opengl es 3 glBlitFramebuffer - 将一个纹理复制到另一个

如何解决opengl es 3 glBlitFramebuffer - 将一个纹理复制到另一个

我正在尝试使用“glBlitFramebuffer”将纹理复制到另一个纹理中，我正在处理来自 android ndk-samples 的经典 open gl 示例 hello-gl2。我更改了着色器以支持纹理，并且可以正确渲染带纹理的三角形。我还更改了 java 端请求的 opengl es 版本，以便请求 opengl-es3，并且我更新了 Cmakelists 文件以链接正确的库。调用 glBlitFramebuffer(0,tw,th,GL_COLOR_BUFFER_BIT,GL_LINEAR); 后，我收到 after blitTexture glBlitFramebuffer() glError (0x502) 错误。造成这种情况的根本原因是什么？

我使用的代码：

生成纹理：

void createTexture(gluint &tex,int width,int height,int r){
    int rowlen = width * 3;
    unsigned char buf[width*3*height];
    for (int i=0; i<rowlen; i+=3)
        for (int j=0; j<height; j++) {
            int col = ((int (i/(3*r))) + (int (j/r)))%2;
            buf[i+j*rowlen] = buf[i+1+j*rowlen] = buf[i+2+j*rowlen] = col * 255;
        }
    glGenTextures(1,&tex);
    glBindTexture(GL_TEXTURE_2D,tex);
    glTexImage2D(GL_TEXTURE_2D,GL_RGB,width,height,GL_UNSIGNED_BYTE,buf);
    // set the texture wrapping/filtering options (on the currently bound texture object)
    glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_WRAP_S,GL_REPEAT);
    glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_WRAP_T,GL_TEXTURE_MIN_FILTER,GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_LINEAR);
    LOGI("DEBUG C++ Texture created [%d]",tex);
}

设置帧缓冲区：

bool SetupFramebuffer(gluint tex,int height)
{
    if (fb == 0)
    {
        glGenFramebuffers(1,&fb);
        glBindFramebuffer(GL_DRAW_FRAMEBUFFER,fb);
        glFramebufferTexture2D(GL_DRAW_FRAMEBUFFER,GL_COLOR_ATTACHMENT0,GL_TEXTURE_2D,tex,0);

        GLenum status = glCheckFramebufferStatus(GL_DRAW_FRAMEBUFFER);
        glBindFramebuffer(GL_DRAW_FRAMEBUFFER,0);

        if (status != GL_FRAMEBUFFER_COMPLETE)
        {
            LOGE("Incomplete frame buffer object!");
            return false;
        }

        LOGI("Created FBO %d for texture %d.",fb,tex);
    }

    return true;
}

在 setupGraphics 函数中构建纹理数组：

    createTexture(tex,6);
    for (int i = 0; i<25; i++) createTexture(aniTex[i],3+i);
    SetupFramebuffer(tex,th);

最后对帧缓冲区进行 blit：

const GLenum attachment[1] = { GL_COLOR_ATTACHMENT0 };

void blitTexture() {
    static int time = 0;
    glBindFramebuffer(GL_FRAMEBUFFER,fb);
    checkGlError("blitTexture glBindFramebuffer");

    glFramebufferTexture2D(GL_FRAMEBUFFER,GL_COLOR_ATTACHMENT1,aniTex[time],0);
    checkGlError("blitTexture glFramebufferTexture2D");
    glreadBuffer(GL_COLOR_ATTACHMENT1);
    checkGlError("blitTexture glreadBuffer");
    glDrawBuffers(1,attachment);
    checkGlError("blitTexture glDrawBuffers");


    GLenum status = glCheckFramebufferStatus(GL_FRAMEBUFFER);
    if (status != GL_FRAMEBUFFER_COMPLETE) LOGE("Incomplete frame buffer object!");

    glBlitFramebuffer(0,GL_LINEAR);
    checkGlError("blitTexture glBlitFramebuffer");
    int samples;
    glGetFramebufferParameteriv(GL_READ_FRAMEBUFFER,GL_FRAMEBUFFER_DEFAULT_SAMPLES,&samples);
    LOGI("SAMPLES draw buffer %d",samples);
    time = ++time%25;
}

可以在此处找到完整的项目：https://github.com/AndrewBloom/BlitFramebufferExample