	#
	| README file for
	|
	| ELSA OGLQUERY for Windows NT 3.51 and 4.0
	|
	|       GLoria-4
	|	GLoria-8
        |       GLoria-M
        |       GLoria-L
	|
	| Copyright (c) 1993-96 ELSA GmbH, Aachen (Germany)
	|
        |                                     Subsidary:
        | ELSA GmbH                           ELSA Inc.
        | Sonnenweg 11                        2150 Trade Zone Blvd.
        | D-52070 Aachen                      Suite 101
        | Germany                             San Jose, CA 95131
        |                                     USA
        |
	| Phone      : +49-241-606-0         Phone: +1-408-935-0350
	| Support Fax: +49-241-606-6399      Phone:  1-800-272-ELSA
	| BBS (modem): +49-241-606-9800      Fax  : +1-408-935-0370
	| BBS (ISDN) : +49-241-606-9820      BBS  : +1-408-935-0380
	| CompuServe : GO ELSA               CIS  : GO ELSA
	| WWW        : http://www.elsa.de    WWW  : http://www.elsa.com
        |
	| November 6th 1996, dt, sf



        Table of Contents:

	1       Abstract
	2       Running The ELSA OpenGL Query Program
	3       Details For The Interested Reader

------------------------------------------------------------------------

1	Abstract

        The ELSA OpenGL Query program is a tool for Windows NT
	to determine if the current screen resolution and color depth
	is capable of double buffering in hardware with the installed
        ELSA GLoria board.
        You find this program under ELSAWARE\OGLQUERY on this CD.

------------------------------------------------------------------------

2       Running The ELSA OpenGL Query Program

        Start the program OGLQUERY.EXE (from the Explorer, Program
        Manager, File Manager, Run.. menu, or Command prompt).

	A message box appears with the following information of the
	currently running OpenGL driver:

	- Vendor name
	- Renderer name
	- Renderer version
	- OpenGL extensions in this driver
	- Horizontal and vertical resolution in pixels
	- Bits per pixel
	- Bytes used/needed for front and back buffer
	- Bytes used/needed for the depth buffer

	For example:

	   (Following texts represent actual values with 8 MB VRAM and
           8MB DRAM on board in 1152*864 HighColor and 1600*1280 TrueColor)

	a) If running an ELSA OpenGL driver:

		-------------------------------------------------------
		Current OpenGL Driver:

		ELSA
		GLoria Installable Client Driver
		2.00.03.002
		GL_EXT_vertex_array GL_EXT_bgra GL_EXT_paletted_texture
		GL_EXT_texture_object

		Xres: 1152, Yres: 864, Bits: 16
		3981312 bytes VRAM used for front plus back buffer.
		3981312 bytes DRAM used for depth buffer.

					[OK]
		--------------------------------------------------------


	b) If running Microsoft's Windows NT OpenGL GDI Generic driver:

		--------------------------------------------------------
		Current OpenGL Driver:

		Microsoft Corporation
		GDI Generic
		1.1.0
		GL_WIN_swap_hint GL_EXT_bgra GL_EXT_paletted_texture

		Xres: 1600, Yres: 1280, Bits: 32
		16384000 bytes needed for front plus back buffer.
		8192000 bytes needed for depth buffer.

		Attention! No ELSA OpenGL driver running!

					[OK]
		--------------------------------------------------------


	The OpenGL animation in the main window of the program shows a
	tumbling golden cube. There is no palette handling included in
	the program, therefore the image may be in wrong colors in 8 bit
	palette mode.

	If no ELSA OpenGL driver was found, you get another message box at
	the end of the program with the following text:

		---------------------------------------------------------
		The previous OpenGL animation was not rendered using the
		ELSA OpenGL driver. If you have an ELSA GLoria installed
		the current screen resolution was not supported with
		hardware accelerated OpenGL and double buffering.

		Please consult the ELSA GLoria manual for the proper
		resolutions with 3D OpenGL hardware acceleration.

					[OK]
		---------------------------------------------------------

------------------------------------------------------------------------

3 	Details For The Interested Reader

	If you would like to know how and why the amount of RAM on the
        board affects the maximum resolution in which hardware 3D
        acceleration with double buffering is possible, please read on.

	The availability of hardware 3D acceleration and double buffering
        on an ELSA GLoria board depends on the amount of VRAM and DRAM
        memory installed.

	The VRAM is used for the front buffer AND the back buffer.
	On the ELSA GLoria the complete visible screen is seen as the
        front buffer. To do double buffering in hardware a second, non
        visible screen area of the same size must be available in
        offscreen (the part of the VRAM which is not visible).

	The DRAM required for the 3D acceleration (the z-buffer) is
        32 bits per pixel regardless of the color depth. The DRAM, also
        called the local buffer, contains the z-buffer and stencil buffer
	(e.g. 32 bits depth and no stencil, 24 bits depth and 8 bits stencil).
        This is important to remember, because in lower color depths the
        DRAM may be the limitation of the maximum 3D screen resolution!

	Try this formula with your desired double buffered screen resolution:

	  VRAM = xRes * yRes * bytesPerPixel * 2; // Front and back buffer
	  DRAM = xRes * yRes * 4;		  // local buffer

	  if (VRAM < VRAM_On_Board && DRAM < DRAM_On_Board)
		Double_Buffering_In_Hardware = TRUE;
	  else
		Double_Buffering_In_Hardware = FALSE;


	Maximum resolutions and color depth for double buffered (OpenGL)
        hardware acceleration on ELSA GLoria boards:

	VRAM/DRAM	Palette		High Color	True Color
	---------------------------------------------------------
	   4/4		1152*864	1152*864	800*600
	   4/8		1600*1280	1152*864	800*600
	   8/8		1600*1280	1600*1280	1152*864
	   8/16		>1600*1280	1600*1280	1152*864


	The bits per pixel value in the message boxes above represent the
	actual layout of the display memory.

	If it is stated as 16 bits the GLiNT is actually using only 15 bits
	for color representation. It uses 5 bits each for red, green, and
	blue. This is because the GLINT is capable of doing hardware
	dithering, which looks nicer with equally distributed color ramps.
	High Color is the recommend choice, if you need high resolution with
	double buffering.

	In True Color you have 32 bits per pixel, 8 bits each for red, green,
	blue, and alpha. This is the recommended color resolution if you use
	alpha blending, alpha test, or overlay planes, or need precise color
	values when reading bitmaps (no dithering!).

------------------------------------------------------------------------


