GLES学习笔记---EGLImage绑定纹理

JNIEXPORT void JNICALL Java_com_sprd_opengl_test_MyNdk_processEglImage
        (JNIEnv *env, jobject obj, jobject bitmap) {
    LOGD("processEglImage1");
    glUseProgram(gl_cxt.program);
    AndroidBitmapInfo bitmapInfo;
    if (AndroidBitmap_getInfo(env, bitmap, &bitmapInfo) < 0) {
        LOGE("AndroidBitmap_getInfo() failed ! ");
        return;
    }
    void *bmpPixels;
    LOGD("processEglImage2, format: %d, stride: %d", bitmapInfo.format, bitmapInfo.stride);
    AndroidBitmap_lockPixels(env, bitmap, &bmpPixels);
    LOGD("processEglImage3");

    uint32_t width = bitmapInfo.width;
    uint32_t height = bitmapInfo.height;

    AHardwareBuffer_Desc desc = {width, height, 1,
                                 AHARDWAREBUFFER_FORMAT_R8G8B8A8_UNORM,
                                 AHARDWAREBUFFER_USAGE_CPU_WRITE_OFTEN|AHARDWAREBUFFER_USAGE_GPU_SAMPLED_IMAGE,
                                 width, 0 ,0};
    AHardwareBuffer *inBuffer;
    int ret = AHardwareBuffer_allocate(&desc, &inBuffer);
    LOGD("AHardwareBuffer_allocate ret: %d", ret);

    // write data>>
    AHardwareBuffer_Planes planes_info = {0};
    LOGD("AHardwareBuffer_lockPlanes E");
    ret = AHardwareBuffer_lockPlanes(inBuffer,
                                         AHARDWAREBUFFER_USAGE_CPU_WRITE_MASK,
                                         -1,
                                         nullptr,
                                         &planes_info);
    LOGD("AHardwareBuffer_lockPlanes X");
    if (ret != 0) {
        LOGE("Failed to AHardwareBuffer_lockPlanes");
    } else {
        memcpy(planes_info.planes[0].data, bmpPixels, width * height * 4);
//        unsigned char *pData = static_cast<unsigned char *>(planes_info.planes[0].data);
//        for (int i = 0; i < width * height * 4; i++) {
//            pData[i] = i % 255;
//        }
        ret = AHardwareBuffer_unlock(inBuffer, nullptr);
        if (ret != 0) {
            LOGE("Failed to AHardwareBuffer_unlock");
        }
    }
    // write data<<

    EGLint eglImageAttributes[] = {EGL_IMAGE_PRESERVED_KHR, EGL_TRUE, EGL_NONE};

    EGLClientBuffer cb = eglGetNativeClientBufferANDROID(inBuffer);
    LOGD("eglGetNativeClientBufferANDROID cb: %p", cb);
    EGLImageKHR eglImageHandle = eglCreateImageKHR(eglGetDisplay(EGL_DEFAULT_DISPLAY), EGL_NO_CONTEXT,
                                                   EGL_NATIVE_BUFFER_ANDROID,
                                                   cb,
                                                   reinterpret_cast<const EGLint *>(eglImageAttributes));
    LOGD("eglCreateImageKHR eglImageHandle: %p", eglImageHandle);
    LOGD("error: %d", eglGetError());

    unsigned int textureId;
    glGenTextures(1, &textureId);
    glActiveTexture(GL_TEXTURE0);
    glBindTexture(GL_TEXTURE_2D, textureId);

    LOGD("glEGLImageTargetTexture2DOES E");
    glEGLImageTargetTexture2DOES(GL_TEXTURE_2D, eglImageHandle);
    LOGD("glEGLImageTargetTexture2DOES X");

    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);

    glBindTexture(GL_TEXTURE_2D, 0);

    AndroidBitmap_unlockPixels(env, bitmap);

    /*顶点               纹理*/
    float vertices[] = {-1.0f, -1.0f, 0.0f, 0.0f, 0.0f,
                        -1.0f, 1.0f,  0.0f, 0.0f, 1.0f,
                        1.0f,  -1.0f, 0.0f, 1.0f, 0.0f,
                        1.0f,  1.0f,  0.0f, 1.0f, 1.0f};

    unsigned int indices[] = {
            0, 1, 2, // first triangle
            1, 2, 3  // second triangle
    };

    // optimal
    unsigned int VBO, EBO, VAO;
    glGenVertexArrays(1, &VAO);
    glBindVertexArray(VAO);

    glGenBuffers(1, &VBO);
    glBindBuffer(GL_ARRAY_BUFFER, VBO);
    glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);

    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 5 * sizeof(float), (void*)0);
    glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 5 * sizeof(float), (void*)((0 + 3)*sizeof(float)));
    glEnableVertexAttribArray(0);
    glEnableVertexAttribArray(1);

    glGenBuffers(1, &EBO);
    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, EBO);
    glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(indices), indices, GL_STATIC_DRAW);

    glBindVertexArray(0);


    glBindVertexArray(VAO);
    glClearColor(1.0f, 1.0f, 1.0f, 1.0f);
    glClear(GL_COLOR_BUFFER_BIT);

    unsigned int fbo;
    glGenFramebuffers(1, &fbo);
    glBindFramebuffer(GL_FRAMEBUFFER, fbo);

    glActiveTexture(GL_TEXTURE0);
    glBindTexture(GL_TEXTURE_2D, textureId);
    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, textureId, 0);

    glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, (void*)0);
    //glBindTexture(GL_TEXTURE_2D, 0);
    glBindFramebuffer(GL_FRAMEBUFFER, 0);

    glDisableVertexAttribArray(0);
    glDisableVertexAttribArray(1);
    glBindVertexArray(0);

    // must, 否则读不出绘制后数据
    glFinish();
    unsigned char *ptrReader = nullptr;
    unsigned char *dstBuffer = static_cast<unsigned char *>(malloc(width * height * 4));
    LOGD("AHardwareBuffer_lock E");
    AHardwareBuffer_lock(inBuffer, AHARDWAREBUFFER_USAGE_CPU_READ_OFTEN, -1, nullptr,
                         (void **) &ptrReader);
    LOGD("AHardwareBuffer_lock X");
    memcpy(dstBuffer, ptrReader, width * height * 4);
    AHardwareBuffer_unlock(inBuffer, nullptr);
    LOGD("%d, %d, %d, %d", *dstBuffer, *(dstBuffer+1), *(dstBuffer+2), *(dstBuffer+3));

    eglSwapBuffers(gl_cxt.display, gl_cxt.winSurface);

    LOGD("X");
}

EGLClientBuffer cb = eglGetNativeClientBufferANDROID(inBuffer);

将HardwareBuffer转换成 eglCreateImageKHR需要的格式

EGLImageKHR eglImageHandle = eglCreateImageKHR(eglGetDisplay(EGL_DEFAULT_DISPLAY), EGL_NO_CONTEXT,
                                               EGL_NATIVE_BUFFER_ANDROID,
                                               cb,
                                               reinterpret_cast<const EGLint *>(eglImageAttributes));

创建EGLImage

glEGLImageTargetTexture2DOES(GL_TEXTURE_2D, eglImageHandle);

绑定EGLImage到纹理

glBindFramebuffer(GL_FRAMEBUFFER, fbo);

    glActiveTexture(GL_TEXTURE0);
    glBindTexture(GL_TEXTURE_2D, textureId);
    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, textureId, 0);

    glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, (void*)0);
    //glBindTexture(GL_TEXTURE_2D, 0);
    glBindFramebuffer(GL_FRAMEBUFFER, 0);

离屏渲染，绘制到fbo对应的纹理上（不是屏幕）

    glFinish();
    unsigned char *ptrReader = nullptr;
    unsigned char *dstBuffer = static_cast<unsigned char *>(malloc(width * height * 4));
    LOGD("AHardwareBuffer_lock E");
    AHardwareBuffer_lock(inBuffer, AHARDWAREBUFFER_USAGE_CPU_READ_OFTEN, -1, nullptr,
                         (void **) &ptrReader);
    LOGD("AHardwareBuffer_lock X");
    memcpy(dstBuffer, ptrReader, width * height * 4);
    AHardwareBuffer_unlock(inBuffer, nullptr);

绘制完了glFinish一下，AHardwareBuffer_lock就能将绘制好的内容读出来。

为啥需要glFinish暂时还不清楚，没有glFinish的话ptrReader里面的像素值还是输入的inBuffer的值。

还有就是不清楚为啥绘制完了，绘制的结果就到了HardwareBuffer里面了，HardwareBuffer是输入啊