You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
40 lines
1.1 KiB
GLSL
40 lines
1.1 KiB
GLSL
// By Jaskirat Randhawa ( http://jaskirat.me/ )
|
|
// For Shader Studio Course https://github.com/patriciogonzalezvivo/ss2015
|
|
|
|
#ifdef GL_ES
|
|
precision mediump float;
|
|
#endif
|
|
|
|
#define PI 3.14159265359
|
|
|
|
uniform vec2 u_resolution;
|
|
uniform float u_time;
|
|
|
|
void main (void)
|
|
{
|
|
// float fade_out = 1.-abs(sin(u_time)-cos(u_time));
|
|
float fade_out = 1.-mod(u_time, 2.); // SAW TOOTH FUNCTION
|
|
|
|
float border = abs(sin(fade_out/3.)); // 0.01
|
|
float circle_radius= 1.-(fade_out); // 0.5
|
|
|
|
vec4 circle_color= vec4(1.0, 1.0, 1.0, fade_out);
|
|
vec2 circle_center= vec2(0.5, 0.5);
|
|
|
|
vec2 st = gl_FragCoord.xy/u_resolution.xy;
|
|
|
|
vec4 bkg_color = vec4(0.);
|
|
|
|
// Offset st with the center of the circle.
|
|
st = st - circle_center;
|
|
|
|
// float dist = sqrt(dot(st/.2, circle_center*2.)); //????
|
|
// float dist = sqrt(st.x*st.x+st.y*st.y); //r^2 = x^2 + y^2 // Equation of circle
|
|
float dist = sqrt(dot(st/.2, st/.2)); //Equation of circle using dot product
|
|
|
|
float t = 1.0 + smoothstep(circle_radius, circle_radius+border, dist)
|
|
- smoothstep(circle_radius-border, circle_radius, dist);
|
|
|
|
gl_FragColor = mix(circle_color, bkg_color,t);
|
|
}
|