Based on my knowledge, there isn't a published minimum system requirement specification for Spine runtimes. The performance requirements indeed vary greatly depending on several factors you've already identified:
Factors affecting performance:
- Skeleton complexity (number of bones, attachments)
- Use of IK constraints
- Mesh deformation
- Texture atlas size and resolution
- Target frame rate
- Number of concurrent skeletons
For embedded systems like your Tamagotchi project:
The Spine runtimes are designed to be lightweight and portable. spine-c and spine-cpp are written in C99 and C++11 respectively, making them suitable for resource-constrained environments.
Practical considerations:
- The runtimes themselves have minimal memory overhead - most memory usage comes from loaded texture atlases and skeleton data
- CPU usage depends primarily on the number of bones being transformed and vertices being deformed each frame
- For a single, simple character (like a Tamagotchi), even modest embedded hardware should suffice
My recommendation:
Start with a prototype on your target board or a similar development board. Create a simplified version of your character in Spine and profile it on the actual hardware. This will give you concrete performance metrics for your specific use case.
If you're working with very constrained hardware, consider:
- Keeping skeleton complexity low (fewer bones)
- Using minimal or no mesh deformation
- Using smaller texture resolutions
- Reducing animation frame rate if needed
The best way to determine if your hardware is sufficient is real-world testing with your actual character design.
