Copyright (c) 2021, Shukant Pal and Contributors \
SPDX-License-Identifier: Apache-2.0
Java bindings for [libktx](https://github.com/KhronosGroup/KTX-Software), made with love by [Shukant Pal](https://github.com/ShukantPal) originally for the [Texture Compression Tool](https://compressor.shukantpal.com).
The `libktx-jni` library is built by the CMake project in the repository root. This library glues the `libktx` API with the interfaces provided in this Java library. You'll need to install `libktx` and `libktx-jni` to use the bindings. These, together with the Java archive `libktx.jar` can be installed from the packages found on the [KTX Software Releases](https://github.com/KhronosGroup/KTX-Software/releases) page.
Note: Java does not support arrays with more than 2³² elements so you should not use this library for images larger than four gigabytes in size.
## Usage
The setup is as follows:
```java
import org.khronos.ktx.KtxTexture2;
import java.nio.file.Paths;
public class App {
static {
// Load libktx-jni, which provides the JNI stubs for natively
// implemented Java methods. This should also load libktx
// automatically! If it doesn't, you may need to load libktx manually.
System.loadLibrary("ktx-jni");
}
public static void main(String[] args) {
KTXTexture2 texture = KTXTexture2.createFromNamedFile(
Paths.get("exampleInput.ktx2").toAbsolutePath().toString());
// Do something special with the texture!
texture.writeToNamedFile(
Paths.get("exampleOutput.ktx2").toAbsolutePath().toString());
}
}
```
## Build
You must have Maven installed.
Pass `-DKTX_FEATURE_JNI=ON` when configuring the CMake build for `libktx` so that `libktx-jni` and `libktx.jar` are built as well.
This will place the libraries in a sub-directory of the build directory you
configured with CMake corresponding to the configuration you are building, usually `Debug` or `Release` and the JAR in the `target` directory in `interfaces/java_binding`. When building your application, include this JAR in the build.
The installers install the JAR is the same library directory as `libktx` and `libktx-jni`. On GNU/Linux and macOS this is `/usr/local/lib`.
## Manually Build JAR
You must have Maven installed:
```
mvn package
```
The JAR is placed in the location described in the previous section.
## Run tests on macOS
It's tricky - I know.
```
_JAVA_OPTIONS=-Djava.library.path=/usr/local/lib mvn test
```
The path shown above is for the case when `libktx` and `libktx-jni` have been installed. If you have only built them then use
```
_JAVA_OPTIONS=-Djava.library.path=/path/to/your/cmake/build/<config> mvn test
```
where `<config>` is your build configuration, usually either `Debug` or `Release`.