I enjoyed experimenting with colours for this week’s homework. I was able to get some interesting results by just repeating shapes and adding exponential functions to them. I only implemented slight animation for this image so it has a subtle, hypnotic feel to it.

```
// Author: Emily Flood
// Title: Wavy circles

#ifdef GL_ES
precision mediump float;
#endif

uniform vec2 u_resolution;
uniform vec2 u_mouse;
uniform float u_time;

float drawRect(vec2 st, vec2 size){
float result = 1.0;

vec2 border = (1.0-size)/2.;

result = step(border.x,st.x);
result *= step(border.x,1.0-st.x);
result *= step(border.y,st.y);
result *= step(border.y,1.-st.y);

return result;
}

float drawCircle(vec2 st, vec2 pos, float size){
float result = distance(st, pos);
result = 1.0-step(size,result);
return result;
}

void main() {
vec2 st = gl_FragCoord.xy/u_resolution.xy;
st.x *= u_resolution.x/u_resolution.y;

//animating the shapes slightly
st.x += sin(st.y *20. + u_time) * -0.0;
st.y += cos(st.x *1. + u_time) * -0.01;

vec3 color = vec3(0.);

//delcaring border for rectangle
float border = 0.01;

//drawing all the circles
float c1 = drawCircle(st, vec2(0.210,0.180),0.4);
float c1b = drawCircle(st, vec2(0.320,0.400),0.512);
float c2 = drawCircle(st, vec2(0.740,0.400),0.4);
float c2b = drawCircle(st, vec2(0.380,0.250),1.088);
float c3 = drawCircle(st, vec2(0.200,0.990),0.472);
float c4 = drawCircle(st, vec2(0.040,0.540),0.240);
float c5 = drawCircle(st, vec2(0.870,0.880),0.288);
float c6 = drawCircle(st, vec2(0.840,0.270),0.152);
float c7 = drawCircle(st, vec2(0.840,0.020),0.320);

//drawing all the rectangles
float r1 = drawRect(st, vec2(0.740,0.720));
float r2 = drawRect(st, vec2(0.550,0.550));
float r3 = drawRect(st, vec2(0.430,0.440));

//implementing colours into the rectangles
color = mix(color, vec3(0.418,0.396,0.440),r1*1.);
color = mix(color, vec3(0.048,0.865,0.791),r2*0.992);
color = mix(color, vec3(0.000,1.000,0.536),r3*1.516);

//implementing colours into the circles
color = mix(color, cos(vec3(0.776,0.609,1.000)),c1*1.572);
color -= mix(color, cos(vec3(0.776,0.609,1.000)),c1b*2.364);
color = mix(color, vec3(0.895,1.000,0.674),c2*0.716);
color = mix(color, sin(vec3(0.890,0.665,1.000)),c2b*1.364);
color = mix(color, vec3(0.946,1.000,0.578),c3*2.268);
color = mix(color, vec3(0.270,1.000,0.981),c4*0.732);
color = mix(color, cos(vec3(1.000,0.389,0.711)),c5*1.876);
color = mix(color, vec3(1.000,0.389,0.711),c6*1.364);
color = mix(color, cos(vec3(0.270,1.000,0.981)),c7*0.652);

/*
color.r = drawRectangle(st, vec2 (0.9,0.9) );
color.g = drawRectangle(st, vec2(0.8,0.8));
color.b = drawRectangle(st, vec2(1.,1.));
*/

gl_FragColor = vec4(color,1.0);
}

```

During the first video Jeremy creates a “fiery box” by animating the waves with this:

```
st.x += sin(st.y *20. + u_time) * -0.108;
st.y += cos(st.x *20. + u_time) * -0.540;

```

So I used this code to create some interesting wavy animations. I also experimented with adding several shapes with the mix() function.

```
// Author: Emily Flood
// Title: Fluorescent waves

#ifdef GL_ES
precision mediump float;
#endif

uniform vec2 u_resolution;
uniform vec2 u_mouse;
uniform float u_time;

//drawCircle function
float drawCircle(vec2 st, vec2 pos, float size){

float result = distance(st,pos);
result = 1.0-step(size,result);
return result;
}

void main() {
vec2 st = gl_FragCoord.xy/u_resolution.xy;
st.x *= u_resolution.x/u_resolution.y;

vec3 color = vec3(0.);

//animating the waves
st.x += sin(st.y *20. + u_time) * -0.108;
st.y += cos(st.x *20. + u_time) * -0.540;

//declaring size variable
vec2 size = vec2(0.1,0.1);

//drawing circles
float c1 = drawCircle(st, vec2(0.100,0.620),0.4);
float c2 = drawCircle(st, vec2(0.400,0.620),0.4);
float c3 = drawCircle(st, vec2(0.700,0.620),0.4);
float c4 = drawCircle(st, vec2(1.0,0.620),0.4);

color = mix(color, vec3(0.0, 0.0, 1.0),c1*0.908);
color = mix(color, vec3(1.000,0.332,0.198),c2*0.5);
color = mix(color, vec3(1.000,0.036,0.888),c3*0.612);
color = mix(color, vec3(1.000,0.948,0.112),c4*0.652);

gl_FragColor = vec4(color,1.0);
}

```

I realized that I enjoy working with fluorescent colours. I made this vibrant grid pattern with a couple of different tiling methods, including a tile() function as well as using the mod() function to repeat this effect, causing an interesting inconsistency in the grid.

```
// Author: Emily Flood
// Title: Vibrant grid
/* Code used from "Patterns" from The Book of Shaders
> @patriciogv ( patriciogonzalezvivo.com ) - 2015
*/

#ifdef GL_ES
precision mediump float;
#endif

uniform vec2 u_resolution;
uniform vec2 u_mouse;
uniform float u_time;

#define PI 3.14159265358979323846

//function to tile the image
vec2 tile(vec2 _st, float _zoom){
_st *= _zoom;
return fract(_st);
}

//function to draw a rectangle
float drawRect(vec2 st, vec2 pos, vec2 size){
float result = 1.0;

vec2 border = (1.0-size)/2.;

st = st - pos + vec2(0.5);

result = step(border.x,st.x);
result *= step(border.x,1.0-st.x);
result *= step(border.y,st.y);
result *= step(border.y,1.-st.y);

return result;
}

//function to draw a circle
float drawCircle(vec2 st, vec2 pos, float size){

float result = distance(st,pos);
result = 1.0-step(size,result);
return result;
}

void main() {
vec2 st = gl_FragCoord.xy/u_resolution.xy;
vec3 color = vec3(0.);

//tiling the image and animating it
st *= 5.;
st = mod(st,1.3);
st = tile(st,1.184);
st.x += sin(st.y *17. + u_time) * 0.1;
st.y -= cos(st.x *17. + u_time) * 0.1;
float size = 0.416;

//drawing out the rectangle and circle
float r1 = drawRect(st, vec2(0.5), vec2(0.5));

float c1 = drawCircle(st, vec2(0.5), size);

color = vec3(st,1.072);

//applying colour
color = mix(color, vec3(0.709,0.548,0.870),r1*0.3);
color = mix(color, vec3(0.975,0.423,0.000),c1*0.3);

gl_FragColor = vec4(color,1.0);
}

```