectFlags flags) = 0;
266 * Does not handle text decoration.
267 * Decorations (underline and stike-thru) will be handled by SkCanvas.
269 virtual void drawText(const SkDraw&, const void* text, size_t len,
270 SkScalar x, SkScalar y, const SkPaint& paint) = 0;
271 virtual void drawPosText(const SkDraw&, const void* text, size_t len,
272 const SkScalar pos[], SkScalar constY,
273 int scalarsPerPos, const SkPaint& paint) = 0;
274 virtual void drawTextOnPath(const SkDraw&, const void* text, size_t len,
275 const SkPath& path, const SkMatrix* matrix,
276 const SkPaint& paint) = 0;
277 virtual void drawVertices(const SkDraw&, SkCanvas::VertexMode, int vertexCount,
278 const SkPoint verts[], const SkPoint texs[],
279 const SkColor colors[], SkXfermode* xmode,
280 const uint16_t indices[], int indexCount,
281 const SkPaint& paint) = 0;
282 /** The SkDevice passed will be an SkDevice which was returned by a call to
283 onCreateCompatibleDevice on this device with kSaveLayer_Usage.
285 virtual void drawDevice(const SkDraw&, SkBaseDevice*, int x, int y,
289 * On success (returns true), copy the device pixels into the bitmap.
290 * On failure, the bitmap parameter is left unchanged and false is
293 * The device's pixels are converted to the bitmap's config. The only
294 * supported config is kARGB_8888_Config, though this is likely to be
295 * relaxed in the future. The meaning of config kARGB_8888_Config is
296 * modified by the enum param config8888. The default value interprets
297 * kARGB_8888_Config as SkPMColor
299 * If the bitmap has pixels already allocated, the device pixels will be
300 * written there. If not, bitmap->allocPixels() will be called
301 * automatically. If the bitmap is backed by a texture readPixels will
304 * The actual pixels written is the intersection of the device's bounds,
305 * and the rectangle formed by the bitmap's width,height and the specified
306 * x,y. If bitmap pixels extend outside of that intersection, they will not
309 * Other failure conditions:
310 * * If the device is not a raster device (e.g. PDF) then readPixels will
312 * * If bitmap is texture-backed then readPixels will fail. (This may be
313 * relaxed in the future.)
315 bool readPixels(SkBitmap* bitmap,
317 SkCanvas::Config8888 config8888);
319 ///////////////////////////////////////////////////////////////////////////
321 /** Update as needed the pixel value in the bitmap, so that the caller can
322 access the pixels directly.
323 @return The device contents as a bitmap
325 virtual const SkBitmap& onAccessBitmap() = 0;
328 * Implements readPixels API. The caller will ensure that:
329 * 1. bitmap has pixel config kARGB_8888_Config.
330 * 2. bitmap has pixels.
331 * 3. The rectangle (x, y, x + bitmap->width(), y + bitmap->height()) is
332 * contained in the device bounds.
334 virtual bool onReadPixels(const SkBitmap& bitmap,
336 SkCanvas::Config8888 config8888) = 0;
338 /** Called when this device is installed into a Canvas. Balanced by a call
339 to unlockPixels() when the device is removed from a Canvas.
341 virtual void lockPixels() = 0;
342 virtual void unlockPixels() = 0;
345 * Returns true if the device allows processing of this imagefilter. If
346 * false is returned, then the filter is ignored. This may happen for
347 * some subclasses that do not support pixel manipulations after drawing
348 * has occurred (e.g. printing). The default implementation returns true.
350 virtual bool allowImageFilter(const SkImageFilter*) = 0;
353 * Override and return true for filters that the device can handle
354 * intrinsically. Doing so means that SkCanvas will pass-through this
355 * filter to drawSprite and drawDevice (and potentially filterImage).
356 * Returning false means the SkCanvas will have apply the filter itself,
357 * and just pass the resulting image to the device.
359 virtual bool canHandleImageFilter(const SkImageFilter*) = 0;
362 * Related (but not required) to canHandleImageFilter, this method returns
363 * true if the device could apply the filter to the src bitmap and return
364 * the result (and updates offset as needed).
365 * If the device does not recognize or support this filter,
366 * it just returns false and leaves result and offset unchanged.
368 virtual bool filterImage(const SkImageFilter*, const SkBitmap&, const SkMatrix&,
369 SkBitmap* result, SkIPoint* offset) = 0;
371 // This is equal kBGRA_Premul_Config8888 or kRGBA_Premul_Config8888 if
372 // either is identical to kNative_Premul_Config8888. Otherwise, -1.
373 static const SkCanvas::Config8888 kPMColorAlias;
376 // default impl returns NULL
377 virtual SkSurface* newSurface(const SkImageInfo&);
379 // default impl returns NULL
380 virtual const void* peekPixels(SkImageInfo*, size_t* rowBytes);
383 * Leaky properties are those which the device should be applying but it isn't.
384 * These properties will be applied by the draw, when and as it can.
385 * If the device does handle a property, that property should be set to the identity value
386 * for that property, effectively making it non-leaky.
388 SkDeviceProperties fLeakyProperties;
391 friend class SkCanvas;
392 friend struct DeviceCM; //for setMatrixClip
394 friend class SkDrawIter;
395 friend class SkDeviceFilteredPaint;
396 friend class SkDeviceImageFilterProxy;
397 friend class DeferredDevice; // for newSurface
399 friend class SkSurface_Raster;
401 // used to change the backend's pixels (and possibly config/rowbytes)
402 // but cannot change the width/height, so there should be no change to
403 // any clip information.
404 // TODO: move to SkBitmapDevice
405 virtual void replaceBitmapBackendForRasterSurface(const SkBitmap&) = 0;
407 // just called by SkCanvas when built as a layer
408 void setOrigin(int x, int y) { fOrigin.set(x, y); }
409 // just called by SkCanvas for saveLayer
410 SkBaseDevice* createCompatibleDeviceForSaveLayer(SkBitmap::Config config,
411 int width, int height,
415 * Subclasses should override this to implement createCompatibleDevice.
417 virtual SkBaseDevice* onCreateCompatibleDevice(SkBitmap::Config config,
418 int width, int height,
422 /** Causes any deferred drawing to the device to be completed.
424 virtual void flush() = 0;
427 SkMetaData* fMetaData;
430 bool fAttachedToCanvas;
433 typedef SkRefCnt INHERITED;