theme mandelbrot

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ntr committed 2022-05-06 16:53:30 +10:00
1 parent 9fea0bdab6
commit 986d37148a
5 files changed
+174 -45

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@@ -37,7 +37,7 @@ public class ThemeShaderBinder : MonoBehaviour
Gradient theme = preferences.Theme();
for (int i = 0; i < textureSize; i++) {
_colorCache[i] = theme.Evaluate(1.0f / i);
_colorCache[i] = theme.Evaluate((float)i / (float)textureSize);
}
_texture.SetPixels(_colorCache);
@@ -7,10 +7,15 @@ Shader "Explorer/Mandelbrot"
_Area("Area", vector) = (0, 0, 4 ,4)
_Angle("Angle", range(-3.1415, 3.1415)) = 0
_MaxIter("Max Iterations", range(0, 555)) = 255
_Color("Color", range(0,1)) = 0.5
_Repeat("Repeat", float) = 1
_Speed("Speed", range(0, 1)) = 0.1
_Colors("Colors", vector) = (3.0, 4.0, 5.0, 0.0)
_EscapeRadius("EscapeRadius", range(2, 2000)) = 255
_SpectrumTexture("SpectrumTexture", 2D) = "white" {}
_SpectrumSize("SpectrumSize", float) = 16
_ThemeTexture("ThemeTexture", 2D) = "white" {}
_ThemeSize("ThemeSize", float) = 16
}
SubShader
{
@@ -46,54 +51,68 @@ Shader "Explorer/Mandelbrot"
}
float4 _Area;
float _Angle;
float _Color;
float3 _Colors;
float _Repeat;
float _Speed;
int _MaxIter;
float _EscapeRadius;
float _Speed;
sampler2D _SpectrumTexture;
int _SpectrumSize;
sampler2D _ThemeTexture;
int _ThemeSize;
sampler2D _MainTex;
float2 rot(float2 p, float2 pivot, float a) {
float s = sin(a);
float c = cos(a);
p -= pivot;
p = float2(p.x*c-p.y*s, p.x*s+p.y*c);
p += pivot;
return p;
}
fixed4 frag (v2f i) : SV_Target {
// drawing stuff
float2 uv = i.uv - 0.5;
float2 offset = _Area.xy + uv * _Area.zw;
float2 z; // track pixel jumping across screen
float2 zPrev;
float r = 20; // escape radius
// cool modulation
float sub = tex2D(_SpectrumTexture, 0.0);
float bass = tex2D(_SpectrumTexture, 0.25);
float mids = tex2D(_SpectrumTexture, 0.50);
float highs = tex2D(_SpectrumTexture, 0.75);
float r = lerp(2.0, 200, bass);
float maxIterations = lerp(2.0, 500, sub);
// fractal bits
float r2 = r*r;
float2 c = _Area.xy + uv * _Area.zw;
float2 z = 0;
float2 zNext;
int iter;
for (iter = 0; iter < maxIterations; iter ++)
{
// f(z) = z^2 + c
zNext.x = z.x * z.x - z.y * z.y + c.x;
zNext.y = 2 * z.x * z.y + c.y;
z = zNext;
float vxsquare = 0;
float vysquare = 0;
float iteration = 0;
float lastIteration = _MaxIter;
do {
vxsquare = uv.x * uv.x;
vysquare = uv.y * uv.y;
uv = float2(vxsquare - vysquare, uv.x * uv.y * 2) + offset;
iteration++;
if ((lastIteration == _MaxIter) && (vxsquare + vysquare) > 4.0) {
lastIteration = iteration + 1;
// unbounded
if (length(zNext) > r)
break;
}
} while (iteration < lastIteration);
float val = (float(iteration) - (log(log(sqrt(vxsquare + vysquare))) / log(2.0))) / float(_MaxIter);
return float4(sin(val * _Colors.x), sin(val * _Colors.y), sin(val * _Colors.z), 1);
// in the set
// make it white
if (iter >= maxIterations) {
return 0;
return 1;
}
float val = iter / float(maxIterations);
float4 col = tex2D(_ThemeTexture, float2(sub, 1.0));
return col * val;
// return float4(val, val, val, 1.0);
// return tex2D(_ThemeTexture, highs);
// float col = tex2D(_ThemeTexture, float2(highs * val, 1.0));
// return col;
// from spinny curvy brot
// float dist = length(z); // distance from origin
// float fracIter = (dist - r) / (r2 - r); // linear interpolation
// fracIter = log2(log(dist) / log(r) ); // double exponential interpolation
@@ -11,7 +11,7 @@ Shader "Explorer/Mandelbrot"
_Repeat("Repeat", float) = 1
_Speed("Speed", range(0, 1)) = 0.1
_Symmetry("Symmetry", range(0, 1)) = 0
_EscapeRadius("EscapeRadius", range(0, 50)) = 20
_EscapeRadius("EscapeRadius", range(2, 200)) = 50
_SpectrumTexture("SpectrumTexture", 2D) = "white" {}
_SpectrumSize("SpectrumSize", float) = 16
@@ -80,17 +80,19 @@ Shader "Explorer/Mandelbrot"
c = rot(c, _Area.xy, _Angle);
float2 z; // track pixel jumping across screen
float2 zPrev;
float r = lerp(2.0f, 20.0f, tex2D(_SpectrumTexture, 0.1f));
// float r = _EscapeRadius;
float r = lerp(2.0f, 50.0f, tex2D(_SpectrumTexture, 1.0f));
float r2 = r*r;
float iter; // track current iteration
for (iter = 0; iter < _MaxIter; iter++) {
// update z based on previous z value and add original starting position
//zPrev = z;
// zPrev = z;
zPrev = rot(z, 0, _Time.y);
// zPrev = rot(z, 0, clamp(tex2D(_SpectrumTexture, 0.1f) * 6.28, 1, 6.28));
z = float2(z.x*z.x-z.y*z.y, 2*z.x*z.y) + c;
if (dot(z, zPrev) > r2) {
//if (length(z) > r) {
break;
}
}
@@ -0,0 +1,98 @@
Shader "Explorer/Mandelbrot"
{
Properties
{
_MainTex ("Texture", 2D) = "white" {}
// first two numbers are center of area, second two - size of area
_Area("Area", vector) = (0, 0, 4 ,4)
_Angle("Angle", range(-3.1415, 3.1415)) = 0
_MaxIter("Max Iterations", range(0, 555)) = 255
// _Speed("Speed", range(0, 1)) = 0.1
_Colors("Colors", vector) = (0.5, 0.5, 0.5, 0.0)
_EscapeRadius("EscapeRadius", range(2, 2000)) = 255
}
SubShader
{
// No culling or depth
Cull Off ZWrite Off ZTest Always
Pass
{
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#include "UnityCG.cginc"
struct appdata
{
float4 vertex : POSITION;
float2 uv : TEXCOORD0;
};
struct v2f
{
float2 uv : TEXCOORD0;
float4 vertex : SV_POSITION;
};
v2f vert (appdata v)
{
v2f o;
o.vertex = UnityObjectToClipPos(v.vertex);
o.uv = v.uv;
return o;
}
float4 _Area;
float _Angle;
float3 _Colors;
// float _Speed;
int _MaxIter;
float _EscapeRadius;
sampler2D _MainTex;
fixed4 frag (v2f i) : SV_Target {
float2 uv = i.uv - 0.5;
float2 offset = _Area.xy + uv * _Area.zw;
float r = _EscapeRadius;
float r2 = r*r;
float2 c = _Area.xy + uv * _Area.zw;
float2 z = 0;
float2 zNext;
int iter;
for (iter = 0; iter < _MaxIter; iter ++)
{
// f(z) = z^2 + c
zNext.x = z.x * z.x - z.y * z.y + c.x;
zNext.y = 2 * z.x * z.y + c.y;
z = zNext;
// Bounded?
if (distance(z, float2(0,0)) > r)
break;
}
float val = iter / float(_MaxIter);
return float4(val, val, val, 1);
return float4(sin(val), sin(val), sin(val), 1);
// float dist = length(z); // distance from origin
// float fracIter = (dist - r) / (r2 - r); // linear interpolation
// fracIter = log2(log(dist) / log(r) ); // double exponential interpolation
// iter -= fracIter;
// float m = sqrt(iter / _MaxIter);
// float4 col = sin(float4(.3, .45, .65, 1) * m * 20)*.5 + .5; // procedural colors
// col = tex2D(_MainTex, float2(m * _Repeat + _Time.y*_Speed, _Color));
// col *= smoothstep(3, 0, fracIter);
// float angle = atan2(z.x, z.y);
// col *= 1 + sin(angle*2 + _Time.y*4)*.2;
// return col;
}
ENDCG
}
}
}
@@ -0,0 +1,10 @@
fileFormatVersion: 2
guid: ac37e4ae67210ed48bd3bb15fca8b2b2
ShaderImporter:
externalObjects: {}
defaultTextures: []
nonModifiableTextures: []
preprocessorOverride: 0
userData:
assetBundleName:
assetBundleVariant: