50Hz light phaser bug

[Naarshakta]

I was playing with the light phaser library and I figured out that the inlib_pollLightPhaser_position function does not work properly in 50Hz emulicious.
Note that in 60Hz, the function works fine.

From what I was able to dig in Emulicious, it seems to be this code that runs differently depending on the PAL/NTSC emulation :

inlib/src/inlib_phaser.c

Lines 46 to 55 in ea3eae6

	wait_th_lowA:
	in a, (#0xDD) ; Read port DD and check if bit
	and a, #0x40 ; 6 (TH port A) is low.
	jp Z, th_lowA ; If it is, light has been sensed!
	in a, (#0x7E) ; Read vertical counter port to
	cp a, #192 ; check if this frame is complete.
	jp C, wait_th_lowA
	jp frame_doneA

When I run step-by-step on 50Hz, I never step into the th_lowA function. Ending to fall in the phaser_common_timeout function...

Not sure if this a the core of the problem...

Here you have the code I use to test ( it's basically the same as the test file for phaser ) :

light_phaser_test.c.txt

[Naarshakta]

I was able to make it work on 50Hz SMS.

It was this code :

inlib/src/inlib_phaser.c

Lines 16 to 19 in ea3eae6

	wait_vblank_end:
	in a, (#0x7E) ; Read vertical counter port
	cp a, #192
	jp NC, wait_vblank_end ; Loop as long as count >= 192

That seems to don't work on 50Hz PAL SMS. So I changed it to this :

wait_vblank_end:
  in a, (#0x7E)                    ; Read vertical counter port
  or a                     
  jp NZ, wait_vblank_end           ; Loop as long as count is NOT 0

Not sure if this is the best solution, but it seems to work well enough.