JmePower Project

The JmePower Project is about promoting the jMonkeyEngine (JME) game engine.

It contains 3 subprojects:

1. JmePowerLibrary: the JmePower startup library for jMonkeyEngine applications
2. JmePowerAssets: generate assets included in the library
3. JmePowerExamples: sample applications using the library

Complete source code (in Java) is provided under a 3-clause BSD license.

Licensing

The source code has a BSD 3-Clause license.

The Jamie model has a BSD 3-Clause license.

How to build JmePower from source

1. Install a Java Development Kit (JDK), if you don't already have one.
2. Point the JAVA_HOME environment variable to your JDK installation: (In other words, set it to the path of a directory/folder containing a "bin" that contains a Java executable. That path might look something like "C:\Program Files\Eclipse Adoptium\jdk-17.0.3.7-hotspot" or "/usr/lib/jvm/java-17-openjdk-amd64/" or "/Library/Java/JavaVirtualMachines/zulu-17.jdk/Contents/Home" .)

• using Bash or Zsh: export JAVA_HOME=" path to installation "
• using Fish: set -g JAVA_HOME " path to installation "
• using Windows Command Prompt: set JAVA_HOME=" path to installation "
• using PowerShell: $env:JAVA_HOME = ' path to installation '

3. Download and extract the JmePower source code from GitHub:

• using Git:
  • git clone https://github.com/stephengold/JmePower.git
  • cd JmePower
  • git checkout -b latest 1.1.1
• using a web browser:
  • browse to the latest release
  • follow the "Source code (zip)" link
  • save the ZIP file
  • extract the contents of the saved ZIP file
  • cd to the extracted directory/folder

4. Run the Gradle wrapper:

• using Bash or Fish or PowerShell or Zsh: ./gradlew build
• using Windows Command Prompt: .\gradlew build

After a successful build, Maven artifacts will be found in JmePowerLibrary/build/libs.

You can install the artifacts to your local Maven repository:

• using Bash or Fish or PowerShell or Zsh: ./gradlew install
• using Windows Command Prompt: .\gradlew install

You can restore the project to a pristine state:

• using Bash or Fish or PowerShell or Zsh: ./gradlew clean
• using Windows Command Prompt: .\gradlew clean

How to add JmePower to an existing project

Adding JmePower to an existing jMonkeyEngine project should be a simple 3-step process:

1. Add the appropriate libraries to the classpaths.
2. Add code to instantiate and attach an AppState.
3. Add code to await completion.

Add to the classpaths

The JmePower library depends on the standard jme3-core library and the Heart library.

For projects built using Maven or Gradle, the build tools should automatically resolve the compile-time dependencies.

Gradle-built projects

Add to the project’s "build.gradle" file:

repositories {
    mavenCentral()
}
dependencies {
    implementation 'com.github.stephengold:JmePower:1.1.1'
}

Instantiate and attach an AppState

Instantiate a JmeLoadingState.

The AppState constructor takes an array of objects to be preloaded into the application's asset cache. If there are none, the array can be empty.

Depending on the application's structure, the instance might be attached explicitly in simpleInitApp():

JmeLoadingState loading = new JmeLoadingState(preloadArray);
stateManager.attach(loading);

or it might be passed to the application's constructor:

private MyApplication() {
    super(
            // other appstates, if desired ...
            new JmeLoadingState(preloadArray)
    );
}

Await completion

The appstate takes indicates completion by disabling itself. A SimpleApplication might check for completion in simpleUpdate():

@Override
public void simpleUpdate(float tpf) {
    AppState loading = stateManager.getState(JmeLoadingState.class);
    if (loading != null && !loading.isEnabled()) {
        getStateManager().detach(loading);
        // additional startup, if desired ...
    }
}