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Re: Extending Turbo Vision with graphics?

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On 2013-12-26, Jim Leonard <MobyGamer@gmail.com> wrote:
> I know this is a longshot as this group is nearly dead, but I have to try
> asking: I will be writing a menu front-end that must run on any DOS-based
> PC (even 808x systems, 

That kills a lot of options. You'll be spending most of your time fighting
memory idiosyncrasies of the 16-bit memory model. Specially if you add
memory hungry graphics.

> this is for a museum project) and would like to
> avoid writing an entire CUI framework from scratch.  Turbo Vision
> obviously comes to mind, however one of the requirements is that, while
> running in text mode is ok, on VGA/SVGA systems the front-end should also
> display a bitmap that changes as the user selects a new item.

The FPC TV clone (called FV) is based on a graphics vision (by Leon de
Boer, who afaik based himself on the PD C++ code), backported to textmode.

One of the major changes was reworking the codebase for changes to the
coordinate system (from pixels back to chars).  If you can keep the
coordinates in chars, you can probably reuse most of any TV clone, and write an
appropriate drivers unit for it (that paints to graph mode)

The result will be less integrated since you still emulate text for most
drawing, so no fancy window borders, and all coordinates would be in
characters still.

> Does anyone have any suggestions on how to (very simply) extend Turbo
> Vision to graphics mode?  Is it as simple as hooking where the 80x25/43/50
> raw screen data is and then redrawing that in graphics mode, or is that
> not feasible?  

It might also read the screen. But I think you can intercept it already
earlier, in the place where TV decides where to draw which parts of the
screen. TV draws incrementally, iow only areas that are changed. Probably
not unimportant on a 8086 :-)

>Is there a prewritten library that I'm unaware of that fits
> the bill?

1) Create a drivers unit implementation for your graphics mode that emulates
the drawing of each widget. I don't know if the TV implementation really
only draws via drivers though.

2) For pixel graphics you could create a TView derivative that registers its
coordinates (on create/change/destroy) and the reference to the picture with
the (drivers/video) drawing backend (using a new interface)

The the drawing backend can use that knowledge to not paint character
emulation (the empty characters) to that tview area, and paint the picture
instead. (and e.g. use the tview background as fill colour for areas of the
tview that are not covered by the image.

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Thread

Extending Turbo Vision with graphics? Jim Leonard <MobyGamer@gmail.com> - 2013-12-26 09:27 -0800
  Re: Extending Turbo Vision with graphics? Dr J R Stockton <reply1300@merlyn.demon.co.uk.invalid> - 2013-12-27 19:31 +0000
    Re: Extending Turbo Vision with graphics? Stefan Strobel <St.Strobel@arcor.de> - 2014-01-20 18:50 +0100
  Re: Extending Turbo Vision with graphics? Marco van de Voort <marcov@toad.stack.nl> - 2013-12-29 15:57 +0000

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