modules/skottie/src/SkottieLayerEffect.cpp

/*
 * Copyright 2018 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

#include "SkottiePriv.h"

#include "SkJSON.h"
#include "SkottieAdapter.h"
#include "SkottieJson.h"
#include "SkottieValue.h"
#include "SkSGColor.h"
#include "SkSGRenderEffect.h"
#include "SkSGColorFilter.h"

namespace skottie {
namespace internal {

namespace {

sk_sp<sksg::RenderNode> AttachTintLayerEffect(const skjson::ArrayValue& jprops,
                                              const AnimationBuilder* abuilder,
                                              AnimatorScope* ascope,
                                              sk_sp<sksg::RenderNode> layer) {
    enum : size_t {
        kMapBlackTo_Index = 0,
        kMapWhiteTo_Index = 1,
        kAmount_Index     = 2,
        // kOpacity_Index    = 3, // currently unused (not exported)

        kMax_Index      = kAmount_Index,
    };

    if (jprops.size() <= kMax_Index) {
        return nullptr;
    }

    const skjson::ObjectValue* color0_prop = jprops[kMapBlackTo_Index];
    const skjson::ObjectValue* color1_prop = jprops[kMapWhiteTo_Index];
    const skjson::ObjectValue* amount_prop = jprops[    kAmount_Index];

    if (!color0_prop || !color1_prop || !amount_prop) {
        return nullptr;
    }

    auto tint_node =
            sksg::GradientColorFilter::Make(std::move(layer),
                                            abuilder->attachColor(*color0_prop, ascope, "v"),
                                            abuilder->attachColor(*color1_prop, ascope, "v"));
    if (!tint_node) {
        return nullptr;
    }

    abuilder->bindProperty<ScalarValue>((*amount_prop)["v"], ascope,
        [tint_node](const ScalarValue& w) {
            tint_node->setWeight(w / 100); // 100-based
        });

    return std::move(tint_node);
}

sk_sp<sksg::RenderNode> AttachTritoneLayerEffect(const skjson::ArrayValue& jprops,
                                                 const AnimationBuilder* abuilder,
                                                 AnimatorScope* ascope,
                                                 sk_sp<sksg::RenderNode> layer) {
    enum : size_t {
        kHiColor_Index     = 0,
        kMiColor_Index     = 1,
        kLoColor_Index     = 2,
        kBlendAmount_Index = 3,

        kMax_Index      = kBlendAmount_Index,
    };

    if (jprops.size() <= kMax_Index) {
        return nullptr;
    }

    const skjson::ObjectValue* hicolor_prop = jprops[    kHiColor_Index];
    const skjson::ObjectValue* micolor_prop = jprops[    kMiColor_Index];
    const skjson::ObjectValue* locolor_prop = jprops[    kLoColor_Index];
    const skjson::ObjectValue*   blend_prop = jprops[kBlendAmount_Index];

    if (!hicolor_prop || !micolor_prop || !locolor_prop || !blend_prop) {
        return nullptr;
    }

    auto tritone_node =
            sksg::GradientColorFilter::Make(std::move(layer), {
                                            abuilder->attachColor(*locolor_prop, ascope, "v"),
                                            abuilder->attachColor(*micolor_prop, ascope, "v"),
                                            abuilder->attachColor(*hicolor_prop, ascope, "v") });
    if (!tritone_node) {
        return nullptr;
    }

    abuilder->bindProperty<ScalarValue>((*blend_prop)["v"], ascope,
        [tritone_node](const ScalarValue& w) {
            tritone_node->setWeight((100 - w) / 100); // 100-based, inverted (!?).
        });

    return std::move(tritone_node);
}

sk_sp<sksg::RenderNode> AttachFillLayerEffect(const skjson::ArrayValue& jprops,
                                              const AnimationBuilder* abuilder,
                                              AnimatorScope* ascope,
                                              sk_sp<sksg::RenderNode> layer) {
    enum : size_t {
        kFillMask_Index = 0,
        kAllMasks_Index = 1,
        kColor_Index    = 2,
        kInvert_Index   = 3,
        kHFeather_Index = 4,
        kVFeather_Index = 5,
        kOpacity_Index  = 6,

        kMax_Index      = kOpacity_Index,
    };

    if (jprops.size() <= kMax_Index) {
        return nullptr;
    }

    const skjson::ObjectValue*   color_prop = jprops[  kColor_Index];
    const skjson::ObjectValue* opacity_prop = jprops[kOpacity_Index];
    if (!color_prop || !opacity_prop) {
        return nullptr;
    }

    sk_sp<sksg::Color> color_node = abuilder->attachColor(*color_prop, ascope, "v");
    if (!color_node) {
        return nullptr;
    }

    abuilder->bindProperty<ScalarValue>((*opacity_prop)["v"], ascope,
        [color_node](const ScalarValue& o) {
            const auto c = color_node->getColor();
            const auto a = sk_float_round2int_no_saturate(SkTPin(o, 0.0f, 1.0f) * 255);
            color_node->setColor(SkColorSetA(c, a));
        });

    return sksg::ModeColorFilter::Make(std::move(layer),
                                       std::move(color_node),
                                       SkBlendMode::kSrcIn);
}

sk_sp<sksg::RenderNode> AttachDropShadowLayerEffect(const skjson::ArrayValue& jprops,
                                                    const AnimationBuilder* abuilder,
                                                    AnimatorScope* ascope,
                                                    sk_sp<sksg::RenderNode> layer) {
    enum : size_t {
        kShadowColor_Index = 0,
        kOpacity_Index     = 1,
        kDirection_Index   = 2,
        kDistance_Index    = 3,
        kSoftness_Index    = 4,
        kShadowOnly_Index  = 5,

        kMax_Index      = kShadowOnly_Index,
    };

    if (jprops.size() <= kMax_Index) {
        return nullptr;
    }

    const skjson::ObjectValue*       color_prop = jprops[kShadowColor_Index];
    const skjson::ObjectValue*     opacity_prop = jprops[    kOpacity_Index];
    const skjson::ObjectValue*   direction_prop = jprops[  kDirection_Index];
    const skjson::ObjectValue*    distance_prop = jprops[   kDistance_Index];
    const skjson::ObjectValue*    softness_prop = jprops[   kSoftness_Index];
    const skjson::ObjectValue* shadow_only_prop = jprops[ kShadowOnly_Index];

    if (!color_prop ||
        !opacity_prop ||
        !direction_prop ||
        !distance_prop ||
        !softness_prop ||
        !shadow_only_prop) {
        return nullptr;
    }

    auto shadow_effect  = sksg::DropShadowImageFilter::Make();
    auto shadow_adapter = sk_make_sp<DropShadowEffectAdapter>(shadow_effect);

    abuilder->bindProperty<VectorValue>((*color_prop)["v"], ascope,
        [shadow_adapter](const VectorValue& c) {
            shadow_adapter->setColor(ValueTraits<VectorValue>::As<SkColor>(c));
        });
    abuilder->bindProperty<ScalarValue>((*opacity_prop)["v"], ascope,
        [shadow_adapter](const ScalarValue& o) {
            shadow_adapter->setOpacity(o);
        });
    abuilder->bindProperty<ScalarValue>((*direction_prop)["v"], ascope,
        [shadow_adapter](const ScalarValue& d) {
            shadow_adapter->setDirection(d);
        });
    abuilder->bindProperty<ScalarValue>((*distance_prop)["v"], ascope,
        [shadow_adapter](const ScalarValue& d) {
            shadow_adapter->setDistance(d);
        });
    abuilder->bindProperty<ScalarValue>((*softness_prop)["v"], ascope,
        [shadow_adapter](const ScalarValue& s) {
            shadow_adapter->setSoftness(s);
        });
    abuilder->bindProperty<ScalarValue>((*shadow_only_prop)["v"], ascope,
        [shadow_adapter](const ScalarValue& s) {
            shadow_adapter->setShadowOnly(SkToBool(s));
        });

    return sksg::ImageFilterEffect::Make(std::move(layer), std::move(shadow_effect));
}

} // namespace

sk_sp<sksg::RenderNode> AnimationBuilder::attachLayerEffects(const skjson::ArrayValue& jeffects,
                                                             AnimatorScope* ascope,
                                                             sk_sp<sksg::RenderNode> layer) const {
    if (!layer) {
        return nullptr;
    }

    enum : int32_t {
        kTint_Effect       = 20,
        kFill_Effect       = 21,
        kTritone_Effect    = 23,
        kDropShadow_Effect = 25,
    };

    for (const skjson::ObjectValue* jeffect : jeffects) {
        if (!jeffect) {
            continue;
        }

        const skjson::ArrayValue* jprops = (*jeffect)["ef"];
        if (!jprops) {
            continue;
        }

        switch (const auto ty = ParseDefault<int>((*jeffect)["ty"], -1)) {
        case kTint_Effect:
            layer = AttachTintLayerEffect(*jprops, this, ascope, std::move(layer));
            break;
        case kFill_Effect:
            layer = AttachFillLayerEffect(*jprops, this, ascope, std::move(layer));
            break;
        case kTritone_Effect:
            layer = AttachTritoneLayerEffect(*jprops, this, ascope, std::move(layer));
            break;
        case kDropShadow_Effect:
            layer = AttachDropShadowLayerEffect(*jprops, this, ascope, std::move(layer));
            break;
        default:
            this->log(Logger::Level::kWarning, nullptr, "Unsupported layer effect type: %d.", ty);
            break;
        }

        if (!layer) {
            this->log(Logger::Level::kError, jeffect, "Invalid layer effect.");
            return nullptr;
        }
    }

    return layer;
}

} // namespace internal
} // namespace skottie