Fix crash on controlSize when image not yet available

Fixes the crash reported here https://2dimensions.slack.com/archives/C078KG6KAJY/p1729725850289449.

For referenced images, we need to store off the layout size and update its size after the image has loaded, so we have its width and height in order to properly scale it to the layout's bounds.

Diffs=
4fec171eac Fix crash on controlSize when image not yet available (#8414)

Co-authored-by: Philip Chung <philterdesign@gmail.com>

.rive_head

@@ -1 +1 @@
-bb3b386c1515ec9e14d7ca583b62da24d7f33a88
+4fec171eac63c83a5c0a6d7abb3df0945d82775c

include/rive/assets/image_asset.hpp

@@ -4,6 +4,7 @@
 #include "rive/generated/assets/image_asset_base.hpp"
 #include "rive/renderer.hpp"
 #include "rive/simple_array.hpp"
+#include <functional>
 #include <string>
 
 namespace rive
@@ -12,6 +13,7 @@ class ImageAsset : public ImageAssetBase
 {
 private:
     rcp<RenderImage> m_RenderImage;
+    std::function<void()> m_imageReadyCallback = nullptr;
 
 public:
     ImageAsset() {}
@@ -24,6 +26,10 @@ class ImageAsset : public ImageAssetBase
     std::string fileExtension() const override;
     RenderImage* renderImage() const { return m_RenderImage.get(); }
     void renderImage(rcp<RenderImage> renderImage);
+    void onImageReady(std::function<void()> callback)
+    {
+        m_imageReadyCallback = callback;
+    }
 };
 } // namespace rive
 

include/rive/shapes/image.hpp

@@ -16,6 +16,11 @@ class Image : public ImageBase, public FileAssetReferencer
 {
 private:
     MeshDrawable* m_Mesh = nullptr;
+    // Since layouts only pass down width/height we store those
+    // and use the image width/height to compute the proper scale
+    float m_layoutWidth = NAN;
+    float m_layoutHeight = NAN;
+    void updateImageScale();
 
 public:
     void setMesh(MeshDrawable* mesh);

src/assets/image_asset.cpp

@@ -12,6 +12,10 @@ bool ImageAsset::decode(SimpleArray<uint8_t>& data, Factory* factory)
     decodedByteSize = data.size();
 #endif
     renderImage(factory->decodeImage(data));
+    if (m_imageReadyCallback != nullptr)
+    {
+        m_imageReadyCallback();
+    }
     return m_RenderImage != nullptr;
 }
 

src/shapes/image.cpp

@@ -107,6 +107,8 @@ void Image::setAsset(FileAsset* asset)
         {
             m_Mesh->onAssetLoaded(imageAsset()->renderImage());
         }
+        asset->as<ImageAsset>()->onImageReady([&]() { updateImageScale(); });
+        updateImageScale();
     }
 }
 
@@ -189,14 +191,31 @@ Vec2D Image::measureLayout(float width,
 
 void Image::controlSize(Vec2D size)
 {
-    auto renderImage = imageAsset()->renderImage();
-    auto newScaleX = size.x / renderImage->width();
-    auto newScaleY = size.y / renderImage->height();
-    if (newScaleX != scaleX() || newScaleY != scaleY())
+    // We store layout width/height because the image asset may not be available
+    // yet (referenced images) and we have defer controlling its size
+    if (m_layoutWidth != size.x || m_layoutHeight != size.y)
     {
-        scaleX(newScaleX);
-        scaleY(newScaleY);
-        addDirt(ComponentDirt::WorldTransform, false);
+        m_layoutWidth = size.x;
+        m_layoutHeight = size.y;
+
+        updateImageScale();
+    }
+}
+
+void Image::updateImageScale()
+{
+    if (imageAsset() != nullptr && imageAsset()->renderImage() != nullptr &&
+        !std::isnan(m_layoutWidth) && !std::isnan(m_layoutHeight))
+    {
+        auto renderImage = imageAsset()->renderImage();
+        auto newScaleX = m_layoutWidth / renderImage->width();
+        auto newScaleY = m_layoutHeight / renderImage->height();
+        if (newScaleX != scaleX() || newScaleY != scaleY())
+        {
+            scaleX(newScaleX);
+            scaleY(newScaleY);
+            addDirt(ComponentDirt::WorldTransform, false);
+        }
     }
 }