Question

EDIT: As suggested I changed the texture target to GL_TEXTURE_2D. So the initialisation looks like that now:

void initTexture( int width, int height )
{
    glGenTextures(1, &tex);
    glBindTexture(GL_TEXTURE_2D, tex);
    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_MAG_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);

    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width,
            height, 0, GL_RGB, GL_UNSIGNED_BYTE, NULL );
    glGenerateMipmap(GL_TEXTURE_2D);
    glBindTexture(GL_TEXTURE_2D, 0);
}

Since it’s a GL_TEXTURE_2D, mipmaps need to be defined. How should that be reflected on the initialisation of the OpenCL Image2D?

texMems.push_back(Image2DGL(clw->context, CL_MEM_READ_ONLY, GL_TEXTURE_2D, 0, tex, &err));

I’m still getting a CL_INVALID_GL_OBJECT, though. So the question still is: How can I check for texture completeness at the point of the initialisation of the OpenCL Image2D?

---

Previous approach:

I’m decoding a video-file with avcodec. The result is an AVFrame. I can display the frames on a GL_TEXTURE_RECTANGLE_ARB.

This is an excerpt from my texture initialisation, following an initialisation of the gl (glew) context:

GLuint tex = 0;

void initTexture( int width, int height )
{
    glGenTextures(1, &tex);
    glBindTexture(GL_TEXTURE_RECTANGLE_ARB, tex);
    glTexImage2D(GL_TEXTURE_RECTANGLE_ARB, 0, GL_RGB8, width,
            height, 0, GL_RGB, GL_UNSIGNED_BYTE, NULL );
    glBindTexture(GL_TEXTURE_RECTANGLE_ARB, 0);
}

Now I want to assign tex to a Image2DGL for an interop between OpenCL and OpenGL. Im using an Nvidia Geforce 310M, Cuda Toolkit 4. OpenGL version is 3.3.0 and GLX version is 1.4.

texMems.push_back(Image2DGL(clw->context, CL_MEM_READ_WRITE, GL_TEXTURE_RECTANGLE_ARB, 0, tex, &err));

This gives back an:

clCreateFromGLBuffer: -60 (CL_INVALID_GL_OBJECT)

This is all happening before I’m starting the render loop. I can display the video frames on the texture just fineafter that. The texture target (GL_TEXTURE_RECTANGLE_ARB) is allowed for the OpenCL context, as the corresponding OpenGL extension is enabled (GL_ARB_texture_rectangle).

Now the error description in the OpenCL 1.1 spec states:

CL_INVALID_GL_OBJECT if texture is not a GL texture object whose type matches
texture_target, if the specified miplevel of texture is not defined, or if the width or height
of the specified miplevel is zero.

I’m using GL_TEXTURE_RECTANGLE_ARB, so there’s not mipmapping (as I understand). However what I found was this statement in the Nvidia OpenCL implementation notes:

If the texture object specified in a call to clCreateFromGLTexture2D or
clCreateFromGLTexture3D is incomplete as per OpenGL rules on texture
completeness then the call will return CL_INVALID_GL_OBJECT in errcode_ret.

How can I validate the texture completeness at that state where I only initialize the texture without providing any actual texture content? Any ideas?

Answer 1

I was able to resolve the issue that I couldn’t create an Image2DGL. I was missing to specify a 4-channel internal format for the texture2D:

void initTexture( int width, int height )
{
    glGenTextures(1, &tex);
    glBindTexture(GL_TEXTURE_2D, tex);
    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0, GL_RGB, GL_UNSIGNED_BYTE, NULL );
    glBindTexture(GL_TEXTURE_2D, 0);
}

By specifying GL_RGBA I was able to successfully create the Image2DGL (which is equivalent to clCreateFromGLTexture2D). It seems that this fulfilled the demand to have texture completeness.