Improve Audio Wave Form Rendering in Song Editor

[achimmihca]

Actual behaviour

• the audio wave disappears when scrolling in the song editor. After stopping, it is rendered again.

Expected behaviour

• The audio wave form should always be visible, also during scrolling.

Implementation

• Currently, the audio wave form is drawn only when the viewport is stable for performance reasons.
  • Current approach to draw the audio wave form: get audio samples for visible viewport, compute audio wave form (i.e. calculating min and max audio sample values in sliding window), draw audio wave form on texture pixel by pixel. All this is done on the CPU
• Needs a prototype to draw an audio wave form more efficiently. Maybe this can be done with a shader.

[achimmihca]

Maybe this can be done with a shader.

Unity does not yet support custom shaders for rendering UI Toolkit elements. However, I found that most of the time is spent for the calculation of the wave form. Applying it to the texture takes only few milliseconds.

The audio wave form should always be visible, also during scrolling.

This has been implemented in Melody Mania v1.4.1