#version 150
//OVE shader_name: Crazy Parametric Fun
//OVE shader_description: by mandubian (License: MIT)


//OVE name: A
//OVE type: FLOAT
//OVE flag: NOT_CONNECTABLE
//OVE min: 0.0
//OVE default: 4
//OVE description:
uniform float a;

//OVE name: B
//OVE type: FLOAT
//OVE flag: NOT_CONNECTABLE
//OVE min: 0.0
//OVE default: 1
//OVE description:
uniform float b;

//OVE name: Amplitude
//OVE type: FLOAT
//OVE flag: NOT_CONNECTABLE
//OVE min: 0.0
//OVE default: 120
//OVE description:
uniform float amplitude;

//OVE name: Smoothness
//OVE type: FLOAT
//OVE flag: NOT_CONNECTABLE
//OVE min: 0.0
//OVE max: 10.0
//OVE default: 1
//OVE description:
uniform float smoothness;

//OVE end

#define LINEAR_CURVE 0
#define EXPONENTIAL_CURVE 1
#define LOGARITHMIC_CURVE 2

uniform sampler2D out_block_in;
uniform sampler2D in_block_in;
uniform bool out_block_in_enabled;
uniform bool in_block_in_enabled;
uniform int curve_in;

/* animated from 0 to 1 */
uniform float ove_tprog_all;

in vec2 ove_texcoord;
out vec4 frag_color;

vec4 getFromColor( vec2 p)
{
  return texture( in_block_in, p);
}

vec4 getToColor( vec2 p)
{
  return texture( out_block_in, p);
}

float TransformCurve(float linear) {
  if (curve_in == EXPONENTIAL_CURVE) {
    return linear * linear;
  } else if (curve_in == LOGARITHMIC_CURVE) {
    return sqrt(linear);
  } else {
    return linear;
  }
}


vec4 transition(vec2 uv, float progress) {
  vec2 p = uv.xy / vec2(1.0).xy;
  vec2 dir = p - vec2(.5);
  float dist = length(dir);
  float x = (a - b) * cos(progress) + b * cos(progress * ((a / b) - 1.) );
  float y = (a - b) * sin(progress) - b * sin(progress * ((a / b) - 1.));
  vec2 offset = dir * vec2(sin(progress  * dist * amplitude * x), sin(progress * dist * amplitude * y)) / smoothness;
  return mix(getFromColor(p + offset), getToColor(p), smoothstep(0.2, 1.0, progress));
}


void main(void) {
    frag_color = transition( ove_texcoord.xy, TransformCurve(1.0 - ove_tprog_all));
}