SDL example has low FPS on Android

[SasLuca]

I compiled and ran the example using SDL3 on Android. I get around 20fps on both a physical Pixel 6 and a Pixel 3 emulator.

I tried disabling NVGL_DEBUG and trying various flags but I only managed to get the fps lower.

Are there any considerations I should be aware of when compiling the demo on Android/iOS to get high fps?

[THZthz]

It emits too many draw calls to GPU, and frequent memory copy/move on CPU.

[pbsurf]

The SDL example has several screens, with different FPS (tapping the screen cycles through them). On a physical Pixel 3 (with the "vtex" backend), the animated UI demo (from the original nanovg) runs at 50 FPS, the large rectangle demo 50 FPS, and the many small paths demo at 9 FPS.