What does GL depth test do?

What does GL depth test do?

When depth testing is enabled, OpenGL tests the depth value of a fragment against the content of the depth buffer. OpenGL performs a depth test and if this test passes, the fragment is rendered and the depth buffer is updated with the new depth value. If the depth test fails, the fragment is discarded.

How do I enable depth in OpenGL?

To enable depth testing, call glEnable with GL_DEPTH_TEST. When rendering to a framebuffer that has no depth buffer, depth testing always behaves as though the test is disabled. When depth testing is disabled, writes to the depth buffer are also disabled.

What is GL color buffer bit?

glClear takes a single argument that is the bitwise OR of several values indicating which buffer is to be cleared. GL_COLOR_BUFFER_BIT. Indicates the buffers currently enabled for color writing. GL_DEPTH_BUFFER_BIT. Indicates the depth buffer.

Why do we use glClear?

The glClear function sets the bitplane area of the window to values previously selected by glClearColor, glClearIndex, glClearDepth, glClearStencil, and glClearAccum. You can clear multiple color buffers simultaneously by selecting more than one buffer at a time using glDrawBuffer.

What happens when the depth test is disabled?

Initially, depth testing is disabled. If depth testing is disabled or if no depth buffer exists, it is as if the depth test always passes. Notes Even if the depth buffer exists and the depth mask is non-zero, the depth buffer is not updated if the depth test is disabled.

What happens when depth testing is disabled in OpenGL?

When depth testing is disabled, writes to the depth buffer are also disabled. When depth testing is active, the depth value from the fragment is compared to the depth value from the matching sample currently in the framebuffer.

What happens when funcis GL _ less is disabled?

The initial value of funcis GL_LESS. Initially, depth testing is disabled. If depth testing is disabled or if no depth buffer exists, it is as if the depth test always passes. Notes

When does GL _ gequal always pass the depth test?

GL_GEQUAL Passes if the incoming depth value is greater than or equal to the stored depth value. GL_ALWAYS Always passes. The initial value of funcis GL_LESS. Initially, depth testing is disabled. If depth testing is disabled or if no depth buffer exists, it is as if the depth test always passes.