[fpc-pascal] PTC Graph - Custom window sizes

Nikolay Nikolov nickysn at gmail.com
Thu Nov 19 19:07:21 CET 2020

On 11/19/20 7:37 PM, Nikolay Nikolov wrote:
> On 11/19/20 3:44 PM, James Richters via fpc-pascal wrote:
>> I've been using PTCGraph from PTCPas and so far I can only use 
>> windows sizes that there happens to be a display driver for,  even if 
>> they are in a window.. so I can make a 640x480 or 1024x768 window,  
>> but if I have a screen in a vertical configuration now I can't get a 
>> 640x480 window, I can only get a 480x640 window because with the 
>> screen vertical, only vertical orientation graphics drivers are 
>> available.    There are times I want a totally custom size window as 
>> well,  like a 100x50.  I see a lot of procedure like 
>> ptc_Init640x480x32bpp with all kinds of configurations of screen 
>> resolutions and color densities, but there is also some named 
>> ptc_InitNonStandard32k.. with other color densities.. but I don't 
>> know how to initialize PTCGraph into my own custom window size.   
>> Does anyone know how I could make my PTCGraph windows a custom weird 
>> size that doesn't necessarily match the available video drivers?
> It's not possible with the current implementation, but right now I'm 
> working on a patch that would make this possible. I'll post here when 
> it's ready for testing.

Implemented and committed in ptcpas and fpc trunk. The new function is 
called InstallUserMode:

function InstallUserMode(Width, Height: SmallInt; Colors: LongInt; 
HardwarePages: SmallInt; XAspect, YAspect: Word): smallint;

Example use:

   {$ifdef UNIX}cthreads,{$endif} ptcgraph, ptccrt;
   gd, gm: SmallInt;
   gd := VESA;
   gm := InstallUserMode(100, 160, 16, 1, 10000, 10000);
   if gm < 0 then
     Writeln(ErrOutput, 'Error installing user mode: ', GraphErrorMsg(gm));
   InitGraph(gd, gm, '');

It supports adding modes with 16, 256, 32768, 65536 and 16777216 colors 
with a custom X and Y resolution, custom number of hardware pages (for 
use with SetActivePage and SetVisualPage) and a custom pixel aspect 
ratio (used for drawing circles instead of ellipses on displays without 
square pixels - for square pixels, use "10000, 10000").

Please test. :)

Best regards,


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