slang-shaders/procedural/srtuss-the-eye.slang
2018-02-24 02:20:43 +01:00

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#version 450
// The Eye - srtuss - 2014-10-08
// https://www.shadertoy.com/view/Xd2XDm
// Another interesting, trippy 2D effect, with a cool retro colorset.
// srtuss, 2014
// a fun little effect based on repetition and motion-blur :)
// enjoy staring at the center, in fullscreen :)
layout(std140, set = 0, binding = 0) uniform UBO
{
mat4 MVP;
vec4 OutputSize;
vec4 OriginalSize;
vec4 SourceSize;
uint FrameCount;
} global;
#pragma stage vertex
layout(location = 0) in vec4 Position;
layout(location = 1) in vec2 TexCoord;
layout(location = 0) out vec2 vTexCoord;
const vec2 madd = vec2(0.5, 0.5);
void main()
{
gl_Position = global.MVP * Position;
vTexCoord = gl_Position.xy;
}
#pragma stage fragment
layout(location = 0) in vec2 vTexCoord;
layout(location = 0) out vec4 FragColor;
float iGlobalTime = float(global.FrameCount)*0.025;
vec2 iResolution = global.OutputSize.xy;
#define pi2 3.1415926535897932384626433832795
float tri(float x, float s)
{
return (abs(fract(x / s) - 0.5) - 0.25) * s;
}
float hash(float x)
{
return fract(sin(x * 171.2972) * 18267.978 + 31.287);
}
vec3 pix(vec2 p, float t, float s)
{
s += floor(t * 0.25);
float scl = (hash(s + 30.0) * 4.0);
scl += sin(t * 2.0) * 0.25 + sin(t) * 0.5;
t *= 3.0;
vec2 pol = vec2(atan(p.y, p.x), length(p));
float v;
float id = floor(pol.y * 2.0 * scl);
pol.x += t * (hash(id + s) * 2.0 - 1.0) * 0.4;
float si = hash(id + s * 2.0);
float rp = floor(hash(id + s * 4.0) * 5.0 + 4.0);
v = (abs(tri(pol.x, pi2 / rp)) - si * 0.1) * pol.y;
v = max(v, abs(tri(pol.y, 1.0 / scl)) - (1.0 - si) * 0.11);
v = smoothstep(0.01, 0.0, v);
return vec3(v);
}
vec3 pix2(vec2 p, float t, float s)
{
return clamp(pix(p, t, s) - pix(p, t, s + 8.0) + pix(p * 0.1, t, s + 80.0) * 0.2, vec3(0.0), vec3(1.0));
}
vec2 hash2(in vec2 p)
{
return fract(1965.5786 * vec2(sin(p.x * 591.32 + p.y * 154.077), cos(p.x * 391.32 + p.y * 49.077)));
}
#define globaltime (iGlobalTime - 2.555)
vec3 blur(vec2 p)
{
vec3 ite = vec3(0.0);
for(int i = 0; i < 20; i ++)
{
float tc = 0.15;
ite += pix2(p, globaltime * 3.0 + (hash2(p + float(i)) - 0.5).x * tc, 5.0);
}
ite /= 20.0;
ite += exp(fract(globaltime * 0.25 * 6.0) * -40.0) * 2.0;
return ite;
}
void mainImage( out vec4 fragColor, in vec2 fragCoord )
{
vec2 uv = fragCoord.xy / iResolution.xy;
uv = 2.0 * uv - 1.0;
uv.x *= iResolution.x / iResolution.y;
uv += (vec2(hash(globaltime), hash(globaltime + 9.999)) - 0.5) * 0.03;
vec3 c = vec3(blur(uv + vec2(0.005, 0.0)).x, blur(uv + vec2(0.0, 0.005)).y, blur(uv).z);
c = pow(c, vec3(0.4, 0.6, 1.0) * 2.0) * 1.5;
c *= exp(length(uv) * -1.0) * 2.5;
c = pow(c, vec3(1.0 / 2.2));
fragColor = vec4(c, 1.0);
}
void main(void)
{
//just some shit to wrap shadertoy's stuff
vec2 FragmentCoord = vTexCoord.xy*global.OutputSize.xy;
FragmentCoord.y = -FragmentCoord.y;
mainImage(FragColor,FragmentCoord);
}