Can't render to render buffer

[kirgene]

I'd like to do offscreen rendering and processing using render buffer and EGL_IMAGE_BRCM_VCSM:

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    GLuint buffer = 0;
    m_gl_funcs->glGenRenderbuffers(1, &buffer);
    m_gl_funcs->glBindRenderbuffer(GL_RENDERBUFFER, buffer);

    m_vcsm_info->width = m_vcsm_info->height = 2048;
    EGLImageKHR eglFbImage = eglCreateImageKHR(egl_display, EGL_NO_CONTEXT,
            EGL_IMAGE_BRCM_VCSM, m_vcsm_info, NULL);
    assert(eglFbImage != EGL_NO_IMAGE_KHR && m_vcsm_info->vcsm_handle != 0);

    glEGLImageTargetRenderbufferStorageOES(GL_RENDERBUFFER, eglFbImage);
    assert(!glGetError());

but getting GL_INVALID_OPERATION error when using glEGLImageTargetRenderbufferStorageOES.
Is glEGLImageTargetRenderbufferStorageOES supported in Raspberry Pi ?

[beddu]

Hi!
I managed to do rendering to texture in a slightly different way.

First of all generate a texture with the same format and dimensions as my viewport and no filtering:

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glGenTextures(1, (GLuint*)&frameBufferTexture);
glBindTexture(GL_TEXTURE_2D, (GLuint)frameBufferTexture);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, viewportWidth, viewportHeight, 0, GL_RGBA, GL_UNSIGNED_BYTE, 0);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);

Then I generate the frame buffer and bind the texture to it in this way:

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glGenFramebuffers(1, &frameBufferHandle);
glBindFramebuffer(GL_FRAMEBUFFER, frameBufferHandle);
glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, (GLuint)frameBufferTexture,0);
glBindFramebuffer(GL_FRAMEBUFFER, 0);

Then I draw a square mesh with screen dimensions and map the texture to it. Selecting the buffer in this way:

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glBindFramebuffer(GL_FRAMEBUFFER, frameBufferHandle);

//draw to the custom buffer

glBindFramebuffer(GL_FRAMEBUFFER, 0)

//draw the custom buffer as a textured mesh to the back-buffer

eglSwapBuffers(display, surface);

Hope it will be useful!