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/*
* Copyright 2012 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#ifndef SkImage_DEFINED
#define SkImage_DEFINED
#include "SkImageInfo.h"
#include "SkImageEncoder.h"
#include "SkRefCnt.h"
#include "SkScalar.h"
#include "SkShader.h"
class SkData;
class SkCanvas;
class SkImageGenerator;
class SkPaint;
class GrContext;
class GrTexture;
/**
* SkImage is an abstraction for drawing a rectagle of pixels, though the
* particular type of image could be actually storing its data on the GPU, or
* as drawing commands (picture or PDF or otherwise), ready to be played back
* into another canvas.
*
* The content of SkImage is always immutable, though the actual storage may
* change, if for example that image can be re-created via encoded data or
* other means.
*/
class SK_API SkImage : public SkRefCnt {
public:
SK_DECLARE_INST_COUNT(SkImage)
typedef SkImageInfo Info;
static SkImage* NewRasterCopy(const Info&, const void* pixels, size_t rowBytes);
static SkImage* NewRasterData(const Info&, SkData* pixels, size_t rowBytes);
static SkImage* NewEncodedData(SkData*);
/**
* GrTexture is a more logical parameter for this factory, but its
* interactions with scratch cache still has issues, so for now we take
* SkBitmap instead. This will be changed in the future. skbug.com/1449
*/
static SkImage* NewTexture(const SkBitmap&);
virtual bool isOpaque() const { return false; }
/**
* Construct a new SkImage based on the given ImageGenerator.
* This function will always take ownership of the passed
* ImageGenerator. Returns NULL on error.
*/
static SkImage* NewFromGenerator(SkImageGenerator*);
int width() const { return fWidth; }
int height() const { return fHeight; }
uint32_t uniqueID() const { return fUniqueID; }
/**
* Return the GrTexture that stores the image pixels. Calling getTexture
* does not affect the reference count of the GrTexture object.
* Will return NULL if the image does not use a texture.
*/
GrTexture* getTexture();
virtual SkShader* newShader(SkShader::TileMode,
SkShader::TileMode,
const SkMatrix* localMatrix = NULL) const;
void draw(SkCanvas*, SkScalar x, SkScalar y, const SkPaint*) const;
/**
* Draw the image, cropped to the src rect, to the dst rect of a canvas.
* If src is larger than the bounds of the image, the rest of the image is
* filled with transparent black pixels.
*
* See SkCanvas::drawBitmapRectToRect for similar behavior.
*/
void draw(SkCanvas*, const SkRect* src, const SkRect& dst, const SkPaint*) const;
/**
* If the image 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 image object is in scope.
*
* On failure, returns NULL and the info and rowBytes parameters are
* ignored.
*/
const void* peekPixels(SkImageInfo* info, size_t* rowBytes) const;
/**
* Encode the image's pixels and return the result as a new SkData, which
* the caller must manage (i.e. call unref() when they are done).
*
* If the image type cannot be encoded, or the requested encoder type is
* not supported, this will return NULL.
*/
SkData* encode(SkImageEncoder::Type t = SkImageEncoder::kPNG_Type,
int quality = 80) const;
protected:
SkImage(int width, int height) :
fWidth(width),
fHeight(height),
fUniqueID(NextUniqueID()) {
SkASSERT(width >= 0);
SkASSERT(height >= 0);
}
private:
const int fWidth;
const int fHeight;
const uint32_t fUniqueID;
static uint32_t NextUniqueID();
typedef SkRefCnt INHERITED;
/**
* Return a copy of the image's pixels, limiting them to the subset
* rectangle's intersection wit the image bounds. If subset is NULL, then
* the entire image will be considered.
*
* If the bitmap's pixels have already been allocated, then readPixels()
* will succeed only if it can support converting the image's pixels into
* the bitmap's ColorType/AlphaType. Any pixels in the bitmap that do not
* intersect with the image's bounds and the subset (if not null) will be
* left untouched.
*
* If the bitmap is initially empty/unallocated, then it will be allocated
* using the default allocator, and the ColorType/AlphaType will be chosen
* to most closely fit the image's configuration.
*
* On failure, false will be returned, and bitmap will unmodified.
*/
// On ice for now:
// - should it respect the particular colortype/alphatype of the src
// - should it have separate entrypoints for preallocated and not bitmaps?
// - isn't it enough to allow the caller to draw() the image into a canvas?
bool readPixels(SkBitmap* bitmap, const SkIRect* subset = NULL) const;
};
#endif
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