Нативный низкоуровневый интерфейс плагина
В дополнение к основному интерфейсу скриптов Native Code Plugins Unity может принимать запросы и вызовы, когда происходят какие-либо события. Обычно это используется для низкоуровневого рендеринга в вашем плагине, а также позволяет работать с многопоточными процессами рендеринга Unity.
Headers defining interfaces exposed by Unity are provided with the editor.
A plugin should export UnityPluginLoad
and UnityPluginUnload
functions to handle main Unity events. See IUnityInterface.h
for the correct signatures. IUnityInterfaces
is provided to the plugin to access further Unity APIs.
#include "IUnityInterface.h"
#include "IUnityGraphics.h"
// Unity plugin load event
extern "C" void UNITY_INTERFACE_EXPORT UNITY_INTERFACE_API
UnityPluginLoad(IUnityInterfaces* unityInterfaces)
{
IUnityGraphics* graphics = unityInterfaces->Get<IUnityGraphics>();
}
Доступ к графическому устройству
A plugin can access generic graphics device functionality by getting the IUnityGraphics
interface. In earlier versions of Unity a UnitySetGraphicsDevice
function had to be exported in order to receive notification about events on the graphics device. Starting with Unity 5.2 the new IUnityGraphics interface (found in IUnityGraphics.h
) provides a way to register a callback.
#include "IUnityInterface.h"
#include "IUnityGraphics.h"
static IUnityInterfaces* s_UnityInterfaces = NULL;
static IUnityGraphics* s_Graphics = NULL;
static UnityGfxRenderer s_RendererType = kUnityGfxRendererNull;
// Unity plugin load event
extern "C" void UNITY_INTERFACE_EXPORT UNITY_INTERFACE_API
UnityPluginLoad(IUnityInterfaces* unityInterfaces)
{
s_UnityInterfaces = unityInterfaces;
s_Graphics = unityInterfaces->Get<IUnityGraphics>();
s_Graphics->RegisterDeviceEventCallback(OnGraphicsDeviceEvent);
// Run OnGraphicsDeviceEvent(initialize) manually on plugin load
// to not miss the event in case the graphics device is already initialized
OnGraphicsDeviceEvent(kUnityGfxDeviceEventInitialize);
}
// Unity plugin unload event
extern "C" void UNITY_INTERFACE_EXPORT UNITY_INTERFACE_API
UnityPluginUnload()
{
s_Graphics->UnregisterDeviceEventCallback(OnGraphicsDeviceEvent);
}
static void UNITY_INTERFACE_API
OnGraphicsDeviceEvent(UnityGfxDeviceEventType eventType)
{
switch (eventType)
{
case kUnityGfxDeviceEventInitialize:
{
s_RendererType = s_Graphics->GetRenderer();
//TODO: user initialization code
break;
}
case kUnityGfxDeviceEventShutdown:
{
s_RendererType = kUnityGfxRendererNull;
//TODO: user shutdown code
break;
}
case kUnityGfxDeviceEventBeforeReset:
{
//TODO: user Direct3D 9 code
break;
}
case kUnityGfxDeviceEventAfterReset:
{
//TODO: user Direct3D 9 code
break;
}
};
}
Вызовы плагина из потока рендеринга
Rendering in Unity can be multithreaded if the platform and number of available CPUs will allow for it. When multithreaded rendering is used, the rendering API commands happen on a thread which is completely separate from the one that runs MonoBehaviour scripts. Consequently, it is not always possible for your plugin to start doing some rendering immediately, because it might interfere with whatever the render thread is doing at the time.
Для того чтобы сделать какой-либо рендеринг из плагина, вы должны вызвать GL.IssuePluginEvent из скрипта, который вызовет ваш плагин из потока отрисовки. Например, если вы вызовите GL.IssuePluginEvent из функции камеры OnPostRender, то получите обратный вызов плагина сразу же после завершения обработки камеры.
Signature for the UnityRenderingEvent
callback is provided in IUnityGraphics.h
.
Native plugin code example:
// Plugin function to handle a specific rendering event
static void UNITY_INTERFACE_API OnRenderEvent(int eventID)
{
//TODO: user rendering code
}
// Freely defined function to pass a callback to plugin-specific scripts
extern "C" UnityRenderingEvent UNITY_INTERFACE_EXPORT UNITY_INTERFACE_API
GetRenderEventFunc()
{
return OnRenderEvent;
}
Managed plugin code example:
#if UNITY_IPHONE && !UNITY_EDITOR
[DllImport ("__Internal")]
#else
[DllImport("RenderingPlugin")]
#endif
private static extern IntPtr GetRenderEventFunc();
// Queue a specific callback to be called on the render thread
GL.IssuePluginEvent(GetRenderEventFunc(), 1);
Such callbacks can now also be added to CommandBuffers via CommandBuffer.IssuePluginEvent.
Пример
Пример плагина низкоуровневого рендеринга можно скачать здесь. В нём продемонстрированы два аспекта:
Проект работает с: