i have some doubts with multisampled textures.
In fragment shader, how to pass multiple samples?
We use glTexImage2DMultisample instead of glTeximage2D. so, how to upload texture data?
I want to use default FBO for this.
It is not possible to directly use a multisampled texture. You have to resolve it to another texture (same format, same size) first.
You can do that by binding the non-multisampled texture and blitting the multisampled one to it with glBlitFramebuffer (you might need to append EXT to function name - use glBlitFramebufferEXT - if you use OpenGL 2).