android - 在 android 上使用帧缓冲区时，场景不渲染

Question

我正在尝试将我的应用程序切换为使用帧缓冲区/渲染缓冲区对象(希望稍后渲染到纹理)但是每当我使用帧缓冲区/渲染缓冲区时，没有任何渲染。当默认帧缓冲区保持打开状态时(默认情况下)，它可以正常渲染；所有与颜色、深度和模板相关的功能都完全按预期工作。

初始化代码:

if(frameBuffer == 0 || !GLES20.glIsFramebuffer(frameBuffer)){
    int[] retVal = new int[1];
    GLES20.glGenFramebuffers(1, retVal, 0);
    frameBuffer = retVal[0];
    retVal[0] = 0;

    if(renderBufferColour != 0 || !GLES20.glIsRenderbuffer(renderBufferColour)){
        GLES20.glGenRenderbuffers(1, retVal, 0);
        renderBufferColour = retVal[0];
    }

    if(renderBufferDepth != 0 || !GLES20.glIsRenderbuffer(renderBufferDepth)){
        GLES20.glGenRenderbuffers(1, retVal, 0);
        renderBufferDepth = retVal[0];
    }

    if(renderBufferStencil != 0 || !GLES20.glIsRenderbuffer(renderBufferStencil)){
        GLES20.glGenRenderbuffers(1, retVal, 0);
        renderBufferStencil = retVal[0];
    }
}

启用帧缓冲区的代码(将其注释掉允许使用默认缓冲区进行渲染):

GLES20.glBindFramebuffer(GLES20.GL_FRAMEBUFFER, frameBuffer);

GLES20.glBindRenderbuffer(GLES20.GL_RENDERBUFFER, renderBufferColour);
GLES20.glRenderbufferStorage(GLES20.GL_RENDERBUFFER, GLES20.GL_RGBA4, width, height);
GLES20.glFramebufferRenderbuffer(
        GLES20.GL_FRAMEBUFFER,
        GLES20.GL_COLOR_ATTACHMENT0,
        GLES20.GL_RENDERBUFFER,
        renderBufferColour);

GLES20.glBindRenderbuffer(GLES20.GL_RENDERBUFFER, renderBufferDepth);
GLES20.glRenderbufferStorage(GLES20.GL_RENDERBUFFER, GLES20.GL_DEPTH_COMPONENT16, width, height);
GLES20.glFramebufferRenderbuffer(
        GLES20.GL_FRAMEBUFFER,
        GLES20.GL_DEPTH_ATTACHMENT,
        GLES20.GL_RENDERBUFFER,
        renderBufferDepth);

GLES20.glBindRenderbuffer(GLES20.GL_RENDERBUFFER, renderBufferStencil);
GLES20.glRenderbufferStorage(GLES20.GL_RENDERBUFFER, GLES20.GL_STENCIL_INDEX8, width, height);
GLES20.glFramebufferRenderbuffer(
        GLES20.GL_FRAMEBUFFER,
        GLES20.GL_STENCIL_ATTACHMENT,
        GLES20.GL_RENDERBUFFER,
        renderBufferStencil);

if (GLES20.glCheckFramebufferStatus(GLES20.GL_FRAMEBUFFER) != GLES20.GL_FRAMEBUFFER_COMPLETE)
    throw new RuntimeException(String.format("Failed to make complete framebuffer object %x", GLES20.glCheckFramebufferStatus(GLES20.GL_FRAMEBUFFER)));

没有抛出最后的异常，并且在每一步之后检查 glGetError() 时，没有返回错误。我在这里遗漏了什么吗？

Answer 1

好的，在阅读 OpenGLES 2.0 手册后，我遇到了这段话:

By allowing the images of a renderbuffer to be attached to a framebuffer,
OpenGL ES provides a mechanism to support off-screen rendering. Further, by
allowing the images of a texture to be attached to a framebuffer, OpenGL ES provides
a mechanism to support render to texture.

在我看来，应用程序渲染缓冲区总是屏幕外，而不是我预期的屏幕上。如果我没看错的话，这就是屏幕上没有图像的原因。