Step 1:

The code we wrote in class is on Odin at:
   /home/fac/gordon/p/3480/code/lab6/in_class_opengl.cpp


Start with your opengl.cpp program.
Follow along in lab class.
Save your opengl.cpp and Makefile to Odin 3480/6/ folder.

You must save your lab work out to Odin folder 6.

Homework

Item #1

Animate your rocket ship on key-press A.

Here is my own animation created after class.



Source code to make your own animated gif...

//The Imagemagick command:
//convert -loop 0 -coalesce -layers OptimizeFrame -delay 10 img*.ppm abc.gif

//Put it inside a system command maybe like this...
char str[] = "convert -loop 0 -coalesce -layers OptimizeFrame -delay 10 img*.ppm abc.gif";
system(str);

//Call the system command just once after your animation has been turned off!


//Here is a function to capture your window and save to an image.
//You should designate another key-press such as 'B' to create the gif.
//Leave your key-press 'A' just to look at the animation.
//
//This function takes a snapshot of your current window.
//To create an animation, many snapshots must be taken.
//Setup a counter that increments each frame.
//Call the screen capture every n frames. Try 10-frames or 6-frames maybe.
//
//The key-press that starts the animation should also turn it off when pressed
//again. This way you can turn off the animation so as not to create a million
//images and fill up your disk or Odin account.
//
//Once your series of images is created, you can use convert as described.
//You can also bring the images into Gimp and create a gif animation.

void screen_capture()
{
    //screen shot, capture, snapshot, opengl screenshot
    static int inc = 0;
    int xres = g.xres;
    int yres = g.yres;
    //get pixels
    unsigned char *data = new unsigned char [xres * yres * 3];
    glReadPixels(0, 0, xres, yres, GL_RGB, GL_UNSIGNED_BYTE, data);
    //write ppm file...
    char ts[256];
    sprintf(ts, "img%03i.ppm", inc++);
    FILE *fpo = fopen(ts, "w");
    fprintf(fpo, "P6\n");
    fprintf(fpo, "%i %i\n", xres, yres);
    fprintf(fpo, "255\n");
    //go backwards a row at a time...
    unsigned char *p = data;
    p = p + ((yres-1) * xres * 3);
    unsigned char *start = p;
    for (int i=0; i<yres; i++) {
        for (int j=0; j<xres*3; j++) {
            fprintf(fpo, "%c", *p);
            ++p;
        }
        start = start - (xres*3);
        p = start;
    }
    fclose(fpo);
}

Web page...

Create a web page on Odin at:

public_html/3480/index.html

NOT x3480!

On the page...

1. Give the title of your semester project.
2. Post a small image with a hint of what your project output might look like.
3. Post your OpenGL lab-6 animation.

Your instructor will find your work out on Odin!