chromium/third_party/skia/modules/skottie/src/effects/LevelsEffect.cpp

/*
 * Copyright 2019 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

#include "include/core/SkColorFilter.h"
#include "include/core/SkRefCnt.h"
#include "include/core/SkScalar.h"
#include "include/private/base/SkAssert.h"
#include "include/private/base/SkFloatingPoint.h"
#include "include/private/base/SkTPin.h"
#include "modules/skottie/src/Adapter.h"
#include "modules/skottie/src/SkottiePriv.h"
#include "modules/skottie/src/SkottieValue.h"
#include "modules/skottie/src/effects/Effects.h"
#include "modules/sksg/include/SkSGColorFilter.h"
#include "modules/sksg/include/SkSGRenderNode.h"

#include <algorithm>
#include <array>
#include <cmath>
#include <cstddef>
#include <cstdint>
#include <utility>

namespace skjson {
class ArrayValue;
}

namespace skottie {
namespace internal {

namespace  {

struct ClipInfo { … };

struct ChannelMapper { … };

// ADBE Easy Levels2 color correction effect.
//
// Maps the selected channel(s) from [inBlack...inWhite] to [outBlack, outWhite],
// based on a gamma exponent.
//
// For [i0..i1] -> [o0..o1]:
//
//   c' = o0 + (o1 - o0) * ((c - i0) / (i1 - i0)) ^ G
//
// The output is optionally clipped to the output range.
//
// In/out intervals are clampped to [0..1].  Inversion is allowed.

class EasyLevelsEffectAdapter final : public DiscardableAdapterBase<EasyLevelsEffectAdapter,
                                                                    sksg::ExternalColorFilter> { … };

// ADBE Pro Levels2 color correction effect.
//
// Similar to ADBE Easy Levels2, but offers separate controls for each channel.

class ProLevelsEffectAdapter final : public DiscardableAdapterBase<ProLevelsEffectAdapter,
                                                                   sksg::ExternalColorFilter> { … };

}  // namespace

sk_sp<sksg::RenderNode> EffectBuilder::attachEasyLevelsEffect(const skjson::ArrayValue& jprops,
                                                              sk_sp<sksg::RenderNode> layer) const { … }

sk_sp<sksg::RenderNode> EffectBuilder::attachProLevelsEffect(const skjson::ArrayValue& jprops,
                                                             sk_sp<sksg::RenderNode> layer) const { … }

} // namespace internal
} // namespace skottie