#if defined(VERTEX) || __VERSION__ > 100 || defined(GL_FRAGMENT_PRECISION_HIGH)
	#define PRECISION highp
#else
	#define PRECISION mediump
#endif

// Card rotation
extern PRECISION vec2 blur;

extern PRECISION number dissolve;
extern PRECISION number time;
extern PRECISION vec4 texture_details;
extern PRECISION vec2 image_details;
extern bool shadow;
extern PRECISION vec4 burn_colour_1;
extern PRECISION vec4 burn_colour_2;

// extern PRECISION number blur_radius;

vec4 RGB(vec4 c);

vec4 HSL(vec4 c);

vec4 dissolve_mask(vec4 final_pixel, vec2 texture_coords, vec2 uv);

// texture_coords = coolds of a original_pixel within the atlas texture
vec4 effect( vec4 colour, Image texture, vec2 texture_coords, vec2 screen_coords )
{
    // GAUSSIAN BLUR SETTINGS {{{
    float direction = 16.0; // BLUR DIRECTIONS (Default 16.0 - More is better but slower)
    float quality = 6.0;    // BLUR QUALITY (Default 4.0 - More is better but slower)
    float size = 4.0;       // BLUR SIZE (radius)
    // GAUSSIAN BLUR SETTINGS }}}

	vec2 uv = (((texture_coords)*(image_details)) - texture_details.xy*texture_details.ba)/texture_details.ba;

	float two_pi = 6.28318530718;
   
    vec2 radius = size/image_details.xy;

	vec4 original_pixel = Texel(texture, texture_coords);
    vec4 blurred_pixel = Texel(texture, texture_coords);
    
    // Blur calculations
	float d_step = two_pi / direction;
	float i_step = 1.0 / quality;

    for (float d = 0.0; d < two_pi; d += d_step) {
		for (float i = i_step; i < 1.001; i+=i_step) {
			blurred_pixel += Texel( texture, texture_coords + vec2(cos(d), sin(d)) * radius * i);
        }
    }
    
    // Final processing 
    blurred_pixel /= quality * direction + 1.;
    vec4 final_pixel =  vec4(blurred_pixel.rgb, original_pixel.a);

    vec4 hsl = HSL(final_pixel);

    // Adjust lightness for a glossy effect

    float t = blur.y*2.221 + mod(time,1.);
	vec2 floored_uv = (floor((uv*texture_details.ba)))/texture_details.ba;
    vec2 uv_scaled_centered = (floored_uv - 0.5) * 50.;
	
	vec2 field_part1 = uv_scaled_centered + 50.*vec2(sin(-t / 143.6340), cos(-t / 99.4324));
	vec2 field_part2 = uv_scaled_centered + 50.*vec2(cos( t / 53.1532),  cos( t / 61.4532));
	vec2 field_part3 = uv_scaled_centered + 50.*vec2(sin(-t / 87.53218), sin(-t / 49.0000));

    float field = (1.+ (
        cos(length(field_part1) / 19.483) + sin(length(field_part2) / 33.155) * cos(field_part2.y / 15.73) +
        cos(length(field_part3) / 27.193) * sin(field_part3.x / 21.92) ))/2.;

    float res = (.5 + .5* cos( (blur.x) * 2.612 + ( field + -.5 ) *3.14));
    // Mostly use original lightness, with slight change from moving the card & with time
	hsl.z = 0.7*hsl.z + sin(hsl.z/2.5 - res/4. + sin(blur.y)/8. + 0.5)/3.;

    final_pixel = RGB(hsl);

	if (final_pixel[3] < 0.7)
		final_pixel[3] = final_pixel[3]/3.;
	return dissolve_mask(final_pixel * colour, texture_coords, uv);
}


number hue(number s, number t, number h)
{
	number hs = mod(h, 1.)*6.;
	if (hs < 1.) return (t-s) * hs + s;
	if (hs < 3.) return t;
	if (hs < 4.) return (t-s) * (4.-hs) + s;
	return s;
}

vec4 RGB(vec4 c)
{
	if (c.y < 0.0001)
		return vec4(vec3(c.z), c.a);

	number t = (c.z < .5) ? c.y*c.z + c.z : -c.y*c.z + (c.y+c.z);
	number s = 2.0 * c.z - t;
	return vec4(hue(s,t,c.x + 1./3.), hue(s,t,c.x), hue(s,t,c.x - 1./3.), c.w);
}

vec4 HSL(vec4 c)
{
	number low = min(c.r, min(c.g, c.b));
	number high = max(c.r, max(c.g, c.b));
	number delta = high - low;
	number sum = high+low;

	vec4 hsl = vec4(.0, .0, .5 * sum, c.a);
	if (delta == .0)
		return hsl;

	hsl.y = (hsl.z < .5) ? delta / sum : delta / (2.0 - sum);

	if (high == c.r)
		hsl.x = (c.g - c.b) / delta;
	else if (high == c.g)
		hsl.x = (c.b - c.r) / delta + 2.0;
	else
		hsl.x = (c.r - c.g) / delta + 4.0;

	hsl.x = mod(hsl.x / 6., 1.);
	return hsl;
}

vec4 dissolve_mask(vec4 final_pixel, vec2 texture_coords, vec2 uv)
{
    if (dissolve < 0.001) {
        return vec4(shadow ? vec3(0.,0.,0.) : final_pixel.xyz, shadow ? final_pixel.a*0.3: final_pixel.a);
    }

    float adjusted_dissolve = (dissolve*dissolve*(3.-2.*dissolve))*1.02 - 0.01; //Adjusting 0.0-1.0 to fall to -0.1 - 1.1 scale so the mask does not pause at extreme values

	float t = time * 10.0 + 2003.;
	vec2 floored_uv = (floor((uv*texture_details.ba)))/max(texture_details.b, texture_details.a);
    vec2 uv_scaled_centered = (floored_uv - 0.5) * 2.3 * max(texture_details.b, texture_details.a);
	
	vec2 field_part1 = uv_scaled_centered + 50.*vec2(sin(-t / 143.6340), cos(-t / 99.4324));
	vec2 field_part2 = uv_scaled_centered + 50.*vec2(cos( t / 53.1532),  cos( t / 61.4532));
	vec2 field_part3 = uv_scaled_centered + 50.*vec2(sin(-t / 87.53218), sin(-t / 49.0000));

    float field = (1.+ (
        cos(length(field_part1) / 19.483) + sin(length(field_part2) / 33.155) * cos(field_part2.y / 15.73) +
        cos(length(field_part3) / 27.193) * sin(field_part3.x / 21.92) ))/2.;
    vec2 borders = vec2(0.2, 0.8);

    float res = (.5 + .5* cos( (adjusted_dissolve) / 82.612 + ( field + -.5 ) *3.14))
    - (floored_uv.x > borders.y ? (floored_uv.x - borders.y)*(5. + 5.*dissolve) : 0.)*(dissolve)
    - (floored_uv.y > borders.y ? (floored_uv.y - borders.y)*(5. + 5.*dissolve) : 0.)*(dissolve)
    - (floored_uv.x < borders.x ? (borders.x - floored_uv.x)*(5. + 5.*dissolve) : 0.)*(dissolve)
    - (floored_uv.y < borders.x ? (borders.x - floored_uv.y)*(5. + 5.*dissolve) : 0.)*(dissolve);

    if (final_pixel.a > 0.01 && burn_colour_1.a > 0.01 && !shadow && res < adjusted_dissolve + 0.8*(0.5-abs(adjusted_dissolve-0.5)) && res > adjusted_dissolve) {
        if (!shadow && res < adjusted_dissolve + 0.5*(0.5-abs(adjusted_dissolve-0.5)) && res > adjusted_dissolve) {
            final_pixel.rgba = burn_colour_1.rgba;
        } else if (burn_colour_2.a > 0.01) {
            final_pixel.rgba = burn_colour_2.rgba;
        }
    }

    return vec4(shadow ? vec3(0.,0.,0.) : final_pixel.xyz, res > adjusted_dissolve ? (shadow ? final_pixel.a*0.3: final_pixel.a) : .0);
}

extern PRECISION vec2 mouse_screen_pos;
extern PRECISION float hovering;
extern PRECISION float screen_scale;

#ifdef VERTEX
vec4 position( mat4 transform_projection, vec4 vertex_position )
{
    if (hovering <= 0.){
        return transform_projection * vertex_position;
    }
    float mid_dist = length(vertex_position.xy - 0.5*love_ScreenSize.xy)/length(love_ScreenSize.xy);
    vec2 mouse_offset = (vertex_position.xy - mouse_screen_pos.xy)/screen_scale;
    float scale = 0.2*(-0.03 - 0.3*max(0., 0.3-mid_dist))
                *hovering*(length(mouse_offset)*length(mouse_offset))/(2. -mid_dist);

    return transform_projection * vertex_position + vec4(0,0,0,scale);
}
#endif