GDI and ArcadeVGA

[Diewrecked]

Hi guys

I know the ArcadeVGA notes on the Ultimarc site say to use DirectDraw and disable hardware stretching, but whenever I use DirectDraw with any number of permutations of the other settings, the games do not display correctly: I'll get the width squashed to 50%, or the height doubled to 200% and only be able to see the bottom half - you get the gist. However when I use GDI everything displays perfectly.

My question is: what is the difference between GDI and DirectDraw in the context of the ArcadeVGA card in MAME, and would selecting GDI automatically enable/disable hardware stretching? I'd like the optimum display with this card but obviously not at the cost of not being able to see the whole image on the games!

Many thanks all

[Gray_Area]

http://en.wikipedia.org/wiki/Graphics_Device_Interface

[Diewrecked]

Hi GrayArea, thanks for coming back. I did see this explanation of GDI before I created this thread but it doesn't explain how GDI relates to hardware stretching. I asked Andy at Ultimarc this question (I sent him that link actually!) and he didn't know either which is why I thought I'd ask you guys.

Do you know what the implications are of running MAME with GDI on an ArcadeVGA please?

Many TIA

[Gray_Area]

I think the answer is in here:

Because of the additional text processing and resolution independence capabilities in GDI+, text rendering is performed by the CPU [2] and it is nearly an order of magnitude slower than in GDI.[3] Chris Jackson, an application compatibility expert working for Microsoft published some tests indicating that a piece of text rendering code he had written could render 99,000 glyphs per second in GDI, but the same code using GDI+ rendered 16,600 glyphs per second.

Games run really slow on my system when using GDI. Unless you're using a super gaming card, I doubt video card much matters here. I don't know why GDI is an option in current MAME. It doesn't seem to be a relevant use.

Regarding the results of your DD use, it would help to know what monitor you're using, and what games are being displayed wonky.