enum SkAlphaType { kUnknown_SkAlphaType, kOpaque_SkAlphaType, kPremul_SkAlphaType, kUnpremul_SkAlphaType, kLastEnum_SkAlphaType = kUnpremul_SkAlphaType, }; static bool SkAlphaTypeIsOpaque(SkAlphaType at); ; enum SkColorType { kUnknown_SkColorType, kAlpha_8_SkColorType, kRGB_565_SkColorType, kARGB_4444_SkColorType, kRGBA_8888_SkColorType, kRGB_888x_SkColorType, kBGRA_8888_SkColorType, kRGBA_1010102_SkColorType, kRGB_101010x_SkColorType, kGray_8_SkColorType, kRGBA_F16_SkColorType, kRGBA_F32_SkColorType, kLastEnum_SkColorType = kRGBA_F32_SkColorType, kN32_SkColorType = kBGRA_8888_SkColorType, kN32_SkColorType = kRGBA_8888_SkColorType, }; int SkColorTypeBytesPerPixel(SkColorType ct); ; bool SkColorTypeIsAlwaysOpaque(SkColorType ct); ; bool SkColorTypeValidateAlphaType(SkColorType colorType, SkAlphaType alphaType, SkAlphaType* canonical = nullptr); ; enum SkYUVColorSpace { kJPEG_SkYUVColorSpace, kRec601_SkYUVColorSpace, kRec709_SkYUVColorSpace, kLastEnum_SkYUVColorSpace = kRec709_SkYUVColorSpace, }; struct SkImageInfo { // SkImageInfo interface };
Image_Info specifies the dimensions and encoding of the pixels in a Bitmap. The dimensions are integral width and height. The encoding is how pixel bits describe Color_Alpha, transparency; Color components red, blue, and green; and Color_Space, the range and linearity of colors.
Image_Info describes an uncompressed raster pixels. In contrast, Image additionally describes compressed pixels like PNG, and Surface describes destinations on the GPU. Image and Surface may be specified by Image_Info, but Image and Surface may not contain Image_Info.
enum SkAlphaType { kUnknown_SkAlphaType, kOpaque_SkAlphaType, kPremul_SkAlphaType, kUnpremul_SkAlphaType, kLastEnum_SkAlphaType = kUnpremul_SkAlphaType, };
Describes how to interpret the alpha component of a pixel. A pixel may be opaque, or Color_Alpha, describing multiple levels of transparency.
In simple blending, Color_Alpha weights the draw color and the destination
color to create a new color. If alpha describes a weight from zero to one,
new color is set to: draw color * alpha + destination color * (1 - alpha)
.
In practice alpha is encoded in two or more bits, where 1.0 equals all bits set.
RGB may have Color_Alpha included in each component value; the stored value is the original RGB multiplied by Color_Alpha. Premultiplied color components improve performance.
Const | Value | Details | Description |
---|---|---|---|
kUnknown_SkAlphaType |
0 | Alpha_Type is uninitialized. | |
kOpaque_SkAlphaType |
1 | Opaque | Pixels are opaque. The Color_Type must have no explicit alpha component, or all alpha components must be set to their maximum value. |
kPremul_SkAlphaType |
2 | Premul | Pixels have Alpha Premultiplied into color components. Surface pixels must be Premultiplied. |
kUnpremul_SkAlphaType |
3 | Unpremul | Pixel color component values are independent of alpha value. Images generated from encoded data like PNG do not Premultiply pixel color components. kUnpremul_SkAlphaType is supported for Image pixels, but not for Surface pixels. |
kLastEnum_SkAlphaType |
3 | Used by tests to iterate through all valid values. |
Use kOpaque_SkAlphaType as a hint to optimize drawing when Alpha component of all pixel is set to its maximum value of 1.0; all alpha component bits are set. If Image_Info is set to kOpaque_SkAlphaType but all alpha values are not 1.0, results are undefined.
Use kPremul_SkAlphaType when stored color components are the original color multiplied by the alpha component. The alpha component range of 0.0 to 1.0 is achieved by dividing the integer bit value by the maximum bit value.
stored color = original color * alpha / max alpha
The color component must be equal to or smaller than the alpha component, or the results are undefined.
Use kUnpremul_SkAlphaType if stored color components are not divided by the alpha component. Some drawing destinations may not support kUnpremul_SkAlphaType.
static bool SkAlphaTypeIsOpaque(SkAlphaType at)
Returns true if SkAlphaType equals kOpaque_SkAlphaType. kOpaque_SkAlphaType is a hint that the SkColorType is opaque, or that all alpha values are set to their 1.0 equivalent. If SkAlphaType is kOpaque_SkAlphaType, and SkColorType is not opaque, then the result of drawing any pixel with a alpha value less than 1.0 is undefined.
at |
one of: |
kUnknown_SkAlphaType, kOpaque_SkAlphaType, kPremul_SkAlphaType, kUnpremul_SkAlphaType
true if at equals kOpaque_SkAlphaType
enum SkColorType { kUnknown_SkColorType, kAlpha_8_SkColorType, kRGB_565_SkColorType, kARGB_4444_SkColorType, kRGBA_8888_SkColorType, kRGB_888x_SkColorType, kBGRA_8888_SkColorType, kRGBA_1010102_SkColorType, kRGB_101010x_SkColorType, kGray_8_SkColorType, kRGBA_F16_SkColorType, kRGBA_F32_SkColorType, kLastEnum_SkColorType = kRGBA_F32_SkColorType, kN32_SkColorType = kBGRA_8888_SkColorType, kN32_SkColorType = kRGBA_8888_SkColorType, };
Describes how pixel bits encode color. A pixel may be an alpha mask, a grayscale, RGB, or ARGB.
kN32_SkColorType selects the native 32-bit ARGB format. On Little_Endian processors, pixels containing 8-bit ARGB components pack into 32-bit kBGRA_8888_SkColorType. On Big_Endian processors, pixels pack into 32-bit kRGBA_8888_SkColorType.
Const | Value | Details | Description |
---|---|---|---|
kUnknown_SkColorType |
0 | Color_Type is set to kUnknown_SkColorType by default. If set, encoding format and size is unknown. | |
kAlpha_8_SkColorType |
1 | Alpha 8 | Stores 8-bit byte pixel encoding that represents transparency. Value of zero is completely transparent; a value of 255 is completely opaque. |
kRGB_565_SkColorType |
2 | RGB 565 | Stores 16-bit word pixel encoding that contains five bits of blue, six bits of green, and five bits of red. |
kARGB_4444_SkColorType |
3 | ARGB 4444 | Stores 16-bit word pixel encoding that contains four bits of alpha, four bits of blue, four bits of green, and four bits of red. |
kRGBA_8888_SkColorType |
4 | RGBA 8888 | Stores 32-bit word pixel encoding that contains eight bits of red, eight bits of green, eight bits of blue, and eight bits of alpha. |
kRGB_888x_SkColorType |
5 | RGB 888 | Stores 32-bit word pixel encoding that contains eight bits of red, eight bits of green, eight bits of blue, and eight unused bits. |
kBGRA_8888_SkColorType |
6 | BGRA 8888 | Stores 32-bit word pixel encoding that contains eight bits of blue, eight bits of green, eight bits of red, and eight bits of alpha. |
kRGBA_1010102_SkColorType |
7 | RGBA 1010102 | Stores 32-bit word pixel encoding that contains ten bits of red, ten bits of green, ten bits of blue, and two bits of alpha. |
kRGB_101010x_SkColorType |
8 | RGB 101010 | Stores 32-bit word pixel encoding that contains ten bits of red, ten bits of green, ten bits of blue, and two unused bits. |
kGray_8_SkColorType |
9 | Gray 8 | Stores 8-bit byte pixel encoding that equivalent to equal values for red, blue, and green, representing colors from black to white. |
kRGBA_F16_SkColorType |
10 | RGBA F16 | Stores 64-bit word pixel encoding that contains 16 bits of blue, 16 bits of green, 16 bits of red, and 16 bits of alpha. Each component is encoded as a half float. |
kRGBA_F32_SkColorType |
11 | RGBA F32 | Stores 128-bit word pixel encoding that contains 32 bits of blue, 32 bits of green, 32 bits of red, and 32 bits of alpha. Each component is encoded as a single precision float. |
kLastEnum_SkColorType |
11 | Used by tests to iterate through all valid values. | |
kN32_SkColorType |
4 or 6 | Encodes ARGB as either kRGBA_8888_SkColorType or kBGRA_8888_SkColorType, whichever is native to the platform. |
Alpha pixels encode transparency without color information. Value of zero is completely transparent; a value of 255 is completely opaque. Bitmap pixels do not visibly draw, because its pixels have no color information. When SkColorType is set to kAlpha_8_SkColorType, the paired SkAlphaType is ignored.
kRGB_565_SkColorType encodes RGB to fit in a 16-bit word. Red and blue components use five bits describing 32 levels. Green components, more sensitive to the eye, use six bits describing 64 levels. kRGB_565_SkColorType has no bits for Alpha. Pixels are fully opaque as if its Color_Alpha was set to one, and should always be paired with kOpaque_SkAlphaType.
kARGB_4444_SkColorType encodes ARGB to fit in 16-bit word. Each component: alpha, blue, green, and red; use four bits, describing 16 levels. Note that kARGB_4444_SkColorType is misnamed; the acronym does not describe the actual component order.
If paired with kPremul_SkAlphaType: blue, green, and red components are Premultiplied by the alpha value. If blue, green, or red is greater than alpha, the drawn result is undefined.
If paired with kUnpremul_SkAlphaType: alpha, blue, green, and red components may have any value. There may be a performance penalty with Unpremultiplied pixels.
If paired with kOpaque_SkAlphaType: all alpha component values are at the maximum; blue, green, and red components are fully opaque. If any alpha component is less than 15, the drawn result is undefined.
kRGBA_8888_SkColorType encodes ARGB into a 32-bit word. Each component: red, green, blue, alpha; use eight bits, describing 256 levels.
If paired with kPremul_SkAlphaType: red, green, and blue components are Premultiplied by the alpha value. If red, green, or blue is greater than alpha, the drawn result is undefined.
If paired with kUnpremul_SkAlphaType: alpha, red, green, and blue components may have any value. There may be a performance penalty with Unpremultiplied pixels.
If paired with kOpaque_SkAlphaType: all alpha component values are at the maximum; red, green, and blue components are fully opaque. If any alpha component is less than 255, the drawn result is undefined.
On Big_Endian platforms, kRGBA_8888_SkColorType is the native Color_Type, and will have the best performance. Use kN32_SkColorType to choose the best Color_Type for the platform at compile time.
kRGB_888x_SkColorType encodes RGB into a 32-bit word. Each component: red, green, blue; use eight bits, describing 256 levels. Eight bits are unused. Pixels described by kRGB_888x_SkColorType are fully opaque as if their Color_Alpha was set to one, and should always be paired with kOpaque_SkAlphaType.
kBGRA_8888_SkColorType encodes ARGB into a 32-bit word. Each component: blue, green, red, and alpha; use eight bits, describing 256 levels.
If paired with kPremul_SkAlphaType: blue, green, and red components are Premultiplied by the alpha value. If blue, green, or red is greater than alpha, the drawn result is undefined.
If paired with kUnpremul_SkAlphaType: blue, green, red, and alpha components may have any value. There may be a performance penalty with Unpremultiplied pixels.
If paired with kOpaque_SkAlphaType: all alpha component values are at the maximum; blue, green, and red components are fully opaque. If any alpha component is less than 255, the drawn result is undefined.
On Little_Endian platforms, kBGRA_8888_SkColorType is the native Color_Type, and will have the best performance. Use kN32_SkColorType to choose the best Color_Type for the platform at compile time.
kRGBA_1010102_SkColorType encodes ARGB into a 32-bit word. Each Color component: red, green, and blue; use ten bits, describing 1024 levels. Two bits contain alpha, describing four levels. Possible alpha values are zero: fully transparent; one: 33% opaque; two: 67% opaque; three: fully opaque.
At present, Color in Paint does not provide enough precision to draw all colors possible to a kRGBA_1010102_SkColorType Surface.
If paired with kPremul_SkAlphaType: red, green, and blue components are Premultiplied by the alpha value. If red, green, or blue is greater than the alpha replicated to ten bits, the drawn result is undefined.
If paired with kUnpremul_SkAlphaType: alpha, red, green, and blue components may have any value. There may be a performance penalty with Unpremultiplied pixels.
If paired with kOpaque_SkAlphaType: all alpha component values are at the maximum; red, green, and blue components are fully opaque. If any alpha component is less than three, the drawn result is undefined.
kRGB_101010x_SkColorType encodes RGB into a 32-bit word. Each Color component: red, green, and blue; use ten bits, describing 1024 levels. Two bits are unused. Pixels described by kRGB_101010x_SkColorType are fully opaque as if its Color_Alpha was set to one, and should always be paired with kOpaque_SkAlphaType.
At present, Color in Paint does not provide enough precision to draw all colors possible to a kRGB_101010x_SkColorType Surface.
kGray_8_SkColorType encodes grayscale level in eight bits that is equivalent to equal values for red, blue, and green, representing colors from black to white. Pixels described by kGray_8_SkColorType are fully opaque as if its Color_Alpha was set to one, and should always be paired with kOpaque_SkAlphaType.
kRGBA_F16_SkColorType encodes ARGB into a 64-bit word. Each component: blue, green, red, and alpha; use 16 bits, describing a floating point value, from -65500 to 65000 with 3.31 decimal digits of precision.
At present, Color in Paint does not provide enough precision or range to draw all colors possible to a kRGBA_F16_SkColorType Surface.
Each component encodes a floating point value using Half floats
. Meaningful colors are represented by the range 0.0 to 1.0, although smaller and larger values may be useful when used in combination with Transfer_Mode.If paired with kPremul_SkAlphaType: blue, green, and red components are Premultiplied by the alpha value. If blue, green, or red is greater than alpha, the drawn result is undefined.
If paired with kUnpremul_SkAlphaType: blue, green, red, and alpha components may have any value. There may be a performance penalty with Unpremultiplied pixels.
If paired with kOpaque_SkAlphaType: all alpha component values are at the maximum; blue, green, and red components are fully opaque. If any alpha component is less than one, the drawn result is undefined.
kRGBA_F32_SkColorType encodes ARGB into a 128-bit word. Each component:
blue, green, red, and alpha; use 32 bits, describing a floating point value,
from -3.402823e
+38 to 3.402823e
+38 with 7.225 decimal digits of precision.
At present, Color in Paint does not provide enough precision or range to draw all colors possible to a kRGBA_F32_SkColorType Surface.
Each component encodes a floating point value using single-precision floats
. Meaningful colors are represented by the range 0.0 to 1.0, although smaller and larger values may be useful when used in combination with Transfer_Mode.If paired with kPremul_SkAlphaType: blue, green, and red components are Premultiplied by the alpha value. If blue, green, or red is greater than alpha, the drawn result is undefined.
If paired with kUnpremul_SkAlphaType: blue, green, red, and alpha components may have any value. There may be a performance penalty with Unpremultiplied pixels.
If paired with kOpaque_SkAlphaType: all alpha component values are at the maximum; blue, green, and red components are fully opaque. If any alpha component is less than one, the drawn result is undefined.
int SkColorTypeBytesPerPixel(SkColorType ct)
Returns the number of bytes required to store a pixel, including unused padding. Returns zero if ct is kUnknown_SkColorType or invalid.
ct |
one of: |
kUnknown_SkColorType, kAlpha_8_SkColorType, kRGB_565_SkColorType, kARGB_4444_SkColorType, kRGBA_8888_SkColorType, kRGB_888x_SkColorType, kBGRA_8888_SkColorType, kRGBA_1010102_SkColorType, kRGB_101010x_SkColorType, kGray_8_SkColorType, kRGBA_F16_SkColorType
bytes per pixel
bool SkColorTypeIsAlwaysOpaque(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.
ct |
one of: |
kUnknown_SkColorType, kAlpha_8_SkColorType, kRGB_565_SkColorType, kARGB_4444_SkColorType, kRGBA_8888_SkColorType, kRGB_888x_SkColorType, kBGRA_8888_SkColorType, kRGBA_1010102_SkColorType, kRGB_101010x_SkColorType, kGray_8_SkColorType, kRGBA_F16_SkColorType
true if alpha is always set to 1.0
bool SkColorTypeValidateAlphaType(SkColorType colorType, SkAlphaType alphaType, SkAlphaType* canonical = nullptr)
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.
For kUnknown_SkColorType: set canonical to kUnknown_SkAlphaType and return true. For kAlpha_8_SkColorType: set canonical to kPremul_SkAlphaType or kOpaque_SkAlphaType and return true if alphaType is not kUnknown_SkAlphaType. For kRGB_565_SkColorType, kRGB_888x_SkColorType, kRGB_101010x_SkColorType, and kGray_8_SkColorType: set canonical to kOpaque_SkAlphaType and return true. For kARGB_4444_SkColorType, kRGBA_8888_SkColorType, kBGRA_8888_SkColorType, kRGBA_1010102_SkColorType, and kRGBA_F16_SkColorType: set canonical to alphaType and return true if alphaType is not kUnknown_SkAlphaType.
colorType |
one of: |
kUnknown_SkColorType, kAlpha_8_SkColorType, kRGB_565_SkColorType, kARGB_4444_SkColorType, kRGBA_8888_SkColorType, kRGB_888x_SkColorType, kBGRA_8888_SkColorType, kRGBA_1010102_SkColorType, kRGB_101010x_SkColorType, kGray_8_SkColorType, kRGBA_F16_SkColorType
alphaType |
one of: |
kUnknown_SkAlphaType, kOpaque_SkAlphaType, kPremul_SkAlphaType, kUnpremul_SkAlphaType
canonical |
storage for SkAlphaType |
true if valid SkAlphaType can be associated with colorType
enum SkYUVColorSpace { kJPEG_SkYUVColorSpace, kRec601_SkYUVColorSpace, kRec709_SkYUVColorSpace, kLastEnum_SkYUVColorSpace = kRec709_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 and RGB.
JPEG YUV values encode the full range of 0 to 255 for all three components. Video YUV values range from 16 to 235 for all three components. Details of encoding and conversion to RGB are described in YCbCr color space
.Const | Value | Description |
---|---|---|
kJPEG_SkYUVColorSpace |
0 | Describes standard JPEG color space; CCIR 601 | with full range of 0 to 255 for components.
kRec601_SkYUVColorSpace
kRec709_SkYUVColorSpace
kLastEnum_SkYUVColorSpace
SkImage::MakeFromYUVTexturesCopy SkImage::MakeFromNV12TexturesCopy
struct SkImageInfo { SkImageInfo(); static SkImageInfo Make(int width, int height, SkColorType ct, SkAlphaType at, sk_sp<SkColorSpace> cs = nullptr); static SkImageInfo MakeN32(int width, int height, SkAlphaType at, sk_sp<SkColorSpace> cs = nullptr); static SkImageInfo MakeS32(int width, int height, SkAlphaType at); static SkImageInfo MakeN32Premul(int width, int height, sk_sp<SkColorSpace> cs = nullptr); static SkImageInfo MakeN32Premul(const SkISize& size); static SkImageInfo MakeA8(int width, int height); static SkImageInfo MakeUnknown(int width, int height); static SkImageInfo MakeUnknown(); int width() const; int height() const; SkColorType colorType() const; SkAlphaType alphaType() const; SkColorSpace* colorSpace() const; sk_sp<SkColorSpace> refColorSpace() const; bool isEmpty() const; bool isOpaque() const; SkISize dimensions() const; SkIRect bounds() const; bool gammaCloseToSRGB() const; SkImageInfo makeWH(int newWidth, int newHeight) const; SkImageInfo makeAlphaType(SkAlphaType newAlphaType) const; SkImageInfo makeColorType(SkColorType newColorType) const; SkImageInfo makeColorSpace(sk_sp<SkColorSpace> cs) const; int bytesPerPixel() const; int shiftPerPixel() const; uint64_t minRowBytes64() const; size_t minRowBytes() const; size_t computeOffset(int x, int y, size_t rowBytes) const; bool operator==(const SkImageInfo& other) const; bool operator!=(const SkImageInfo& other) const; size_t computeByteSize(size_t rowBytes) const; size_t computeMinByteSize() const; static bool ByteSizeOverflowed(size_t byteSize); bool validRowBytes(size_t rowBytes) const; void reset(); void validate() const; };
Describes pixel dimensions and encoding. Bitmap, Image, Pixmap, and Surface can be created from Image_Info. Image_Info can be retrieved from Bitmap and Pixmap, but not from Image and Surface. For example, Image and Surface implementations may defer pixel depth, so may not completely specify Image_Info.
Image_Info contains dimensions, the pixel integral width and height. It encodes how pixel bits describe Color_Alpha, transparency; Color components red, blue, and green; and Color_Space, the range and linearity of colors.
SkImageInfo()
Creates an empty SkImageInfo with kUnknown_SkColorType, kUnknown_SkAlphaType, a width and height of zero, and no SkColorSpace.
empty SkImageInfo
static SkImageInfo Make(int width, int height, SkColorType ct, SkAlphaType at, sk_sp<SkColorSpace> cs = nullptr)
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.
width |
pixel column count; must be zero or greater |
height |
pixel row count; must be zero or greater |
ct |
one of: |
kUnknown_SkColorType, kAlpha_8_SkColorType, kRGB_565_SkColorType, kARGB_4444_SkColorType, kRGBA_8888_SkColorType, kRGB_888x_SkColorType, kBGRA_8888_SkColorType, kRGBA_1010102_SkColorType, kRGB_101010x_SkColorType, kGray_8_SkColorType, kRGBA_F16_SkColorType
at |
one of: |
kUnknown_SkAlphaType, kOpaque_SkAlphaType, kPremul_SkAlphaType, kUnpremul_SkAlphaType
cs |
range of colors; may be nullptr |
created SkImageInfo
MakeN32 MakeN32Premul MakeS32 MakeA8
static SkImageInfo MakeN32(int width, int height, SkAlphaType at, sk_sp<SkColorSpace> cs = nullptr)
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.
width |
pixel column count; must be zero or greater |
height |
pixel row count; must be zero or greater |
at |
one of: |
kUnknown_SkAlphaType, kOpaque_SkAlphaType, kPremul_SkAlphaType, kUnpremul_SkAlphaType
cs |
range of colors; may be nullptr |
created SkImageInfo
Make MakeN32Premul MakeS32 MakeA8
static SkImageInfo MakeS32(int width, int height, SkAlphaType at)
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.
width |
pixel column count; must be zero or greater |
height |
pixel row count; must be zero or greater |
at |
one of: |
kUnknown_SkAlphaType, kOpaque_SkAlphaType, kPremul_SkAlphaType, kUnpremul_SkAlphaType
created SkImageInfo
Make MakeN32 MakeN32Premul MakeA8
static SkImageInfo MakeN32Premul(int width, int height, sk_sp<SkColorSpace> cs = nullptr)
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.
width |
pixel column count; must be zero or greater |
height |
pixel row count; must be zero or greater |
cs |
range of colors; may be nullptr |
created SkImageInfo
static SkImageInfo MakeN32Premul(const SkISize& size)
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.
size |
width and height, each must be zero or greater |
created SkImageInfo
static SkImageInfo MakeA8(int width, int height)
Creates SkImageInfo from integral dimensions width and height, kAlpha_8_SkColorType, kPremul_SkAlphaType, with SkColorSpace set to nullptr.
width |
pixel column count; must be zero or greater |
height |
pixel row count; must be zero or greater |
created SkImageInfo
static SkImageInfo MakeUnknown(int width, int height)
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.
width |
pixel column count; must be zero or greater |
height |
pixel row count; must be zero or greater |
created SkImageInfo
SkImageInfo() MakeN32 MakeS32 Make
static SkImageInfo MakeUnknown()
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.
created SkImageInfo
SkImageInfo() MakeN32 MakeS32 Make
int width()const
Returns pixel count in each row.
pixel width
height SkBitmap::width SkPixelRef::width SkImage::width SkSurface::width
int height()const
Returns pixel row count.
pixel height
width SkBitmap::height SkPixelRef::height SkImage::height SkSurface::height
SkColorType colorType()const
Returns Color_Type, one of: kUnknown_SkColorType, kAlpha_8_SkColorType, kRGB_565_SkColorType, kARGB_4444_SkColorType, kRGBA_8888_SkColorType, kRGB_888x_SkColorType, kBGRA_8888_SkColorType, kRGBA_1010102_SkColorType, kRGB_101010x_SkColorType, kGray_8_SkColorType, kRGBA_F16_SkColorType .
alphaType SkPixmap::colorType SkBitmap::colorType
SkAlphaType alphaType()const
Returns Alpha_Type, one of: kUnknown_SkAlphaType, kOpaque_SkAlphaType, kPremul_SkAlphaType, kUnpremul_SkAlphaType .
colorType SkPixmap::alphaType SkBitmap::alphaType
SkColorSpace* colorSpace()const
Returns SkColorSpace, the range of colors. The reference count of SkColorSpace is unchanged. The returned SkColorSpace is immutable.
SkColorSpace, or nullptr
gammaCloseToSRGB: false gammaIsLinear: true isSRGB: false
Color_Space SkPixmap::colorSpace SkBitmap::colorSpace
sk_sp<SkColorSpace> refColorSpace()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.
SkColorSpace wrapped in a smart pointer
Color_Space SkBitmap::refColorSpace
bool isEmpty()const
Returns if SkImageInfo describes an empty area of pixels by checking if either width or height is zero or smaller.
true if either dimension is zero or smaller
dimensions bounds SkBitmap::empty SkPixmap::bounds
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. 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.
true if SkAlphaType is kOpaque_SkAlphaType
Color_Alpha SkColorTypeValidateAlphaType SkBitmap::isOpaque SkImage::isOpaque SkPixmap::isOpaque
SkISize dimensions()const
Returns SkISize { width(), height() }.
integral size of width() and height()
width height bounds SkBitmap::dimensions
SkIRect bounds()const
Returns SkIRect { 0, 0, width(), height() }.
integral rectangle from origin to width() and height()
bool gammaCloseToSRGB()const
Returns true if associated Color_Space is not nullptr, and Color_Space gamma is approximately the same as sRGB. This includes the sRGB transfer function
as well as a gamma curve described by a 2.2 exponent.true if Color_Space gamma is approximately the same as sRGB
SkColorSpace::gammaCloseToSRGB
SkImageInfo makeWH(int newWidth, int newHeight)const
Creates SkImageInfo with the same SkColorType, SkColorSpace, and SkAlphaType, with dimensions set to width and height.
newWidth |
pixel column count; must be zero or greater |
newHeight |
pixel row count; must be zero or greater |
created SkImageInfo
Make makeAlphaType makeColorSpace makeColorType
SkImageInfo makeAlphaType(SkAlphaType newAlphaType)const
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.
newAlphaType |
one of: |
kUnknown_SkAlphaType, kOpaque_SkAlphaType, kPremul_SkAlphaType, kUnpremul_SkAlphaType
created SkImageInfo
Make MakeA8 makeColorType makeColorSpace
SkImageInfo makeColorType(SkColorType newColorType)const
Creates SkImageInfo with same SkAlphaType, SkColorSpace, width, and height, with SkColorType set to newColorType.
newColorType |
one of: |
kUnknown_SkColorType, kAlpha_8_SkColorType, kRGB_565_SkColorType, kARGB_4444_SkColorType, kRGBA_8888_SkColorType, kRGB_888x_SkColorType, kBGRA_8888_SkColorType, kRGBA_1010102_SkColorType, kRGB_101010x_SkColorType, kGray_8_SkColorType, kRGBA_F16_SkColorType
created SkImageInfo
Make makeAlphaType makeColorSpace
SkImageInfo makeColorSpace(sk_sp<SkColorSpace> cs)const
Creates SkImageInfo with same SkAlphaType, SkColorType, width, and height, with SkColorSpace set to cs.
cs |
range of colors; may be nullptr |
created SkImageInfo
Make MakeS32 makeAlphaType makeColorType
int bytesPerPixel()const
Returns number of bytes per pixel required by SkColorType. Returns zero if colorType( is kUnknown_SkColorType.
bytes in pixel
width shiftPerPixel SkBitmap::bytesPerPixel
int shiftPerPixel()const
Returns bit shift converting row bytes to row pixels. Returns zero for kUnknown_SkColorType.
one of: 0, 1, 2, 3; left shift to convert pixels to bytes
bytesPerPixel minRowBytes SkBitmap::shiftPerPixel SkPixmap::shiftPerPixel
uint64_t minRowBytes64()const
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.
width() times bytesPerPixel() as unsigned 64-bit integer
minRowBytes computeByteSize computeMinByteSize validRowBytes
size_t minRowBytes()const
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.
width() times bytesPerPixel() as signed 32-bit integer
minRowBytes64 computeByteSize computeMinByteSize validRowBytes
size_t computeOffset(int x, int y, size_t rowBytes)const
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.
x |
column index, zero or greater, and less than width() |
y |
row index, zero or greater, and less than height() |
rowBytes |
size of pixel row or larger |
offset within pixel array
height width minRowBytes computeByteSize
bool operator==(const SkImageInfo& other)const
Compares SkImageInfo with other, and returns true if width, height, SkColorType, SkAlphaType, and SkColorSpace are equivalent.
other |
SkImageInfo to compare |
true if SkImageInfo equals other
operator!=(const SkImageInfo& other) const SkColorSpace::Equals
bool operator!=(const SkImageInfo& other)const
Compares SkImageInfo with other, and returns true if width, height, SkColorType, SkAlphaType, and SkColorSpace are not equivalent.
other |
SkImageInfo to compare |
true if SkImageInfo is not equal to other
operator==(const SkImageInfo& other) const SkColorSpace::Equals
size_t computeByteSize(size_t rowBytes)const
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.
rowBytes |
size of pixel row or larger |
memory required by pixel buffer
computeMinByteSize validRowBytes
size_t computeMinByteSize()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.
least memory required by pixel buffer
static bool ByteSizeOverflowed(size_t byteSize)
Returns true if byteSize equals SIZE_MAX. computeByteSize() and computeMinByteSize() return SIZE_MAX if size_t can not hold buffer size.
byteSize |
result of computeByteSize() or computeMinByteSize() |
true if computeByteSize() or computeMinByteSize() result exceeds size_t
computeByteSize computeMinByteSize validRowBytes
bool validRowBytes(size_t rowBytes)const
Returns true if rowBytes is smaller than width times pixel size.
rowBytes |
size of pixel row or larger |
true if rowBytes is large enough to contain pixel row
ByteSizeOverflowed computeByteSize computeMinByteSize
void reset()
Creates an empty SkImageInfo with kUnknown_SkColorType, kUnknown_SkAlphaType, a width and height of zero, and no SkColorSpace.
void validate()const