OpenGL OpenGL Shaders 2

Question 1

What GLSL built-in function returns the dot product of two vectors?

Accepted Answer

dot()

Answer

The GLSL dot(genType x, genType y) function computes the scalar dot product of two vectors.

Question 2

Which GLSL type represents a 4×4 floating-point matrix?

Accepted Answer

mat4

Answer

mat4 is a 4×4 matrix of float components, commonly used for model-view-projection transforms.

Question 3

What does the GLSL built-in texture() function do?

Accepted Answer

Samples a texture at given coordinates

Answer

texture(sampler, coord) fetches a texel from the texture bound to the sampler at the specified coordinates.

Question 4

Which GLSL qualifier marks a fragment shader output variable that writes to a color attachment?

Accepted Answer

out

Answer

Fragment shader output variables declared with 'out' are written to the corresponding framebuffer color attachment.

Question 5

What is the purpose of the GLSL normalize() function?

Accepted Answer

Scales a vector to unit length

Answer

normalize(v) divides a vector by its magnitude, returning a direction vector of length 1.

OpenGL Practice Test