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

/*
 * Copyright 2020 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/SkCanvas.h"
#include "include/core/SkM44.h"
#include "include/core/SkMatrix.h"
#include "include/core/SkPaint.h"
#include "include/core/SkPicture.h"
#include "include/core/SkPictureRecorder.h"
#include "include/core/SkRect.h"
#include "include/core/SkRefCnt.h"
#include "include/core/SkSamplingOptions.h"
#include "include/core/SkScalar.h"
#include "include/core/SkShader.h"
#include "include/core/SkSize.h"
#include "include/core/SkString.h"
#include "include/core/SkTileMode.h"
#include "include/effects/SkRuntimeEffect.h"
#include "include/private/SkColorData.h"
#include "include/private/base/SkAssert.h"
#include "modules/skottie/src/Adapter.h"
#include "modules/skottie/src/Layer.h"
#include "modules/skottie/src/SkottieJson.h"
#include "modules/skottie/src/SkottiePriv.h"
#include "modules/skottie/src/SkottieValue.h"
#include "modules/skottie/src/effects/Effects.h"
#include "modules/sksg/include/SkSGNode.h"
#include "modules/sksg/include/SkSGRenderNode.h"
#include "src/utils/SkJSON.h"

#include <algorithm>
#include <cmath>
#include <cstdio>
#include <tuple>
#include <utility>
#include <vector>

struct SkPoint;

namespace sksg {
class InvalidationController;
}

namespace skottie::internal {
namespace {

// AE's displacement map effect [1] is somewhat similar to SVG's feDisplacementMap [2].  Main
// differences:
//
//   - more selector options: full/half/off, luminance, hue/saturation/lightness
//   - the scale factor is anisotropic (independent x/y values)
//   - displacement coverage is restricted to non-transparent source for some selectors
//     (specifically: r, g, b, h, s, l).
//
// [1] https://helpx.adobe.com/after-effects/using/distort-effects.html#displacement_map_effect
// [2] https://www.w3.org/TR/SVG11/filters.html#feDisplacementMapElement

// |selector_matrix| and |selector_offset| are set up to select and scale the x/y displacement
// in R/G, and the x/y coverage modulation in B/A.
static constexpr char gDisplacementSkSL[] = …
;

static sk_sp<SkRuntimeEffect> displacement_effect_singleton() { … }

class DisplacementNode final : public sksg::CustomRenderNode { … };

class DisplacementMapAdapter final : public DiscardableAdapterBase<DisplacementMapAdapter,
                                                                   DisplacementNode> { … };

} // namespace

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

} // namespace skottie::internal