The usefulness of a matrix in computer graphics is its ability to convert geometric data into different coordinate systems. A matrix is composed of elements arranged in rows and columns.

There are several transformations that are used in computer graphics, but the most common ones are translation (moving the object), rotation (spinning it) and scaling (changing its size). They come up often in graphics because they are applied not only to objects, but to things like the camera and lighting sources.

🔗Computer graphics on Wikipedia

🔗Transformation matrix on Wikipedia

A fundamental operation in computer graphics is to draw lines and circles. 

Line drawing in computer graphics refers to the process of plotting a straight path between two specified points on a digital display, often utilizing algorithms to ensure efficient rendering and smooth appearance. 

Circle drawing involves generating points that form a circular shape on a screen by employing mathematical calculations to determine their positions.

🔗CS Field Guide

Line algorithms are methods used to determine the optimal path and coordinates for drawing lines on a digital display, ensuring smooth and efficient rendering.  An example includes line-drawing algorithms (such as Bresenham's line algorithm) for rendering straight lines.

Circle algorithms, on the other hand, are techniques employed to accurately plot points that form a circular shape on a screen using mathematical calculations. An example includes circle-drawing algorithms (like the Midpoint circle algorithm) for generating circular shapes.

🔗CS Field Guide

🔗Bresenham's line algorithm

🔗Midpoint Circle Algorithm

🔗DDA Line generation Algorithm

🔗More Algorithms

Graphics algorithms encompass various techniques to create and manipulate visual elements. Examples include polygon-filling algorithms (such as 📺Scanline fill and Flood fill) to color enclosed regions. Additionally, graphics algorithms cover transformations like translation, rotation, scaling, shading, and rendering techniques such as 🧾Phong shading and  🧾ray tracing.

Rendering or image synthesis is the process of generating a photorealistic or non-photorealistic image from a 2D or 3D model by means of a computer program. The resulting image is referred to as the render.  Wikipedia

🧾Lighting in computer graphics refers to the simulation of how light interacts with objects to create realistic and visually appealing scenes. It involves calculations to determine how light sources illuminate surfaces, affecting their color, shadow, and reflection. 

For example, in a 3D game, dynamic lighting can be used to create dramatic effects as a player moves a torch around a dark environment, casting realistic shadows and illuminating objects in a lifelike manner.