¢
In the code glColor3f(0.0, 1.0, 0.0)
Ø
What do the numbers in parentheses represent?
Red,
Green, and Blue components of the color
Ø
What does f stand for?
floating point or numbers with
decimals
¢
Write the function that forces previously issued OpenGl command to begin
execution
glFlush() or glFinish()
¢
Blocks of code enclosed by glBegin(mode) and glEnd() are used to draw
in OpenGL.
Provide the code
for mode in order to draw the following items.
Ø
Individual points
GL_POINTS
Ø
Line segments
GL_LINES or GL_LINE_STRIP_ or GL_LINE_LOOP
Ø A
convex polygon
GL_POLYGON
¢
Write code that will set line width to 2.0
glLineWidth(2.0);
¢
What does the GL in OpenGL stand for?
Graphics library.
¢
OpenGL is referred to as a State Machine. What does this mean?
You can put it into various states or modes that remain effective until you
change
them.
¢
The following code is used in many applications: #include <GL/gl.h>.
What is the purpose of the brackets (<>)?
Tells compiler to look in the standard
directory for C++.
¢
Code prefaced with # is referred to as what?
Preprocessor Directive
¢
What is the purpose of the glutInit() function?
Initializes glut and
processes any command line arguments.
¢
What is the purpose of the glutInitDisplayMode () function?
Specifies whether to
use an RGBA or color-index color model. You can also specify
whether you want a single or
double buffered window.
¢
What is the purpose of the glutMainLoop (void) function and when is it called?
The last thing
called. All windows that have been created are now displayed. Event
processing begins.
¢
By default, the camera is located where?
At the Origin.
¢
By default, the camera is pointing in which direction?
Toward
the negative z axis
¢
Write code, using gluLookAt() that will position the camera on the x axis, 4
units from the origin, looking toward the origin, with positive y as the
positive direction.
gluLookAt(4.0, 0.0, 0.0, 0.0, 0.0,
0.0, 0.0, 1.0, 0.0)
¢
Fill in the blanks with the name of the function being decribed.
Ø __________________________
sets the current matrix with a matrix that has 1’s along
the diagonal and
0s elsewhere
glLoadIdentify()
Ø ________________________
moves the camera to the location specified by the 3
parameters
glTranslate (a,b,c)
Ø
__________________________ multiplies the current matrix by a matrix that
stretches,
shrinks, or
reflects an object
along the axes.
glScale()
Ø __________________________
multiplies the current matrix by a matrix that rotates an
object through the
speficied angle in a counerclockwise direction about the ray from the origin
through the point specified by the x, y, and z parameters
glRotate(angle, x, y, z)
Ø
__________________________ defines a pixel rectangle in the rectangle into which
the final image is
mapped. The x,y parameters specify the lower left corner of the viewport and the
width and height are the size of the viewport
rectangle
glViewport()
Ø
__________________________is used to specify the desired shading technique.
glShadeModel().
Ø __________________________initialized
the window size
glutInitWindowSize()
Ø __________________________initializes
the window position
glutInitWindowPosition()
¢
The glFrustrum() function takes the following parameters
Ø
________________left
Ø _________________right
Ø
________________bottom
Ø
________________top
Ø
________________near
Ø ________________far
¢ What is the
difference between a perspective an an orthographic projection?
A perspective projection presents the object as it appears, with items in the distance appearing smaller. An orthographic projections keeps
original dimensions.
¢ Fill in the
blanks
Ø The
human eye perceives color when certain cells in the retina, called
_______________
become excited after being struck by photons.
Cone cells or cones
Ø The A
in RGBA stands for ________________________
alpha, the transparency
Ø With
________________________________ display mode, OpenGL uses a lookup
table. color-index
Ø ___________________
is the technique of using combinations of some colors to create
the effect of other colors
dithering
Ø When
primitives are ____________________________ they are converted to a
two-dimensional image. This process involves determining which squares of an
integer grid in window coordinates are occupied by the primitive and then
assigning color and other values to each such square.
Rasterized
Ø A grid
square along with its associated values of color, z (depth), and texture
coordinates is called a ____________________________
fragment
Ø What
does GLUT stand for? Graphics
Library Utility Toolkit
Ø What
does GLU stand for? OpenGl
Utility Library
Ø We
refer to the OpenGL API. What does API stand for?
Application Programming Interface
Ø TOpenGL
was originally developed by ___________________________________ (name of
company) Silicon Graphics
Ø
What is accomplished by the viewing transformation?
Positions and aims
the camera.
Ø What
is the purpose of the modeling transformation?
Manipulates the position and sets the
orientation of a model by moving, rotating, or scaling it.
Ø What
is the purpose of the projection transformation?
Defines the viewing volumn and
clipping planes.
Ø Place
code between the begin and end statements below that will draw a polygon with 5
sides. Do not specify a color
glBegin(GL_POLYGON);
glVertex2f(2.0, 3.0);
glVertex2f(6.0, 3.0);
glVertex2f(6.0, 2.0);
glVertex2f(3.0, 0.0);