OpenGL OpenGL MCQ 2

Question 1

Which OpenGL function is used to specify the clear color for the color buffer?

Accepted Answer

glClearColor()

Answer

glClearColor() sets the RGBA values used when clearing the color buffer with glClear(GL_COLOR_BUFFER_BIT).

Question 2

What does the OpenGL function glViewport() do?

Accepted Answer

Defines the region of the window used for rendering

Answer

glViewport() maps NDC coordinates to a rectangular region of the window, controlling where rendering appears on screen.

Question 3

Which GLSL built-in variable contains the output position of a vertex in clip space?

Accepted Answer

gl_Position

Answer

gl_Position is a required output of the vertex shader that holds the final clip-space position of each vertex.

Question 4

What is the purpose of a Vertex Array Object (VAO) in OpenGL?

Accepted Answer

Records vertex attribute configuration for reuse

Answer

A VAO stores the state of vertex attribute pointers and which VBOs are bound, so the configuration can be restored with a single bind call.

Question 5

Which OpenGL primitive type draws a series of connected line segments forming a closed loop?

Accepted Answer

GL_LINE_LOOP

Answer

GL_LINE_LOOP connects each vertex to the next and also connects the last vertex back to the first, forming a closed polygon outline.

OpenGL Practice Test