| /* |
| * 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 "SkottieJson.h" |
| #include "SkottieValue.h" |
| #include "SkMakeUnique.h" |
| #include "SkSGRenderNode.h" |
| #include "SkSGScene.h" |
| #include "SkTLazy.h" |
| |
| namespace skottie { |
| namespace internal { |
| |
| sk_sp<sksg::RenderNode> AnimationBuilder::attachPrecompLayer(const skjson::ObjectValue& jlayer, |
| const LayerInfo&, |
| AnimatorScope* ascope) const { |
| const skjson::ObjectValue* time_remap = jlayer["tm"]; |
| // Empirically, a time mapper supersedes start/stretch. |
| const auto start_time = time_remap ? 0.0f : ParseDefault<float>(jlayer["st"], 0.0f), |
| stretch_time = time_remap ? 1.0f : ParseDefault<float>(jlayer["sr"], 1.0f); |
| const auto requires_time_mapping = !SkScalarNearlyEqual(start_time , 0) || |
| !SkScalarNearlyEqual(stretch_time, 1) || |
| time_remap; |
| |
| AnimatorScope local_animators; |
| auto precomp_layer = this->attachAssetRef(jlayer, |
| requires_time_mapping ? &local_animators : ascope, |
| [this] (const skjson::ObjectValue& jcomp, |
| AnimatorScope* ascope) { |
| return this->attachComposition(jcomp, ascope); |
| }); |
| |
| // Applies a bias/scale/remap t-adjustment to child animators. |
| class CompTimeMapper final : public sksg::GroupAnimator { |
| public: |
| CompTimeMapper(sksg::AnimatorList&& layer_animators, float time_bias, float time_scale) |
| : INHERITED(std::move(layer_animators)) |
| , fTimeBias(time_bias) |
| , fTimeScale(time_scale) {} |
| |
| void onTick(float t) override { |
| // When time remapping is active, |t| is driven externally. |
| if (fRemappedTime.isValid()) { |
| t = *fRemappedTime.get(); |
| } |
| |
| this->INHERITED::onTick((t + fTimeBias) * fTimeScale); |
| } |
| |
| void remapTime(float t) { fRemappedTime.set(t); } |
| |
| private: |
| const float fTimeBias, |
| fTimeScale; |
| SkTLazy<float> fRemappedTime; |
| |
| using INHERITED = sksg::GroupAnimator; |
| }; |
| |
| if (requires_time_mapping) { |
| const auto t_bias = -start_time, |
| t_scale = sk_ieee_float_divide(1, stretch_time); |
| auto time_mapper = |
| skstd::make_unique<CompTimeMapper>(std::move(local_animators), t_bias, |
| sk_float_isfinite(t_scale) ? t_scale : 0); |
| if (time_remap) { |
| // The lambda below captures a raw pointer to the mapper object. That should be safe, |
| // because both the lambda and the mapper are scoped/owned by ctx->fAnimators. |
| auto* raw_mapper = time_mapper.get(); |
| auto frame_rate = fFrameRate; |
| this->bindProperty<ScalarValue>(*time_remap, ascope, |
| [raw_mapper, frame_rate](const ScalarValue& t) { |
| raw_mapper->remapTime(t * frame_rate); |
| }); |
| } |
| ascope->push_back(std::move(time_mapper)); |
| } |
| |
| return precomp_layer; |
| } |
| |
| } // namespace internal |
| } // namespace skottie |