22C151 Homework 8

Homework 8

22C:151 Introduction to Computer Graphics

Due Tuesday, Dec. 2, 2008

20 points

1. Implement and submit a program corresponding to Exercise 9.1 of the textbook.

Note: your score will depend slightly on how interesting your program is. That is, if it seems to me that you put very little effort into creating the program, essentially making trivial modifications to examples from the book or web, then you will likely lose some points.

Notes on compiling and running programs with shaders:

Shader programming requires a machine that has OpenGL 2.0 (or newer) installed.
If you want to find out what OpenGL version is installed on your machine, compile and run this program, glversion.c. The first number displayed is the version number (the rest of the info gives more detail about exactly which OpenGL implementation is being used - e.g. version associated nVidia graphics card drivers or Mesa, a open-source implementation of OpenGL often used on machines without good graphics cards)
The CS linux machines in 301 MLH all have OpenGL 2.0 (or 2.1). However, to compile shader programs on these machine, you do need two small changes from earlier homeworks in this class. You need to:
- include an additional header file, glext.h
  #include <GL/glext.h>
- add another "compiler flag" in the Makefile you use to compile things. Thus, in the simple good-for-one-file makefile I provided for the class, you need
  GCC_OPTIONS=-Wall -pedantic -DGL_GLEXT_PROTOTYPES
  instead of the original line. If you don't use a makefile you can just add the -DGL_GLEXT_PROTOTYPES part to your gcc/g++ line.
You will not be able to successfully run OpenGL 2.0 programs using the "NoMachine" client to remotely access CS department linux machines. The machine that you connect to via "NoMachine" does not have OpenGL 2.0. Thus, to use CS Linux machines for this assignment you must physically go to the lab.
On Macs (newish ones, at least), you do not need the glext.h and extra compiler flag. (I believe, actually, that you *shouldn't* need them on the CS Linux machines either, but ...)
Many MS Windows machines only have OpenGL 1.1 (or other pre-2.0 version) installed. You can get OpenGL 2.0 by installing new drivers either from your graphics card manufacturer or downloading and installing a recent version of Mesa.

NOTE ON ALTERNATIVE ACCEPTABLE HOMEWORK: as discussed in 11/21/08 email message to class, working with reflection and normal mapping starting from the files in this folder is also acceptable for homework 8. You can compile cubetex.c using the given Makefile, and run it to see the results of simple reflection mapping and normal mapping using cube maps (see textbook for background on reflection/normal/cube/environment mapping). Your HW8 job would be to achieve the same results using shaders. Shaders to start with (actually, they fully handle one of the two cases - reflection or normal mapping - you just have to figure out which) with are provided. To use them and see their effect, modify cubetex.c, adding shader handling code. (Also, to be CERTAIN that your shaders are having the intended effect, rather than the texture code in the application, it's worth commenting out, or removing, the three glEnable(GL_TEXTURE_GEN_...) and three glTexGeni(...) lines.)