This code is a fragment shader that generates a colorful...
This code is a fragment shader that generates a colorful circular pattern on the screen. The mainImage function takes in the fragColor and fragCoord variables as input and outputs a final color for each pixel of the screen.
The field function calculates a value based on the input distance (d) from the center of the screen, and returns this value multiplied by some smoothstep functions and a power function.
The mainImage function first converts the input fragCoord to a normalized coordinate system (uv). It then calculates the angle (a) between the x-axis and the point represented by uv. Using this angle and a fixed radius (r), it calculates the distance (d) from the center of the screen for that point.
Next, it initializes a vec3 variable (res) to zero and sets a color (col) to a red shade. It then calls the field function five times with different parameters, adding the result to res each time. It then multiplies res by 0.9 and applies a saturation function before outputting the final fragColor as a vec4 with transparency set to 1.0.