.PP
Leap tall buildings! Crush stupid robots beneath your feet! Wield your
extra-terrestrial powers in the defence of humanity, and send those alien
-invaders back from whence they came! Do all these things (apart from the last
-one at the moment) in Yoink! You play the part of a flying alien heroine who
-must defend her home on Earth from other airborne alien invaders. The game
-draws inspiration from classic arcade games like Joust, Bombjack, Rampage, and
-Defender--simple, fast-moving action.
+invaders back from whence they came! This is Yoink.
.PP
+You play the part of a flying alien heroine who must defend her home on Earth
+from other airborne alien invaders. The game draws inspiration from classic
+arcade games like Joust, Bombjack, Rampage, and Defender--simple, fast-moving
+action. Basic arguments include:
.TP
.B -h, --help
display this help and exit
.TP
.B -v, --version
output version information and exit
+.br
+.SH TIPS
.PP
To attack, you must dive on the enemy at high speed. If you're going too
slowly, you'll just drift harmlessly by. Diving from above gives different
This is a specific user's configuration file.
.TP
3. /etc/yoinkrc
-This is a system-wide configuration file.
+This is the system-wide configuration file.
.TP
4. @DATADIR@/yoinkrc
This is the base configuration file which should be considered read-only. Look
the configuration file(s). This mechanism is good for running the game with a
temporary setting which you do not intend to retain. Keep in mind that if you
edit and save options in-game, any options you have passed as arguments during
-the invocation of the game will be saved to the $HOME/.yoinkrc configuration
-file. You may have to go into that file and remove any options you didn't
-intend to set. When passing options as arguments, you must use the fully
-qualified name of the option if it exists in a subgroup. For example:
+the invocation of the game will be saved to the
+.I $HOME/.yoinkrc
+configuration file. You may have to go into that file and remove any options
+you didn't intend to set. When passing options as arguments, you must use the
+fully qualified name of the option if it exists in a subgroup. For example:
.PP
.TP
yoink video.fullscreen=true
-Set the option video.fullscreen to true. This will run the game in full-screen
-mode.
+Set the option
+.I video.fullscreen
+to true. This will run the game in full-screen mode.
.TP
yoink video.maxfps=60
-Set the option video.maxfps to 60. This will cap the display rate at 60Hz.
+Set the option
+.I video.maxfps
+to 60. This will cap the display rate at 60Hz.
.PP
-You can also set options with array values. Arrays can be passed on the
-command line by surrounding all the parts with square brackets and separating
-each part by a comma. For example:
+You can also set options with array values. Arrays can be passed on the command
+line by surrounding all the parts with square brackets and separating each part
+by a comma. For example:
.TP
yoink video.mode=[1024,768]
-Set the option video.mode to an array with numbers 1024 and 768. The video size
-will be 1024x768.
+Set the option
+.I video.mode
+to an array with numbers 1024 and 768. The video size will be 1024x768.
.PP
Here is a list of some of the options available:
.TP
.B engine.timestep
The amount of time in seconds between each update of the physics state. A value
of 0.01 or lower is ideal for accurate physics approximations. Values that are
-much lower may introduce errors in the game.
+much higher cause the CPU to do less work, but accuracy will suffer. Errors
+could be introduced in the game with extremely high values.
+.TP
+.B game.detail
+The level of detail. Possible values are high, medium, and low. This effects
+the number of objects drawn to the screen. A high level of detail will draw
+everything but could cause poor frame rates if the graphics driver can't keep up
+with the load. Lower levels will omit certain details which aren't crucial for
+playing the game with the benefit of higher frame rates. See the Notes for more
+ways to get good performance.
.TP
.B input.grab
Takes a boolean (true or false). If true, the cursor pointer will be "stuck"
use for red, green, blue, and the alpha channel. This is a low-level option of
limited usefulness. The default value is almost always preferable.
.TP
-.B video.cursor
+.B video.showcursor
This option effects the visibility of the cursor while it is "hovering" over the
window. If the value is true, the cursor will be visible. Otherwise, the
cursor will be hidden.
.B video.mode
The resolution or size of the window. The value is an array with three number
elements representing the width, height, and bits per pixel that make up the
-video mode.. A typical value is [800,600,32] for a size of 800x600 pixels with
-millions of colors.
+video mode. A typical value is [800,600] for a size of 800x600 pixels with
+millions of colors (the third number is optional).
.TP
.B video.multisamplebuffers
The number of multisample buffers used.
variable if you move the game's assets to another directory or want to load your
own assets.
.br
+.SH NOTES
+.PP
+Yoink may or may not be playable with acceptable frame rates without a hardware
+accelerated OpenGL driver installed and working, depending on how fast your CPU
+is. Yoink is really not all that heavy on graphics, but it doesn't take much to
+overload a software implementation. If you're stuck without hardware
+acceleration, there are some things you can do to get better frame rates:
+.PP
+1. Decrease the resolution with the
+.I video.mode
+option. Due to the nature of the graphics in the game, you can go as low as
+320x240 and not notice a large reduction in image quality. You can take
+advantage of this by decreasing the resolution and running full-screen (so the
+window is not so itty bitty on your monitor). This will help out a lot. Try
+this:
+.TP
+yoink video.mode=[320,240] video.fullscreen=true
+.PP
+2. Decrease the level of detail with the
+.I game.detail
+option.
+.PP
+On the other hand, if you already get high frame rates, you may also want to cap
+the rate so that your computer doesn't do more work than it really needs to.
+This may be useful when you run
+.B yoink
+on your production server at work. You can get reasonably smooth animation at
+around 30fps, but you can probably tell a difference between that and a higher
+rate like 50fps. The latter will look noticeably smoother and nice, while the
+former is just "acceptable." See the
+.I video.maxfps
+option.
+.br
.SH BUGS
.PP
+No sound yet. The original game never had sound, but it would probably be a
+good idea.
+.PP
The pixelated graphics are actually intentional. It adds to the charm of the
game, don't you think?
.PP
-Send bug reports and patches to:
+Send bug reports, patches, and love notes to:
.br
Charles McGarvey <onefriedrice@brokenzipper.com>
.SH AUTHOR
timestep = scalar(ts);
long maxfps = 40;
- config.get("engine.maxfps", maxfps);
+ config.getNumber("video.maxfps", maxfps);
drawrate = 1.0 / scalar(maxfps);
printfps = false;
- config.get("engine.printfps", printfps);
+ config.get("video.printfps", printfps);
}
~engine_impl()
}
+ /**
+ * The main loop. This just calls dispatchEvents(), update(), and draw()
+ * over and over again. The timing of the update and draw are decoupled.
+ * The actual frame rate is also calculated here. This function will return
+ * with a value of 0 if the member variable running becomes true.
+ */
+
int run()
{
scalar ticksNow = ticks();
scalar nextFPSUpdate = ticksNow + 1.0;
scalar totalTime = 0.0;
+ scalar deltaTime = 0.0;
scalar accumulator = timestep;
fps = 0;
running = true;
do
{
- dispatchEvents();
-
scalar newTicks = ticks();
- accumulator += newTicks - ticksNow;
+ deltaTime = newTicks - ticksNow;
ticksNow = newTicks;
- if (accumulator >= timestep)
+ if (deltaTime >= 0.25) deltaTime = 0.25;
+ accumulator += deltaTime;
+
+ while (accumulator >= timestep)
{
+ dispatchEvents();
interface->update(totalTime, timestep);
totalTime += timestep;
accumulator -= timestep;
nextStep += timestep;
- if (ticksNow >= nextStep)
- {
- // we missed some scheduled steps, so reset the schedule
- nextStep = ticksNow + timestep;
- accumulator = 0.0;
- }
}
if (ticksNow >= nextDraw)
projects / chaz / yoink / commitdiff
