HW#4 --- last modified March 02 2019 21:08:39..

Solution set.

Due date: Nov 17

Files to be submitted:
  viewport.cpp

Purpose: To learn about the world coordinate to clipping window to screen viewport mapping. To learn about GLUT windowing functions.

Specification:

For this homework, your program will be run from the command line with a line like:

viewport world.txt

Here viewport is the compiled name of the .cpp file you will submit; world.txt is a text file specifying a ``3D world''. An example such file is:

500 300 200
2
3 20 20 20 50 60 70 200 200 100
4 40 50 20 50 60 70 90 200 100 30 40 100

The first line gives respectively the x, y, z sizes of the 3D world. The second line says how many polylines are contained in the file. The third line through the end of the file lists out the polylines. A polyline is given in the format: NumberOfPoints p1x p1y p1z p2x p2y p2z ... pLastx pLasty pLastz . You can assume that the polylines in the test file will be completely contained within the world sizes given by the first line of the file. When your program is run, it opens two windows: The first window has dimensions the x and y sizes of the world, the second window has dimensions half these values in both the x and y coordinates. Drawn in the first window are polylines from the file where we have projected down on the z axis. That is, the 3D point (3, 4, 5) becomes the 2D point (3, 4). In the first window, you should also draw a dashed rectangle, with lower corner at (0,0) of half the screen width and screen height. In the second window, I want drawn the contents of the first window where you have clipped the scene using the appropriate GLU clipping window functions to the area given by the dashed rectangle.

To make the program more interesting, when a person hits the `x', `y', or `z' keys I want you to change from whatever coordinate you are currently projecting out to the new coordinate given by this letter. i.e., If we have the point (3, 4, 5) and I hit x this point is now project to (4, 5). I want the two windows also to change size to the dimensions of the world in this new plane. If the person switches views, say from x to y, you can resize the clipping window to half of the new direction's window size and you can reset the clipping window to the origin. Finally, I want the user to also be able to move the rectangle in the first window around and so affect what the user sees clipped in the second window. To do this I want you to handle the up and down keys as moving the rectangle forwards and backwards, and I want you to handle the left and right keys as making the window rotate left and right. Do something reasonable to prevent the rectangle from going off the first window's screen.

Point Breakdown