vec4 render()

in src/elm_src/Algorithm/fractals.c [574:652]

• 60 lines of code
• 12 McCabe index (conditional complexity)

vec4 render(vec2 pixel)
{
    vec3  ray_direction = rayDirection(pixel);
    float ray_length = minRange;
    vec3  ray = cameraPosition + ray_length * ray_direction;
    vec4  bg_color = vec4(clamp(mix(background2Color, background1Color, (sin(ray_direction.y * HALFPI) + 1.0) * 0.5), 0.0, 1.0), 1.0);
    vec4  color = bg_color;

    float eps = MIN_EPSILON;
    vec3  dist;
    vec3  normal = vec3(0);
    int   steps = 0;
    bool  hit = false;
    float tmin = 0.0;
    float tmax = 10000.0;

    if (intersectBoundingSphere(ray, ray_direction, tmin, tmax)) {
        ray_length = tmin;
        ray = cameraPosition + ray_length * ray_direction;

        for (int i = 0; i < stepLimit; i++) {
            steps = i;
            dist = dE(ray);
            dist.x *= surfaceSmoothness;

            // If we hit the surface on the previous step check again to make sure it wasn't
            // just a thin filament
            if (hit && dist.x < eps || ray_length > tmax || ray_length < tmin) {
                steps--;
                break;
            }

            hit = false;
            ray_length += dist.x;
            ray = cameraPosition + ray_length * ray_direction;
            eps = ray_length * epsfactor;

            if (dist.x < eps || ray_length < tmin) {
                hit = true;
            }
        }
    }

    // Found intersection?
    float glowAmount = float(steps)/float(stepLimit);
    float glow;

    if (hit) {
        float aof = 1.0, shadows = 1.0;
        glow = clamp(glowAmount * innerGlowIntensity * 3.0, 0.0, 1.0);

        if (steps < 1 || ray_length < tmin) {
            normal = normalize(ray);
        } else {
            normal = generateNormal(ray, eps);
            aof = ambientOcclusion(ray, normal, eps);
        }

        color.rgb = mix(color1, mix(color2, color3, dist.y * color2Intensity), dist.z * color3Intensity);
        color.rgb = blinnPhong(clamp(color.rgb * color1Intensity, 0.0, 1.0), ray, normal);
        color.rgb *= aof;
        color.rgb = mix(color.rgb, innerGlowColor, glow);
        color.rgb = mix(bg_color.rgb, color.rgb, exp(-pow(ray_length * exp(fogFalloff), 2.0) * fog));
        color.a = 1.0;
    } else {
        // Apply outer glow and fog
        ray_length = tmax;
        color.rgb = mix(bg_color.rgb, color.rgb, exp(-pow(ray_length * exp(fogFalloff), 2.0)) * fog);
        glow = clamp(glowAmount * outerGlowIntensity * 3.0, 0.0, 1.0);
        color.rgb = mix(color.rgb, outerGlowColor, glow);
        if (transparent) color = vec4(0.0);
    }

    // if (depthMap) {
    //     color.rgb = vec3(ray_length / 10.0);
    // }

    return color;
}