[SOLVED] Anyone know a fair deal about glClear()?

[Zeotronic]

C++/OpenGL: My specific question is about how glClear works... I know there are the four buffers it can clear, but I don't entirely understand how that works... GL_COLOR_BUFFER_BIT seems pretty straight forward to me (though if it's not truely so obvious, please inform me), but if I declare glClear(GL_DEPTH_BUFFER_BIT), for example (and most specifically) what will that do? Does that ignore the depth of all the previous things I rendered, thus allowing me to essentially draw things behind the previously rendered things, through them in a seemingly glitchy manner that I am realizing I may not clearly be explaining? (and made more confusing by writing my realization of such?) I figure I need to know because I might be able to make use of that. So if someone could tell me what glClear(GL_DEPTH_BUFFER_BIT) does, and how to render things regardless of their depth? (though I still want depth testing on... yea, this is a HUD thing)

[hod139]

Have you read the man page description?
http://www.opengl.org/documentation/specs/man_pages/hardcopy/GL/html/gl/clear.html

glClear will clear the specified buffer (specified by the bitwise mask passed to the function) to the specified clear color. Therefore, glClear(GL_DEPTH_BUFFER_BIT) will clear the depth buffer. The depth buffer (also called the z-buffer) stores depth information about each pixel in the framebuffer. For more details on the frame buffer and the various buffers it contains, I suggest you look at the openGL red book. An older version of the red book is available online for free, and chapter 10 explains the framebuffer and the z-buffer:

http://glprogramming.com/red/index.html