/** Returns the number of bytes required to store a pixel, including unused padding. Returns zero if ct is kUnknown_SkColorType or invalid.
@return bytes per pixel
*/
SK_API int SkColorTypeBytesPerPixel(SkColorType ct);
/** Returns true if SkColorType always decodes alpha to 1.0, making the pixel fully opaque. If true, SkColorType does not reserve bits to encode alpha.
@return true if alpha is always set to 1.0
*/
SK_API bool SkColorTypeIsAlwaysOpaque(SkColorType ct);
/** Returns true if canonical can be set to a valid SkAlphaType for colorType. If there is more than one valid canonical SkAlphaType, set to alphaType, if valid. If true is returned and canonical is not nullptr, store valid SkAlphaType.
Returns false only if alphaType is kUnknown_SkAlphaType, color type is not kUnknown_SkColorType, and SkColorType is not always opaque. If false is returned, canonical is ignored.
@param canonical storage for SkAlphaType @return true if valid SkAlphaType can be associated with colorType
*/
SK_API bool SkColorTypeValidateAlphaType(SkColorType colorType, SkAlphaType alphaType,
SkAlphaType* canonical = nullptr);
/** \enum SkImageInfo::SkYUVColorSpace Describes color range of YUV pixels. The color mapping from YUV to RGB varies depending on the source. YUV pixels may be generated by JPEG images, standard video streams, or high definition video streams. Each has its own mapping from YUV to RGB.
JPEG YUV values encode the full range of 0 to 255 for all three components. Video YUV values often range from 16 to 235 for Y and from 16 to 240 for U and V (limited). Details of encoding and conversion to RGB are described in YCbCr color space.
The identity colorspace exists to provide a utility mapping from Y to R, U to G and V to B. It can be used to visualize the YUV planes or to explicitly post process the YUV channels.
*/ enum SkYUVColorSpace : int {
kJPEG_Full_SkYUVColorSpace, //!< describes full range
kRec601_Limited_SkYUVColorSpace, //!< describes SDTV range
kRec709_Full_SkYUVColorSpace, //!< describes HDTV range
kRec709_Limited_SkYUVColorSpace,
kBT2020_8bit_Full_SkYUVColorSpace, //!< describes UHDTV range, non-constant-luminance
kBT2020_8bit_Limited_SkYUVColorSpace,
kBT2020_10bit_Full_SkYUVColorSpace,
kBT2020_10bit_Limited_SkYUVColorSpace,
kBT2020_12bit_Full_SkYUVColorSpace,
kBT2020_12bit_Limited_SkYUVColorSpace,
kBT2020_16bit_Full_SkYUVColorSpace,
kBT2020_16bit_Limited_SkYUVColorSpace,
kFCC_Full_SkYUVColorSpace, //!< describes FCC range
kFCC_Limited_SkYUVColorSpace,
kSMPTE240_Full_SkYUVColorSpace, //!< describes SMPTE240M range
kSMPTE240_Limited_SkYUVColorSpace,
kYDZDX_Full_SkYUVColorSpace, //!< describes YDZDX range
kYDZDX_Limited_SkYUVColorSpace,
kGBR_Full_SkYUVColorSpace, //!< describes GBR range
kGBR_Limited_SkYUVColorSpace,
kYCgCo_8bit_Full_SkYUVColorSpace, //!< describes YCgCo matrix
kYCgCo_8bit_Limited_SkYUVColorSpace,
kYCgCo_10bit_Full_SkYUVColorSpace,
kYCgCo_10bit_Limited_SkYUVColorSpace,
kYCgCo_12bit_Full_SkYUVColorSpace,
kYCgCo_12bit_Limited_SkYUVColorSpace,
kYCgCo_16bit_Full_SkYUVColorSpace,
kYCgCo_16bit_Limited_SkYUVColorSpace,
kIdentity_SkYUVColorSpace, //!< maps Y->R, U->G, V->B
kLastEnum_SkYUVColorSpace = kIdentity_SkYUVColorSpace, //!< last valid value
/** \struct SkColorInfo Describes pixel and encoding. SkImageInfo can be created from SkColorInfo by providing dimensions.
It encodes how pixel bits describe alpha, transparency; color components red, blue, and green; and SkColorSpace, the range and linearity of colors.
*/ class SK_API SkColorInfo { public: /** Creates an SkColorInfo with kUnknown_SkColorType, kUnknown_SkAlphaType, and no SkColorSpace.
/** Creates SkColorInfo from SkColorType ct, SkAlphaType at, and optionally SkColorSpace cs.
If SkColorSpace cs is nullptr and SkColorInfo is part of drawing source: SkColorSpace defaults to sRGB, mapping into SkSurface SkColorSpace.
Parameters are not validated to see if their values are legal, or that the combination is supported. @return created SkColorInfo
*/
SkColorInfo(SkColorType ct, SkAlphaType at, sk_sp<SkColorSpace> cs);
/** Does other represent the same color type, alpha type, and color space? */ booloperator==(const SkColorInfo& other) const;
/** Does other represent a different color type, alpha type, or color space? */ booloperator!=(const SkColorInfo& other) const;
/** Creates SkColorInfo with same SkColorType, SkColorSpace, with SkAlphaType set to newAlphaType.
Created SkColorInfo contains newAlphaType even if it is incompatible with SkColorType, in which case SkAlphaType in SkColorInfo is ignored.
*/
SkColorInfo makeAlphaType(SkAlphaType newAlphaType) const;
/** Creates new SkColorInfo with same SkAlphaType, SkColorSpace, with SkColorType set to newColorType.
*/
SkColorInfo makeColorType(SkColorType newColorType) const;
/** Creates SkColorInfo with same SkAlphaType, SkColorType, with SkColorSpace set to cs. cs may be nullptr.
*/
SkColorInfo makeColorSpace(sk_sp<SkColorSpace> cs) const;
/** Returns number of bytes per pixel required by SkColorType. Returns zero if colorType() is kUnknown_SkColorType.
/** \struct SkImageInfo Describes pixel dimensions and encoding. SkBitmap, SkImage, PixMap, and SkSurface can be created from SkImageInfo. SkImageInfo can be retrieved from SkBitmap and SkPixmap, but not from SkImage and SkSurface. For example, SkImage and SkSurface implementations may defer pixel depth, so may not completely specify SkImageInfo.
SkImageInfo contains dimensions, the pixel integral width and height. It encodes how pixel bits describe alpha, transparency; color components red, blue, and green; and SkColorSpace, the range and linearity of colors.
*/ struct SK_API SkImageInfo { public:
/** Creates an empty SkImageInfo with kUnknown_SkColorType, kUnknown_SkAlphaType, a width and height of zero, and no SkColorSpace.
/** Creates SkImageInfo from integral dimensions width and height, SkColorType ct, SkAlphaType at, and optionally SkColorSpace cs.
If SkColorSpace cs is nullptr and SkImageInfo is part of drawing source: SkColorSpace defaults to sRGB, mapping into SkSurface SkColorSpace.
Parameters are not validated to see if their values are legal, or that the combination is supported.
@param width pixel column count; must be zero or greater @param height pixel row count; must be zero or greater @param cs range of colors; may be nullptr @return created SkImageInfo
*/ static SkImageInfo Make(int width, int height, SkColorType ct, SkAlphaType at); static SkImageInfo Make(int width, int height, SkColorType ct, SkAlphaType at,
sk_sp<SkColorSpace> cs); static SkImageInfo Make(SkISize dimensions, SkColorType ct, SkAlphaType at); static SkImageInfo Make(SkISize dimensions, SkColorType ct, SkAlphaType at,
sk_sp<SkColorSpace> cs);
/** Creates SkImageInfo from integral dimensions and SkColorInfo colorInfo,
Parameters are not validated to see if their values are legal, or that the combination is supported.
@param dimensions pixel column and row count; must be zeros or greater @param SkColorInfo the pixel encoding consisting of SkColorType, SkAlphaType, and SkColorSpace (which may be nullptr) @return created SkImageInfo
*/ static SkImageInfo Make(SkISize dimensions, const SkColorInfo& colorInfo) { return SkImageInfo(dimensions, colorInfo);
} static SkImageInfo Make(SkISize dimensions, SkColorInfo&& colorInfo) { return SkImageInfo(dimensions, std::move(colorInfo));
}
/** Creates SkImageInfo from integral dimensions width and height, kN32_SkColorType, SkAlphaType at, and optionally SkColorSpace cs. kN32_SkColorType will equal either kBGRA_8888_SkColorType or kRGBA_8888_SkColorType, whichever is optimal.
If SkColorSpace cs is nullptr and SkImageInfo is part of drawing source: SkColorSpace defaults to sRGB, mapping into SkSurface SkColorSpace.
Parameters are not validated to see if their values are legal, or that the combination is supported.
@param width pixel column count; must be zero or greater @param height pixel row count; must be zero or greater @param cs range of colors; may be nullptr @return created SkImageInfo
*/ static SkImageInfo MakeN32(int width, int height, SkAlphaType at); static SkImageInfo MakeN32(int width, int height, SkAlphaType at, sk_sp<SkColorSpace> cs);
/** Creates SkImageInfo from integral dimensions width and height, kN32_SkColorType, SkAlphaType at, with sRGB SkColorSpace.
Parameters are not validated to see if their values are legal, or that the combination is supported.
@param width pixel column count; must be zero or greater @param height pixel row count; must be zero or greater @return created SkImageInfo
/** Creates SkImageInfo from integral dimensions width and height, kN32_SkColorType, kPremul_SkAlphaType, with optional SkColorSpace.
If SkColorSpace cs is nullptr and SkImageInfo is part of drawing source: SkColorSpace defaults to sRGB, mapping into SkSurface SkColorSpace.
Parameters are not validated to see if their values are legal, or that the combination is supported.
@param width pixel column count; must be zero or greater @param height pixel row count; must be zero or greater @param cs range of colors; may be nullptr @return created SkImageInfo
*/ static SkImageInfo MakeN32Premul(int width, int height); static SkImageInfo MakeN32Premul(int width, int height, sk_sp<SkColorSpace> cs);
/** Creates SkImageInfo from integral dimensions width and height, kN32_SkColorType, kPremul_SkAlphaType, with SkColorSpace set to nullptr.
If SkImageInfo is part of drawing source: SkColorSpace defaults to sRGB, mapping into SkSurface SkColorSpace.
Parameters are not validated to see if their values are legal, or that the combination is supported.
@param dimensions width and height, each must be zero or greater @param cs range of colors; may be nullptr @return created SkImageInfo
*/ static SkImageInfo MakeN32Premul(SkISize dimensions); static SkImageInfo MakeN32Premul(SkISize dimensions, sk_sp<SkColorSpace> cs);
/** Creates SkImageInfo from integral dimensions width and height, kAlpha_8_SkColorType, kPremul_SkAlphaType, with SkColorSpace set to nullptr.
@param width pixel column count; must be zero or greater @param height pixel row count; must be zero or greater @return created SkImageInfo
*/ static SkImageInfo MakeA8(int width, int height); /** Creates SkImageInfo from integral dimensions, kAlpha_8_SkColorType, kPremul_SkAlphaType, with SkColorSpace set to nullptr.
@param dimensions pixel row and column count; must be zero or greater @return created SkImageInfo
*/ static SkImageInfo MakeA8(SkISize dimensions);
/** Creates SkImageInfo from integral dimensions width and height, kUnknown_SkColorType, kUnknown_SkAlphaType, with SkColorSpace set to nullptr.
Returned SkImageInfo as part of source does not draw, and as part of destination can not be drawn to.
@param width pixel column count; must be zero or greater @param height pixel row count; must be zero or greater @return created SkImageInfo
*/ static SkImageInfo MakeUnknown(int width, int height);
/** Creates SkImageInfo from integral dimensions width and height set to zero, kUnknown_SkColorType, kUnknown_SkAlphaType, with SkColorSpace set to nullptr.
Returned SkImageInfo as part of source does not draw, and as part of destination can not be drawn to.
/** Returns SkColorSpace, the range of colors. The reference count of SkColorSpace is unchanged. The returned SkColorSpace is immutable.
@return SkColorSpace, or nullptr
*/
SkColorSpace* colorSpace() const;
/** Returns smart pointer to SkColorSpace, the range of colors. 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 wrapped in a smart pointer
*/
sk_sp<SkColorSpace> refColorSpace() const;
/** Returns if SkImageInfo describes an empty area of pixels by checking if either width or height is zero or smaller.
@return true if either dimension is zero or smaller
*/ bool isEmpty() const { return fDimensions.isEmpty(); }
/** Returns the dimensionless SkColorInfo that represents the same color type, alpha type, and color space as this SkImageInfo.
*/ const SkColorInfo& colorInfo() const { return fColorInfo; }
/** 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 SkAlphaType is kOpaque_SkAlphaType
*/ bool isOpaque() const { return fColorInfo.isOpaque(); }
/** Returns SkISize { width(), height() }.
@return integral size of width() and height()
*/
SkISize dimensions() const { return fDimensions; }
/** Returns SkIRect { 0, 0, width(), height() }.
@return integral rectangle from origin to width() and height()
*/
SkIRect bounds() const { return SkIRect::MakeSize(fDimensions); }
/** Returns true if associated SkColorSpace is not nullptr, and SkColorSpace gamma is approximately the same as sRGB. This includes the
@return true if SkColorSpace gamma is approximately the same as sRGB
*/ bool gammaCloseToSRGB() const { return fColorInfo.gammaCloseToSRGB(); }
/** Creates SkImageInfo with the same SkColorType, SkColorSpace, and SkAlphaType, with dimensions set to width and height.
@param newWidth pixel column count; must be zero or greater @param newHeight pixel row count; must be zero or greater @return created SkImageInfo
*/
SkImageInfo makeWH(int newWidth, int newHeight) const { return Make({newWidth, newHeight}, fColorInfo);
}
/** Creates SkImageInfo with the same SkColorType, SkColorSpace, and SkAlphaType, with dimensions set to newDimensions.
@param newSize pixel column and row count; must be zero or greater @return created SkImageInfo
*/
SkImageInfo makeDimensions(SkISize newSize) const { return Make(newSize, fColorInfo);
}
/** Creates SkImageInfo with same SkColorType, SkColorSpace, width, and height, with SkAlphaType set to newAlphaType.
Created SkImageInfo contains newAlphaType even if it is incompatible with SkColorType, in which case SkAlphaType in SkImageInfo is ignored.
/** Creates SkImageInfo with same SkAlphaType, SkColorType, width, and height, with SkColorSpace set to cs.
@param cs range of colors; may be nullptr @return created SkImageInfo
*/
SkImageInfo makeColorSpace(sk_sp<SkColorSpace> cs) const;
/** Returns number of bytes per pixel required by SkColorType. Returns zero if colorType( is kUnknown_SkColorType.
@return bytes in pixel
*/ int bytesPerPixel() const { return fColorInfo.bytesPerPixel(); }
/** 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 fColorInfo.shiftPerPixel(); }
/** Returns minimum bytes per row, computed from pixel width() and SkColorType, which specifies bytesPerPixel(). SkBitmap maximum value for row bytes must fit in 31 bits.
@return width() times bytesPerPixel() as unsigned 64-bit integer
*/
uint64_t minRowBytes64() const { return (uint64_t)sk_64_mul(this->width(), this->bytesPerPixel());
}
/** Returns minimum bytes per row, computed from pixel width() and SkColorType, which specifies bytesPerPixel(). SkBitmap maximum value for row bytes must fit in 31 bits.
@return width() times bytesPerPixel() as size_t
*/
size_t minRowBytes() const {
uint64_t minRowBytes = this->minRowBytes64(); if (!SkTFitsIn<int32_t>(minRowBytes)) { return 0;
} return (size_t)minRowBytes;
}
/** Returns byte offset of pixel from pixel base address.
Asserts in debug build if x or y is outside of bounds. Does not assert if rowBytes is smaller than minRowBytes(), even though result may be incorrect.
@param x column index, zero or greater, and less than width() @param y row index, zero or greater, and less than height() @param rowBytes size of pixel row or larger @return offset within pixel array
/** Compares SkImageInfo with other, and returns true if width, height, SkColorType, SkAlphaType, and SkColorSpace are equivalent.
@param other SkImageInfo to compare @return true if SkImageInfo equals other
*/ booloperator==(const SkImageInfo& other) const { return fDimensions == other.fDimensions && fColorInfo == other.fColorInfo;
}
/** Compares SkImageInfo with other, and returns true if width, height, SkColorType, SkAlphaType, and SkColorSpace are not equivalent.
@param other SkImageInfo to compare @return true if SkImageInfo is not equal to other
*/ booloperator!=(const SkImageInfo& other) const { return !(*this == other);
}
/** Returns storage required by pixel array, given SkImageInfo dimensions, SkColorType, and rowBytes. rowBytes is assumed to be at least as large as minRowBytes().
Returns zero if height is zero. Returns SIZE_MAX if answer exceeds the range of size_t.
@param rowBytes size of pixel row or larger @return memory required by pixel buffer
*/
size_t computeByteSize(size_t rowBytes) const;
/** Returns storage required by pixel array, given SkImageInfo dimensions, and SkColorType. Uses minRowBytes() to compute bytes for pixel row.
Returns zero if height is zero. Returns SIZE_MAX if answer exceeds the range of size_t.
@return least memory required by pixel buffer
*/
size_t computeMinByteSize() const { return this->computeByteSize(this->minRowBytes());
}
/** Returns true if byteSize equals SIZE_MAX. computeByteSize() and computeMinByteSize() return SIZE_MAX if size_t can not hold buffer size.
@param byteSize result of computeByteSize() or computeMinByteSize() @return true if computeByteSize() or computeMinByteSize() result exceeds size_t
*/ staticbool ByteSizeOverflowed(size_t byteSize) { return SIZE_MAX == byteSize;
}
/** Returns true if rowBytes is valid for this SkImageInfo.
@param rowBytes size of pixel row including padding @return true if rowBytes is large enough to contain pixel row and is properly aligned
*/ bool validRowBytes(size_t rowBytes) const { if (rowBytes < this->minRowBytes64()) { returnfalse;
} int shift = this->shiftPerPixel();
size_t alignedRowBytes = rowBytes >> shift << shift; return alignedRowBytes == rowBytes;
}
/** Creates an empty SkImageInfo with kUnknown_SkColorType, kUnknown_SkAlphaType, a width and height of zero, and no SkColorSpace.
*/ void reset() { *this = {}; }
/** Asserts if internal values are illegal or inconsistent. Only available if SK_DEBUG is defined at compile time.
*/
SkDEBUGCODE(void validate() const;)
Die Informationen auf dieser Webseite wurden
nach bestem Wissen sorgfältig zusammengestellt. Es wird jedoch weder Vollständigkeit, noch Richtigkeit,
noch Qualität der bereit gestellten Informationen zugesichert.
Bemerkung:
Die farbliche Syntaxdarstellung und die Messung sind noch experimentell.
