glsl.frag

glsl.frag

// draw border with step
float drawBorder(vec2 st, float thickness) {
    // bottom-left
    vec2 bl = step(vec2(thickness),st); 
    // top-right 
    vec2 tr = step(vec2(thickness),1.0-st);
    float pct = bl.x * bl.y * tr.x * tr.y;
    return pct;
}

// draw border with smoothstep
float drawBorder(vec2 st, float thickness) {
    // bottom-left
    vec2 bl = smoothstep(0.0, thickness, st); 
    // top-right 
    vec2 tr = smoothstep(0.0, thickness, 1.0 - st);
    float pct = bl.x * bl.y * tr.x * tr.y;
    return pct;
}

// draw border with floor
float drawBorder(vec2 st, float thickness) {
    // bottom-left
    vec2 bl = floor(st + (1.0 - thickness));
    // top-right 
    vec2 tr = floor(st - (1.0 - thickness));
    float pct = bl.x * bl.y * tr.x * tr.y;
    pct = bl.x * bl.y * tr.x * tr.y;
    return pct;
}

float circle(in vec2 _st, in float _radius){
    vec2 dist = _st-vec2(0.5);
	return 1.-smoothstep(_radius-(_radius*0.01),
                         _radius+(_radius*0.01),
                         dot(dist,dist)*4.0);
}

/**
 * Draw Rect
 *
 * @param {vec2} angle - The callback that handles the response.
 * @example
 * rect(0.1);
 * @returns {vec2} Returns the coordinate.
 */
float rect(in vec2 st, in vec2 size){
	size = 0.25-size*0.25;
    vec2 uv = smoothstep(size,size+size*vec2(0.002),st*(1.0-st));
	return uv.x*uv.y;
}

float box(vec2 _st, vec2 _size, float _smoothEdges){
    _size = vec2(0.5)-_size*0.5;
    vec2 aa = vec2(_smoothEdges*0.5);
    vec2 uv = smoothstep(_size,_size+aa,_st);
    uv *= smoothstep(_size,_size+aa,vec2(1.0)-_st);
    return uv.x*uv.y;
}

/**
 * Rotate 2D
 *
 * @param {_angle} angle - The callback that handles the response.
 * @example
 * st = rotate2d( sin(u_time)*PI ) * st;
 * @returns {mat2} Returns the coordinate.
 */
mat2 rotate2d(float _angle){
    return mat2(cos(_angle),-sin(_angle),
                sin(_angle),cos(_angle));
}

/**
 * Scale
 *
 * @param {_angle} angle - The callback that handles the response.
 * @example
 * st -= vec2(0.5);
 * st = scale( vec2(sin(u_time)+1.0) ) * st;
 * st += vec2(0.5);
 * @returns {mat2} Returns the coordinate.
 */

mat2 scale(vec2 _scale){
    return mat2(_scale.x,0.0,
                0.0,_scale.y);
}

vec2 tile(vec2 _st, float _zoom){
    _st *= _zoom;
    return fract(_st);
}