diff options
Diffstat (limited to 'include/core')
| -rw-r--r-- | include/core/SkBitmap.h | 15 | ||||
| -rw-r--r-- | include/core/SkCanvas.h | 41 | ||||
| -rw-r--r-- | include/core/SkDevice.h | 31 |
3 files changed, 71 insertions, 16 deletions
diff --git a/include/core/SkBitmap.h b/include/core/SkBitmap.h index e98a294bde..ae56739c5f 100644 --- a/include/core/SkBitmap.h +++ b/include/core/SkBitmap.h @@ -225,12 +225,11 @@ public: /** Copies the bitmap's pixels to the location pointed at by dst and returns true if possible, returns false otherwise. - In the event that the bitmap's stride is equal to dstRowBytes, and if - it is greater than strictly required by the bitmap's current config - (this may happen if the bitmap is an extracted subset of another), then - this function will copy bytes past the eand of each row, excluding the - last row. No copies are made outside of the declared size of dst, - however. + In the case when the dstRowBytes matches the bitmap's rowBytes, the copy + may be made faster by copying over the dst's per-row padding (for all + rows but the last). By setting preserveDstPad to true the caller can + disable this optimization and ensure that pixels in the padding are not + overwritten. Always returns false for RLE formats. @@ -239,8 +238,10 @@ public: pixels using indicated stride. @param dstRowBytes Width of each line in the buffer. If -1, uses bitmap's internal stride. + @param preserveDstPad Must we preserve padding in the dst */ - bool copyPixelsTo(void* const dst, size_t dstSize, int dstRowBytes = -1) + bool copyPixelsTo(void* const dst, size_t dstSize, int dstRowBytes = -1, + bool preserveDstPad = false) const; /** Use the standard HeapAllocator to create the pixelref that manages the diff --git a/include/core/SkCanvas.h b/include/core/SkCanvas.h index b2bdafe738..90bc1f433e 100644 --- a/include/core/SkCanvas.h +++ b/include/core/SkCanvas.h @@ -105,14 +105,45 @@ public: /////////////////////////////////////////////////////////////////////////// + /**
+ * On success (returns true), copy the canvas pixels into the bitmap.
+ * On failure, the bitmap parameter is left unchanged and false is
+ * returned.
+ *
+ * If the canvas is backed by a non-raster device (e.g. PDF) then
+ * readPixels will fail.
+ *
+ * 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 canvas' pixels are converted to the bitmap's config. The only
+ * supported config is kARGB_8888_Config, though this may be relaxed in
+ * future.
+ *
+ * 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.
+ *
+ * Example that reads the entire canvas into a bitmap:
+ * 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); + /** - * Copy the pixels from the device into bitmap. Returns true on success. - * If false is returned, then the bitmap parameter is left unchanged. - * The bitmap parameter is treated as output-only, and will be completely - * overwritten (if the method returns true). + * 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); - bool readPixels(SkBitmap* bitmap); /** * Similar to draw sprite, this method will copy the pixels in bitmap onto diff --git a/include/core/SkDevice.h b/include/core/SkDevice.h index 95b63892ae..5d184e478f 100644 --- a/include/core/SkDevice.h +++ b/include/core/SkDevice.h @@ -108,11 +108,23 @@ public: /** * Copy the pixels from the device into bitmap. Returns true on success. - * If false is returned, then the bitmap parameter is left unchanged. - * The bitmap parameter is treated as output-only, and will be completely - * overwritten (if the method returns true). + * If false is returned, then the bitmap parameter is left unchanged. The + * rectangle read is defined by x, y and the bitmap's width and height. + * + * If the bitmap has pixels allocated the canvas will write directly to + * into that memory (if the call succeeds). + * + * The read is clipped to the device bounds. If bitmap pixels were + * preallocated then pixels outside the clip are left unmodified. If the + * call allocates bitmap pixels then pixels outside the clip will be + * uninitialized. + * + * Currently bitmap must have kARGB_8888_Config or readPixels will fail. + * This will likely be relaxed in the future. + * + * The bitmap parameter is not modified if the call fails. */ - virtual bool readPixels(const SkIRect& srcRect, SkBitmap* bitmap); + bool readPixels(SkBitmap* bitmap, int x, int y); /** * Similar to draw sprite, this method will copy the pixels in bitmap onto @@ -256,6 +268,17 @@ protected: fBitmap.setPixelRef(pr, offset); return pr; } + + /** + * Implements readPixels API. The caller will ensure that: + * 1. bitmap has pixel config kARGB_8888_Config. + * 2. bitmap has pixels. + * 3. The rectangle (x, y, x + bitmap->width(), y + bitmap->height()) is + * contained in the device bounds. + * 4. the bitmap struct is safe to partially overwrite in case of failure + */ + virtual bool onReadPixels(const SkBitmap* bitmap, int x, int y); + /** Called when this device is installed into a Canvas. Balanaced by a call to unlockPixels() when the device is removed from a Canvas. |