rlottie/api: Added support for rendering without keeping aspect ratio

inc/rlottie.h

@@ -340,6 +340,7 @@ public:
      *
      *  @param[in] frameNo Content corresponds to the @p frameNo needs to be drawn
      *  @param[in] surface Surface in which content will be drawn
+     *  @param[in] keepAspectRatio whether to keep the aspect ratio while scaling the content.
      *
      *  @return future that will hold the result when rendering finished.
      *
@@ -348,7 +349,7 @@ public:
      *  @see Surface
      *  @internal
      */
-    std::future<Surface> render(size_t frameNo, Surface surface);
+    std::future<Surface> render(size_t frameNo, Surface surface, bool keepAspectRatio=true);
 
     /**
      *  @brief Renders the content to surface synchronously.
@@ -356,10 +357,11 @@ public:
      *
      *  @param[in] frameNo Content corresponds to the @p frameNo needs to be drawn
      *  @param[in] surface Surface in which content will be drawn
+     *  @param[in] keepAspectRatio whether to keep the aspect ratio while scaling the content.
      *
      *  @internal
      */
-    void              renderSync(size_t frameNo, Surface surface);
+    void              renderSync(size_t frameNo, Surface surface, bool keepAspectRatio=true);
 
     /**
      *  @brief Returns root layer of the composition updated with

src/lottie/lottieanimation.cpp

@@ -32,20 +32,21 @@ struct RenderTask {
     AnimationImpl *       playerImpl{nullptr};
     size_t                frameNo{0};
     Surface               surface;
+    bool                  keepAspectRatio{true};
 };
 using SharedRenderTask = std::shared_ptr<RenderTask>;
 
 class AnimationImpl {
 public:
     void    init(const std::shared_ptr<LOTModel> &model);
-    bool    update(size_t frameNo, const VSize &size);
+    bool    update(size_t frameNo, const VSize &size, bool keepAspectRatio);
     VSize   size() const { return mModel->size(); }
     double  duration() const { return mModel->duration(); }
     double  frameRate() const { return mModel->frameRate(); }
     size_t  totalFrame() const { return mModel->totalFrame(); }
     size_t  frameAtPos(double pos) const { return mModel->frameAtPos(pos); }
-    Surface render(size_t frameNo, const Surface &surface);
+    Surface render(size_t frameNo, const Surface &surface, bool keepAspectRatio);
-    std::future<Surface> renderAsync(size_t frameNo, Surface &&surface);
+    std::future<Surface> renderAsync(size_t frameNo, Surface &&surface, bool keepAspectRatio);
     const LOTLayerNode * renderTree(size_t frameNo, const VSize &size);
 
     const LayerInfoList &layerInfoList() const
@@ -71,13 +72,13 @@ void AnimationImpl::setValue(const std::string &keypath, LOTVariant &&value)
 
 const LOTLayerNode *AnimationImpl::renderTree(size_t frameNo, const VSize &size)
 {
-    if (update(frameNo, size)) {
+    if (update(frameNo, size, true)) {
         mCompItem->buildRenderTree();
     }
     return mCompItem->renderTree();
 }
 
-bool AnimationImpl::update(size_t frameNo, const VSize &size)
+bool AnimationImpl::update(size_t frameNo, const VSize &size, bool keepAspectRatio)
 {
     frameNo += mModel->startFrame();
 
@@ -85,11 +86,10 @@ bool AnimationImpl::update(size_t frameNo, const VSize &size)
 
     if (frameNo < mModel->startFrame()) frameNo = mModel->startFrame();
 
-    mCompItem->resize(size);
+    return mCompItem->update(int(frameNo), size, keepAspectRatio);
-    return mCompItem->update(int(frameNo));
 }
 
-Surface AnimationImpl::render(size_t frameNo, const Surface &surface)
+Surface AnimationImpl::render(size_t frameNo, const Surface &surface, bool keepAspectRatio)
 {
     bool renderInProgress = mRenderInProgress.load();
     if (renderInProgress) {
@@ -99,7 +99,7 @@ Surface AnimationImpl::render(size_t frameNo, const Surface &surface)
 
     mRenderInProgress.store(true);
     update(frameNo,
-           VSize(int(surface.drawRegionWidth()), int(surface.drawRegionHeight())));
+           VSize(int(surface.drawRegionWidth()), int(surface.drawRegionHeight())), keepAspectRatio);
     mCompItem->render(surface);
     mRenderInProgress.store(false);
 
@@ -149,7 +149,7 @@ class RenderTaskScheduler {
             if (!success && !_q[i].pop(task)) break;
 
             auto result =
-                task->playerImpl->render(task->frameNo, task->surface);
+                task->playerImpl->render(task->frameNo, task->surface, task->keepAspectRatio);
             task->sender.set_value(result);
         }
     }
@@ -211,7 +211,8 @@ public:
 #endif
 
 std::future<Surface> AnimationImpl::renderAsync(size_t    frameNo,
-                                                Surface &&surface)
+                                                Surface &&surface,
+                                                bool keepAspectRatio)
 {
     if (!mTask) {
         mTask = std::make_shared<RenderTask>();
@@ -222,6 +223,7 @@ std::future<Surface> AnimationImpl::renderAsync(size_t    frameNo,
     mTask->playerImpl = this;
     mTask->frameNo = frameNo;
     mTask->surface = std::move(surface);
+    mTask->keepAspectRatio = keepAspectRatio;
 
     return RenderTaskScheduler::instance().process(mTask);
 }
@@ -300,14 +302,14 @@ const LOTLayerNode *Animation::renderTree(size_t frameNo, size_t width,
     return d->renderTree(frameNo, VSize(int(width), int(height)));
 }
 
-std::future<Surface> Animation::render(size_t frameNo, Surface surface)
+std::future<Surface> Animation::render(size_t frameNo, Surface surface, bool keepAspectRatio)
 {
-    return d->renderAsync(frameNo, std::move(surface));
+    return d->renderAsync(frameNo, std::move(surface), keepAspectRatio);
 }
 
-void Animation::renderSync(size_t frameNo, Surface surface)
+void Animation::renderSync(size_t frameNo, Surface surface, bool keepAspectRatio)
 {
-    d->render(frameNo, surface);
+    d->render(frameNo, surface, keepAspectRatio);
 }
 
 const LayerInfoList &Animation::layers() const

src/lottie/lottieitem.cpp

@@ -70,7 +70,7 @@ static bool strokeProp(rlottie::Property prop)
 }
 
 LOTCompItem::LOTCompItem(LOTModel *model)
-    : mUpdateViewBox(false), mCurFrameNo(-1)
+    : mCurFrameNo(-1)
 {
     mCompData = model->mRoot.get();
     mRootLayer = createLayerItem(mCompData->mRootLayer.get());
@@ -109,38 +109,36 @@ std::unique_ptr<LOTLayerItem> LOTCompItem::createLayerItem(
     }
 }
 
-void LOTCompItem::resize(const VSize &size)
+bool LOTCompItem::update(int frameNo, const VSize &size, bool keepAspectRatio)
-{
-    if (mViewSize == size) return;
-    mViewSize = size;
-    mUpdateViewBox = true;
-}
-
-bool LOTCompItem::update(int frameNo)
 {
     // check if cached frame is same as requested frame.
-    if (!mUpdateViewBox && (mCurFrameNo == frameNo)) return false;
+    if ((mViewSize == size) &&
+        (mCurFrameNo == frameNo) &&
+        (mKeepAspectRatio == keepAspectRatio)) return false;
+
+    mViewSize = size;
+    mCurFrameNo = frameNo;
+    mKeepAspectRatio = keepAspectRatio;
 
     /*
      * if viewbox dosen't scale exactly to the viewport
      * we scale the viewbox keeping AspectRatioPreserved and then align the
      * viewbox to the viewport using AlignCenter rule.
      */
+    VMatrix m;
     VSize viewPort = mViewSize;
     VSize viewBox = mCompData->size();
-
     float sx = float(viewPort.width()) / viewBox.width();
     float sy = float(viewPort.height()) / viewBox.height();
+    if (mKeepAspectRatio) {
         float scale = std::min(sx, sy);
         float tx = (viewPort.width() - viewBox.width() * scale) * 0.5f;
         float ty = (viewPort.height() - viewBox.height() * scale) * 0.5f;
-
-    VMatrix m;
         m.translate(tx, ty).scale(scale, scale);
+    } else {
+       m.scale(sx, sy);
+    }
     mRootLayer->update(frameNo, m, 1.0);
-
-    mCurFrameNo = frameNo;
-    mUpdateViewBox = false;
     return true;
 }
 

src/lottie/lottieitem.h

@@ -65,8 +65,7 @@ class LOTCompItem
 public:
    explicit LOTCompItem(LOTModel *model);
    static std::unique_ptr<LOTLayerItem> createLayerItem(LOTLayerData *layerData);
-   bool update(int frameNo);
+   bool update(int frameNo, const VSize &size, bool keepAspectRatio);
-   void resize(const VSize &size);
    VSize size() const { return mViewSize;}
    void buildRenderTree();
    const LOTLayerNode * renderTree()const;
@@ -77,7 +76,7 @@ private:
    VSize                                       mViewSize;
    LOTCompositionData                         *mCompData;
    std::unique_ptr<LOTLayerItem>               mRootLayer;
-   bool                                        mUpdateViewBox;
+   bool                                        mKeepAspectRatio{true};
    int                                         mCurFrameNo;
    std::vector<LOTNode *>                      mRenderList;
    std::vector<VDrawable *>                    mDrawableList;