Rendering to multiple textures

To render to multiple textures, you still use the glDrawBuffers function. However, you use the enums from GL_EXT_framebuffer_object.

Example:

GLenum buffers[] = { GL_COLOR_ATTACHMENT0_EXT, GL_COLOR_ATTACHMENT1_EXT };
glDrawBuffers(2, buffers);

If a framebuffer object is bound with textures attached to GL_COLOR_ATTACHMENT0_EXT and GL_COLOR_ATTACHMENT1_EXT, they will both be rendered to now.