Add frametime-based dynamic resolution in FSR 2.0 sample

[Calinou]

I noticed that in the official FSR 2.0 sample, the Dynamic resolution checkbox only makes the resolution vary in a sine wave (from 0.5× scaling on each axis to 1.0×).

Would it be possible to add dynamic resolution based on a framerate target which the user can define (while keeping the sine wave option for debugging purposes)? This would make it more representative of a typical use of DRS in a game. It would likely need to expose a few adjustment knobs, such as:

• Target FPS
• Resolution scale percent increase per frame when above target
• Resolution scale percent decrease per frame when below target (should be more aggressive than the above)
• Minimum resolution scale
• Maximum resolution scale

This would improve FSR2's image quality by maximizing the use of the frametime budget, as dynamic resolution + temporal upscaling is often a very effective combination.