I'm using pbuffer for rendering to texture. In the final texture I want a black/transparent background, as parts of it should be transparent.Rendering things into the texture works fine, and I can display it using 2 triangles. The problem is that the parts which hasn't been rendered to are supposed to be transparent, but they are displayed as black (which I cleared it to, but the alpha seems to be ignored).

I'm creating the config whith these params:

Code :
    EGLint pi32ConfigAttribs[] = {
		EGL_CONFIG_CAVEAT, EGL_NONE,
        EGL_SURFACE_TYPE, EGL_WINDOW_BIT | EGL_PBUFFER_BIT,
        EGL_BIND_TO_TEXTURE_RGBA, EGL_TRUE,
        EGL_NONE
    };
 
    int iConfigs;
    eglChooseConfig(y_gles_config.display,
                    pi32ConfigAttribs,
                    &y_gles_config.config,
                    1,
                    &iConfigs);

then I create the pBuffer with this:
Code :
                     EGLint attribs[] = { EGL_WIDTH, fTexWidth,
        					 EGL_HEIGHT, fTexHeight,
        					 EGL_TEXTURE_TARGET, EGL_TEXTURE_2D,
        					 EGL_TEXTURE_FORMAT, EGL_TEXTURE_RGBA,
        					 EGL_NONE};
 
		fEglSurface = eglCreatePbufferSurface(y_gles_config.display,
								y_gles_config.config,
								attribs);

then I create the texture with this:
Code :
                glGenTextures(1, &fTexId);
		glBindTexture(GL_TEXTURE_2D, fTexId);
 
		y_glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
		y_glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
		y_glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
		y_glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
 
		glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, fTexWidth, fTexHeight, 0, GL_RGBA,  GL_UNSIGNED_BYTE, 0);

I use rgba for all texture formats.

I then set up the rendertarget with makeCurrent, set up viewport etc and clear it with:
Code :
    y_glClearColor(yGLreal(0), yGLreal(0), yGLreal(0), yGLreal(0));
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

I also enable blending, and set up the blendingfunction before rendering the 2 triangles with the final texture, so I think the problem is in the texture/surface. I searched on google and it seems that under regular GL, one must use GLUT_RGBA on glutInitialize to get alpha on framebuffers, but haven't found any similar options for GL ES 1.1. Any one got any tips ?