GlideHack performs some special effects with a 3Dfx card by interposing itself between the
Glide library and its clients. To install it, simply put GlideHackLib in the extensions
folder by dropping it on the system folder. You don't need to restart your Mac. Use the
GlideHack Setup application to configure GlideHack's operation.
What it does

* Crash cleanup. If a game that uses the 3Dfx card dies unexpectedly, GlideHack tries to
  shut things down properly so you get your 2D screen back.

* Screen capture. Ordinary screen dump methods don't work with the 3Dfx screen, and not
  all games provide this functionality on their own. GlideHack lets you capture both
  snapshots and movies.

* Various tweaks. This includes things like screen gamma manipulation.

Configurations

GlideHack lets you use different settings for different games. Simply create a configuration
document in GlideHack Setup and save it in the same folder as the game application.
If GlideHack can't find a game-specific configuration, it uses its defaults
(which can be edited with GlideHack Setup too).

The settings

Override default gamma
Default gamma
Some games don't let you set the output gamma of the 3Dfx card. These let you specify a
default gamma value for those games.

Scale client gamma
Gamma scale factor
Some games do let you set the output gamma, but only within a limited range. These let
you specify a scale factor for those gamma values in order to widen the range.

Limit texture unit count
Texture unit count
Not very useful except for Voodoo 2 owners who wish to see how much worse Unreal looks on
a Voodoo 1. :-)

Limit texture RAM
Texture RAM
Some games (such as Carmageddon) get confused by cards with more than 2 MB of texture memory.
These let you un-confuse them.

Disable triple buffering
Some Voodoo 2 cards don't let you do screen dumps from the third buffer. Check this if
you get nonsense in one-third of the snapshots or in every third frame of the movies.

Screen capture gamma
Screen captures from some very dark games (such as Unreal) may need a bit of brightening
to be useful.

Byte swap (Voodoo3)
Voodoo3 cards don't seem do byte swapping in hardware when reading from the frame buffer.
Check this if you get nonsense colours in Voodoo3 screen captures.

Play sounds
Check this to make the various screen capture operations play sounds.

Output folder
Lets you specify where screen capture files are saved.

Snapshot keys
Begin movie keys
End movie keys
These buttons bring up a dialog where you can set the key combination that triggers each
function. Any combination of one to four keys is allowed.

Full size movie
Movies are saved in thousands of colours, uncompressed. This eats up disk fast, so the
spatial dimensions are scaled by 1/2 in order to save space unless you check this box.

Precision movie
Frame rate
Divisor
When the precision checkbox isn't checked, frames are captured as fast as possible. This
is actually rather slow; on my 7600 with a Techworks card, I get about 6 frames per second
at 640x480.
When the precision checkbox is checked, the captured movies have the specified frame rate
but are recorded at a slower speed, as specified by the divisor. For Myth, you'd set the
frame rate to 30 and the divisor to 8, then start recording with Myth's replay speed set
to 1/8.
If you set the divisor to 0, frames are not recorded automatically. Instead, one frame is
added to the movie each time you press the snapshot key combination. This is useful for
games that have a replay function with single-stepping, such as Carmageddon.

Version history

1.0
Initial release.
1.1
Added individual configuration files.
Added sounds.
Added support for strange code that runs the 3Dfx card in BGR rather than RGB mode. (Hi Miklós!)
Fixed a bug in the half-scale screen grab code (incorrect blue values).
Tweaked the number formatting code in the setup.
1.11
Fixed an embarrassing bug in the update library initialization.
1.2
Added support for Voodoo3 screen captures.

Misc

GlideHack is freeware; distribute anywhere.

Send any comments, complaints, threats, or job offers to:
d88-bli@nada.kth.se