java - Unity3d在android中将openGL FBO渲染为纹理(java)

Question

我正在尝试在Android(java)中为Unity3D制作一个插件，以使用OpenGL纹理进行渲染，获取 native 指针并在Unity中映射Quad。到目前为止，我的 Unity 代码很简单:

    // Use this for initialization
void Start () {
    AndroidJavaClass jc = new AndroidJavaClass("com.unity3d.player.UnityPlayer"); 
    context = jc.GetStatic<AndroidJavaObject>("currentActivity");
    surface2Unity = new AndroidJavaObject("com.everywoah.surface2unity.Surface2Unity"); 

    int i = surface2Unity.Call<int> ("getTextureID");
    t =Texture2D.CreateExternalTexture (1280, 720, TextureFormat.ARGB32, false,false, new IntPtr(i));
    t.filterMode = FilterMode.Bilinear;
    t.wrapMode = TextureWrapMode.Repeat;
    debug.text = "" + i;
    GetComponent<MeshRenderer> ().material.mainTexture = t;
}

// Update is called once per frame
void Update () {
    //transform.Rotate(1f,1f,1f);
    surface2Unity.Call ("draw");
}

在 Java 中我有:

public MyRenderer(){
    initGL();
    initFBO();
}

private void initGL(){
    GLstatics.checkGlError("initGL_S");

    String vertexShader = "attribute vec4 aPosition;\n" +
            "attribute vec4 aTex;\n" +
            "varying vec2 tex;\n" +
            "void main() {\n" +
            "    gl_Position = aPosition;\n" +
            "tex=aTex.xy;\n" +
            "}";

    String fragmentShader = "precision mediump float;\n" +
            "\n" +
            "void main(){\n" +
            "        gl_FragColor = vec4(1.0,1.0,0.0,1.0);\n" +
            "\n" +
            "}";

    mProgram         = GLstatics.createProgram(vertexShader, fragmentShader);
    maPositionHandle = GLES30.glGetAttribLocation(mProgram, "aPosition");
    maTexHandle = GLES30.glGetAttribLocation(mProgram, "aTex");

    GLstatics.checkGlError("initGL_E");

}


private void initFBO(){
    GLstatics.checkGlError("initFBO_S");


    GLES30.glGenFramebuffers(1, mFboId, 0);
    GLES30.glGenRenderbuffers(1, mRboId, 0);
    GLES30.glGenTextures(1, mTexId, 0);

    GLES30.glGenBuffers(1,buffer, 0);

    GLES30.glBindRenderbuffer(GLES30.GL_RENDERBUFFER, mRboId[0]);
    GLES30.glRenderbufferStorage(GLES30.GL_RENDERBUFFER, GLES30.GL_DEPTH_COMPONENT16, 1280,
            720);

    GLES30.glBindFramebuffer(GLES30.GL_FRAMEBUFFER, mFboId[0]);
    GLES30.glFramebufferRenderbuffer(GLES30.GL_FRAMEBUFFER, GLES30.GL_DEPTH_ATTACHMENT,
            GLES30.GL_RENDERBUFFER, mRboId[0]);

    GLES30.glActiveTexture(GLES30.GL_TEXTURE0);
    GLES30.glBindTexture(GLES30.GL_TEXTURE_2D, mTexId[0]);
    GLES30.glTexParameteri(GLES30.GL_TEXTURE_2D, GLES30.GL_TEXTURE_MIN_FILTER, GLES30.GL_LINEAR);
    GLES30.glTexParameteri(GLES30.GL_TEXTURE_2D, GLES30.GL_TEXTURE_MAG_FILTER, GLES30.GL_LINEAR);
    GLES30.glTexParameteri(GLES30.GL_TEXTURE_2D, GLES30.GL_TEXTURE_WRAP_S, GLES30.GL_CLAMP_TO_EDGE);
    GLES30.glTexParameteri(GLES30.GL_TEXTURE_2D, GLES30.GL_TEXTURE_WRAP_T, GLES30.GL_CLAMP_TO_EDGE);

    GLES30.glTexImage2D(GLES30.GL_TEXTURE_2D, 0, GLES30.GL_RGBA, 1280, 720, 0,
            GLES30.GL_RGBA, GLES30.GL_UNSIGNED_BYTE, null);

    GLES30.glFramebufferTexture2D(GLES30.GL_FRAMEBUFFER, GLES30.GL_COLOR_ATTACHMENT0,
            GLES30.GL_TEXTURE_2D, mTexId[0], 0);
    GLstatics.checkGlError("initFBO_E ");
}

public void draw() {
    GLstatics.checkGlError("draw_S");

    GLES30.glBindFramebuffer(GLES30.GL_FRAMEBUFFER, mFboId[0]);
    GLES30.glClearColor(0.0f,0.0f,1.0f,1.0f);

    GLES30.glViewport(0, 0, 1280, 720);

    GLES30.glClear(GLES30.GL_DEPTH_BUFFER_BIT | GLES30.GL_COLOR_BUFFER_BIT);

    GLES30.glUseProgram(mProgram);

    mVtxBuf.position(0);
    GLES30.glBindBuffer(GLES30.GL_ARRAY_BUFFER, buffer[0]);

    GLES30.glVertexAttribPointer(maPositionHandle,
            3, GLES30.GL_FLOAT, false, 4*(3+2), mVtxBuf);
    GLES30.glEnableVertexAttribArray(maPositionHandle);

    mVtxBuf.position(3);
    GLES30.glVertexAttribPointer(maTexHandle, 2, GLES30.GL_FLOAT, false, 4 * (3 + 2), mVtxBuf);
    GLES30.glEnableVertexAttribArray(maTexHandle);

    GLES30.glDrawArrays(GLES30.GL_TRIANGLE_STRIP, 0, 4);

    GLstatics.checkGlError("draw_E ");
}

这应该是一个非常简单的代码，只需在蓝色背景中绘制一个黄色矩形，我就可以让它在 Activity 中工作。这里的问题是我的应用程序看起来像这样:

从那里我认为我弄乱了已经绑定(bind)的openGL缓冲区，因为我的矩形的顶点被绘制了，但里面有一个奇怪的东西。我尝试保存它们并在绘制函数之后绑定(bind)它们，但我得到了相同的结果。有什么想法我做错了吗？如果可能的话，我真的很想用 Java 解决这个问题，我使用 NDK 的经验最多为 0。

Answer 1

好吧，问题是我必须自己控制 EGLContex，我无法在与 Unity 相同的上下文中进行渲染，所以我需要这个类:

public class SurfaceManager {

public final static String TAG = "TextureManager";

private static final int EGL_RECORDABLE_ANDROID = 0x3142;

// Contexto donde dibujar
private EGLContext mEGLContext = null;
// Contexto compartido entre hilos. Para poder pasar el FBO de un hilo a otro
private EGLContext mEGLSharedContext = null;
private EGLSurface mEGLSurface = null;
private EGLDisplay mEGLDisplay = null;

// La surface donde se va a dibujar
private Surface mSurface;

/**
 * Creates an EGL context and an EGL surface.
 */
public SurfaceManager(Surface surface) {
    EGLContext shared = EGL14.eglGetCurrentContext();
    if (surface == null) {
        throw new NullPointerException();
    }
    mSurface = surface;
    mEGLSharedContext = shared;
    Log.d("Surface2UnityDebug", "vamos al setup");
    eglSetup();
}

// Hace que la surface actual sea esta
public void makeCurrent() {
    if (!EGL14.eglMakeCurrent(mEGLDisplay, mEGLSurface, mEGLSurface, mEGLContext))
        throw new RuntimeException("eglMakeCurrent failed");
}

// Cambia el buffer donde se está pintando por el de la surface. es decir, guarda lo que se haya pintado.
public void swapBuffers() {
    EGL14.eglSwapBuffers(mEGLDisplay, mEGLSurface);
}

/**
 * Sends the presentation time stamp to EGL.  Time is expressed in nanoseconds.
 */
public void setPresentationTime(long nsecs) {
    EGLExt.eglPresentationTimeANDROID(mEGLDisplay, mEGLSurface, nsecs);
    checkEglError("eglPresentationTimeANDROID");
}

/**
 * Prepares EGL.  We want a GLES 2.0 context and a surface that supports recording.
 */
private void eglSetup() {
    mEGLDisplay = EGL14.eglGetDisplay(EGL14.EGL_DEFAULT_DISPLAY);
    if (mEGLDisplay == EGL14.EGL_NO_DISPLAY) {
        Log.d("Surface2UnityDebug", "unable to get EGL14 display");
        throw new RuntimeException("unable to get EGL14 display");
    }
    int[] version = new int[2];
    if (!EGL14.eglInitialize(mEGLDisplay, version, 0, version, 1)) {
        Log.d("Surface2UnityDebug", "unable to initialize EGL14");
        throw new RuntimeException("unable to initialize EGL14");
    }

    // Configure EGL for recording and OpenGL ES 2.0.
    int[] attribList;
    attribList = new int[]{
            EGL14.EGL_RED_SIZE, 8,
            EGL14.EGL_GREEN_SIZE, 8,
            EGL14.EGL_BLUE_SIZE, 8,
            EGL14.EGL_RENDERABLE_TYPE, EGL14.EGL_OPENGL_ES2_BIT,
            EGL_RECORDABLE_ANDROID, 1,
            EGL14.EGL_NONE
    };
    EGLConfig[] configs = new EGLConfig[1];
    int[] numConfigs = new int[1];

    EGL14.eglChooseConfig(mEGLDisplay, attribList, 0, configs, 0, configs.length,
            numConfigs, 0);
    checkEglError("eglCreateContext RGB888+recordable ES2");

    // Configure context for OpenGL ES 2.0.
    int[] attrib_list = {
            EGL14.EGL_CONTEXT_CLIENT_VERSION, 3,
            EGL14.EGL_NONE
    };

    mEGLContext = EGL14.eglCreateContext(mEGLDisplay, configs[0], mEGLSharedContext, attrib_list, 0);
    checkEglError("eglCreateContext");

    // Create a window surface, and attach it to the Surface we received.
    int[] surfaceAttribs = {
            EGL14.EGL_NONE
    };
    mEGLSurface = EGL14.eglGetCurrentSurface(EGL14.EGL_DRAW);
    checkEglError("eglCreateWindowSurface");


}

/**
 * Discards all resources held by this class, notably the EGL context.  Also releases the
 * Surface that was passed to our constructor.
 */
public void release() {
    if (mEGLDisplay != EGL14.EGL_NO_DISPLAY) {
        EGL14.eglMakeCurrent(mEGLDisplay, EGL14.EGL_NO_SURFACE, EGL14.EGL_NO_SURFACE,
                EGL14.EGL_NO_CONTEXT);
        EGL14.eglDestroySurface(mEGLDisplay, mEGLSurface);
        EGL14.eglDestroyContext(mEGLDisplay, mEGLContext);
        EGL14.eglReleaseThread();
        EGL14.eglTerminate(mEGLDisplay);
    }
    mEGLDisplay = EGL14.EGL_NO_DISPLAY;
    mEGLContext = EGL14.EGL_NO_CONTEXT;
    mEGLSurface = EGL14.EGL_NO_SURFACE;
    mSurface.release();
}

/**
 * Checks for EGL errors. Throws an exception if one is found.
 */
private void checkEglError(String msg) {
    int error;
    if ((error = EGL14.eglGetError()) != EGL14.EGL_SUCCESS) {
        Log.d("Surface2UnityDebug", msg + ": EGL error: 0x" + Integer.toHexString(error));
        throw new RuntimeException(msg + ": EGL error: 0x" + Integer.toHexString(error));
    }
}}

和方法:

    // Guarda el estado actual
public void saveRenderState() {
    mSavedEglDisplay     = EGL14.eglGetCurrentDisplay();
    mSavedEglDrawSurface = EGL14.eglGetCurrentSurface(EGL14.EGL_DRAW);
    mSavedEglReadSurface = EGL14.eglGetCurrentSurface(EGL14.EGL_READ);
    mSavedEglContext     = EGL14.eglGetCurrentContext();
}

// Carga el estado guardado
public void restoreRenderState() {
    if (!EGL14.eglMakeCurrent(
            mSavedEglDisplay,
            mSavedEglDrawSurface,
            mSavedEglReadSurface,
            mSavedEglContext)) {
        throw new RuntimeException("eglMakeCurrent failed");
    }
}

这样我就可以调用 saveRenderState()、makeCurrent()、draw() 和 RestoreRenderState()，现在一切正常。