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720 lines
29 KiB
720 lines
29 KiB
/*
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* Copyright 2013 Google Inc.
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*
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* Use of this source code is governed by a BSD-style license that can be
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* found in the LICENSE file.
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*/
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#ifndef SkImageInfo_DEFINED
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#define SkImageInfo_DEFINED
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#include "include/core/SkColorSpace.h"
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#include "include/core/SkMath.h"
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#include "include/core/SkRect.h"
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#include "include/core/SkSize.h"
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#include "include/private/SkTFitsIn.h"
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#include "include/private/SkTo.h"
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class SkReadBuffer;
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class SkWriteBuffer;
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/** \enum SkImageInfo::SkAlphaType
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Describes how to interpret the alpha component of a pixel. A pixel may
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be opaque, or alpha, describing multiple levels of transparency.
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In simple blending, alpha weights the draw color and the destination
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color to create a new color. If alpha describes a weight from zero to one:
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new color = draw color * alpha + destination color * (1 - alpha)
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In practice alpha is encoded in two or more bits, where 1.0 equals all bits set.
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RGB may have alpha included in each component value; the stored
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value is the original RGB multiplied by alpha. Premultiplied color
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components improve performance.
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*/
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enum SkAlphaType {
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kUnknown_SkAlphaType, //!< uninitialized
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kOpaque_SkAlphaType, //!< pixel is opaque
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kPremul_SkAlphaType, //!< pixel components are premultiplied by alpha
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kUnpremul_SkAlphaType, //!< pixel components are independent of alpha
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kLastEnum_SkAlphaType = kUnpremul_SkAlphaType, //!< last valid value
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};
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/** Returns true if SkAlphaType equals kOpaque_SkAlphaType.
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kOpaque_SkAlphaType is a hint that the SkColorType is opaque, or that all
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alpha values are set to their 1.0 equivalent. If SkAlphaType is
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kOpaque_SkAlphaType, and SkColorType is not opaque, then the result of
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drawing any pixel with a alpha value less than 1.0 is undefined.
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*/
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static inline bool SkAlphaTypeIsOpaque(SkAlphaType at) {
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return kOpaque_SkAlphaType == at;
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}
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///////////////////////////////////////////////////////////////////////////////
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/** \enum SkImageInfo::SkColorType
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Describes how pixel bits encode color. A pixel may be an alpha mask, a grayscale, RGB, or ARGB.
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kN32_SkColorType selects the native 32-bit ARGB format for the current configuration. This can
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lead to inconsistent results across platforms, so use with caution.
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*/
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enum SkColorType {
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kUnknown_SkColorType, //!< uninitialized
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kAlpha_8_SkColorType, //!< pixel with alpha in 8-bit byte
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kRGB_565_SkColorType, //!< pixel with 5 bits red, 6 bits green, 5 bits blue, in 16-bit word
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kARGB_4444_SkColorType, //!< pixel with 4 bits for alpha, red, green, blue; in 16-bit word
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kRGBA_8888_SkColorType, //!< pixel with 8 bits for red, green, blue, alpha; in 32-bit word
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kRGB_888x_SkColorType, //!< pixel with 8 bits each for red, green, blue; in 32-bit word
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kBGRA_8888_SkColorType, //!< pixel with 8 bits for blue, green, red, alpha; in 32-bit word
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kRGBA_1010102_SkColorType, //!< 10 bits for red, green, blue; 2 bits for alpha; in 32-bit word
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kBGRA_1010102_SkColorType, //!< 10 bits for blue, green, red; 2 bits for alpha; in 32-bit word
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kRGB_101010x_SkColorType, //!< pixel with 10 bits each for red, green, blue; in 32-bit word
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kBGR_101010x_SkColorType, //!< pixel with 10 bits each for blue, green, red; in 32-bit word
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kGray_8_SkColorType, //!< pixel with grayscale level in 8-bit byte
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kRGBA_F16Norm_SkColorType, //!< pixel with half floats in [0,1] for red, green, blue, alpha;
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// in 64-bit word
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kRGBA_F16_SkColorType, //!< pixel with half floats for red, green, blue, alpha;
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// in 64-bit word
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kRGBA_F32_SkColorType, //!< pixel using C float for red, green, blue, alpha; in 128-bit word
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// The following 6 colortypes are just for reading from - not for rendering to
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kR8G8_unorm_SkColorType, //!< pixel with a uint8_t for red and green
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kA16_float_SkColorType, //!< pixel with a half float for alpha
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kR16G16_float_SkColorType, //!< pixel with a half float for red and green
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kA16_unorm_SkColorType, //!< pixel with a little endian uint16_t for alpha
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kR16G16_unorm_SkColorType, //!< pixel with a little endian uint16_t for red and green
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kR16G16B16A16_unorm_SkColorType, //!< pixel with a little endian uint16_t for red, green, blue
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// and alpha
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kLastEnum_SkColorType = kR16G16B16A16_unorm_SkColorType, //!< last valid value
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#if SK_PMCOLOR_BYTE_ORDER(B,G,R,A)
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kN32_SkColorType = kBGRA_8888_SkColorType,//!< native 32-bit BGRA encoding
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#elif SK_PMCOLOR_BYTE_ORDER(R,G,B,A)
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kN32_SkColorType = kRGBA_8888_SkColorType,//!< native 32-bit RGBA encoding
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#else
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#error "SK_*32_SHIFT values must correspond to BGRA or RGBA byte order"
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#endif
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};
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/** Returns the number of bytes required to store a pixel, including unused padding.
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Returns zero if ct is kUnknown_SkColorType or invalid.
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@return bytes per pixel
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*/
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SK_API int SkColorTypeBytesPerPixel(SkColorType ct);
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/** Returns true if SkColorType always decodes alpha to 1.0, making the pixel
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fully opaque. If true, SkColorType does not reserve bits to encode alpha.
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@return true if alpha is always set to 1.0
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*/
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SK_API bool SkColorTypeIsAlwaysOpaque(SkColorType ct);
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/** Returns true if canonical can be set to a valid SkAlphaType for colorType. If
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there is more than one valid canonical SkAlphaType, set to alphaType, if valid.
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If true is returned and canonical is not nullptr, store valid SkAlphaType.
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Returns false only if alphaType is kUnknown_SkAlphaType, color type is not
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kUnknown_SkColorType, and SkColorType is not always opaque. If false is returned,
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canonical is ignored.
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@param canonical storage for SkAlphaType
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@return true if valid SkAlphaType can be associated with colorType
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*/
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SK_API bool SkColorTypeValidateAlphaType(SkColorType colorType, SkAlphaType alphaType,
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SkAlphaType* canonical = nullptr);
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/** \enum SkImageInfo::SkYUVColorSpace
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Describes color range of YUV pixels. The color mapping from YUV to RGB varies
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depending on the source. YUV pixels may be generated by JPEG images, standard
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video streams, or high definition video streams. Each has its own mapping from
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YUV to RGB.
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JPEG YUV values encode the full range of 0 to 255 for all three components.
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Video YUV values often range from 16 to 235 for Y and from 16 to 240 for U and V (limited).
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Details of encoding and conversion to RGB are described in YCbCr color space.
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The identity colorspace exists to provide a utility mapping from Y to R, U to G and V to B.
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It can be used to visualize the YUV planes or to explicitly post process the YUV channels.
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*/
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enum SkYUVColorSpace {
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kJPEG_Full_SkYUVColorSpace, //!< describes full range
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kRec601_Limited_SkYUVColorSpace, //!< describes SDTV range
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kRec709_Full_SkYUVColorSpace, //!< describes HDTV range
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kRec709_Limited_SkYUVColorSpace,
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kBT2020_8bit_Full_SkYUVColorSpace, //!< describes UHDTV range, non-constant-luminance
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kBT2020_8bit_Limited_SkYUVColorSpace,
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kBT2020_10bit_Full_SkYUVColorSpace,
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kBT2020_10bit_Limited_SkYUVColorSpace,
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kBT2020_12bit_Full_SkYUVColorSpace,
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kBT2020_12bit_Limited_SkYUVColorSpace,
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kIdentity_SkYUVColorSpace, //!< maps Y->R, U->G, V->B
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kLastEnum_SkYUVColorSpace = kIdentity_SkYUVColorSpace, //!< last valid value
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// Legacy (deprecated) names:
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kJPEG_SkYUVColorSpace = kJPEG_Full_SkYUVColorSpace,
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kRec601_SkYUVColorSpace = kRec601_Limited_SkYUVColorSpace,
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kRec709_SkYUVColorSpace = kRec709_Limited_SkYUVColorSpace,
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kBT2020_SkYUVColorSpace = kBT2020_8bit_Limited_SkYUVColorSpace,
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};
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/** \struct SkColorInfo
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Describes pixel and encoding. SkImageInfo can be created from SkColorInfo by
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providing dimensions.
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It encodes how pixel bits describe alpha, transparency; color components red, blue,
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and green; and SkColorSpace, the range and linearity of colors.
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*/
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class SK_API SkColorInfo {
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public:
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/** Creates an SkColorInfo with kUnknown_SkColorType, kUnknown_SkAlphaType,
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and no SkColorSpace.
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@return empty SkImageInfo
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*/
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SkColorInfo() = default;
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/** Creates SkColorInfo from SkColorType ct, SkAlphaType at, and optionally SkColorSpace cs.
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If SkColorSpace cs is nullptr and SkColorInfo is part of drawing source: SkColorSpace
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defaults to sRGB, mapping into SkSurface SkColorSpace.
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Parameters are not validated to see if their values are legal, or that the
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combination is supported.
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@return created SkColorInfo
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*/
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SkColorInfo(SkColorType ct, SkAlphaType at, sk_sp<SkColorSpace> cs)
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: fColorSpace(std::move(cs)), fColorType(ct), fAlphaType(at) {}
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SkColorInfo(const SkColorInfo&) = default;
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SkColorInfo(SkColorInfo&&) = default;
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SkColorInfo& operator=(const SkColorInfo&) = default;
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SkColorInfo& operator=(SkColorInfo&&) = default;
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SkColorSpace* colorSpace() const { return fColorSpace.get(); }
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sk_sp<SkColorSpace> refColorSpace() const { return fColorSpace; }
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SkColorType colorType() const { return fColorType; }
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SkAlphaType alphaType() const { return fAlphaType; }
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bool isOpaque() const {
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return SkAlphaTypeIsOpaque(fAlphaType)
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|| SkColorTypeIsAlwaysOpaque(fColorType);
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}
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bool gammaCloseToSRGB() const { return fColorSpace && fColorSpace->gammaCloseToSRGB(); }
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/** Does other represent the same color type, alpha type, and color space? */
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bool operator==(const SkColorInfo& other) const {
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return fColorType == other.fColorType && fAlphaType == other.fAlphaType &&
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SkColorSpace::Equals(fColorSpace.get(), other.fColorSpace.get());
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}
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/** Does other represent a different color type, alpha type, or color space? */
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bool operator!=(const SkColorInfo& other) const { return !(*this == other); }
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/** Creates SkColorInfo with same SkColorType, SkColorSpace, with SkAlphaType set
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to newAlphaType.
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Created SkColorInfo contains newAlphaType even if it is incompatible with
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SkColorType, in which case SkAlphaType in SkColorInfo is ignored.
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*/
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SkColorInfo makeAlphaType(SkAlphaType newAlphaType) const {
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return SkColorInfo(this->colorType(), newAlphaType, this->refColorSpace());
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}
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/** Creates new SkColorInfo with same SkAlphaType, SkColorSpace, with SkColorType
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set to newColorType.
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*/
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SkColorInfo makeColorType(SkColorType newColorType) const {
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return SkColorInfo(newColorType, this->alphaType(), this->refColorSpace());
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}
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/** Creates SkColorInfo with same SkAlphaType, SkColorType, with SkColorSpace
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set to cs. cs may be nullptr.
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*/
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SkColorInfo makeColorSpace(sk_sp<SkColorSpace> cs) const {
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return SkColorInfo(this->colorType(), this->alphaType(), std::move(cs));
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}
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/** Returns number of bytes per pixel required by SkColorType.
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Returns zero if colorType() is kUnknown_SkColorType.
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@return bytes in pixel
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example: https://fiddle.skia.org/c/@ImageInfo_bytesPerPixel
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*/
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int bytesPerPixel() const;
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/** Returns bit shift converting row bytes to row pixels.
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Returns zero for kUnknown_SkColorType.
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@return one of: 0, 1, 2, 3, 4; left shift to convert pixels to bytes
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example: https://fiddle.skia.org/c/@ImageInfo_shiftPerPixel
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*/
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int shiftPerPixel() const;
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private:
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sk_sp<SkColorSpace> fColorSpace;
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SkColorType fColorType = kUnknown_SkColorType;
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SkAlphaType fAlphaType = kUnknown_SkAlphaType;
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};
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/** \struct SkImageInfo
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Describes pixel dimensions and encoding. SkBitmap, SkImage, PixMap, and SkSurface
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can be created from SkImageInfo. SkImageInfo can be retrieved from SkBitmap and
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SkPixmap, but not from SkImage and SkSurface. For example, SkImage and SkSurface
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implementations may defer pixel depth, so may not completely specify SkImageInfo.
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SkImageInfo contains dimensions, the pixel integral width and height. It encodes
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how pixel bits describe alpha, transparency; color components red, blue,
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and green; and SkColorSpace, the range and linearity of colors.
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*/
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struct SK_API SkImageInfo {
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public:
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/** Creates an empty SkImageInfo with kUnknown_SkColorType, kUnknown_SkAlphaType,
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a width and height of zero, and no SkColorSpace.
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@return empty SkImageInfo
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*/
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SkImageInfo() = default;
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/** Creates SkImageInfo from integral dimensions width and height, SkColorType ct,
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SkAlphaType at, and optionally SkColorSpace cs.
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If SkColorSpace cs is nullptr and SkImageInfo is part of drawing source: SkColorSpace
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defaults to sRGB, mapping into SkSurface SkColorSpace.
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Parameters are not validated to see if their values are legal, or that the
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combination is supported.
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@param width pixel column count; must be zero or greater
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@param height pixel row count; must be zero or greater
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@param cs range of colors; may be nullptr
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@return created SkImageInfo
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*/
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static SkImageInfo Make(int width, int height, SkColorType ct, SkAlphaType at,
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sk_sp<SkColorSpace> cs = nullptr) {
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return SkImageInfo({width, height}, {ct, at, std::move(cs)});
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}
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static SkImageInfo Make(SkISize dimensions, SkColorType ct, SkAlphaType at,
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sk_sp<SkColorSpace> cs = nullptr) {
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return SkImageInfo(dimensions, {ct, at, std::move(cs)});
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}
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/** Creates SkImageInfo from integral dimensions and SkColorInfo colorInfo,
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Parameters are not validated to see if their values are legal, or that the
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combination is supported.
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@param dimensions pixel column and row count; must be zeros or greater
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@param SkColorInfo the pixel encoding consisting of SkColorType, SkAlphaType, and
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SkColorSpace (which may be nullptr)
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@return created SkImageInfo
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*/
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static SkImageInfo Make(SkISize dimensions, const SkColorInfo& colorInfo) {
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return SkImageInfo(dimensions, colorInfo);
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}
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static SkImageInfo Make(SkISize dimensions, SkColorInfo&& colorInfo) {
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return SkImageInfo(dimensions, std::move(colorInfo));
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}
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/** Creates SkImageInfo from integral dimensions width and height, kN32_SkColorType,
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SkAlphaType at, and optionally SkColorSpace cs. kN32_SkColorType will equal either
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kBGRA_8888_SkColorType or kRGBA_8888_SkColorType, whichever is optimal.
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If SkColorSpace cs is nullptr and SkImageInfo is part of drawing source: SkColorSpace
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defaults to sRGB, mapping into SkSurface SkColorSpace.
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Parameters are not validated to see if their values are legal, or that the
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combination is supported.
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@param width pixel column count; must be zero or greater
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@param height pixel row count; must be zero or greater
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@param cs range of colors; may be nullptr
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@return created SkImageInfo
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*/
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static SkImageInfo MakeN32(int width, int height, SkAlphaType at,
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sk_sp<SkColorSpace> cs = nullptr) {
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return Make({width, height}, kN32_SkColorType, at, std::move(cs));
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}
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/** Creates SkImageInfo from integral dimensions width and height, kN32_SkColorType,
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SkAlphaType at, with sRGB SkColorSpace.
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Parameters are not validated to see if their values are legal, or that the
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combination is supported.
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@param width pixel column count; must be zero or greater
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@param height pixel row count; must be zero or greater
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@return created SkImageInfo
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example: https://fiddle.skia.org/c/@ImageInfo_MakeS32
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*/
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static SkImageInfo MakeS32(int width, int height, SkAlphaType at);
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/** Creates SkImageInfo from integral dimensions width and height, kN32_SkColorType,
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kPremul_SkAlphaType, with optional SkColorSpace.
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If SkColorSpace cs is nullptr and SkImageInfo is part of drawing source: SkColorSpace
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defaults to sRGB, mapping into SkSurface SkColorSpace.
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Parameters are not validated to see if their values are legal, or that the
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combination is supported.
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@param width pixel column count; must be zero or greater
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@param height pixel row count; must be zero or greater
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@param cs range of colors; may be nullptr
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@return created SkImageInfo
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*/
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static SkImageInfo MakeN32Premul(int width, int height, sk_sp<SkColorSpace> cs = nullptr) {
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return Make({width, height}, kN32_SkColorType, kPremul_SkAlphaType, std::move(cs));
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}
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/** Creates SkImageInfo from integral dimensions width and height, kN32_SkColorType,
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kPremul_SkAlphaType, with SkColorSpace set to nullptr.
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If SkImageInfo is part of drawing source: SkColorSpace defaults to sRGB, mapping
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into SkSurface SkColorSpace.
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Parameters are not validated to see if their values are legal, or that the
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combination is supported.
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@param dimensions width and height, each must be zero or greater
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@param cs range of colors; may be nullptr
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@return created SkImageInfo
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*/
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static SkImageInfo MakeN32Premul(SkISize dimensions, sk_sp<SkColorSpace> cs = nullptr) {
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return Make(dimensions, kN32_SkColorType, kPremul_SkAlphaType, std::move(cs));
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}
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/** Creates SkImageInfo from integral dimensions width and height, kAlpha_8_SkColorType,
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kPremul_SkAlphaType, with SkColorSpace set to nullptr.
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@param width pixel column count; must be zero or greater
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@param height pixel row count; must be zero or greater
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@return created SkImageInfo
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*/
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static SkImageInfo MakeA8(int width, int height) {
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return Make({width, height}, kAlpha_8_SkColorType, kPremul_SkAlphaType, nullptr);
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}
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/** Creates SkImageInfo from integral dimensions, kAlpha_8_SkColorType,
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kPremul_SkAlphaType, with SkColorSpace set to nullptr.
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@param dimensions pixel row and column count; must be zero or greater
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@return created SkImageInfo
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*/
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static SkImageInfo MakeA8(SkISize dimensions) {
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return Make(dimensions, kAlpha_8_SkColorType, kPremul_SkAlphaType, nullptr);
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}
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/** Creates SkImageInfo from integral dimensions width and height, kUnknown_SkColorType,
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kUnknown_SkAlphaType, with SkColorSpace set to nullptr.
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Returned SkImageInfo as part of source does not draw, and as part of destination
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can not be drawn to.
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@param width pixel column count; must be zero or greater
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@param height pixel row count; must be zero or greater
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@return created SkImageInfo
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*/
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static SkImageInfo MakeUnknown(int width, int height) {
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return Make({width, height}, kUnknown_SkColorType, kUnknown_SkAlphaType, nullptr);
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}
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/** Creates SkImageInfo from integral dimensions width and height set to zero,
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kUnknown_SkColorType, kUnknown_SkAlphaType, with SkColorSpace set to nullptr.
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Returned SkImageInfo as part of source does not draw, and as part of destination
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can not be drawn to.
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@return created SkImageInfo
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*/
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static SkImageInfo MakeUnknown() {
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return MakeUnknown(0, 0);
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}
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/** Returns pixel count in each row.
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@return pixel width
|
|
*/
|
|
int width() const { return fDimensions.width(); }
|
|
|
|
/** Returns pixel row count.
|
|
|
|
@return pixel height
|
|
*/
|
|
int height() const { return fDimensions.height(); }
|
|
|
|
SkColorType colorType() const { return fColorInfo.colorType(); }
|
|
|
|
SkAlphaType alphaType() const { return fColorInfo.alphaType(); }
|
|
|
|
/** 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 { return fColorInfo.colorSpace(); }
|
|
|
|
/** 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 { return fColorInfo.refColorSpace(); }
|
|
|
|
/** 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.
|
|
|
|
@return created SkImageInfo
|
|
*/
|
|
SkImageInfo makeAlphaType(SkAlphaType newAlphaType) const {
|
|
return Make(fDimensions, fColorInfo.makeAlphaType(newAlphaType));
|
|
}
|
|
|
|
/** Creates SkImageInfo with same SkAlphaType, SkColorSpace, width, and height,
|
|
with SkColorType set to newColorType.
|
|
|
|
@return created SkImageInfo
|
|
*/
|
|
SkImageInfo makeColorType(SkColorType newColorType) const {
|
|
return Make(fDimensions, fColorInfo.makeColorType(newColorType));
|
|
}
|
|
|
|
/** 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 {
|
|
return Make(fDimensions, fColorInfo.makeColorSpace(std::move(cs)));
|
|
}
|
|
|
|
/** 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
|
|
|
|
example: https://fiddle.skia.org/c/@ImageInfo_computeOffset
|
|
*/
|
|
size_t computeOffset(int x, int y, size_t rowBytes) const;
|
|
|
|
/** 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
|
|
*/
|
|
bool operator==(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
|
|
*/
|
|
bool operator!=(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
|
|
|
|
example: https://fiddle.skia.org/c/@ImageInfo_computeByteSize
|
|
*/
|
|
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
|
|
*/
|
|
static bool 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()) {
|
|
return false;
|
|
}
|
|
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;)
|
|
|
|
private:
|
|
SkColorInfo fColorInfo;
|
|
SkISize fDimensions = {0, 0};
|
|
|
|
SkImageInfo(SkISize dimensions, const SkColorInfo& colorInfo)
|
|
: fColorInfo(colorInfo), fDimensions(dimensions) {}
|
|
|
|
SkImageInfo(SkISize dimensions, SkColorInfo&& colorInfo)
|
|
: fColorInfo(std::move(colorInfo)), fDimensions(dimensions) {}
|
|
};
|
|
|
|
#endif
|