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Rust library to handle the dynamic load of the OpenCL shared library.

## Description

This library in general is a rewritten version of the [opencl-sys-rs](https://github.com/kenba/opencl-sys-rs) library.
The main difference is a way in which the OpenCL library will be linked to the program:
it will be loaded dynamically in the runtime during the first call to the OpenCL API with the help of the
[dlopen2](https://github.com/OpenByteDev/dlopen2) library.

If the OpenCL library not found, the error code `CL_RUNTIME_LOAD_FAILED = -2000` will be returned.

If the OpenCL library doesn't have some API functions
(such as [clCreateBufferWithProperties](https://registry.khronos.org/OpenCL/sdk/3.0/docs/man/html/clCreateBuffer.html),
it is v3.0 API function), the error code `CL_FUNCTION_NOT_AVAILABLE = -2001` will be returned.

## Usage

You do *not* need to install any OpenCL hardware driver(s) to run your code which depends on `opencl-dynamic-sys` library.

Just include the library in the `dependencies` section in your `Cargo.toml` file:
```
[dependencies]
opencl-dynamic-sys = "0.1"
```

## Search path

By default, the OpenCL shared library is searched as follows:

- on Windows: `OpenCL.dll`
- on macOS: `/System/Library/Frameworks/OpenCL.framework/OpenCL`
- otherwise: `libOpenCL.so`

If you have the OpenCL shared library in non-standard place, you can use an environment variable `OPENCL_DYLIB_PATH`
to define where to look for the library (the value of the variable is a comma-separated string):
```
OPENCL_DYLIB_PATH=/usr/lib/libOpenCL.so;/var/lib/OpenCL;%DESKTOP%/OpenCL.dll
```

If the OpenCL shared library is found, then the call of `opencl-dynamic-sys::is_opencl_runtime_available()` will return `true`.

## License
This library is distributed under the terms of the MIT license, see [LICENSE](https://github.com/passware/opencl-dynamic-sys-rs/blob/main/LICENSE) for details.