Skia
2D Graphics Library
SkBitmap Class Reference

SkBitmap describes a two-dimensional raster pixel array. More...

#include <SkBitmap.h>

Classes

class  Allocator
 Asserts if internal values are illegal or inconsistent. More...
 
class  HeapAllocator
 Subclass of SkBitmap::Allocator that returns a SkPixelRef that allocates its pixel memory from the heap. More...
 

Public Types

enum  AllocFlags { kZeroPixels_AllocFlag = 1 << 0 }
 

Public Member Functions

 SkBitmap ()
 Creates an empty SkBitmap without pixels, with kUnknown_SkColorType, kUnknown_SkAlphaType, and with a width and height of zero. More...
 
 SkBitmap (const SkBitmap &src)
 Copies settings from src to returned SkBitmap. More...
 
 SkBitmap (SkBitmap &&src)
 Copies settings from src to returned SkBitmap. More...
 
 ~SkBitmap ()
 Decrements SkPixelRef reference count, if SkPixelRef is not nullptr. More...
 
SkBitmapoperator= (const SkBitmap &src)
 Copies settings from src to returned SkBitmap. More...
 
SkBitmapoperator= (SkBitmap &&src)
 Copies settings from src to returned SkBitmap. More...
 
void swap (SkBitmap &other)
 Swaps the fields of the two bitmaps. More...
 
const SkPixmappixmap () const
 Returns a constant reference to the SkPixmap holding the SkBitmap pixel address, row bytes, and SkImageInfo. More...
 
const SkImageInfoinfo () const
 Returns width, height, SkAlphaType, SkColorType, and SkColorSpace. More...
 
int width () const
 Returns pixel count in each row. More...
 
int height () const
 Returns pixel row count. More...
 
SkColorType colorType () const
 
SkAlphaType alphaType () const
 
SkColorSpacecolorSpace () const
 Returns SkColorSpace, the range of colors, associated with SkImageInfo. More...
 
sk_sp< SkColorSpacerefColorSpace () const
 Returns smart pointer to SkColorSpace, the range of colors, associated with SkImageInfo. More...
 
int bytesPerPixel () const
 Returns number of bytes per pixel required by SkColorType. More...
 
int rowBytesAsPixels () const
 Returns number of pixels that fit on row. More...
 
int shiftPerPixel () const
 Returns bit shift converting row bytes to row pixels. More...
 
bool empty () const
 Returns true if either width() or height() are zero. More...
 
bool isNull () const
 Returns true if SkPixelRef is nullptr. More...
 
bool drawsNothing () const
 Returns true if width() or height() are zero, or if SkPixelRef is nullptr. More...
 
size_t rowBytes () const
 Returns row bytes, the interval from one pixel row to the next. More...
 
bool setAlphaType (SkAlphaType alphaType)
 Sets SkAlphaType, if alphaType is compatible with SkColorType. More...
 
void * getPixels () const
 Returns pixel address, the base address corresponding to the pixel origin. More...
 
size_t computeByteSize () const
 Returns minimum memory required for pixel storage. More...
 
bool isImmutable () const
 Returns true if pixels can not change. More...
 
void setImmutable ()
 Sets internal flag to mark SkBitmap as immutable. More...
 
bool isOpaque () const
 Returns true if SkAlphaType is set to hint that all pixels are opaque; their alpha value is implicitly or explicitly 1.0. More...
 
void reset ()
 Resets to its initial state; all fields are set to zero, as if SkBitmap had been initialized by SkBitmap(). More...
 
void getBounds (SkRect *bounds) const
 Returns SkRect { 0, 0, width(), height() }. More...
 
void getBounds (SkIRect *bounds) const
 Returns SkIRect { 0, 0, width(), height() }. More...
 
SkIRect bounds () const
 Returns SkIRect { 0, 0, width(), height() }. More...
 
SkISize dimensions () const
 Returns SkISize { width(), height() }. More...
 
SkIRect getSubset () const
 Returns the bounds of this bitmap, offset by its SkPixelRef origin. More...
 
bool setInfo (const SkImageInfo &imageInfo, size_t rowBytes=0)
 Sets width, height, SkAlphaType, SkColorType, SkColorSpace, and optional rowBytes. More...
 
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. More...
 
void allocPixelsFlags (const SkImageInfo &info, uint32_t flags)
 Sets SkImageInfo to info following the rules in setInfo() and allocates pixel memory. More...
 
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. More...
 
void allocPixels (const SkImageInfo &info, size_t rowBytes)
 Sets SkImageInfo to info following the rules in setInfo() and allocates pixel memory. More...
 
bool SK_WARN_UNUSED_RESULT tryAllocPixels (const SkImageInfo &info)
 Sets SkImageInfo to info following the rules in setInfo() and allocates pixel memory. More...
 
void allocPixels (const SkImageInfo &info)
 Sets SkImageInfo to info following the rules in setInfo() and allocates pixel memory. More...
 
bool SK_WARN_UNUSED_RESULT tryAllocN32Pixels (int width, int height, bool isOpaque=false)
 Sets SkImageInfo to width, height, and native color type; and allocates pixel memory. More...
 
void allocN32Pixels (int width, int height, bool isOpaque=false)
 Sets SkImageInfo to width, height, and the native color type; and allocates pixel memory. More...
 
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. More...
 
bool installPixels (const SkImageInfo &info, void *pixels, size_t rowBytes)
 Sets SkImageInfo to info following the rules in setInfo(), and creates SkPixelRef containing pixels and rowBytes. More...
 
bool installPixels (const SkPixmap &pixmap)
 Sets SkImageInfo to pixmap.info() following the rules in setInfo(), and creates SkPixelRef containing pixmap.addr() and pixmap.rowBytes(). More...
 
bool installMaskPixels (const SkMask &mask)
 Deprecated. More...
 
void setPixels (void *pixels)
 Replaces SkPixelRef with pixels, preserving SkImageInfo and rowBytes(). More...
 
bool SK_WARN_UNUSED_RESULT tryAllocPixels ()
 Allocates pixel memory with HeapAllocator, and replaces existing SkPixelRef. More...
 
void allocPixels ()
 Allocates pixel memory with HeapAllocator, and replaces existing SkPixelRef. More...
 
bool SK_WARN_UNUSED_RESULT tryAllocPixels (Allocator *allocator)
 Allocates pixel memory with allocator, and replaces existing SkPixelRef. More...
 
void allocPixels (Allocator *allocator)
 Allocates pixel memory with allocator, and replaces existing SkPixelRef. More...
 
SkPixelRefpixelRef () const
 Returns SkPixelRef, which contains: pixel base address; its dimensions; and rowBytes(), the interval from one row to the next. More...
 
SkIPoint pixelRefOrigin () const
 Returns origin of pixels within SkPixelRef. More...
 
void setPixelRef (sk_sp< SkPixelRef > pixelRef, int dx, int dy)
 Replaces pixelRef and origin in SkBitmap. More...
 
bool readyToDraw () const
 Returns true if SkBitmap is can be drawn. More...
 
uint32_t getGenerationID () const
 Returns a unique value corresponding to the pixels in SkPixelRef. More...
 
void notifyPixelsChanged () const
 Marks that pixels in SkPixelRef have changed. More...
 
void eraseColor (SkColor c) const
 Replaces pixel values with c, interpreted as being in the sRGB SkColorSpace. More...
 
void eraseARGB (U8CPU a, U8CPU r, U8CPU g, U8CPU b) const
 Replaces pixel values with unpremultiplied color built from a, r, g, and b, interpreted as being in the sRGB SkColorSpace. More...
 
void erase (SkColor c, const SkIRect &area) const
 Replaces pixel values inside area with c. More...
 
void eraseArea (const SkIRect &area, SkColor c) const
 Deprecated. More...
 
SkColor getColor (int x, int y) const
 Returns pixel at (x, y) as unpremultiplied color. More...
 
float getAlphaf (int x, int y) const
 Look up the pixel at (x,y) and return its alpha component, normalized to [0..1]. More...
 
void * getAddr (int x, int y) const
 Returns pixel address at (x, y). More...
 
uint32_t * getAddr32 (int x, int y) const
 Returns address at (x, y). More...
 
uint16_t * getAddr16 (int x, int y) const
 Returns address at (x, y). More...
 
uint8_t * getAddr8 (int x, int y) const
 Returns address at (x, y). More...
 
bool extractSubset (SkBitmap *dst, const SkIRect &subset) const
 Shares SkPixelRef with dst. More...
 
bool readPixels (const SkImageInfo &dstInfo, void *dstPixels, size_t dstRowBytes, int srcX, int srcY) const
 Copies a SkRect of pixels from SkBitmap to dstPixels. More...
 
bool readPixels (const SkPixmap &dst, int srcX, int srcY) const
 Copies a SkRect of pixels from SkBitmap to dst. More...
 
bool readPixels (const SkPixmap &dst) const
 Copies a SkRect of pixels from SkBitmap to dst. More...
 
bool writePixels (const SkPixmap &src, int dstX, int dstY)
 Copies a SkRect of pixels from src. More...
 
bool writePixels (const SkPixmap &src)
 Copies a SkRect of pixels from src. More...
 
bool extractAlpha (SkBitmap *dst) const
 Sets dst to alpha described by pixels. More...
 
bool extractAlpha (SkBitmap *dst, const SkPaint *paint, SkIPoint *offset) const
 Sets dst to alpha described by pixels. More...
 
bool extractAlpha (SkBitmap *dst, const SkPaint *paint, Allocator *allocator, SkIPoint *offset) const
 Sets dst to alpha described by pixels. More...
 
bool peekPixels (SkPixmap *pixmap) const
 Copies SkBitmap pixel address, row bytes, and SkImageInfo to pixmap, if address is available, and returns true. More...
 
sk_sp< SkShadermakeShader (SkTileMode tmx, SkTileMode tmy, const SkMatrix *localMatrix=nullptr) const
 
sk_sp< SkShadermakeShader (const SkMatrix *localMatrix=nullptr) const
 

Static Public Member Functions

static bool ComputeIsOpaque (const SkBitmap &bm)
 Returns true if all pixels are opaque. More...
 

Public Attributes

class SK_API Allocator
 

Friends

class SkImage_Raster
 
class SkReadBuffer
 

Detailed Description

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.

Member Enumeration Documentation

◆ AllocFlags

Enumerator
kZeroPixels_AllocFlag 

zero pixel memory. No effect. This is the default.

Constructor & Destructor Documentation

◆ SkBitmap() [1/3]

SkBitmap::SkBitmap ( )

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).

Use setInfo() to associate SkColorType, SkAlphaType, width, and height after SkBitmap has been created.

Returns
empty SkBitmap

example: https://fiddle.skia.org/c/@Bitmap_empty_constructor

◆ SkBitmap() [2/3]

SkBitmap::SkBitmap ( const SkBitmap src)

Copies settings from src to returned SkBitmap.

Shares pixels if src has pixels allocated, so both bitmaps reference the same pixels.

Parameters
srcSkBitmap to copy SkImageInfo, and share SkPixelRef
Returns
copy of src

example: https://fiddle.skia.org/c/@Bitmap_copy_const_SkBitmap

◆ SkBitmap() [3/3]

SkBitmap::SkBitmap ( SkBitmap &&  src)

Copies settings from src to returned SkBitmap.

Moves ownership of src pixels to SkBitmap.

Parameters
srcSkBitmap to copy SkImageInfo, and reassign SkPixelRef
Returns
copy of src

example: https://fiddle.skia.org/c/@Bitmap_move_SkBitmap

◆ ~SkBitmap()

SkBitmap::~SkBitmap ( )

Decrements SkPixelRef reference count, if SkPixelRef is not nullptr.

Member Function Documentation

◆ allocN32Pixels()

void SkBitmap::allocN32Pixels ( 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.

Parameters
widthpixel column count; must be zero or greater
heightpixel row count; must be zero or greater
isOpaquetrue if pixels do not have transparency

example: https://fiddle.skia.org/c/@Bitmap_allocN32Pixels

◆ allocPixels() [1/4]

void SkBitmap::allocPixels ( 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().

Parameters
infocontains width, height, SkAlphaType, SkColorType, SkColorSpace
rowBytessize of pixel row or larger; may be zero

example: https://fiddle.skia.org/c/@Bitmap_allocPixels

◆ allocPixels() [2/4]

void SkBitmap::allocPixels ( const SkImageInfo info)

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().

Parameters
infocontains width, height, SkAlphaType, SkColorType, SkColorSpace

example: https://fiddle.skia.org/c/@Bitmap_allocPixels_2

◆ allocPixels() [3/4]

void SkBitmap::allocPixels ( )

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

◆ allocPixels() [4/4]

void SkBitmap::allocPixels ( 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.

Parameters
allocatorinstance of SkBitmap::Allocator instantiation

example: https://fiddle.skia.org/c/@Bitmap_allocPixels_4

◆ allocPixelsFlags()

void SkBitmap::allocPixelsFlags ( 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().

Parameters
infocontains width, height, SkAlphaType, SkColorType, SkColorSpace
flagskZeroPixels_AllocFlag, or zero

example: https://fiddle.skia.org/c/@Bitmap_allocPixelsFlags

◆ alphaType()

SkAlphaType SkBitmap::alphaType ( ) const
inline

◆ bounds()

SkIRect SkBitmap::bounds ( ) const
inline

Returns SkIRect { 0, 0, width(), height() }.

Returns
integral rectangle from origin to width() and height()

◆ bytesPerPixel()

int SkBitmap::bytesPerPixel ( ) const
inline

Returns number of bytes per pixel required by SkColorType.

Returns zero if colorType( is kUnknown_SkColorType.

Returns
bytes in pixel

◆ colorSpace()

SkColorSpace* SkBitmap::colorSpace ( ) const
inline

Returns SkColorSpace, the range of colors, associated with SkImageInfo.

The reference count of SkColorSpace is unchanged. The returned SkColorSpace is immutable.

Returns
SkColorSpace in SkImageInfo, or nullptr

◆ colorType()

SkColorType SkBitmap::colorType ( ) const
inline

◆ computeByteSize()

size_t SkBitmap::computeByteSize ( ) const
inline

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.

Returns
size in bytes of image buffer

◆ ComputeIsOpaque()

static bool SkBitmap::ComputeIsOpaque ( const SkBitmap bm)
inlinestatic

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.

Parameters
bmSkBitmap to check
Returns
true if all pixels have opaque values or SkColorType is opaque

◆ dimensions()

SkISize SkBitmap::dimensions ( ) const
inline

Returns SkISize { width(), height() }.

Returns
integral size of width() and height()

◆ drawsNothing()

bool SkBitmap::drawsNothing ( ) const
inline

Returns true if width() or height() are zero, or if SkPixelRef is nullptr.

If true, SkBitmap has no effect when drawn or drawn into.

Returns
true if drawing has no effect

◆ empty()

bool SkBitmap::empty ( ) const
inline

Returns true if either width() or height() are zero.

Does not check if SkPixelRef is nullptr; call drawsNothing() to check width(), height(), and SkPixelRef.

Returns
true if dimensions do not enclose area

◆ erase()

void SkBitmap::erase ( SkColor  c,
const SkIRect area 
) const

Replaces pixel values inside area with c.

interpreted as being in the sRGB SkColorSpace. 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.

Parameters
cunpremultiplied color
arearectangle to fill

example: https://fiddle.skia.org/c/@Bitmap_erase

◆ eraseArea()

void SkBitmap::eraseArea ( const SkIRect area,
SkColor  c 
) const
inline

Deprecated.

◆ eraseARGB()

void SkBitmap::eraseARGB ( U8CPU  a,
U8CPU  r,
U8CPU  g,
U8CPU  b 
) const
inline

Replaces pixel values with unpremultiplied color built from a, r, g, and b, interpreted as being in the sRGB SkColorSpace.

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.

Parameters
aamount of alpha, from fully transparent (0) to fully opaque (255)
ramount of red, from no red (0) to full red (255)
gamount of green, from no green (0) to full green (255)
bamount of blue, from no blue (0) to full blue (255)

◆ eraseColor()

void SkBitmap::eraseColor ( SkColor  c) const

Replaces pixel values with c, interpreted as being in the sRGB SkColorSpace.

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.

Parameters
cunpremultiplied color

example: https://fiddle.skia.org/c/@Bitmap_eraseColor

◆ extractAlpha() [1/3]

bool SkBitmap::extractAlpha ( SkBitmap dst) const
inline

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.

Parameters
dstholds SkPixelRef to fill with alpha layer
Returns
true if alpha layer was constructed in dst SkPixelRef

◆ extractAlpha() [2/3]

bool SkBitmap::extractAlpha ( SkBitmap dst,
const SkPaint paint,
SkIPoint offset 
) const
inline

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.

Parameters
dstholds SkPixelRef to fill with alpha layer
paintholds optional SkMaskFilter; may be nullptr
offsettop-left position for dst; may be nullptr
Returns
true if alpha layer was constructed in dst SkPixelRef

◆ extractAlpha() [3/3]

bool SkBitmap::extractAlpha ( SkBitmap dst,
const SkPaint paint,
Allocator allocator,
SkIPoint offset 
) const

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.

Parameters
dstholds SkPixelRef to fill with alpha layer
paintholds optional SkMaskFilter; may be nullptr
allocatorfunction to reserve memory for SkPixelRef; may be nullptr
offsettop-left position for dst; may be nullptr
Returns
true if alpha layer was constructed in dst SkPixelRef

◆ extractSubset()

bool SkBitmap::extractSubset ( SkBitmap dst,
const SkIRect subset 
) 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.

Return false if:

Parameters
dstSkBitmap set to subset
subsetrectangle of pixels to reference
Returns
true if dst is replaced by subset

example: https://fiddle.skia.org/c/@Bitmap_extractSubset

◆ getAddr()

void* SkBitmap::getAddr ( int  x,
int  y 
) const

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().

Parameters
xcolumn index, zero or greater, and less than width()
yrow index, zero or greater, and less than height()
Returns
generic pointer to pixel

example: https://fiddle.skia.org/c/@Bitmap_getAddr

◆ getAddr16()

uint16_t * SkBitmap::getAddr16 ( int  x,
int  y 
) const
inline

Returns address at (x, y).

Input is not validated. Triggers an assert() if built with SK_DEBUG defined and:

Parameters
xcolumn index, zero or greater, and less than width()
yrow index, zero or greater, and less than height()
Returns
unsigned 16-bit pointer to pixel at (x, y)

◆ getAddr32()

uint32_t * SkBitmap::getAddr32 ( int  x,
int  y 
) const
inline

Returns address at (x, y).

Input is not validated. Triggers an assert() if built with SK_DEBUG defined and:

Parameters
xcolumn index, zero or greater, and less than width()
yrow index, zero or greater, and less than height()
Returns
unsigned 32-bit pointer to pixel at (x, y)

◆ getAddr8()

uint8_t * SkBitmap::getAddr8 ( int  x,
int  y 
) const
inline

Returns address at (x, y).

Input is not validated. Triggers an assert() if built with SK_DEBUG defined and:

Parameters
xcolumn index, zero or greater, and less than width()
yrow index, zero or greater, and less than height()
Returns
unsigned 8-bit pointer to pixel at (x, y)

◆ getAlphaf()

float SkBitmap::getAlphaf ( int  x,
int  y 
) const
inline

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).

Parameters
xcolumn index, zero or greater, and less than width()
yrow index, zero or greater, and less than height()
Returns
alpha converted to normalized float

◆ getBounds() [1/2]

void SkBitmap::getBounds ( SkRect bounds) const

Returns SkRect { 0, 0, width(), height() }.

Parameters
boundscontainer for floating point rectangle

example: https://fiddle.skia.org/c/@Bitmap_getBounds

◆ getBounds() [2/2]

void SkBitmap::getBounds ( SkIRect bounds) const

Returns SkIRect { 0, 0, width(), height() }.

Parameters
boundscontainer for integral rectangle

example: https://fiddle.skia.org/c/@Bitmap_getBounds_2

◆ getColor()

SkColor SkBitmap::getColor ( int  x,
int  y 
) const
inline

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.

Parameters
xcolumn index, zero or greater, and less than width()
yrow index, zero or greater, and less than height()
Returns
pixel converted to unpremultiplied color

◆ getGenerationID()

uint32_t SkBitmap::getGenerationID ( ) const

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.

Returns
unique value for pixels in SkPixelRef

example: https://fiddle.skia.org/c/@Bitmap_getGenerationID

◆ getPixels()

void* SkBitmap::getPixels ( ) const
inline

Returns pixel address, the base address corresponding to the pixel origin.

Returns
pixel address

◆ getSubset()

SkIRect SkBitmap::getSubset ( ) const
inline

Returns the bounds of this bitmap, offset by its SkPixelRef origin.

Returns
bounds within SkPixelRef bounds

◆ height()

int SkBitmap::height ( ) const
inline

Returns pixel row count.

Maybe be less than pixelRef().height(). Will not exceed pixelRef().height() less pixelRefOrigin().fY.

Returns
pixel height in SkImageInfo

◆ info()

const SkImageInfo& SkBitmap::info ( ) const
inline

Returns width, height, SkAlphaType, SkColorType, and SkColorSpace.

Returns
reference to SkImageInfo

◆ installMaskPixels()

bool SkBitmap::installMaskPixels ( const SkMask &  mask)

Deprecated.

◆ installPixels() [1/3]

bool SkBitmap::installPixels ( const SkImageInfo info,
void *  pixels,
size_t  rowBytes,
void(*)(void *addr, void *context)  releaseProc,
void *  context 
)

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.

Parameters
infocontains width, height, SkAlphaType, SkColorType, SkColorSpace
pixelsaddress or pixel storage; may be nullptr
rowBytessize of pixel row or larger
releaseProcfunction called when pixels can be deleted; may be nullptr
contextcaller state passed to releaseProc; may be nullptr
Returns
true if SkImageInfo is set to info

◆ installPixels() [2/3]

bool SkBitmap::installPixels ( const SkImageInfo info,
void *  pixels,
size_t  rowBytes 
)
inline

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.

Parameters
infocontains width, height, SkAlphaType, SkColorType, SkColorSpace
pixelsaddress or pixel storage; may be nullptr
rowBytessize of pixel row or larger
Returns
true if SkImageInfo is set to info

◆ installPixels() [3/3]

bool SkBitmap::installPixels ( const SkPixmap pixmap)

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.

Parameters
pixmapSkImageInfo, pixel address, and rowBytes()
Returns
true if SkImageInfo was set to pixmap.info()

example: https://fiddle.skia.org/c/@Bitmap_installPixels_3

◆ isImmutable()

bool SkBitmap::isImmutable ( ) const

Returns true if pixels can not change.

Most immutable SkBitmap checks trigger an assert only on debug builds.

Returns
true if pixels are immutable

example: https://fiddle.skia.org/c/@Bitmap_isImmutable

◆ isNull()

bool SkBitmap::isNull ( ) const
inline

Returns true if SkPixelRef is nullptr.

Does not check if width() or height() are zero; call drawsNothing() to check width(), height(), and SkPixelRef.

Returns
true if no SkPixelRef is associated

◆ isOpaque()

bool SkBitmap::isOpaque ( ) const
inline

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.

Returns
true if SkImageInfo SkAlphaType is kOpaque_SkAlphaType

◆ makeShader() [1/2]

sk_sp<SkShader> SkBitmap::makeShader ( SkTileMode  tmx,
SkTileMode  tmy,
const SkMatrix localMatrix = nullptr 
) const

◆ makeShader() [2/2]

sk_sp<SkShader> SkBitmap::makeShader ( const SkMatrix localMatrix = nullptr) const

◆ notifyPixelsChanged()

void SkBitmap::notifyPixelsChanged ( ) const

Marks that pixels in SkPixelRef have changed.

Subsequent calls to getGenerationID() return a different value.

example: https://fiddle.skia.org/c/@Bitmap_notifyPixelsChanged

◆ operator=() [1/2]

SkBitmap& SkBitmap::operator= ( const SkBitmap src)

Copies settings from src to returned SkBitmap.

Shares pixels if src has pixels allocated, so both bitmaps reference the same pixels.

Parameters
srcSkBitmap to copy SkImageInfo, and share SkPixelRef
Returns
copy of src

example: https://fiddle.skia.org/c/@Bitmap_copy_operator

◆ operator=() [2/2]

SkBitmap& SkBitmap::operator= ( SkBitmap &&  src)

Copies settings from src to returned SkBitmap.

Moves ownership of src pixels to SkBitmap.

Parameters
srcSkBitmap to copy SkImageInfo, and reassign SkPixelRef
Returns
copy of src

example: https://fiddle.skia.org/c/@Bitmap_move_operator

◆ peekPixels()

bool SkBitmap::peekPixels ( SkPixmap pixmap) 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.

Parameters
pixmapstorage for pixel state if pixels are readable; otherwise, ignored
Returns
true if SkBitmap has direct access to pixels

example: https://fiddle.skia.org/c/@Bitmap_peekPixels

◆ pixelRef()

SkPixelRef* SkBitmap::pixelRef ( ) const
inline

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.

Returns
SkPixelRef, or nullptr

◆ pixelRefOrigin()

SkIPoint SkBitmap::pixelRefOrigin ( ) const

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.

Returns
pixel origin within SkPixelRef

example: https://fiddle.skia.org/c/@Bitmap_pixelRefOrigin

◆ pixmap()

const SkPixmap& SkBitmap::pixmap ( ) const
inline

Returns a constant reference to the SkPixmap holding the SkBitmap pixel address, row bytes, and SkImageInfo.

Returns
reference to SkPixmap describing this SkBitmap

◆ readPixels() [1/3]

bool SkBitmap::readPixels ( const SkImageInfo dstInfo,
void *  dstPixels,
size_t  dstRowBytes,
int  srcX,
int  srcY 
) 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().

Parameters
dstInfodestination width, height, SkColorType, SkAlphaType, SkColorSpace
dstPixelsdestination pixel storage
dstRowBytesdestination row length
srcXcolumn index whose absolute value is less than width()
srcYrow index whose absolute value is less than height()
Returns
true if pixels are copied to dstPixels

◆ readPixels() [2/3]

bool SkBitmap::readPixels ( const SkPixmap dst,
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:

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().

Parameters
dstdestination SkPixmap: SkImageInfo, pixels, row bytes
srcXcolumn index whose absolute value is less than width()
srcYrow index whose absolute value is less than height()
Returns
true if pixels are copied to dst

example: https://fiddle.skia.org/c/@Bitmap_readPixels_2

◆ readPixels() [3/3]

bool SkBitmap::readPixels ( const SkPixmap dst) const
inline

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:

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.

Parameters
dstdestination SkPixmap: SkImageInfo, pixels, row bytes
Returns
true if pixels are copied to dst

◆ readyToDraw()

bool SkBitmap::readyToDraw ( ) const
inline

Returns true if SkBitmap is can be drawn.

Returns
true if getPixels() is not nullptr

◆ refColorSpace()

sk_sp<SkColorSpace> SkBitmap::refColorSpace ( ) const
inline

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.

Returns
SkColorSpace in SkImageInfo wrapped in a smart pointer

◆ reset()

void SkBitmap::reset ( )

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

◆ rowBytes()

size_t SkBitmap::rowBytes ( ) const
inline

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.

Returns
byte length of pixel row

◆ rowBytesAsPixels()

int SkBitmap::rowBytesAsPixels ( ) const
inline

Returns number of pixels that fit on row.

Should be greater than or equal to width().

Returns
maximum pixels per row

◆ setAlphaType()

bool SkBitmap::setAlphaType ( SkAlphaType  alphaType)

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.

Returns
true if SkAlphaType is set

example: https://fiddle.skia.org/c/@Bitmap_setAlphaType

◆ setImmutable()

void SkBitmap::setImmutable ( )

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

◆ setInfo()

bool SkBitmap::setInfo ( const SkImageInfo imageInfo,
size_t  rowBytes = 0 
)

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()
Parameters
imageInfocontains width, height, SkAlphaType, SkColorType, SkColorSpace
rowBytesimageInfo.minRowBytes() or larger; or zero
Returns
true if SkImageInfo set successfully

example: https://fiddle.skia.org/c/@Bitmap_setInfo

◆ setPixelRef()

void SkBitmap::setPixelRef ( sk_sp< SkPixelRef pixelRef,
int  dx,
int  dy 
)

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.

Parameters
pixelRefSkPixelRef describing pixel address and rowBytes()
dxcolumn offset in SkPixelRef for bitmap origin
dyrow offset in SkPixelRef for bitmap origin

example: https://fiddle.skia.org/c/@Bitmap_setPixelRef

◆ setPixels()

void SkBitmap::setPixels ( void *  pixels)

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.

Parameters
pixelsaddress of pixel storage, managed by caller

example: https://fiddle.skia.org/c/@Bitmap_setPixels

◆ shiftPerPixel()

int SkBitmap::shiftPerPixel ( ) const
inline

Returns bit shift converting row bytes to row pixels.

Returns zero for kUnknown_SkColorType.

Returns
one of: 0, 1, 2, 3; left shift to convert pixels to bytes

◆ swap()

void SkBitmap::swap ( SkBitmap other)

Swaps the fields of the two bitmaps.

Parameters
otherSkBitmap exchanged with original

example: https://fiddle.skia.org/c/@Bitmap_swap

◆ tryAllocN32Pixels()

bool SK_WARN_UNUSED_RESULT SkBitmap::tryAllocN32Pixels ( int  width,
int  height,
bool  isOpaque = false 
)

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.

Parameters
widthpixel column count; must be zero or greater
heightpixel row count; must be zero or greater
isOpaquetrue if pixels do not have transparency
Returns
true if pixel storage is allocated

◆ tryAllocPixels() [1/4]

bool SK_WARN_UNUSED_RESULT SkBitmap::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.

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().

Parameters
infocontains width, height, SkAlphaType, SkColorType, SkColorSpace
rowBytessize of pixel row or larger; may be zero
Returns
true if pixel storage is allocated

◆ tryAllocPixels() [2/4]

bool SK_WARN_UNUSED_RESULT SkBitmap::tryAllocPixels ( const SkImageInfo info)
inline

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().

Parameters
infocontains width, height, SkAlphaType, SkColorType, SkColorSpace
Returns
true if pixel storage is allocated

◆ tryAllocPixels() [3/4]

bool SK_WARN_UNUSED_RESULT SkBitmap::tryAllocPixels ( )
inline

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.

Returns
true if the allocation succeeds

◆ tryAllocPixels() [4/4]

bool SK_WARN_UNUSED_RESULT SkBitmap::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.

Returns false if Allocator::allocPixelRef return false.

Parameters
allocatorinstance of SkBitmap::Allocator instantiation
Returns
true if custom allocator reports success

◆ tryAllocPixelsFlags()

bool SK_WARN_UNUSED_RESULT SkBitmap::tryAllocPixelsFlags ( const SkImageInfo info,
uint32_t  flags 
)

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().

Parameters
infocontains width, height, SkAlphaType, SkColorType, SkColorSpace
flagskZeroPixels_AllocFlag, or zero
Returns
true if pixels allocation is successful

◆ width()

int SkBitmap::width ( ) const
inline

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.

Returns
pixel width in SkImageInfo

◆ writePixels() [1/2]

bool SkBitmap::writePixels ( const SkPixmap src,
int  dstX,
int  dstY 
)

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:

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().

Parameters
srcsource SkPixmap: SkImageInfo, pixels, row bytes
dstXcolumn index whose absolute value is less than width()
dstYrow index whose absolute value is less than height()
Returns
true if src pixels are copied to SkBitmap

example: https://fiddle.skia.org/c/@Bitmap_writePixels

◆ writePixels() [2/2]

bool SkBitmap::writePixels ( const SkPixmap src)
inline

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:

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.

Parameters
srcsource SkPixmap: SkImageInfo, pixels, row bytes
Returns
true if src pixels are copied to SkBitmap

Friends And Related Function Documentation

◆ SkImage_Raster

friend class SkImage_Raster
friend

◆ SkReadBuffer

friend class SkReadBuffer
friend

Member Data Documentation

◆ Allocator


The documentation for this class was generated from the following file: