======GTF0======

The goal for this project is to observe the skeleton code and understand the functions well enough to meet the project objectives listed at the top of this page. Look at the different functions to divulge information about how this graphics library works and revise the code to meet expectations. 
=====GRABIT=====

Once you are in your class folder you can make a directory for this project using: 
<code>
mkdir gtf0
</code> 

After entering the directory you can retrieve the project files like so: 
<code>
grabit DESIG gtf0
</code>
Where DESIG is your class designation (e.g. cprog). 
=====REPOSITORY STEPS=====
  * Create a public html directory with the following command
<code>
mkdir -p ~/public_html
</code>

  * Allow public permissions on the directory with the following
<code>
chmod 0711 ~/public_html
</code>
=====BUILD THE CODE=====
  * While in your gtf0 directory use the make command to build the code
<code>
make gtf0
</code>

It is also possible to compile manually as such: 
<code>
gcc -Wall --std=gnu18 -o gtf0 gtf0.c -lgd
</code>

<wrap hi>gcc</wrap> is the name of the compiler or collection of compilers used to compile C/C++ code. It can be invoked with the gcc command with flags such as what is shown above. 
=====RUN THE PROGRAM=====

To run the program you've modified/created, simply invoke it on the command line while in its directory like so: 
<code>
./gtf0
</code>

You should now notice gtf0.png in the directory that you ran the program.

From here, you can move it to your public_html directory for viewing.
=====VIEW THE IMAGE=====
  * Using the mv command, move the resulting image from your gtf0 dir to your public html dir
<code>
mv gtf0.png ~/public_html
</code>
  * To allow public viewing of the image use the chmod command
<code>
chmod 0644 ~/public_html/gtf0.png
</code>
  * Finally to see the image go to [[https://lab46.g7n.org/~USER/gtf0.png|https://lab46.g7n.org/~USER/gtf0.png]]
  * Replacing USER with your username
=====LIBGD FUNCTIONALITY=====
====MIXING A COLOR====
<code>
int color = gdImageColorAllocate (gdImagePtr im, int r, int g, int b);
</code>
[[https://libgd.github.io/manuals/2.1.1/files/gd-h.html#gdImagePtr|gdImagePtr]] im is the image the function edits

int r, int g, and int b are the red, green, and blue components of the color. Typically represented as hex values between 0x00 and 0xFF

There are many ways to find a colors hex value, including [[https://g.co/kgs/jbxvqkT|google's]]

[[https://libgd.github.io/manuals/2.2.5/files/gd-c.html#gdImageColorAllocate|Official gdImageColorAllocate wiki page]]
====DRAWING A LINE==== 
<code>
gdImageLine (image, x1, y1, x2, y2, color);
</code>

x1 and y1 are the starting coordinates and x2 and y2 are the ending coordinates 
====DRAWING A RECTANGLE====
<code>
gdImageRectangle (gdImagePtr im, int x1, int y1, int x2, int y2, int color);
</code>
[[https://libgd.github.io/manuals/2.1.1/files/gd-h.html#gdImagePtr|gdImagePtr]] im is the image the function edits

int x1 is the left bound

int y1 is the upper bound

int x2 is the right bound

int y2 is the lower bound

int color is the color the rectangle is drawn as

[[https://libgd.github.io/manuals/2.2.5/files/gd-c.html#gdImageRectangle|Official gdImageRectangle wiki page]]
====FILLING AN ENCLOSED SPACE====
<code>
gdImageFill (gdImagePtr im, int x, int y, int color);
</code>
[[https://libgd.github.io/manuals/2.1.1/files/gd-h.html#gdImagePtr|gdImagePtr]] im is the image the function edits

int x and int y are the coordinates the fill propagates from

int color is the color that is drawn as

[[https://libgd.github.io/manuals/2.2.5/files/gd-c.html#gdImageFill|Official gdImageFill wiki page]]
====DRAWING A FILLED RECTANGLE====
<code>
gdImageFilledRectangle (gdImagePtr im, int x1, int y1, int x2, int y2, int color);
</code>
[[https://libgd.github.io/manuals/2.1.1/files/gd-h.html#gdImagePtr|gdImagePtr]] im is the image the function edits

int x1 is the left bound

int y1 is the upper bound

int x2 is the right bound

int y2 is the lower bound

int color is the color the rectangle is drawn as

[[https://libgd.github.io/manuals/2.2.5/files/gd-c.html#gdImageFilledRectangle|Official gdImageFilledRectangle wiki page]]
====DRAWING A CIRCLE====
<code>
gdImageEllipse (gdImagePtr im, int mx, int my, int w, int h, int color);
</code>
[[https://libgd.github.io/manuals/2.1.1/files/gd-h.html#gdImagePtr|gdImagePtr]] im is the image the function edits

int mx and int my is the coordinates of the circle center

int w is the horizontal diameter of the circle

int h is the vertical diameter of the circle

w and h must be the same to create a circle

int color is the color the circle is drawn as

[[https://libgd.github.io/manuals/2.2.5/files/gd-c.html#gdImageEllipse|Official gdImageEllipse wiki page]]
====DRAWING A Ellipse====
<code>
gdImageEllipse (gdImagePtr im, int mx, int my, int w, int h, int color);
</code>
[[https://libgd.github.io/manuals/2.1.1/files/gd-h.html#gdImagePtr|gdImagePtr]] im is the image the function edits

int mx and int my is the coordinates of the ellipse center

int w is the horizontal diameter of the ellipse

int h is the vertical diameter of the ellipse

int color is the color the ellipse is drawn as

[[https://libgd.github.io/manuals/2.2.5/files/gd-c.html#gdImageEllipse|Official gdImageEllipse wiki page]]