// Rolls — GLSL ES 3.00, generated from https://github.com/gl-transitions/gl-transitions/blob/master/transitions/Rolls.glsl
// Author: Mark Craig
// mrmcsoftware on github and youtube ( http://www.youtube.com/MrMcSoftware )
// License: MIT
// Description: The outgoing image rolls away around a corner, revealing the incoming one
// Tags: rotate, roll

// Rolls Transition by Mark Craig (Copyright © 2022)

// @range(0, 3, 1) Corner to roll around
uniform int type; // = 0
// @param Roll the outgoing image down instead of up
uniform bool RotDown; // = false
// type (0-3): Rotate/Roll from which corner
// RotDown: if true rotate old image down, otherwise rotate old image up

#define M_PI 3.14159265358979323846

vec4 transition(vec2 uv)
{
float theta, c1, s1;
vec2 iResolution = vec2(ratio, 1.0);
vec2 uvi;
// I used if/else instead of switch in case it's an old GPU
if (type == 0) { theta = (RotDown ? M_PI : -M_PI) / 2.0 * progress; uvi.x = 1.0 - uv.x; uvi.y = uv.y; }
else if (type == 1) { theta = (RotDown ? M_PI : -M_PI) / 2.0 * progress; uvi = uv; }
else if (type == 2) { theta = (RotDown ? -M_PI : M_PI) / 2.0 * progress; uvi.x = uv.x; uvi.y = 1.0 - uv.y; }
else if (type == 3) { theta = (RotDown ? -M_PI : M_PI) / 2.0 * progress; uvi = 1.0 - uv; }
c1 = cos(theta); s1 = sin(theta);
vec2 uv2;
uv2.x = (uvi.x * iResolution.x * c1 - uvi.y * iResolution.y * s1);
uv2.y = (uvi.x * iResolution.x * s1 + uvi.y * iResolution.y * c1);
if ((uv2.x >= 0.0) && (uv2.x <= iResolution.x) && (uv2.y >= 0.0) && (uv2.y <= iResolution.y))
	{
	uv2 /= iResolution;
	if (type == 0) { uv2.x = 1.0 - uv2.x; }
	else if (type == 2) { uv2.y = 1.0 - uv2.y; }
	else if (type == 3) { uv2 = 1.0 - uv2; }
	return(getFromColor(uv2));
	}
return(getToColor(uv));
}