OpenGL OpenGL Extensions and Modern OpenGL 2

Question 1

What does the ARB suffix in an OpenGL extension name indicate?

Accepted Answer

The extension has been reviewed and approved by the OpenGL Architecture Review Board

Answer

ARB extensions are cross-vendor and vetted by the Architecture Review Board; they often become core features in future OpenGL versions.

Question 2

What feature does OpenGL 4.3's GL_ARB_compute_shader extension add?

Accepted Answer

General-purpose compute shaders dispatched outside the draw pipeline

Answer

ARB_compute_shader introduced compute shaders to OpenGL, enabling GPGPU workloads dispatched with glDispatchCompute.

Question 3

What is a sync object (glFenceSync) used for in OpenGL?

Accepted Answer

Inserting a fence into the command stream to detect when the GPU has completed prior commands

Answer

glFenceSync inserts a fence; the application can then wait (glClientWaitSync) or poll until the GPU has passed that point.

Question 4

What does the OpenGL function glMemoryBarrier do?

Accepted Answer

Ensures that memory writes by shaders are visible to subsequent operations as specified by the barrier bits

Answer

glMemoryBarrier(barriers) enforces ordering guarantees for incoherent memory accesses such as image load/store and SSBO writes.

Question 5

What does sparse texture support (ARB_sparse_texture) allow in OpenGL?

Accepted Answer

Allocates only the mipmap tiles that are actually needed, saving GPU memory

Answer

Sparse textures let the application commit and de-commit individual mipmap tiles, enabling virtual texturing of huge datasets.

OpenGL Practice Test