Use the demo program horiz_stripes3.cpp as a guide to write a display function that draws vertical stripes instead of horizontal stripes.

Now put the horizontal stripes and vertical stripes together in the same program, using multiple windows. Have one window display horizontal stripes and a second window display vertical stripes.

Add a third window to the program you wrote in exercise 2 so that it displays a "checkerboard".

Suppose you have called glOrtho(0.0, 10.0, 0.0, 6.0, -1.0 1.0) and you are using the default viewport (entire screen window). The screen window width is 600 pixels (0 to 599) and its height is 400 pixels (0 to 399).

• To what pixel value does the center of the frame (real window) (5.0, 3.0) map?
• To what pixel value does the real point (4.0, 2.0) map?

Suppose you have called glOrtho(-10.0, 10.0, -6.0, 6.0, -1.0, 1.0) and you are using the default viewport (entire screen window). The screen window width is 600 pixels (0 to 599) and its height is 400 pixels (0 to 399).

• To what pixel value does the center of the frame (real window) (0.0, 0.0) map?
• To what pixel value does the real point (4.0, -2.0) map?

What is the aspect ratio of the real window frame defined in the previoius exercise?   If you are still using the default viewport,

• suggest appropriate screen window dimensions to use that would preserve the aspect ratio of the scene.
• what screen window height would you use if you need to set the screen window width to be 500 pixels?
• what screen window width would you use if you need to set the screen window height to be 500 pixels?

If you want to preserve the aspect ratio of the real window frame defined in exercise 7, but must use a square screen window (800 by 800 pixels), what values would you use for left, bottom, width, height in the call to

glViewport(left, bottom, width, height);

so that the viewport is centered both vertically and horizontally in the screen window and uses as much of the window as possible?

Re-do exercise 9 using the real window frame defined by:

glOrtho(-6.0, 6.0, -10.0, 10.0, -1.0, 1.0)

 

Do exercise 3.2.1 on page 958of the Hill textbook. *Don't skip this one.