#version 150
//OVE shader_name: Kaleidoscope
//OVE shader_description: by nwoeanhinnogaehr (Licence MIT)

//OVE name: Speed
//OVE type: FLOAT
//OVE flag: NOT_CONNECTABLE
//OVE min: 0.0
//OVE max: 100.0
//OVE default: 1.0
//OVE description:
uniform float speed;

//OVE name: Angle
//OVE type: FLOAT
//OVE flag: NOT_CONNECTABLE
//OVE min: 0.0
//OVE default: 1.0
//OVE description:
uniform float angle;

//OVE name: Power
//OVE type: FLOAT
//OVE flag: NOT_CONNECTABLE
//OVE min: 0.0
//OVE max: 100.0
//OVE default: 1.5
//OVE description:
uniform float power;


//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 q = p;
  float t = pow(progress, power)*speed;
  p = p -0.5;
  for (int i = 0; i < 7; i++) {
    p = vec2(sin(t)*p.x + cos(t)*p.y, sin(t)*p.y - cos(t)*p.x);
    t += angle;
    p = abs(mod(p, 2.0) - 1.0);
  }
  abs(mod(p, 1.0));
  return mix(
    mix(getFromColor(q), getToColor(q), progress),
    mix(getFromColor(p), getToColor(p), progress), 1.0 - 2.0*abs(progress - 0.5));
}

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