construo

Construo is a gradle plugin to cross compile JVM apps.

Setup

Add the plugin to your project

Kotlin DSL

plugins {
  id("io.github.fourlastor.construo") version "1.1.1"
}

Groovy DSL

plugins {
  id "io.github.fourlastor.construo" version "1.1.1"
}

Configuration

General config

These are the base options to set when using construo.

construo {
    // name of the executable
    name.set("game")
    // human-readable name, used for example in the `.app` name for macOS
    humanName.set("Game")
    // Optional, defaults to project version
    version.set("0.0.0")
    // Optional, defaults to application.mainClass or jar task main class
    mainClass.set("io.github.fourlastor.gdx.Main")
    // Optional, defaults to $buildDir/construo/dist
    // where to put the packaged zips
    outputDir.set(rootProject.file("dist"))
}

JLink options

You can add extra modules to the minimized JDK via the jlink block.

construo {
    jlink {
        // add extra modules to be included when running jlink
        modules.addAll("jdk.zipfs")
    }
}

Roast options

Construo uses roast to run the application, a few options can be specified and will be set in its config.json.

construo {
    roast {
        // use ZGC garbage collector, defaults to true
        useZgc.set(false)
        // use the main class as the context class loader, defaults to false, useful for compose apps
        useMainAsContextClassLoader.set(true)
        // vm startup options
        vmArgs.addAll("-Xmx1G")
    }
}

Defining targets

Targets define the output bundles construo will generate, each target will need to define the architecture, and an optional (if using the foojay api) JDK url for that specific target (you cannot use a JRE for cross compilation).

Windows

Windows targets support only the X86_64 architecture.

The useGpuHint option specifies whether the packaged app will use the discrete GPU in hybrid systems (defaults to true).

Macos

The identifier option is mandatory.

An icon can be optionally specified with macOsIcon on each target.

Kotlin DSL

import io.github.fourlastor.construo.Target

construo {
    targets {
        create<Target.Linux>("linuxX64") {
            architecture.set(Target.Architecture.X86_64)
            jdkUrl.set("https://github.com/adoptium/temurin17-binaries/releases/download/jdk-17.0.11%2B9/OpenJDK17U-jdk_x64_linux_hotspot_17.0.11_9.tar.gz")
        }
        create<Target.MacOs>("macM1") {
            architecture.set(Target.Architecture.AARCH64)
            jdkUrl.set("https://github.com/adoptium/temurin17-binaries/releases/download/jdk-17.0.11%2B9/OpenJDK17U-jdk_aarch64_mac_hotspot_17.0.11_9.tar.gz")
            // macOS needs an identifier
            identifier.set("io.github.fourlastor.Game")
            // Optional: icon for macOS
            macIcon.set(project.file("path/to/mac-icon.icns"))
        }
        create<Target.Windows>("winX64") {
            architecture.set(Target.Architecture.X86_64)
            jdkUrl.set("https://github.com/adoptium/temurin17-binaries/releases/download/jdk-17.0.11%2B9/OpenJDK17U-jdk_x64_windows_hotspot_17.0.11_9.zip")
            // use executable with GPU hints, defaults to true
            useGpuHint.set(false)
        }
    }
}

Groovy DSL

import io.github.fourlastor.construo.Target

construo {
    targets.configure {
        create("linuxX64", Target.Linux) {
            architecture.set(Target.Architecture.X86_64)
            jdkUrl.set("https://github.com/adoptium/temurin17-binaries/releases/download/jdk-17.0.11%2B9/OpenJDK17U-jdk_x64_linux_hotspot_17.0.11_9.tar.gz")
        }
        create("macM1", Target.MacOs) {
            architecture.set(Target.Architecture.AARCH64)
            jdkUrl.set("https://github.com/adoptium/temurin17-binaries/releases/download/jdk-17.0.11%2B9/OpenJDK17U-jdk_aarch64_mac_hotspot_17.0.11_9.tar.gz")
            // macOS needs an identifier
            identifier.set("io.github.fourlastor.Game")
            // Optional: icon for macOS
            macIcon.set(project.file("path/to/mac-icon.icns"))
        }
        create("winX64", Target.Windows) {
            architecture.set(Target.Architecture.X86_64)
            jdkUrl.set("https://github.com/adoptium/temurin17-binaries/releases/download/jdk-17.0.11%2B9/OpenJDK17U-jdk_x64_windows_hotspot_17.0.11_9.zip")
            // use executable with GPU hints, defaults to true
            useGpuHint.set(false)
        }
    }
}

Packaging the targets

Each defined target will generate a packageXXX task, where XXX is the capitalized name of the target (for example: packageLinuxX64). Running the task will produce a zip inside the outputDir folder containing the fully packaged app.

Using foojay instead of JDK URLs

Construo can figure out the JDK url for a specific build via the foojay discovery api. This makes the jdkUrl option inside targets optional.

Kotlin DSL

import io.github.fourlastor.construo.Target
import io.github.fourlastor.construo.ToolchainOptions
import io.github.fourlastor.construo.ToolchainVersion

construo {
    toolchain.set(ToolchainOptions(
        ToolchainVersion.of("17.0.9+9.1"),
        JvmVendorSpec.ADOPTIUM,
    ))
    targets {
        create<Target.Linux>("linuxX64") {
            // no need to specify a jdkUrl
            architecture.set(Target.Architecture.X86_64)
        }
    }
}

Groovy DSL

import io.github.fourlastor.construo.Target
import io.github.fourlastor.construo.ToolchainOptions
import io.github.fourlastor.construo.ToolchainVersion

construo {
    toolchain.set(new ToolchainOptions(
        ToolchainVersion.of("17.0.9+9.1"),
        JvmVendorSpec.ADOPTIUM,
    ))
    targets {
        create("linuxX64", Target.Linux) {
            // no need to specify a jdkUrl
            architecture.set(Target.Architecture.X86_64)
        }
    }
}

ToolchainVersion.of() accepts either a string, which must be a specific JDK version for that vendor, or an integer, which must be a major java version number (ie ToolchainVersion.of(17)).