drm: make pageflips drive the frames

[gulafaran]

make the pageflips drive the frames instead of waiting on the idle dispatch, it adds unnecessery latency at the beginning of each frame.

[vaxerski]

I dont understand what this changes

[gulafaran]

I dont understand what this changes

instead of output->commit(), pageflip waits for fence in the waylandloop, poof triggers and emits presented. but since other things have scheduled frames this pageflip will not begin rendering nor frame.emit(). it returns and wastes time in handling other junk. before the waylandloop finally dispatches the idleframe callback and doing frame.emit().

what it is attempting to do instead is once the pageflip occurs, it emits.frame() and continues. HL itself wont commit or schedule frames if it isnt necessery and as such the idleframe callback becomes more of a begin rendering when idle, instead of the driving function for frame.emit() "when things are continously occuring"

that start of each frame delay is measurable

[vaxerski]

k