The first step towards completing the project is to get the skeleton code and Makefile Lab46 has a command you can run called grabit, it can be used by typing the command, followed by the course designation, followed by the project in this case it would be

 grabit cprog gtf0 

Edit the provided skeletal code from the grabit using a txt editor like nano. edit this code to fit the criteria for the project

To be able to run the gtf0.c file use the following command in the grabit file:

make debug

Issue the command ls -l and if there is a green “gft0” file, everything worked :) {for now}

If you execute this command it should produce a .png image

The image can either be viewed, if on a Pi, from the GUI file explorer

Or if in lab46: 1. Copy the file to ~/public_html/

username@lab46:~/src/spring2024/gtf0$ cp ./gft0.png ~/public_html

2. Change current directory to ~/public_html

cd ~/public_html

3. Change permissions to be able to be read by all

chmod +r gtf0.png

4.view image from web browser

https://lab46.g7n.org/~username/gtf0.png

You can make custom colors in C with commands from the libgd library so do this specify the integer variable that will have the color assigned to it

int black = 0;

then using the gdImageColorAllocate command, specify the intensity of each color, red green and blue, and reassign the output to the color

                         image  red   green blue
black = gdColorAllocate (image, 0x00, 0x00, 0x00);

red green blue sections are in hexcode so the most intense value is 0xFF and the least being 0x00

so if red and blue = 0xFF

and green = 0x00

you will get purple

Syntax for drawing a graphics line

gdImageFill (image, x1, y1, x2, y2, color);

Syntax for drawing a graphics line

gdImageRectangle (image, topleftX, topleftY, bottomrightX, bottomrightY, colorofRectlines)

Basically the Fill bucket from any drawing software. You specify where the coordinates of the fill is (another way of thinking is that the coordinates is specifying where the “click” of the paint bucket tool would be on the screen) and all space within enclosed lines around the coord's get flooded with the specified color

gdImageFill (image, x1, y1, color);

Syntax for drawing a graphics line

gdImageFilledRectangle (image, topleftX, topleftY, bottomrightX, bottomrightY, color)

This will draw a solid rectangle of color

Syntax for a circle uses an arc command but the start angle is 0° and the end is 360° (also the diameters are equal)

Arc syntax:

gdImageArc (image, centerX, centerY, diameterWidth, diameterHeight, start°, end°, colorofLine);

Circle Ex:

gdImageArc (image 150, 300, 100, 100, 0, 360, black);

Syntax for an Ellipse

gdImageEllipse ( X1, Y2, width, height, colorofLine);

(could also be used for a circle)

Syntax for an Filled Ellipse

gdImageFilledEllipse ( X1, Y2, width, height, colorofFill);