skia2/include/core/SkBlendMode.h
Michael Ludwig cc836871cb Make SkBlendMode_AsCoeff() public
Change-Id: Ie704f0f83b1034ff8ee1a5d3cd194e555cae20a3
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/252600
Commit-Queue: Michael Ludwig <michaelludwig@google.com>
Commit-Queue: Mike Klein <mtklein@google.com>
Auto-Submit: Michael Ludwig <michaelludwig@google.com>
Reviewed-by: Mike Klein <mtklein@google.com>
2019-11-04 20:41:56 +00:00

94 lines
4.9 KiB
C

/*
* Copyright 2016 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#ifndef SkBlendMode_DEFINED
#define SkBlendMode_DEFINED
#include "include/core/SkTypes.h"
enum class SkBlendMode {
kClear, //!< replaces destination with zero: fully transparent
kSrc, //!< replaces destination
kDst, //!< preserves destination
kSrcOver, //!< source over destination
kDstOver, //!< destination over source
kSrcIn, //!< source trimmed inside destination
kDstIn, //!< destination trimmed by source
kSrcOut, //!< source trimmed outside destination
kDstOut, //!< destination trimmed outside source
kSrcATop, //!< source inside destination blended with destination
kDstATop, //!< destination inside source blended with source
kXor, //!< each of source and destination trimmed outside the other
kPlus, //!< sum of colors
kModulate, //!< product of premultiplied colors; darkens destination
kScreen, //!< multiply inverse of pixels, inverting result; brightens destination
kLastCoeffMode = kScreen, //!< last porter duff blend mode
kOverlay, //!< multiply or screen, depending on destination
kDarken, //!< darker of source and destination
kLighten, //!< lighter of source and destination
kColorDodge, //!< brighten destination to reflect source
kColorBurn, //!< darken destination to reflect source
kHardLight, //!< multiply or screen, depending on source
kSoftLight, //!< lighten or darken, depending on source
kDifference, //!< subtract darker from lighter with higher contrast
kExclusion, //!< subtract darker from lighter with lower contrast
kMultiply, //!< multiply source with destination, darkening image
kLastSeparableMode = kMultiply, //!< last blend mode operating separately on components
kHue, //!< hue of source with saturation and luminosity of destination
kSaturation, //!< saturation of source with hue and luminosity of destination
kColor, //!< hue and saturation of source with luminosity of destination
kLuminosity, //!< luminosity of source with hue and saturation of destination
kLastMode = kLuminosity, //!< last valid value
};
/**
* For Porter-Duff SkBlendModes (those <= kLastCoeffMode), these coefficients describe the blend
* equation used. Coefficient-based blend modes specify an equation:
* ('dstCoeff' * dst + 'srcCoeff' * src), where the coefficient values are constants, functions of
* the src or dst alpha, or functions of the src or dst color.
*/
enum class SkBlendModeCoeff {
kZero, /** 0 */
kOne, /** 1 */
kSC, /** src color */
kISC, /** inverse src color (i.e. 1 - sc) */
kDC, /** dst color */
kIDC, /** inverse dst color (i.e. 1 - dc) */
kSA, /** src alpha */
kISA, /** inverse src alpha (i.e. 1 - sa) */
kDA, /** dst alpha */
kIDA, /** inverse dst alpha (i.e. 1 - da) */
kCoeffCount
};
/**
* Returns true if 'mode' is a coefficient-based blend mode (<= kLastCoeffMode). If true is
* returned, the mode's src and dst coefficient functions are set in 'src' and 'dst'.
*/
SK_API bool SkBlendMode_AsCoeff(SkBlendMode mode, SkBlendModeCoeff* src, SkBlendModeCoeff* dst);
/** Returns name of blendMode as null-terminated C string.
@param blendMode one of:
SkBlendMode::kClear, SkBlendMode::kSrc, SkBlendMode::kDst,
SkBlendMode::kSrcOver, SkBlendMode::kDstOver, SkBlendMode::kSrcIn,
SkBlendMode::kDstIn, SkBlendMode::kSrcOut, SkBlendMode::kDstOut,
SkBlendMode::kSrcATop, SkBlendMode::kDstATop, SkBlendMode::kXor,
SkBlendMode::kPlus, SkBlendMode::kModulate, SkBlendMode::kScreen,
SkBlendMode::kOverlay, SkBlendMode::kDarken, SkBlendMode::kLighten,
SkBlendMode::kColorDodge, SkBlendMode::kColorBurn, SkBlendMode::kHardLight,
SkBlendMode::kSoftLight, SkBlendMode::kDifference, SkBlendMode::kExclusion,
SkBlendMode::kMultiply, SkBlendMode::kHue, SkBlendMode::kSaturation,
SkBlendMode::kColor, SkBlendMode::kLuminosity
@return C string
*/
SK_API const char* SkBlendMode_Name(SkBlendMode blendMode);
#endif