Scaling an entire screen

Anything QL Software or Programming Related.
User avatar
mk79
QL Wafer Drive
Posts: 1349
Joined: Sun Feb 02, 2014 10:54 am
Location: Esslingen/Germany
Contact:

Re: Scaling an entire screen

Post by mk79 »

bwinkel67 wrote:Why was the coordinate system changed for NTSC?
I guess because pixels have a different shape/ratio and thus circles weren't circles with the PAL settings. I personally think it's a mistake, but well.


User avatar
bwinkel67
QL Wafer Drive
Posts: 1187
Joined: Thu Oct 03, 2019 2:09 am

Re: Scaling an entire screen

Post by bwinkel67 »

mk79 wrote:
bwinkel67 wrote:Why was the coordinate system changed for NTSC?
I guess because pixels have a different shape/ratio and thus circles weren't circles with the PAL settings. I personally think it's a mistake, but well.
But they don't have different apsect ratio. In Monitor mode, both NTSC and PAL give you 512x256 so it's one-to-one. It doesn't make sense to me why the coordinate system is different.


User avatar
mk79
QL Wafer Drive
Posts: 1349
Joined: Sun Feb 02, 2014 10:54 am
Location: Esslingen/Germany
Contact:

Re: Scaling an entire screen

Post by mk79 »

bwinkel67 wrote:But they don't have different apsect ratio. In Monitor mode, both NTSC and PAL give you 512x256 so it's one-to-one. It doesn't make sense to me why the coordinate system is different.
It's not like the US-QLs were a well-thought-out venture. In Minerva (there is no NTSC version of Minerva, but the code was prepared for it) it's

Code: Select all

* Push screen aspect ratio onto stack
gw_asp
; if ntsc
;       move.l  #$6623b79c,-(a1) 2/(4/3*575/512*51.2/51.95) * 1.173
;       move.w  #$801,-(a1)
; else
*        move.l  #$56b851ec,-(a1) 2 / ( (4/3) * (575/512) * (51.2/51.95) )
*        move.w  #$801,-(a1)      (acually rounded(?) to 1.355)
And in mode 8 this value is simply divided by two, so it does simply have a different aspect ratio in general. Again, not that I approve of this, it's just the way it is.


User avatar
bwinkel67
QL Wafer Drive
Posts: 1187
Joined: Thu Oct 03, 2019 2:09 am

Re: Scaling an entire screen

Post by bwinkel67 »

I fixed the scaling issues so now it works properly in NTSC TV and Monitor mode as well in PAL TV and Monitor mode.
QBQLSoundsv5.zip
(22.43 KiB) Downloaded 91 times


Post Reply