OpenGL error 'invalid value' when calling glTexSubImage2D

Question

I have a small application that I'm using for testing that is doing some post processing effects. My goal is to read the pixels using double PBO's and then render the pixels to a full screen texture quad and modify/add my effects in a fragment shader. Similar to here. The application is using OSG but I am using openGL calls to do the full screen texturing.

My problem is that when I copy the pixels to the texture each frame using glTexSubImage2D, I get an invalid value openGL error. I have verified with gDEBugger that this is the call generating the errors. The first time the error happens the pointer address is different than in all the subsequent frames. Also, by making the width and height parameters of the glTexSubImage2d 0 the error is not generated. So I'm not really sure what's going.

Here is the relevant code:

MyCallbackClass()
{
    pImgData = (unsigned char*) malloc(1024*512*3);
    setupTextureAndShaders();
}
void setupTextureAndShaders()
{
    glGenTextures(1, &screenTexture);
    glBindTexture(GL_TEXTURE_2D, screenTexture);
    glPixelStorei(GL_UNPACK_ALIGNMENT, 1);

    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);

    memset(pImgData, 0, 1024*512*3);

    glTexImage2D (GL_TEXTURE_2D, 0, GL_RGB, 1024, 512, 0, GL_RGB, GL_UNSIGNED_BYTE, pImgData);
    glBindTexture(GL_TEXTURE_2D, 0);
}


//callback called every frame
virtual void operator () (osg::RenderInfo& renderInfo) const
{
    // buffer and context stuff unchanged from the sample program

    if(!shaderInit) // only executed once
    {
        GLuint vs = glCreateShader(GL_VERTEX_SHADER);
        const GLchar* vs_source = shaderLoadFile("vert.glsl");

        glShaderSource(vs, 1, &vs_source, NULL);
        glCompileShader(vs);
        checkShader(&vs);

        GLuint fs = glCreateShader(GL_FRAGMENT_SHADER);
        const GLchar* fs_source = shaderLoadFile("frag.glsl");

        glShaderSource(fs, 1, &fs_source, NULL);
        glCompileShader(fs);
        checkShader(&fs);

        prog = glCreateProgram();

        glAttachShader(prog, vs);
        glAttachShader(prog, fs);

        glLinkProgram(prog);
        texLoc = glGetUniformLocation(prog, "screenTex");

        shaderInit = true;
    }

    read();  // does the double pbo operations to read the image data into pImgData

    glUseProgram(prog);

    glMatrixMode(GL_PROJECTION);
    glPushMatrix();
    glLoadIdentity();
    glMatrixMode(GL_MODELVIEW);
    glPushMatrix();
    glLoadIdentity();

    glEnable(GL_TEXTURE_2D);
    glBindTexture(GL_TEXTURE_2D, screenTexture);
    glUniform1i(texLoc, 0);
    glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, 1024, 512, GL_RGB, GL_UNSIGNED_BYTE, pImgData);

    glBegin(GL_QUADS);
        glTexCoord2f(0, 1);
        glVertex2f(-1,-1);
        glTexCoord2f(0, 0);
        glVertex2f(-1,1);
        glTexCoord2f(1,0);
        glVertex2f(1,1);
        glTexCoord2f(1,1);
        glVertex2f(1,-1);
    glEnd();

    glDisable(GL_TEXTURE_2D);

    glMatrixMode (GL_MODELVIEW);
    glPopMatrix();
    glMatrixMode (GL_PROJECTION);
    glPopMatrix ();
    glMatrixMode (GL_MODELVIEW);


    glUseProgram(0);

    }

What does the read() function do? The things which generate the error you listed are having the mip-map level set below 0 or above the max, which you don't, or having the width and/or height be negative or outside the border of the image, which it isn't in your case. So maybe your pbo operations have set the state to something other than what you expect? (By the way, you should probably switch from PBOs to FBOs going forward, as PBOs are deprecated.) — user1118321, Jan 05 '12 at 04:32
PBO are not deprecated and are still present in latest OpenGL 4.x specifications — CoffeDeveloper, Jul 02 '14 at 20:24

score 2 · Accepted Answer · answered Jan 05 '12 at 16:20

I looked into the state changing in the read() call, however the real problem was with my setupTexturesAndShaders() function being in a different context. I believe this resulted in the glTexSubImage2D being called without having called the glTexImage2D first in the same context which would make any size image be out of range. Thanks for getting me thinking on the right track

OpenGL error 'invalid value' when calling glTexSubImage2D

1 Answers1