blob: 936e8ed654e6167b6fd17bfe02aa3e7d7f862929 [file] [log] [blame]
* Copyright 2017 Google Inc.
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
#include "include/effects/SkHighContrastFilter.h"
#include "include/core/SkAlphaType.h"
#include "include/core/SkColorFilter.h"
#include "include/core/SkColorSpace.h"
#include "include/core/SkData.h"
#include "include/core/SkRefCnt.h"
#include "include/core/SkTypes.h"
#include "include/effects/SkRuntimeEffect.h"
#include "include/private/base/SkTPin.h"
#include "modules/skcms/skcms.h"
#include "src/core/SkColorFilterPriv.h"
#include "src/core/SkKnownRuntimeEffects.h"
#include <cfloat>
sk_sp<SkColorFilter> SkHighContrastFilter::Make(const SkHighContrastConfig& config) {
if (!config.isValid()) {
return nullptr;
struct Uniforms { float grayscale, invertStyle, contrast; };
// A contrast setting of exactly +1 would divide by zero (1+c)/(1-c), so pull in to +1-ε.
// I'm not exactly sure why we've historically pinned -1 up to -1+ε, maybe just symmetry?
float c = SkTPin(config.fContrast,
-1.0f + FLT_EPSILON,
+1.0f - FLT_EPSILON);
Uniforms uniforms = {
config.fGrayscale ? 1.0f : 0.0f,
(float)config.fInvertStyle, // 0.0f for none, 1.0f for brightness, 2.0f for lightness
const SkRuntimeEffect* highContrastEffect =
skcms_TransferFunction linear = SkNamedTransferFn::kLinear;
SkAlphaType unpremul = kUnpremul_SkAlphaType;
return SkColorFilterPriv::WithWorkingFormat(
&linear, nullptr/*use dst gamut*/, &unpremul);