source: trunk/Utilities/DirectShowReferenceSource/Sample/Unity01/UnityProject/Assets/UseRenderingPlugin.cs @ 937

// on OpenGL ES there is no way to query texture extents from native texture id
#if (UNITY_IPHONE || UNITY_ANDROID) && !UNITY_EDITOR
        #define UNITY_GLES_RENDERER
#endif


using UnityEngine;
using System;
using System.Collections;
using System.Runtime.InteropServices;


public class UseRenderingPlugin : MonoBehaviour
{
        // Native plugin rendering events are only called if a plugin is used
        // by some script. This means we have to DllImport at least
        // one function in some active script.
        // For this example, we'll call into plugin's SetTimeFromUnity
        // function and pass the current time so the plugin can animate.

#if UNITY_IPHONE && !UNITY_EDITOR
        [DllImport ("__Internal")]
#else
        [DllImport ("RenderingPlugin")]
#endif
        private static extern void SetTimeFromUnity(float t);


        // We'll also pass native pointer to a texture in Unity.
        // The plugin will fill texture data from native code.
#if UNITY_IPHONE && !UNITY_EDITOR
        [DllImport ("__Internal")]
#else
        [DllImport ("RenderingPlugin")]
#endif
#if UNITY_GLES_RENDERER
        private static extern void SetTextureFromUnity(System.IntPtr texture, int w, int h);
#else
        private static extern void SetTextureFromUnity(System.IntPtr texture);
#endif


#if UNITY_IPHONE && !UNITY_EDITOR
        [DllImport ("__Internal")]
#else
        [DllImport("RenderingPlugin")]
#endif
        private static extern void SetUnityStreamingAssetsPath([MarshalAs(UnmanagedType.LPStr)] string path);


#if UNITY_IPHONE && !UNITY_EDITOR
        [DllImport ("__Internal")]
#else
        [DllImport("RenderingPlugin")]
#endif
        private static extern IntPtr GetRenderEventFunc();


        IEnumerator Start()
        {
                SetUnityStreamingAssetsPath(Application.streamingAssetsPath);

                CreateTextureAndPassToPlugin();
                yield return StartCoroutine("CallPluginAtEndOfFrames");
        }

        private void CreateTextureAndPassToPlugin()
        {
        // NOTE: https://en.wikipedia.org/wiki/Display_resolution

        // Create a texture
        Texture2D tex = new Texture2D(2048, 1536, TextureFormat.BGRA32, false);
                // Set point filtering just so we can see the pixels clearly
                tex.filterMode = FilterMode.Point;
                // Call Apply() so it's actually uploaded to the GPU
                tex.Apply();

                // Set texture onto our matrial
                GetComponent<Renderer>().material.mainTexture = tex;

                // Pass texture pointer to the plugin
        #if UNITY_GLES_RENDERER
                SetTextureFromUnity (tex.GetNativeTexturePtr(), tex.width, tex.height);
        #else
                SetTextureFromUnity (tex.GetNativeTexturePtr());
        #endif
        }

        private IEnumerator CallPluginAtEndOfFrames()
        {
                while (true) {
                        // Wait until all frame rendering is done
                        yield return new WaitForEndOfFrame();

                        // Set time for the plugin
                        SetTimeFromUnity (Time.timeSinceLevelLoad);

                        // Issue a plugin event with arbitrary integer identifier.
                        // The plugin can distinguish between different
                        // things it needs to do based on this ID.
                        // For our simple plugin, it does not matter which ID we pass here.
                        GL.IssuePluginEvent(GetRenderEventFunc(), 1);
                }
        }
}