Re: [GD-Windows] Monitor aspect detection

[brian s. <pud...@po...>]

Does GetDeviceCaps() give you a clue about whether pixels are square?  
I'm thinking specifically of the ASPECTX and ASPECTY arguments.

--brian

On Tuesday, December 9, 2003, at 03:00  AM, Nicolas Romantzoff wrote:

> Thanks Jon for the feedback...
>
> Getting the "maximum resolution" for width/height and using this as the
> base aspect ratio (guessing the monitor do have square pixels) is what
> I'm currently doing... And it seems to work fine on most CRTs, but for
> my wife's computer. Sticked to a 1280x1024 heighest resolution (desktop
> also in that resolution), this algorithm detects a ... 5:4 monitor.
>
> Other problem I came across was with a vertically positioned LCD (and
> the funny thing is: a 1280x1024 vertically positioned 4:3 monitor).
> Under that config, I detect a 4:5 monitor (I have no clue the monitor
> has been positioned vertically).
>
> Final problem I already found: weird resolution LCDs. Things like
> 1300x1060.
>
> One solution could have been to:
> - Enumerate modes and compute a monitor-ratio based on highest width /
> highest height displayable.
> - Select the closest "well-known" format matching that ratio (4:3, 
> 16:9,
> 3:4...) [if identical, stop here].
> - Enumerate modes and find the closest mode to "1:1" pixel-ratio for
> that fixed monitor-ratio.
> - Use that mode to compute the final monitor ratio.
>
> I'm currently using the first step only.
> Adding the second step would solve trivial 1280x1024 best resolution
> problems.
> Adding the last 2 steps would solves strange resolution monitor 
> problems
> some LCDs do have.
>
> Unfortunately, here is the configuration I'm currently using: ViewSonic
> P95f + GeForce 3.
> Highest resolution width: 1920
> Highest resolution height: 1200
> Resulting "ratio": 8:5
> Closest "well-known" ratio: 16:9
> Resolution matching that ratio: 1920x1080 => Monitor detected as a 16:9
> monitor !
>
>
> With different drivers:
> Highest resolution width: 1920
> Highest resolution height: 1440
> Resulting "ratio": 4:3
> (though 1920x1080 and 1920x1200 resolutions still present).
>
>
> I could select the well-known ratio by limiting myself to "lower" 
> ratios
> only (giving me a 4:3 format for the first case), but I fear that on
> some configs, the highest resolution would be 1920x1080 and back to a
> wrong 16:9 detection.
>
>
> Nicolas.
>
>
> -----Original Message-----
> From: gam...@li...
> [mailto:gam...@li...] On Behalf Of
> Jon Watte
> Sent: Tuesday, December 09, 2003 1:11 AM
> To: gam...@li...
> Subject: RE: [GD-Windows] (no subject)
>
>
> To make things exciting, many LCD 1280x1024 monitors have square 
> pixels.
>
> I'd go with the assumption that monitors do have square pixels, and 
> thus
> the view ratio == resolution ratio. Then supply a "special" option to
> compensate for the known oddball cases, of which 1280x1024 on a 4x3
> monitor is the only obvious one.
>
> Well, there's the case of 800x600 being blown up to fullscreen on a 
> 16:9
> display, too, and stretching like mad. There's no good way of finding
> this out. The best you can do is capture the resolution at start-up,
> before mode switch, and assume it's square.