Can a GL_FLOAT texture be assigned to a FBO as a COLOR attachment?

For offscreen rendering to a texture, I'm attaching at the attachment GL_COLOR_ATTACHMENT0 a texture defined by

glTexImage2D(GL_TEXTURE_2D,0,GL_RGBA,width,height,0,GL_RGBA,GL_FLOAT,NULL);

I then render to the FBO using a fragment shader that outputs a vec4, so normally, that should be ok. To check that I display the texture correctly, I use the function

glTexSubImage2D()

to add some grey pixels in the middle of the texture. The texture IS correctly displayed (I can perfectly see these pixels at the right place), but the rest of the texture is only noisy artifacts (when it's not black).

Does this come from the fact that I use GL_FLOAT for a GL_RGBA texture? If yes, how can I, in GLSL, convert a uvec4 to vec4? The output of my main shader is a vec4, and I don't know how to convert t开发者_如何学编程he uvec4 output of a usampler2D texture to my final vec4.

Thank you for any answer you might provide :)

EDIT : I found the solution : I didn't clear the GL_COLOR_BUFFER_BIT between my 2 renders.

I know this question was self-answered, but a discussion need to be had about this:

glTexImage2D(GL_TEXTURE_2D,0,GL_RGBA,width,height,0,GL_RGBA,GL_FLOAT,NULL);

That does not create a floating-point texture. It creates a texture that contains normalized, unsigned integers.

The actual format of a texture is the third parameter; that defines what the texture actually contains. The last three parameters define how you are trying to upload data to the texture; if the pointer is NULL (and no PBO is bound), then the parameters mean nothing.