This FAQ tries to answer the most commonly asked questions.about Minueto. It will be updated as we receive more questions.
Minueto is a component of Alexandre Denault's master thesis. He is currently researching "Game Frameworks for Undergraduate Studies". When not working/playing on his computer, he can be found on the McGill squash courts.
Undergraduate students at McGill are heavily exposed to Java in their early course. Since Minueto's goal is to make game programming more accessible to them, it would have been counter productive to choose another programming language.
When we first started working on Minueto, Alexandre Denault was shopping for a newer and quieter computer casing. At the time, he was hesitating between Antec's Sonata and Antec's Minuet. Although he choose the Sonata in the end, he thought that a variation of Minuet would make a cool project name.
We are always happy to hear suggestions for Minueto. If you have any ideas for Minueto, please send an email at alexandre.denault@adinfo.qc.ca . Some people have even taken the source code to Minueto and added the features themselves. If this the case, we would like to see your modification. We might even add it to the main release.
Minueto 0.8.0, 1.0.0 and 2.0.0 introduced many changes, some of which broke compatibility which previous Minueto application. The chances required to use this new version of Minueto are relatively minor and show not require you to modify more than a few lines of code. Exact detail on these changes can be found in the changelog.
What is probably happening is that you are trying to create a Minueto window from an Swing/AWT thread (i.e. in response to the press of a button). Since Minueto window's requires some special graphic acceleration attribute, it cannot be created from a Swing/AWT thread.
Fortunately, the solution is pretty easy. All you need to do is to create the window from another thread. You can either do this from your main thread or you can spawn a new thread, allowing it to create the window and let it the swing process terminate. The new Minueto 1.1 package available from the download section here provides an example of this.
This is a known problem. Some JVM react badly to been switch from/to fullscreen mode. We have had problems with both Sun's and Apple's Java 1.4.2. However, Java 5.0 seems to be perfectly stable. My suggestions are:
Fullscreen mode doesn't work under Linux. Sun plans to add it to it's next release of 5.x, but no promise have been made. If you have problems under Windows, it's possible you don't have sufficient access rights to change the display mode.
Minueto uses Java2D's hardware acceleration features to accelerate drawing speed. Depending on the Java Virtual Machine used, Minueto might or might not be able to conserve the previous frame. Since Minueto's goal is to be easy to learn, we have decided to only offer one model of double-buffering.
Advanced users of Minueto can bypass this limitation by using their own
double-buffering technique. To do this, the programmer must create a
blank MinuetoImage of the same size as the screen. Instead of drawing
to the screen, the programmer draws to that MinuetoImage. When the
programmer is ready to display the next frame, he only needs to draw
this MinuetoImage to the MinuetoWindow and call the render method. The
content of the MinuetoImage will not lost.
The performance impact of this technique depends on the amount of
changes done to the MinuetoImage at each frames. Tests have shown that
drawing multiple small images is slower than drawing a large image.
MinuetoImage
faster than drawing to a MinuetoWindow?Depending on which JVM is used,
Minueto objects can be stored in main
memory or in video memory. However, tests have shown that there
is very little speed difference between drawing to a MinuetoWindow and
drawing to another MinuetoImage.
Depending on the angle of the image, the size of the returned image might have been increased. This prevents the rotated image from being clipped. Also, the returned image might be smaller on one axis (either width or height) as unused space is cropped off.
getWidth() and getWindowWidth()?As explained in the API,
getWidth() returns the width of the area are allowed to draw
in, as opposed to getWindowWidth() which returns the actually width of the
window. The value return by getWidth() will always correspond
to the width specified to the MinuetoWindow constructor. With a MinuetoFrame, the
value returned by getWindowWidth() is slightly higher since it takes into
account the width of the border added by the operating system.
This is a known bug in Minueto and we are currently working to fx it. It is caused by a timing issue in the JVM and several window managers not correctly reporting the size of their borders. Some window managers, such as Fluxbox and WindowMaker seem less affected by this problem. This problem only occurs under Linux.
An OutOfMemoryError exception is thrown when the Java Virtual Machine cannot allocate an object because it is out of memory, and no more memory could be made available by the garbage collector. The culprit in a Minueto application is often found in the rendering loop. If a particular image must be drawn in several frame, it should not be initialized in the rendering loop. For example,
MinuetoImage rectangle;
while(true) {
rectangle = new MinuetoRectangle(200,100,MinuetoColor.BLACK,false);
window.draw(rectangle, 10, 10);
window.render();
Thread.yield();
}
will produce an OutOfMemoryError exception because the image of a rectangle is created at each frame. An application running at 60 frames per second will allocate 3600 image buffers after a minute, thus requiring an estimated 68 megabytes of memory per minute. A simple solution would be to move the rectangle constructor out of the rendering loop.
MinuetoImage rectangle;
rectangle = new MinuetoRectangle(200,100,MinuetoColor.BLACK,false);
while(true) {
window.draw(rectangle, 10, 10);
window.render();
Thread.yield();
}
Initializing the rectangle once would only require an estimated 19 kilobytes of memory.
MinuetoWindow? Why can't I create a MinuetoWindow anymore?In version of 1.0.0 of Minueto Core, MinuetoWindow is now an abstract class. To
create a full screen window, you need to use MinuetoFullscreen. To create a normal
windowed frame, you need to use MinuetoFrame. Note that both of these classes are
subtypes of MinuetoWindow, so you don't need to change all your application.
As of Minueto 1.1, MinuetoWindow has been converted to an
interface; however, this shouldn't affect any code that works with Minueto
1.0.0.
As of version 1.0.0, Minueto now supports Alpha transparencies. Be warn that
this is an experimental feature. Check out the MinuetoOptions class for information
on how to activate alpha transparencies.
As of version 1.0.0, Minueto now supports options to force hardware
acceleration. Be warn that this is an experimental feature.
Check out the MinuetoOptions class for information on how to activate
hardware acceleration.
MinuetoKeyboard?The constants in MinuetoKeyboard enumerate the most commonly used keys
on the Keyboard. However, you can still capture a keystroke, even if
it's not listen in MinuetoKeyboard. Keys are described as integer
values. You simply need to find the value of the key you want to use.
A key press event is generated when a user presses a key on the key board. A key release event is generated when the user removes his finger from a key and the key returns to its original position. A key press event is always eventually followed by a key release event.
Depending on the situation, you might need both. For example, some games determine the lenght of a throw depending on the amount of time the space bar was pressed. In that case, you need to measure the time between the key press and the key release events.
The Key Type is rarely used in game development. However, it is offered as a feature to make implementing text boxes easier. If you don't need to manipulate text, I suggest you stick with Key Press and Key Release.