A village

In this assignment you should use OpenGL to practice using simple transformations. Your code should behave like my example: /chalmers/groups/thomas_math/VIS/OpenGL/village .

Note the following:

There are nine houses (a village) on some grass. Your program should draw the houses by calling a routine, DrawHouse(), nine times. The routine must not have any arguments and may not have access to any global variables. So in order to get the houses in the correct positions, your program have to perform suitable transformations, before calling DrawHouse(). Note the windows on the back and the two different red colours on the gables of the house.
DrawHouse() should draw a house with the same modeling coordinates each time.
Your program should draw a coordinate system (attached to the village) and the grass as well.
Typing x should rotate the village around an x-axis (clockwise when looking along the negative x-direction). Pressing X should rotate ccw. Similarly for pressing y, Y and z, Z. There should be two choices of coordinate systems (that is the reason why it says "an x-axis", rather than "the x-axis"). The user can choose coordinate system by using the menu, described below.
There is a menu with three alternatives, Village, Window and Quit.
Picking Village or Window should reset the scene so that we see it from the positive z-direction towards the origin.
The first alternative, Village, should be the default. The rotations, as described above, are relative the village (relative to the coordinate system attached to the village).
The second alternative, Window, should cause the rotations to be relative the window coordinate system (window refers to the figure window, and not any window in any of the houses). Think of a plus-sign in a square window, where the centre of the plus is in the middle of the window. The x-axis is the horizontal line of the plus. The y-axis, is the vertical line. The z-axis goes out orthogonally from the centre of the screen (plus-sign) towards the viewer. Note that this coordinate system is not affected by any of the rotations performed by the user.
Quit should terminate the execution of the program.
Pressing q should also end the run.
The scene should not be deformed (i.e. the x-, y- and z-proportions should be unaltered) if the window is resized.

Your program does not have to be more fancy than my example code. So, you can use simple color (glColor) and not light. My coordinate system is not drawn perfectly (pieces are sometimes hidden by the grass).

Hint: in one of the menu-choices you may find it useful to handle the matrix operations yourself. Start by reading the following manual page glLoadMatrix.