Microsoft KB Archive/97541

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The information in this article applies to:
 * The App Studio included with: Microsoft Visual C++ for Windows, version 1.0

SUMMARY
The text below presents information in Part 3 of the README.WRI file distributed with Microsoft Visual C++ version 1.0. Setup installs README.WRI in the MSVC\HELP directory.

App Studio Graphics Editor and Display Drivers
You may find that the App Studio graphics editor behaves improperly when running on display hardware that supports resolutions greater than 800 x 600 or more than 16 colors. These problems are usually caused by the display driver provided by your hardware manufacturer.

Here is a list of symptoms that have been traced to driver bugs:


 * The rightmost column of pixels in odd-width images is set to black.
 * A GP fault occurs when editing an icon (see &quot;Improving Display Performance&quot; below).
 * An INT 3 is executed in the driver file while debugging with Visual Workbench.
 * Extra pixels are painted while using the brush on a monochrome image.
 * One-pixel lines drawn diagonally are thicker than they should be.
 * Changing a monochrome image to color corrupts the image.
 * The fill tool does not fill correctly.

If you are having these problems when using the App Studio graphics editor, and if you are running Windows at high resolution or with more than 16 colors, you should first see if the problem is being caused by your display driver. If so, then you should get an updated driver from the hardware manufacturer or from the Windows Driver Library to correct the problem. To see if the problem is caused by your display driver, install one of the standard Microsoft display drivers using the following procedure:


 * 1) Run the Windows setup program (not the Visual C++ setup).
 * 2) Choose the Change System Settings command from the Options menu.
 * 3) In the Display drop-down box, choose either VGA or Super VGA (if your display hardware supports 800 x 600 resolution), choose OK, and follow the instructions to install the new driver.

After you restart Windows with the new driver, run App Studio and see if the problem you were experiencing still occurs. If the problem no longer occurs, then your display driver was the cause of the problem. You can avoid problems by simply continuing to use one of the standard Windows display drivers. However, to take advantage of the higher resolution and/or number of colors supported by your display hardware, you must get an updated display driver that fixes the problems. The best way to get an updated version of your display driver is to contact your hardware manufacturer directly. You can also get some drivers from the Microsoft Windows Driver Library.

A list of drivers known to cause problems in App Studio are listed below. Following this are instructions for getting drivers from the Windows Driver Library.

Drivers Known To Cause Problems in App Studio
ATI Ultra and ATI Ultra Pro. The ATI drivers that ship with Gateway 2000 and other machines had several known display driver bugs at the time that Visual C++ 1.0 shipped. ATI is aware of these problems and is working to fix them. You can contact ATI directly at (905) 882-2626. Updated ATI drivers were not available in the Windows Driver Library at the time Visual C++ shipped.

Procedure for Obtaining a New Display Driver
Microsoft has made available the Windows Driver Library (WDL). The WDL offers support for many printers, displays, sound cards, and network card adapters not provided with Windows 3.1. If you have a modem, the drivers are available at no charge on Microsoft OnLine and the Microsoft Download Service (MSDL). However, note that standard connect-time fees and long- distance telephone charges, if any, still apply during downloading. When you connect to any of these services, please read the WDL.TXT file for downloading instructions and a complete list of devices supported in the WDL. If you don't find your display supported in this file, you may be able to use the SVGA256 driver, a new high-speed 256-color display driver that supports most non-accelerated Super VGA displays. The displays that the SVGA256 driver supports are listed below.

The phone number for the MSDL is (425) 936-MSDL (6735). There is no connect-time charge for using this service. The WDL is in the Microsoft Software Library. To find WDL.TXT, search on S13354.

If you do not have a modem, you can obtain individual Windows drivers on disk by calling Microsoft Product Support Services at (425) 635-7007. It will take a minimum of ten working days to receive driver disks.

Supported Displays
Displays supported by the SVGA256 driver include the following:

ATI VGA Wonder Cirrus Logic VGA(6420, 5420 series) Oak Technology VGA (077 series) Paradise VGA Trident VGA (8900 series) Tseng ET4000 based, including: Boca VGA Cardinal VGA Diamond Speedstar series Everex Viewpoint series Metheus Premier VGA Orchid Prodesigner II     Sigma VGA Legend STB Powergraph Video Seven VGA FastWrite 1024i VRAM VRAM II  Western Digital VGA

Improving Display Performance
App Studio has a built-in workaround to avoid severe bugs when running on some common display hardware at resolutions above 800 x 600 or with more than 16 colors. This workaround was added because display drivers for common display hardware did not implement the StretchBlt graphics function correctly at the time Visual C++ 1.0 shipped. The App Studio workaround causes repaint performance in the graphics editor to be slower than it would be otherwise. It is possible that you are using a display driver that does not require this workaround, in which case you can improve repaint performance in the App Studio graphics editor.

To improve the performance of the graphics editor place the following line in the [Graphics Editor] section of your APSTUDIO.INI file:

[Graphics Editor] DriverCanStretch=1 To test this change, run App Studio and create a new bitmap. If you can create the bitmap and draw in it successfully, then your display driver does not have the StretchBlt problem. Leave the new line in your .INI file for improved performance in the graphics editor. If App Studio behaves improperly when you create a new bitmap, then your driver has the StretchBlt problem. You should remove the DriverCanStretch line from the .INI file and contact your hardware vendor to see if an updated driver is available.

Resizing the Drop-down for a Combo Box
To change the initial size of a combo box drop-down in the App Studio dialog editor, you normally click the control's drop-down arrow. This displays the drop-down portion of the combo box and activates the sizing handle at the bottom of the control. In some cases, especially when the drop-down portion of the combo box has a height of zero, the appearance of the resize handles may not change.

However, you can still resize the combo box vertically. Click the drop-down arrow and place the mouse cursor on the bottom sizing handle. The mouse cursor changes to an up-and-down sizing arrow, and you can resize the combo box vertically in the usual way. For complete information about resizing combo box drop-downs, see pages 47-48 in the &quot;App Studio User's Guide.&quot;
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Last reviewed: September 28, 1998

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