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skia2/include/core/SkBitmap.h
Mike Klein 1cb5527bc6 remove enum docs 
These docs repeat the possible values for these enums at
the time they were written ad nauseum.  They're not kept
up to date.

This is the result of searching for "one of" and deleting most.
I did keep one set of docs where some enum values were permitted
on some platforms and others on others.  And I kept docs for args
that didn't take enums but only accepted a particular range, like
[0,8] for matrix value indices or 0-4 for pixel size shifts.

Change-Id: Ib21ec54ebbc4abe456e9b3f436f3823d7da9097d
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/270107
Auto-Submit: Mike Klein <mtklein@google.com>
Commit-Queue: Mike Reed <reed@google.com>
Reviewed-by: Mike Reed <reed@google.com>
2020-02-11 21:43:07 +00:00

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/*
* 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 SkBitmap_DEFINED
#define SkBitmap_DEFINED
#include "include/core/SkColor.h"
#include "include/core/SkImageInfo.h"
#include "include/core/SkMatrix.h"
#include "include/core/SkPixmap.h"
#include "include/core/SkPoint.h"
#include "include/core/SkRefCnt.h"
#include "include/core/SkTileMode.h"
struct SkMask;
struct SkIRect;
struct SkRect;
class SkPaint;
class SkPixelRef;
class SkShader;
/** \class SkBitmap
SkBitmap describes a two-dimensional raster pixel array. SkBitmap is built on
SkImageInfo, containing integer width and height, SkColorType and SkAlphaType
describing the pixel format, and SkColorSpace describing the range of colors.
SkBitmap points to SkPixelRef, which describes the physical array of pixels.
SkImageInfo bounds may be located anywhere fully inside SkPixelRef bounds.
SkBitmap can be drawn using SkCanvas. SkBitmap can be a drawing destination for SkCanvas
draw member functions. SkBitmap flexibility as a pixel container limits some
optimizations available to the target platform.
If pixel array is primarily read-only, use SkImage for better performance.
If pixel array is primarily written to, use SkSurface for better performance.
Declaring SkBitmap const prevents altering SkImageInfo: the SkBitmap height, width,
and so on cannot change. It does not affect SkPixelRef: a caller may write its
pixels. Declaring SkBitmap const affects SkBitmap configuration, not its contents.
SkBitmap is not thread safe. Each thread must have its own copy of SkBitmap fields,
although threads may share the underlying pixel array.
*/
class SK_API SkBitmap {
public:
class SK_API Allocator;
/** Creates an empty SkBitmap without pixels, with kUnknown_SkColorType,
kUnknown_SkAlphaType, and with a width and height of zero. SkPixelRef origin is
set to (0, 0). SkBitmap is not volatile.
Use setInfo() to associate SkColorType, SkAlphaType, width, and height
after SkBitmap has been created.
@return empty SkBitmap
example: https://fiddle.skia.org/c/@Bitmap_empty_constructor
*/
SkBitmap();
/** Copies settings from src to returned SkBitmap. Shares pixels if src has pixels
allocated, so both bitmaps reference the same pixels.
@param src SkBitmap to copy SkImageInfo, and share SkPixelRef
@return copy of src
example: https://fiddle.skia.org/c/@Bitmap_copy_const_SkBitmap
*/
SkBitmap(const SkBitmap& src);
/** Copies settings from src to returned SkBitmap. Moves ownership of src pixels to
SkBitmap.
@param src SkBitmap to copy SkImageInfo, and reassign SkPixelRef
@return copy of src
example: https://fiddle.skia.org/c/@Bitmap_move_SkBitmap
*/
SkBitmap(SkBitmap&& src);
/** Decrements SkPixelRef reference count, if SkPixelRef is not nullptr.
*/
~SkBitmap();
/** Copies settings from src to returned SkBitmap. Shares pixels if src has pixels
allocated, so both bitmaps reference the same pixels.
@param src SkBitmap to copy SkImageInfo, and share SkPixelRef
@return copy of src
example: https://fiddle.skia.org/c/@Bitmap_copy_operator
*/
SkBitmap& operator=(const SkBitmap& src);
/** Copies settings from src to returned SkBitmap. Moves ownership of src pixels to
SkBitmap.
@param src SkBitmap to copy SkImageInfo, and reassign SkPixelRef
@return copy of src
example: https://fiddle.skia.org/c/@Bitmap_move_operator
*/
SkBitmap& operator=(SkBitmap&& src);
/** Swaps the fields of the two bitmaps.
@param other SkBitmap exchanged with original
example: https://fiddle.skia.org/c/@Bitmap_swap
*/
void swap(SkBitmap& other);
/** Returns a constant reference to the SkPixmap holding the SkBitmap pixel
address, row bytes, and SkImageInfo.
@return reference to SkPixmap describing this SkBitmap
*/
const SkPixmap& pixmap() const { return fPixmap; }
/** Returns width, height, SkAlphaType, SkColorType, and SkColorSpace.
@return reference to SkImageInfo
*/
const SkImageInfo& info() const { return fPixmap.info(); }
/** Returns pixel count in each row. Should be equal or less than
rowBytes() / info().bytesPerPixel().
May be less than pixelRef().width(). Will not exceed pixelRef().width() less
pixelRefOrigin().fX.
@return pixel width in SkImageInfo
*/
int width() const { return fPixmap.width(); }
/** Returns pixel row count.
Maybe be less than pixelRef().height(). Will not exceed pixelRef().height() less
pixelRefOrigin().fY.
@return pixel height in SkImageInfo
*/
int height() const { return fPixmap.height(); }
SkColorType colorType() const { return fPixmap.colorType(); }
SkAlphaType alphaType() const { return fPixmap.alphaType(); }
/** Returns SkColorSpace, the range of colors, associated with SkImageInfo. The
reference count of SkColorSpace is unchanged. The returned SkColorSpace is
immutable.
@return SkColorSpace in SkImageInfo, or nullptr
*/
SkColorSpace* colorSpace() const { return fPixmap.colorSpace(); }
/** Returns smart pointer to SkColorSpace, the range of colors, associated with
SkImageInfo. The smart pointer tracks the number of objects sharing this
SkColorSpace reference so the memory is released when the owners destruct.
The returned SkColorSpace is immutable.
@return SkColorSpace in SkImageInfo wrapped in a smart pointer
*/
sk_sp<SkColorSpace> refColorSpace() const { return fPixmap.info().refColorSpace(); }
/** Returns number of bytes per pixel required by SkColorType.
Returns zero if colorType( is kUnknown_SkColorType.
@return bytes in pixel
*/
int bytesPerPixel() const { return fPixmap.info().bytesPerPixel(); }
/** Returns number of pixels that fit on row. Should be greater than or equal to
width().
@return maximum pixels per row
*/
int rowBytesAsPixels() const { return fPixmap.rowBytesAsPixels(); }
/** Returns bit shift converting row bytes to row pixels.
Returns zero for kUnknown_SkColorType.
@return one of: 0, 1, 2, 3; left shift to convert pixels to bytes
*/
int shiftPerPixel() const { return fPixmap.shiftPerPixel(); }
/** Returns true if either width() or height() are zero.
Does not check if SkPixelRef is nullptr; call drawsNothing() to check width(),
height(), and SkPixelRef.
@return true if dimensions do not enclose area
*/
bool empty() const { return fPixmap.info().isEmpty(); }
/** Returns true if SkPixelRef is nullptr.
Does not check if width() or height() are zero; call drawsNothing() to check
width(), height(), and SkPixelRef.
@return true if no SkPixelRef is associated
*/
bool isNull() const { return nullptr == fPixelRef; }
/** Returns true if width() or height() are zero, or if SkPixelRef is nullptr.
If true, SkBitmap has no effect when drawn or drawn into.
@return true if drawing has no effect
*/
bool drawsNothing() const {
return this->empty() || this->isNull();
}
/** Returns row bytes, the interval from one pixel row to the next. Row bytes
is at least as large as: width() * info().bytesPerPixel().
Returns zero if colorType() is kUnknown_SkColorType, or if row bytes supplied to
setInfo() is not large enough to hold a row of pixels.
@return byte length of pixel row
*/
size_t rowBytes() const { return fPixmap.rowBytes(); }
/** Sets SkAlphaType, if alphaType is compatible with SkColorType.
Returns true unless alphaType is kUnknown_SkAlphaType and current SkAlphaType
is not kUnknown_SkAlphaType.
Returns true if SkColorType is kUnknown_SkColorType. alphaType is ignored, and
SkAlphaType remains kUnknown_SkAlphaType.
Returns true if SkColorType is kRGB_565_SkColorType or kGray_8_SkColorType.
alphaType is ignored, and SkAlphaType remains kOpaque_SkAlphaType.
If SkColorType is kARGB_4444_SkColorType, kRGBA_8888_SkColorType,
kBGRA_8888_SkColorType, or kRGBA_F16_SkColorType: returns true unless
alphaType is kUnknown_SkAlphaType and SkAlphaType is not kUnknown_SkAlphaType.
If SkAlphaType is kUnknown_SkAlphaType, alphaType is ignored.
If SkColorType is kAlpha_8_SkColorType, returns true unless
alphaType is kUnknown_SkAlphaType and SkAlphaType is not kUnknown_SkAlphaType.
If SkAlphaType is kUnknown_SkAlphaType, alphaType is ignored. If alphaType is
kUnpremul_SkAlphaType, it is treated as kPremul_SkAlphaType.
This changes SkAlphaType in SkPixelRef; all bitmaps sharing SkPixelRef
are affected.
@return true if SkAlphaType is set
example: https://fiddle.skia.org/c/@Bitmap_setAlphaType
*/
bool setAlphaType(SkAlphaType alphaType);
/** Returns pixel address, the base address corresponding to the pixel origin.
@return pixel address
*/
void* getPixels() const { return fPixmap.writable_addr(); }
/** Returns minimum memory required for pixel storage.
Does not include unused memory on last row when rowBytesAsPixels() exceeds width().
Returns SIZE_MAX if result does not fit in size_t.
Returns zero if height() or width() is 0.
Returns height() times rowBytes() if colorType() is kUnknown_SkColorType.
@return size in bytes of image buffer
*/
size_t computeByteSize() const { return fPixmap.computeByteSize(); }
/** Returns true if pixels can not change.
Most immutable SkBitmap checks trigger an assert only on debug builds.
@return true if pixels are immutable
example: https://fiddle.skia.org/c/@Bitmap_isImmutable
*/
bool isImmutable() const;
/** Sets internal flag to mark SkBitmap as immutable. Once set, pixels can not change.
Any other bitmap sharing the same SkPixelRef are also marked as immutable.
Once SkPixelRef is marked immutable, the setting cannot be cleared.
Writing to immutable SkBitmap pixels triggers an assert on debug builds.
example: https://fiddle.skia.org/c/@Bitmap_setImmutable
*/
void setImmutable();
/** Returns true if SkAlphaType is set to hint that all pixels are opaque; their
alpha value is implicitly or explicitly 1.0. If true, and all pixels are
not opaque, Skia may draw incorrectly.
Does not check if SkColorType allows alpha, or if any pixel value has
transparency.
@return true if SkImageInfo SkAlphaType is kOpaque_SkAlphaType
*/
bool isOpaque() const {
return SkAlphaTypeIsOpaque(this->alphaType());
}
/** Provides a hint to caller that pixels should not be cached. Only true if
setIsVolatile() has been called to mark as volatile.
Volatile state is not shared by other bitmaps sharing the same SkPixelRef.
@return true if marked volatile
example: https://fiddle.skia.org/c/@Bitmap_isVolatile
*/
bool isVolatile() const;
/** Sets if pixels should be read from SkPixelRef on every access. SkBitmap are not
volatile by default; a GPU back end may upload pixel values expecting them to be
accessed repeatedly. Marking temporary SkBitmap as volatile provides a hint to
SkBaseDevice that the SkBitmap pixels should not be cached. This can
improve performance by avoiding overhead and reducing resource
consumption on SkBaseDevice.
@param isVolatile true if backing pixels are temporary
example: https://fiddle.skia.org/c/@Bitmap_setIsVolatile
*/
void setIsVolatile(bool isVolatile);
/** Resets to its initial state; all fields are set to zero, as if SkBitmap had
been initialized by SkBitmap().
Sets width, height, row bytes to zero; pixel address to nullptr; SkColorType to
kUnknown_SkColorType; and SkAlphaType to kUnknown_SkAlphaType.
If SkPixelRef is allocated, its reference count is decreased by one, releasing
its memory if SkBitmap is the sole owner.
example: https://fiddle.skia.org/c/@Bitmap_reset
*/
void reset();
/** Returns true if all pixels are opaque. SkColorType determines how pixels
are encoded, and whether pixel describes alpha. Returns true for SkColorType
without alpha in each pixel; for other SkColorType, returns true if all
pixels have alpha values equivalent to 1.0 or greater.
For SkColorType kRGB_565_SkColorType or kGray_8_SkColorType: always
returns true. For SkColorType kAlpha_8_SkColorType, kBGRA_8888_SkColorType,
kRGBA_8888_SkColorType: returns true if all pixel alpha values are 255.
For SkColorType kARGB_4444_SkColorType: returns true if all pixel alpha values are 15.
For kRGBA_F16_SkColorType: returns true if all pixel alpha values are 1.0 or
greater.
Returns false for kUnknown_SkColorType.
@param bm SkBitmap to check
@return true if all pixels have opaque values or SkColorType is opaque
*/
static bool ComputeIsOpaque(const SkBitmap& bm) {
return bm.pixmap().computeIsOpaque();
}
/** Returns SkRect { 0, 0, width(), height() }.
@param bounds container for floating point rectangle
example: https://fiddle.skia.org/c/@Bitmap_getBounds
*/
void getBounds(SkRect* bounds) const;
/** Returns SkIRect { 0, 0, width(), height() }.
@param bounds container for integral rectangle
example: https://fiddle.skia.org/c/@Bitmap_getBounds_2
*/
void getBounds(SkIRect* bounds) const;
/** Returns SkIRect { 0, 0, width(), height() }.
@return integral rectangle from origin to width() and height()
*/
SkIRect bounds() const { return fPixmap.info().bounds(); }
/** Returns SkISize { width(), height() }.
@return integral size of width() and height()
*/
SkISize dimensions() const { return fPixmap.info().dimensions(); }
/** Returns the bounds of this bitmap, offset by its SkPixelRef origin.
@return bounds within SkPixelRef bounds
*/
SkIRect getSubset() const {
SkIPoint origin = this->pixelRefOrigin();
return SkIRect::MakeXYWH(origin.x(), origin.y(), this->width(), this->height());
}
/** Sets width, height, SkAlphaType, SkColorType, SkColorSpace, and optional
rowBytes. Frees pixels, and returns true if successful.
imageInfo.alphaType() may be altered to a value permitted by imageInfo.colorSpace().
If imageInfo.colorType() is kUnknown_SkColorType, imageInfo.alphaType() is
set to kUnknown_SkAlphaType.
If imageInfo.colorType() is kAlpha_8_SkColorType and imageInfo.alphaType() is
kUnpremul_SkAlphaType, imageInfo.alphaType() is replaced by kPremul_SkAlphaType.
If imageInfo.colorType() is kRGB_565_SkColorType or kGray_8_SkColorType,
imageInfo.alphaType() is set to kOpaque_SkAlphaType.
If imageInfo.colorType() is kARGB_4444_SkColorType, kRGBA_8888_SkColorType,
kBGRA_8888_SkColorType, or kRGBA_F16_SkColorType: imageInfo.alphaType() remains
unchanged.
rowBytes must equal or exceed imageInfo.minRowBytes(). If imageInfo.colorSpace() is
kUnknown_SkColorType, rowBytes is ignored and treated as zero; for all other
SkColorSpace values, rowBytes of zero is treated as imageInfo.minRowBytes().
Calls reset() and returns false if:
- rowBytes exceeds 31 bits
- imageInfo.width() is negative
- imageInfo.height() is negative
- rowBytes is positive and less than imageInfo.width() times imageInfo.bytesPerPixel()
@param imageInfo contains width, height, SkAlphaType, SkColorType, SkColorSpace
@param rowBytes imageInfo.minRowBytes() or larger; or zero
@return true if SkImageInfo set successfully
example: https://fiddle.skia.org/c/@Bitmap_setInfo
*/
bool setInfo(const SkImageInfo& imageInfo, size_t rowBytes = 0);
/** \enum SkBitmap::AllocFlags
AllocFlags is obsolete. We always zero pixel memory when allocated.
*/
enum AllocFlags {
kZeroPixels_AllocFlag = 1 << 0, //!< zero pixel memory. No effect. This is the default.
};
/** Sets SkImageInfo to info following the rules in setInfo() and allocates pixel
memory. Memory is zeroed.
Returns false and calls reset() if SkImageInfo could not be set, or memory could
not be allocated, or memory could not optionally be zeroed.
On most platforms, allocating pixel memory may succeed even though there is
not sufficient memory to hold pixels; allocation does not take place
until the pixels are written to. The actual behavior depends on the platform
implementation of calloc().
@param info contains width, height, SkAlphaType, SkColorType, SkColorSpace
@param flags kZeroPixels_AllocFlag, or zero
@return true if pixels allocation is successful
*/
bool SK_WARN_UNUSED_RESULT tryAllocPixelsFlags(const SkImageInfo& info, uint32_t flags);
/** Sets SkImageInfo to info following the rules in setInfo() and allocates pixel
memory. Memory is zeroed.
Aborts execution if SkImageInfo could not be set, or memory could
not be allocated, or memory could not optionally
be zeroed. Abort steps may be provided by the user at compile time by defining
SK_ABORT.
On most platforms, allocating pixel memory may succeed even though there is
not sufficient memory to hold pixels; allocation does not take place
until the pixels are written to. The actual behavior depends on the platform
implementation of calloc().
@param info contains width, height, SkAlphaType, SkColorType, SkColorSpace
@param flags kZeroPixels_AllocFlag, or zero
example: https://fiddle.skia.org/c/@Bitmap_allocPixelsFlags
*/
void allocPixelsFlags(const SkImageInfo& info, uint32_t flags);
/** Sets SkImageInfo to info following the rules in setInfo() and allocates pixel
memory. rowBytes must equal or exceed info.width() times info.bytesPerPixel(),
or equal zero. Pass in zero for rowBytes to compute the minimum valid value.
Returns false and calls reset() if SkImageInfo could not be set, or memory could
not be allocated.
On most platforms, allocating pixel memory may succeed even though there is
not sufficient memory to hold pixels; allocation does not take place
until the pixels are written to. The actual behavior depends on the platform
implementation of malloc().
@param info contains width, height, SkAlphaType, SkColorType, SkColorSpace
@param rowBytes size of pixel row or larger; may be zero
@return true if pixel storage is allocated
*/
bool SK_WARN_UNUSED_RESULT tryAllocPixels(const SkImageInfo& info, size_t rowBytes);
/** Sets SkImageInfo to info following the rules in setInfo() and allocates pixel
memory. rowBytes must equal or exceed info.width() times info.bytesPerPixel(),
or equal zero. Pass in zero for rowBytes to compute the minimum valid value.
Aborts execution if SkImageInfo could not be set, or memory could
not be allocated. Abort steps may be provided by
the user at compile time by defining SK_ABORT.
On most platforms, allocating pixel memory may succeed even though there is
not sufficient memory to hold pixels; allocation does not take place
until the pixels are written to. The actual behavior depends on the platform
implementation of malloc().
@param info contains width, height, SkAlphaType, SkColorType, SkColorSpace
@param rowBytes size of pixel row or larger; may be zero
example: https://fiddle.skia.org/c/@Bitmap_allocPixels
*/
void allocPixels(const SkImageInfo& info, size_t rowBytes);
/** Sets SkImageInfo to info following the rules in setInfo() and allocates pixel
memory.
Returns false and calls reset() if SkImageInfo could not be set, or memory could
not be allocated.
On most platforms, allocating pixel memory may succeed even though there is
not sufficient memory to hold pixels; allocation does not take place
until the pixels are written to. The actual behavior depends on the platform
implementation of malloc().
@param info contains width, height, SkAlphaType, SkColorType, SkColorSpace
@return true if pixel storage is allocated
*/
bool SK_WARN_UNUSED_RESULT tryAllocPixels(const SkImageInfo& info) {
return this->tryAllocPixels(info, info.minRowBytes());
}
/** Sets SkImageInfo to info following the rules in setInfo() and allocates pixel
memory.
Aborts execution if SkImageInfo could not be set, or memory could
not be allocated. Abort steps may be provided by
the user at compile time by defining SK_ABORT.
On most platforms, allocating pixel memory may succeed even though there is
not sufficient memory to hold pixels; allocation does not take place
until the pixels are written to. The actual behavior depends on the platform
implementation of malloc().
@param info contains width, height, SkAlphaType, SkColorType, SkColorSpace
example: https://fiddle.skia.org/c/@Bitmap_allocPixels_2
*/
void allocPixels(const SkImageInfo& info);
/** Sets SkImageInfo to width, height, and native color type; and allocates
pixel memory. If isOpaque is true, sets SkImageInfo to kOpaque_SkAlphaType;
otherwise, sets to kPremul_SkAlphaType.
Calls reset() and returns false if width exceeds 29 bits or is negative,
or height is negative.
Returns false if allocation fails.
Use to create SkBitmap that matches SkPMColor, the native pixel arrangement on
the platform. SkBitmap drawn to output device skips converting its pixel format.
@param width pixel column count; must be zero or greater
@param height pixel row count; must be zero or greater
@param isOpaque true if pixels do not have transparency
@return true if pixel storage is allocated
*/
bool SK_WARN_UNUSED_RESULT tryAllocN32Pixels(int width, int height, bool isOpaque = false);
/** Sets SkImageInfo to width, height, and the native color type; and allocates
pixel memory. If isOpaque is true, sets SkImageInfo to kOpaque_SkAlphaType;
otherwise, sets to kPremul_SkAlphaType.
Aborts if width exceeds 29 bits or is negative, or height is negative, or
allocation fails. Abort steps may be provided by the user at compile time by
defining SK_ABORT.
Use to create SkBitmap that matches SkPMColor, the native pixel arrangement on
the platform. SkBitmap drawn to output device skips converting its pixel format.
@param width pixel column count; must be zero or greater
@param height pixel row count; must be zero or greater
@param isOpaque true if pixels do not have transparency
example: https://fiddle.skia.org/c/@Bitmap_allocN32Pixels
*/
void allocN32Pixels(int width, int height, bool isOpaque = false);
/** Sets SkImageInfo to info following the rules in setInfo(), and creates SkPixelRef
containing pixels and rowBytes. releaseProc, if not nullptr, is called
immediately on failure or when pixels are no longer referenced. context may be
nullptr.
If SkImageInfo could not be set, or rowBytes is less than info.minRowBytes():
calls releaseProc if present, calls reset(), and returns false.
Otherwise, if pixels equals nullptr: sets SkImageInfo, calls releaseProc if
present, returns true.
If SkImageInfo is set, pixels is not nullptr, and releaseProc is not nullptr:
when pixels are no longer referenced, calls releaseProc with pixels and context
as parameters.
@param info contains width, height, SkAlphaType, SkColorType, SkColorSpace
@param pixels address or pixel storage; may be nullptr
@param rowBytes size of pixel row or larger
@param releaseProc function called when pixels can be deleted; may be nullptr
@param context caller state passed to releaseProc; may be nullptr
@return true if SkImageInfo is set to info
*/
bool installPixels(const SkImageInfo& info, void* pixels, size_t rowBytes,
void (*releaseProc)(void* addr, void* context), void* context);
/** Sets SkImageInfo to info following the rules in setInfo(), and creates SkPixelRef
containing pixels and rowBytes.
If SkImageInfo could not be set, or rowBytes is less than info.minRowBytes():
calls reset(), and returns false.
Otherwise, if pixels equals nullptr: sets SkImageInfo, returns true.
Caller must ensure that pixels are valid for the lifetime of SkBitmap and SkPixelRef.
@param info contains width, height, SkAlphaType, SkColorType, SkColorSpace
@param pixels address or pixel storage; may be nullptr
@param rowBytes size of pixel row or larger
@return true if SkImageInfo is set to info
*/
bool installPixels(const SkImageInfo& info, void* pixels, size_t rowBytes) {
return this->installPixels(info, pixels, rowBytes, nullptr, nullptr);
}
/** Sets SkImageInfo to pixmap.info() following the rules in setInfo(), and creates
SkPixelRef containing pixmap.addr() and pixmap.rowBytes().
If SkImageInfo could not be set, or pixmap.rowBytes() is less than
SkImageInfo::minRowBytes(): calls reset(), and returns false.
Otherwise, if pixmap.addr() equals nullptr: sets SkImageInfo, returns true.
Caller must ensure that pixmap is valid for the lifetime of SkBitmap and SkPixelRef.
@param pixmap SkImageInfo, pixel address, and rowBytes()
@return true if SkImageInfo was set to pixmap.info()
example: https://fiddle.skia.org/c/@Bitmap_installPixels_3
*/
bool installPixels(const SkPixmap& pixmap);
/** Deprecated.
*/
bool installMaskPixels(const SkMask& mask);
/** Replaces SkPixelRef with pixels, preserving SkImageInfo and rowBytes().
Sets SkPixelRef origin to (0, 0).
If pixels is nullptr, or if info().colorType() equals kUnknown_SkColorType;
release reference to SkPixelRef, and set SkPixelRef to nullptr.
Caller is responsible for handling ownership pixel memory for the lifetime
of SkBitmap and SkPixelRef.
@param pixels address of pixel storage, managed by caller
example: https://fiddle.skia.org/c/@Bitmap_setPixels
*/
void setPixels(void* pixels);
/** Allocates pixel memory with HeapAllocator, and replaces existing SkPixelRef.
The allocation size is determined by SkImageInfo width, height, and SkColorType.
Returns false if info().colorType() is kUnknown_SkColorType, or allocation fails.
@return true if the allocation succeeds
*/
bool SK_WARN_UNUSED_RESULT tryAllocPixels() {
return this->tryAllocPixels((Allocator*)nullptr);
}
/** Allocates pixel memory with HeapAllocator, and replaces existing SkPixelRef.
The allocation size is determined by SkImageInfo width, height, and SkColorType.
Aborts if info().colorType() is kUnknown_SkColorType, or allocation fails.
Abort steps may be provided by the user at compile
time by defining SK_ABORT.
example: https://fiddle.skia.org/c/@Bitmap_allocPixels_3
*/
void allocPixels();
/** Allocates pixel memory with allocator, and replaces existing SkPixelRef.
The allocation size is determined by SkImageInfo width, height, and SkColorType.
If allocator is nullptr, use HeapAllocator instead.
Returns false if Allocator::allocPixelRef return false.
@param allocator instance of SkBitmap::Allocator instantiation
@return true if custom allocator reports success
*/
bool SK_WARN_UNUSED_RESULT tryAllocPixels(Allocator* allocator);
/** Allocates pixel memory with allocator, and replaces existing SkPixelRef.
The allocation size is determined by SkImageInfo width, height, and SkColorType.
If allocator is nullptr, use HeapAllocator instead.
Aborts if Allocator::allocPixelRef return false. Abort steps may be provided by
the user at compile time by defining SK_ABORT.
@param allocator instance of SkBitmap::Allocator instantiation
example: https://fiddle.skia.org/c/@Bitmap_allocPixels_4
*/
void allocPixels(Allocator* allocator);
/** Returns SkPixelRef, which contains: pixel base address; its dimensions; and
rowBytes(), the interval from one row to the next. Does not change SkPixelRef
reference count. SkPixelRef may be shared by multiple bitmaps.
If SkPixelRef has not been set, returns nullptr.
@return SkPixelRef, or nullptr
*/
SkPixelRef* pixelRef() const { return fPixelRef.get(); }
/** Returns origin of pixels within SkPixelRef. SkBitmap bounds is always contained
by SkPixelRef bounds, which may be the same size or larger. Multiple SkBitmap
can share the same SkPixelRef, where each SkBitmap has different bounds.
The returned origin added to SkBitmap dimensions equals or is smaller than the
SkPixelRef dimensions.
Returns (0, 0) if SkPixelRef is nullptr.
@return pixel origin within SkPixelRef
example: https://fiddle.skia.org/c/@Bitmap_pixelRefOrigin
*/
SkIPoint pixelRefOrigin() const;
/** Replaces pixelRef and origin in SkBitmap. dx and dy specify the offset
within the SkPixelRef pixels for the top-left corner of the bitmap.
Asserts in debug builds if dx or dy are out of range. Pins dx and dy
to legal range in release builds.
The caller is responsible for ensuring that the pixels match the
SkColorType and SkAlphaType in SkImageInfo.
@param pixelRef SkPixelRef describing pixel address and rowBytes()
@param dx column offset in SkPixelRef for bitmap origin
@param dy row offset in SkPixelRef for bitmap origin
example: https://fiddle.skia.org/c/@Bitmap_setPixelRef
*/
void setPixelRef(sk_sp<SkPixelRef> pixelRef, int dx, int dy);
/** Returns true if SkBitmap is can be drawn.
@return true if getPixels() is not nullptr
*/
bool readyToDraw() const {
return this->getPixels() != nullptr;
}
/** Returns a unique value corresponding to the pixels in SkPixelRef.
Returns a different value after notifyPixelsChanged() has been called.
Returns zero if SkPixelRef is nullptr.
Determines if pixels have changed since last examined.
@return unique value for pixels in SkPixelRef
example: https://fiddle.skia.org/c/@Bitmap_getGenerationID
*/
uint32_t getGenerationID() const;
/** Marks that pixels in SkPixelRef have changed. Subsequent calls to
getGenerationID() return a different value.
example: https://fiddle.skia.org/c/@Bitmap_notifyPixelsChanged
*/
void notifyPixelsChanged() const;
/** Replaces pixel values with c. All pixels contained by bounds() are affected.
If the colorType() is kGray_8_SkColorType or kRGB_565_SkColorType, then alpha
is ignored; RGB is treated as opaque. If colorType() is kAlpha_8_SkColorType,
then RGB is ignored.
@param c unpremultiplied color
example: https://fiddle.skia.org/c/@Bitmap_eraseColor
*/
void eraseColor(SkColor c) const;
/** Replaces pixel values with unpremultiplied color built from a, r, g, and b.
All pixels contained by bounds() are affected.
If the colorType() is kGray_8_SkColorType or kRGB_565_SkColorType, then a
is ignored; r, g, and b are treated as opaque. If colorType() is kAlpha_8_SkColorType,
then r, g, and b are ignored.
@param a amount of alpha, from fully transparent (0) to fully opaque (255)
@param r amount of red, from no red (0) to full red (255)
@param g amount of green, from no green (0) to full green (255)
@param b amount of blue, from no blue (0) to full blue (255)
*/
void eraseARGB(U8CPU a, U8CPU r, U8CPU g, U8CPU b) const {
this->eraseColor(SkColorSetARGB(a, r, g, b));
}
/** Replaces pixel values inside area with c. If area does not intersect bounds(),
call has no effect.
If the colorType() is kGray_8_SkColorType or kRGB_565_SkColorType, then alpha
is ignored; RGB is treated as opaque. If colorType() is kAlpha_8_SkColorType,
then RGB is ignored.
@param c unpremultiplied color
@param area rectangle to fill
example: https://fiddle.skia.org/c/@Bitmap_erase
*/
void erase(SkColor c, const SkIRect& area) const;
/** Deprecated.
*/
void eraseArea(const SkIRect& area, SkColor c) const {
this->erase(c, area);
}
/** Returns pixel at (x, y) as unpremultiplied color.
Returns black with alpha if SkColorType is kAlpha_8_SkColorType.
Input is not validated: out of bounds values of x or y trigger an assert() if
built with SK_DEBUG defined; and returns undefined values or may crash if
SK_RELEASE is defined. Fails if SkColorType is kUnknown_SkColorType or
pixel address is nullptr.
SkColorSpace in SkImageInfo is ignored. Some color precision may be lost in the
conversion to unpremultiplied color; original pixel data may have additional
precision.
@param x column index, zero or greater, and less than width()
@param y row index, zero or greater, and less than height()
@return pixel converted to unpremultiplied color
*/
SkColor getColor(int x, int y) const {
return this->pixmap().getColor(x, y);
}
/** Look up the pixel at (x,y) and return its alpha component, normalized to [0..1].
This is roughly equivalent to SkGetColorA(getColor()), but can be more efficent
(and more precise if the pixels store more than 8 bits per component).
@param x column index, zero or greater, and less than width()
@param y row index, zero or greater, and less than height()
@return alpha converted to normalized float
*/
float getAlphaf(int x, int y) const {
return this->pixmap().getAlphaf(x, y);
}
/** Returns pixel address at (x, y).
Input is not validated: out of bounds values of x or y, or kUnknown_SkColorType,
trigger an assert() if built with SK_DEBUG defined. Returns nullptr if
SkColorType is kUnknown_SkColorType, or SkPixelRef is nullptr.
Performs a lookup of pixel size; for better performance, call
one of: getAddr8(), getAddr16(), or getAddr32().
@param x column index, zero or greater, and less than width()
@param y row index, zero or greater, and less than height()
@return generic pointer to pixel
example: https://fiddle.skia.org/c/@Bitmap_getAddr
*/
void* getAddr(int x, int y) const;
/** Returns address at (x, y).
Input is not validated. Triggers an assert() if built with SK_DEBUG defined and:
- SkPixelRef is nullptr
- bytesPerPixel() is not four
- x is negative, or not less than width()
- y is negative, or not less than height()
@param x column index, zero or greater, and less than width()
@param y row index, zero or greater, and less than height()
@return unsigned 32-bit pointer to pixel at (x, y)
*/
inline uint32_t* getAddr32(int x, int y) const;
/** Returns address at (x, y).
Input is not validated. Triggers an assert() if built with SK_DEBUG defined and:
- SkPixelRef is nullptr
- bytesPerPixel() is not two
- x is negative, or not less than width()
- y is negative, or not less than height()
@param x column index, zero or greater, and less than width()
@param y row index, zero or greater, and less than height()
@return unsigned 16-bit pointer to pixel at (x, y)
*/
inline uint16_t* getAddr16(int x, int y) const;
/** Returns address at (x, y).
Input is not validated. Triggers an assert() if built with SK_DEBUG defined and:
- SkPixelRef is nullptr
- bytesPerPixel() is not one
- x is negative, or not less than width()
- y is negative, or not less than height()
@param x column index, zero or greater, and less than width()
@param y row index, zero or greater, and less than height()
@return unsigned 8-bit pointer to pixel at (x, y)
*/
inline uint8_t* getAddr8(int x, int y) const;
/** Shares SkPixelRef with dst. Pixels are not copied; SkBitmap and dst point
to the same pixels; dst bounds() are set to the intersection of subset
and the original bounds().
subset may be larger than bounds(). Any area outside of bounds() is ignored.
Any contents of dst are discarded. isVolatile() setting is copied to dst.
dst is set to colorType(), alphaType(), and colorSpace().
Return false if:
- dst is nullptr
- SkPixelRef is nullptr
- subset does not intersect bounds()
@param dst SkBitmap set to subset
@param subset rectangle of pixels to reference
@return true if dst is replaced by subset
example: https://fiddle.skia.org/c/@Bitmap_extractSubset
*/
bool extractSubset(SkBitmap* dst, const SkIRect& subset) const;
/** Copies a SkRect of pixels from SkBitmap to dstPixels. Copy starts at (srcX, srcY),
and does not exceed SkBitmap (width(), height()).
dstInfo specifies width, height, SkColorType, SkAlphaType, and SkColorSpace of
destination. dstRowBytes specifics the gap from one destination row to the next.
Returns true if pixels are copied. Returns false if:
- dstInfo has no address
- dstRowBytes is less than dstInfo.minRowBytes()
- SkPixelRef is nullptr
Pixels are copied only if pixel conversion is possible. If SkBitmap colorType() is
kGray_8_SkColorType, or kAlpha_8_SkColorType; dstInfo.colorType() must match.
If SkBitmap colorType() is kGray_8_SkColorType, dstInfo.colorSpace() must match.
If SkBitmap alphaType() is kOpaque_SkAlphaType, dstInfo.alphaType() must
match. If SkBitmap colorSpace() is nullptr, dstInfo.colorSpace() must match. Returns
false if pixel conversion is not possible.
srcX and srcY may be negative to copy only top or left of source. Returns
false if width() or height() is zero or negative.
Returns false if abs(srcX) >= Bitmap width(), or if abs(srcY) >= Bitmap height().
@param dstInfo destination width, height, SkColorType, SkAlphaType, SkColorSpace
@param dstPixels destination pixel storage
@param dstRowBytes destination row length
@param srcX column index whose absolute value is less than width()
@param srcY row index whose absolute value is less than height()
@return true if pixels are copied to dstPixels
*/
bool readPixels(const SkImageInfo& dstInfo, void* dstPixels, size_t dstRowBytes,
int srcX, int srcY) const;
/** Copies a SkRect of pixels from SkBitmap to dst. Copy starts at (srcX, srcY), and
does not exceed SkBitmap (width(), height()).
dst specifies width, height, SkColorType, SkAlphaType, SkColorSpace, pixel storage,
and row bytes of destination. dst.rowBytes() specifics the gap from one destination
row to the next. Returns true if pixels are copied. Returns false if:
- dst pixel storage equals nullptr
- dst.rowBytes is less than SkImageInfo::minRowBytes()
- SkPixelRef is nullptr
Pixels are copied only if pixel conversion is possible. If SkBitmap colorType() is
kGray_8_SkColorType, or kAlpha_8_SkColorType; dst SkColorType must match.
If SkBitmap colorType() is kGray_8_SkColorType, dst SkColorSpace must match.
If SkBitmap alphaType() is kOpaque_SkAlphaType, dst SkAlphaType must
match. If SkBitmap colorSpace() is nullptr, dst SkColorSpace must match. Returns
false if pixel conversion is not possible.
srcX and srcY may be negative to copy only top or left of source. Returns
false if width() or height() is zero or negative.
Returns false if abs(srcX) >= Bitmap width(), or if abs(srcY) >= Bitmap height().
@param dst destination SkPixmap: SkImageInfo, pixels, row bytes
@param srcX column index whose absolute value is less than width()
@param srcY row index whose absolute value is less than height()
@return true if pixels are copied to dst
example: https://fiddle.skia.org/c/@Bitmap_readPixels_2
*/
bool readPixels(const SkPixmap& dst, int srcX, int srcY) const;
/** Copies a SkRect of pixels from SkBitmap to dst. Copy starts at (0, 0), and
does not exceed SkBitmap (width(), height()).
dst specifies width, height, SkColorType, SkAlphaType, SkColorSpace, pixel storage,
and row bytes of destination. dst.rowBytes() specifics the gap from one destination
row to the next. Returns true if pixels are copied. Returns false if:
- dst pixel storage equals nullptr
- dst.rowBytes is less than SkImageInfo::minRowBytes()
- SkPixelRef is nullptr
Pixels are copied only if pixel conversion is possible. If SkBitmap colorType() is
kGray_8_SkColorType, or kAlpha_8_SkColorType; dst SkColorType must match.
If SkBitmap colorType() is kGray_8_SkColorType, dst SkColorSpace must match.
If SkBitmap alphaType() is kOpaque_SkAlphaType, dst SkAlphaType must
match. If SkBitmap colorSpace() is nullptr, dst SkColorSpace must match. Returns
false if pixel conversion is not possible.
@param dst destination SkPixmap: SkImageInfo, pixels, row bytes
@return true if pixels are copied to dst
*/
bool readPixels(const SkPixmap& dst) const {
return this->readPixels(dst, 0, 0);
}
/** Copies a SkRect of pixels from src. Copy starts at (dstX, dstY), and does not exceed
(src.width(), src.height()).
src specifies width, height, SkColorType, SkAlphaType, SkColorSpace, pixel storage,
and row bytes of source. src.rowBytes() specifics the gap from one source
row to the next. Returns true if pixels are copied. Returns false if:
- src pixel storage equals nullptr
- src.rowBytes is less than SkImageInfo::minRowBytes()
- SkPixelRef is nullptr
Pixels are copied only if pixel conversion is possible. If SkBitmap colorType() is
kGray_8_SkColorType, or kAlpha_8_SkColorType; src SkColorType must match.
If SkBitmap colorType() is kGray_8_SkColorType, src SkColorSpace must match.
If SkBitmap alphaType() is kOpaque_SkAlphaType, src SkAlphaType must
match. If SkBitmap colorSpace() is nullptr, src SkColorSpace must match. Returns
false if pixel conversion is not possible.
dstX and dstY may be negative to copy only top or left of source. Returns
false if width() or height() is zero or negative.
Returns false if abs(dstX) >= Bitmap width(), or if abs(dstY) >= Bitmap height().
@param src source SkPixmap: SkImageInfo, pixels, row bytes
@param dstX column index whose absolute value is less than width()
@param dstY row index whose absolute value is less than height()
@return true if src pixels are copied to SkBitmap
example: https://fiddle.skia.org/c/@Bitmap_writePixels
*/
bool writePixels(const SkPixmap& src, int dstX, int dstY);
/** Copies a SkRect of pixels from src. Copy starts at (0, 0), and does not exceed
(src.width(), src.height()).
src specifies width, height, SkColorType, SkAlphaType, SkColorSpace, pixel storage,
and row bytes of source. src.rowBytes() specifics the gap from one source
row to the next. Returns true if pixels are copied. Returns false if:
- src pixel storage equals nullptr
- src.rowBytes is less than SkImageInfo::minRowBytes()
- SkPixelRef is nullptr
Pixels are copied only if pixel conversion is possible. If SkBitmap colorType() is
kGray_8_SkColorType, or kAlpha_8_SkColorType; src SkColorType must match.
If SkBitmap colorType() is kGray_8_SkColorType, src SkColorSpace must match.
If SkBitmap alphaType() is kOpaque_SkAlphaType, src SkAlphaType must
match. If SkBitmap colorSpace() is nullptr, src SkColorSpace must match. Returns
false if pixel conversion is not possible.
@param src source SkPixmap: SkImageInfo, pixels, row bytes
@return true if src pixels are copied to SkBitmap
*/
bool writePixels(const SkPixmap& src) {
return this->writePixels(src, 0, 0);
}
/** Sets dst to alpha described by pixels. Returns false if dst cannot be written to
or dst pixels cannot be allocated.
Uses HeapAllocator to reserve memory for dst SkPixelRef.
@param dst holds SkPixelRef to fill with alpha layer
@return true if alpha layer was constructed in dst SkPixelRef
*/
bool extractAlpha(SkBitmap* dst) const {
return this->extractAlpha(dst, nullptr, nullptr, nullptr);
}
/** Sets dst to alpha described by pixels. Returns false if dst cannot be written to
or dst pixels cannot be allocated.
If paint is not nullptr and contains SkMaskFilter, SkMaskFilter
generates mask alpha from SkBitmap. Uses HeapAllocator to reserve memory for dst
SkPixelRef. Sets offset to top-left position for dst for alignment with SkBitmap;
(0, 0) unless SkMaskFilter generates mask.
@param dst holds SkPixelRef to fill with alpha layer
@param paint holds optional SkMaskFilter; may be nullptr
@param offset top-left position for dst; may be nullptr
@return true if alpha layer was constructed in dst SkPixelRef
*/
bool extractAlpha(SkBitmap* dst, const SkPaint* paint,
SkIPoint* offset) const {
return this->extractAlpha(dst, paint, nullptr, offset);
}
/** Sets dst to alpha described by pixels. Returns false if dst cannot be written to
or dst pixels cannot be allocated.
If paint is not nullptr and contains SkMaskFilter, SkMaskFilter
generates mask alpha from SkBitmap. allocator may reference a custom allocation
class or be set to nullptr to use HeapAllocator. Sets offset to top-left
position for dst for alignment with SkBitmap; (0, 0) unless SkMaskFilter generates
mask.
@param dst holds SkPixelRef to fill with alpha layer
@param paint holds optional SkMaskFilter; may be nullptr
@param allocator function to reserve memory for SkPixelRef; may be nullptr
@param offset top-left position for dst; may be nullptr
@return true if alpha layer was constructed in dst SkPixelRef
*/
bool extractAlpha(SkBitmap* dst, const SkPaint* paint, Allocator* allocator,
SkIPoint* offset) const;
/** Copies SkBitmap pixel address, row bytes, and SkImageInfo to pixmap, if address
is available, and returns true. If pixel address is not available, return
false and leave pixmap unchanged.
pixmap contents become invalid on any future change to SkBitmap.
@param pixmap storage for pixel state if pixels are readable; otherwise, ignored
@return true if SkBitmap has direct access to pixels
example: https://fiddle.skia.org/c/@Bitmap_peekPixels
*/
bool peekPixels(SkPixmap* pixmap) const;
sk_sp<SkShader> makeShader(SkTileMode tmx, SkTileMode tmy,
const SkMatrix* localMatrix = nullptr) const;
// defaults to Clamp in x, and y
sk_sp<SkShader> makeShader(const SkMatrix* localMatrix = nullptr) const;
/** Asserts if internal values are illegal or inconsistent. Only available if
SK_DEBUG is defined at compile time.
*/
SkDEBUGCODE(void validate() const;)
/** \class SkBitmap::Allocator
Abstract subclass of HeapAllocator.
*/
class Allocator : public SkRefCnt {
public:
/** Allocates the pixel memory for the bitmap, given its dimensions and
SkColorType. Returns true on success, where success means either setPixels()
or setPixelRef() was called.
@param bitmap SkBitmap containing SkImageInfo as input, and SkPixelRef as output
@return true if SkPixelRef was allocated
*/
virtual bool allocPixelRef(SkBitmap* bitmap) = 0;
private:
typedef SkRefCnt INHERITED;
};
/** \class SkBitmap::HeapAllocator
Subclass of SkBitmap::Allocator that returns a SkPixelRef that allocates its pixel
memory from the heap. This is the default SkBitmap::Allocator invoked by
allocPixels().
*/
class HeapAllocator : public Allocator {
public:
/** Allocates the pixel memory for the bitmap, given its dimensions and
SkColorType. Returns true on success, where success means either setPixels()
or setPixelRef() was called.
@param bitmap SkBitmap containing SkImageInfo as input, and SkPixelRef as output
@return true if pixels are allocated
example: https://fiddle.skia.org/c/@Bitmap_HeapAllocator_allocPixelRef
*/
bool allocPixelRef(SkBitmap* bitmap) override;
};
private:
enum Flags {
kImageIsVolatile_Flag = 0x02,
};
sk_sp<SkPixelRef> fPixelRef;
SkPixmap fPixmap;
uint8_t fFlags;
friend class SkReadBuffer; // unflatten
};
///////////////////////////////////////////////////////////////////////////////
inline uint32_t* SkBitmap::getAddr32(int x, int y) const {
SkASSERT(fPixmap.addr());
return fPixmap.writable_addr32(x, y);
}
inline uint16_t* SkBitmap::getAddr16(int x, int y) const {
SkASSERT(fPixmap.addr());
return fPixmap.writable_addr16(x, y);
}
inline uint8_t* SkBitmap::getAddr8(int x, int y) const {
SkASSERT(fPixmap.addr());
return fPixmap.writable_addr8(x, y);
}
#endif
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