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nih-plug/src/wrapper/clap/factory.rs
Robbert van der Helm 4c0b07c578 💥 Move re-exports to a prelude module
So you can import everything at once, because you're likely going to
need at least 90% of it anyways.
2022-03-03 23:23:51 +01:00

73 lines
2.3 KiB
Rust

use clap_sys::host::clap_host;
use clap_sys::plugin::{clap_plugin, clap_plugin_descriptor};
use clap_sys::plugin_factory::clap_plugin_factory;
use std::ffi::CStr;
use std::os::raw::c_char;
use std::ptr;
use std::sync::Arc;
use super::descriptor::PluginDescriptor;
use super::wrapper::Wrapper;
use crate::plugin::ClapPlugin;
/// The plugin's factory. Initialized using a lazy_static from the entry poiunt's `get_factory()`
/// function. From this point onwards we don't need to generate code with macros anymore.
#[doc(hidden)]
#[repr(C)]
pub struct Factory<P: ClapPlugin> {
// Keep the vtable as the first field so we can do a simple pointer cast
pub clap_plugin_factory: clap_plugin_factory,
plugin_descriptor: PluginDescriptor<P>,
}
impl<P: ClapPlugin> Default for Factory<P> {
fn default() -> Self {
Self {
clap_plugin_factory: clap_plugin_factory {
get_plugin_count: Self::get_plugin_count,
get_plugin_descriptor: Self::get_plugin_descriptor,
create_plugin: Self::create_plugin,
},
plugin_descriptor: PluginDescriptor::default(),
}
}
}
impl<P: ClapPlugin> Factory<P> {
unsafe extern "C" fn get_plugin_count(_factory: *const clap_plugin_factory) -> u32 {
1
}
unsafe extern "C" fn get_plugin_descriptor(
factory: *const clap_plugin_factory,
index: u32,
) -> *const clap_plugin_descriptor {
let factory = &*(factory as *const Self);
if index == 0 {
factory.plugin_descriptor.clap_plugin_descriptor()
} else {
ptr::null()
}
}
unsafe extern "C" fn create_plugin(
factory: *const clap_plugin_factory,
host: *const clap_host,
plugin_id: *const c_char,
) -> *const clap_plugin {
let factory = &*(factory as *const Self);
if !plugin_id.is_null() && CStr::from_ptr(plugin_id) == factory.plugin_descriptor.clap_id()
{
// Arc does not have a convenient leak function like Box, so this gets a bit awkward
// This pointer gets turned into an Arc and its reference count decremented in
// [Wrapper::destroy()]
&(*Arc::into_raw(Wrapper::<P>::new(host))).clap_plugin
} else {
ptr::null()
}
}
}