mandelbrot.cl

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#include "utils.cl"
 
#ifndef DISABLE_FREE_CAMERA_MANDELBROT
#define DISABLE_FREE_CAMERA_MANDELBROT true
#endif
 
#if DISABLE_FREE_CAMERA_MANDELBROT
 
#define CAMERA_POSITIONS_LENGTH 1
#define CAMERA_POSITIONS_ARRAY { (float4)(0, -1.5, 0, 0) }
#define CAMERA_FACING_DIRECTIONS_LENGTH 1
#define CAMERA_FACING_DIRECTIONS_ARRAY { (float4)(normalise((float3)(-0.7, -0.3, -0.7)), 0) }
#define CAMERA_SPEED 0.1f
 
#endif
 
#define MAXIMUM_MARCH_STEPS 100
#define MAXIMUM_MARCH_DISTANCE 50.0f
#define SURFACE_INTERSECTION_EPSILON 0.001f
#define CAMERA_FOCUS_DISTANCE 0.0001f
#define SCENE_BACKGROUND_COLOUR (float3)(0.1f, 0.1f, 0.1f)
 
#define DO_AMBIENT_LIGHTING true
#define DO_DIFFUSE_LIGHTING false
#define DO_SPECULAR_HIGHLIGHTS false
 
#include "types.cl"
#include "sdf.cl"
 
 
 
#ifndef ITERATIONS
#define ITERATIONS 500
#endif 
 
#ifndef ESCAPE
#define ESCAPE 4
#endif
 
#ifndef SCALE
#define SCALE 0.5f
#endif
 
float3 getMandelbrot(float2 position)
{
    // http://www.fractalforums.com/3d-fractal-generation/true-3d-mandlebrot-type-fractal/msg8505/#msg8505
 
    float x_temp;
    float dx_temp;
    float r, dr, dist;
    float escape;
 
    //Initialize iteration variables
    float x0 = position.x;
    float y0 = position.y;
    float x = 0.0f;
    float y = 0.0f;
    float dx = 0.0f;
    float dy = 0.0f;
 
    int i;
    for (i = 0; i < ITERATIONS && x * x + y * y < ESCAPE; i++)
    {
        //Update z'
        dx_temp = 2.0f * (x * dx - y * dy) + 1.0f;
        dy = 2.0f * (x * dy + y * dx);
        dx = dx_temp;
 
        //Update z
        x_temp = x * x - y * y + x0;
        y = 2.0f * x * y + y0;
        x = x_temp;
    }
 
    // Calculate distance
    //r = sqrt(x * x + y * y);
    //dr = sqrt(dx * dx + dy * dy);
    //dist = 0.5f * r * log(r) / dr;
 
    float3 colour;
    // Outside the mandelbrot
    if (i < ITERATIONS)
    {
        colour = (float3)(0.75f, 0.0f, 0.0f);
    }
    // Inside the mandelbrot
    else
    {
        colour = (float3)(0);
    }
 
    return colour;
}
 
 
 
Light getLight(float time)
{
    Light light;
    light.ambient = (float3)(1.0f, 1.0f, 1.0f);
    light.diffuse = (float3)(0);
    light.specular = (float3)(0);
    light.position = (float3)(0, -1, 0);
 
    return light;
}
 
#if DISABLE_FREE_CAMERA_MANDELBROT
 
float2 getSamplePoint(float x, float y, float time)
{
    return (float2)(x, y) * SCALE;
}
 
#endif
 
Material getMaterial(float3 position, float time)
{
    // Material
    Material material;
    material.ambient = getMandelbrot(getSamplePoint(position.x, position.z, time));
    material.diffuse = material.ambient;
    material.specular = (float3)(0.5f, 0.5f, 0.5f);
    material.shininess = 25.0f;
 
    return material;
}
 
float DE(float3 position, float time)
{
    // Distance estimation
    return f_abs(position.y);
}
 
#include "main.cl"