JOGL Interview Questions

A list of top frequently asked JOGL interview questions and answers are given below.

1) What is JOGL?

JOGL is an open source wrapper library that allows us to use the functionality of OpenGL within Java program. Thus, it provides a platform where a programmer can quickly build and design computer graphic using java program.

2) What is OpenGL?

OpenGL is a standard specification that provides cross-platform API to draw 2D and 3D graphics images.

3) What is the role of Java Native Interface (JNI) in JOGL?

In JOGL, JNI provides the platform through which java program can easily access the features of OpenGL.

4) In which package GLEventListener and the GLAutoDrawable interface is present?

Both GLEventListener and GLAutoDrawable interface is present in javax.media.opengl package.

5) What is the role of the GLEventListener interface in JOGL?

The GLEventListener interface is used to provide the graphical functionality to Java program.

6) What are the methods of GLEventListener interface that are mandatory to override?

Following are the four methods of GLEventListener interface that are required to override: -

• display(GLAutodrawable drawable)
• init(GLAutoDrawable drawable)
• void displayChanged(GLAutoDrawable drawable, boolean modeChanged, boolean deviceChanged)
• void reshape(GLAutoDrawable drawable, int x, int y, int width, int height)

7) What is the role of the GLAutoDrawable interface in JOGL?

The GLAutoDrawable interface provides an event-based mechanism to generate an image.

8) What is the difference between the GLCanvas and GLJPanel class?

9) What is the role of GLProfile class in JOGL?

The GLProfile class is used to specify the OpenGL interface such as GL2, GL3 andGL4.

10) What is the role of the GLCapabilities class in JOGL?

The GLCapabilities class is used to define the capabilities of OpenGL such as OpenGL profile, color depth, etc.

11) What are JOGL primitives?

JOGL primitives are inbuilt parameters used to draw two-dimensional and three-dimensional graphics objects.

12) List out the types of JOGL primitives?

Following are the various types of primitives used by JOGL: -

• GL_LIMES
• GL_LINES_STRIP
• GL_LINES_LOOP
• GL_TRIANGLE
• GL_TRIANGLE_FAN
• GL_TRIANGLE_STRIP
• GL_QUADS
• GL_QUAD_STRIP
• GL_POLYGON

13) What type of code display() method contains?

The display() method used to draw and display graphics objects. Thus, it contains the primitive parameters with the methods containing the dimensions and all other attributes used to provide the special effect to an image such as coloring, scaling, rotating, etc.

14) How can you diminish an image in JOGL?

In JOGL, an image can be diminished by using glScalef() method of GLMATRIXFUNC interface.

15) What is the role of an Animator class in JOGL?

Animator class is a subclass of FPSAnimator class. It is used to rotate an object at the rate of frame per second.