Computer Science 102
                                  Major Program 1
                               Due 20 February 11:59PM

Adhere to the following programming standards.  Violations will
lead to deductions.

(1) no function should be longer than 30 lines code + whitespace.
(2) the maximum nesting level in any function is ONE
(3) code lines should not extend beyond column 72
(4) no more that one statement may be written on a single line
(5) use reasonably descriptive names for variables and functions
(6) your program should compile without any warnings with gcc -Wall
(7) indenting should be consistent with logical nesting
(8) diagnostic / debug prints should be disabled in
    your submission.

For this asssignment you will complete the ambient-lighting only
raytracer that supports infinite plane, tiled-plane and sphere
type objects, and you will build your own model description
file, mymodel.txt that demonstrates your program works correctly
in a technically interesting and artistic way.

New functions that must be written include:

Module          Functions
-------
camera.c        camera_setpix()
                camera_write_image()

image.c         image_create()
                make_row()
                make_pixel()

ray.c           raytrace()
                find_closest_object()

material.c      material_getamb()

tplane.c        tplane_init()
                tplane_getamb()
                tplane_dump()

For testing START WITH A SINGLE plane. When that works, add a
second plane. Then go back a do a single sphere, then add a
second sphere. Then mix spheres and planes. Some sample
input/outputs are in the mp1 directory. They should be tested in
the order: mp1a mp1b,.... mp1f. ONLY when all of that works add
the tiled plane.

DO NOT submit broken or incomplete components!!!  A submission
that correctly produces the image on page 22 will get an 80.
A submission that correctly produces the image on page 22 along
with an incorrect sphere and an incorrect tiled plane will score
somewhere between 60 and 70.

Grading regimen
---------------
Functionality           Max score
One plane                      75
Two planes or more             80
Two planes + two spheres       90
Two planes + two spheres +    100
tiled_plane


Finally create and turn in your own model file named
mymodel.txt.  You will find that the most interesting pictures
(e.g. the "snowman") can be produced by using intersecting and
overlapping objects and letting the ray tracer do its job of
showing only the visible parts.

Too many planes of quasi random orientation can create something
of a mess, so please avoid that. The model should also have
enough depth along with properly chosen ambient intensities that
varying brightness provides visible depth cues.

Particulary meritorious model designs can earn up to 10
points extra credit.

Its best to carefully layout spheres that intersect planes and
each other. A good size for your image is 800 x 600 pixels.

The turn in directory is mp1 and as usual your program should
build an executable program named a.out when you say "make" and
when I say "make".

The image file should go to the standard output.  THIS IS
NOT THE SAME AS IN CPSC 101.

To run the program enter the command:

a.out < mymodel.txt  1> mymodel.ppm 2> mymodel.log