1/**
2 * Mandelbulber v2, a 3D fractal generator  _%}}i*<.        ____                _______
3 * Copyright (C) 2020 Mandelbulber Team   _>]|=||i=i<,     / __ \___  ___ ___  / ___/ /
4 *                                        \><||i|=>>%)    / /_/ / _ \/ -_) _ \/ /__/ /__
5 * This file is part of Mandelbulber.     )<=i=]=|=i<>    \____/ .__/\__/_//_/\___/____/
6 * The project is licensed under GPLv3,   -<>>=|><|||`        /_/
7 * see also COPYING file in this folder.    ~+{i%+++
8 *
9 * knotv2
10 * knot thingy by knighty (2012). Based on an idea by DarkBeam from fractalforums
11 *(http://www.fractalforums.com/new-theories-and-research/not-fractal-but-funny-trefoil-knot-routine/30/)
12
13 * This file has been autogenerated by tools/populateUiInformation.php
14 * from the file "fractal_knot_v2.cpp" in the folder formula/definition
15 * D O    N O T    E D I T    T H I S    F I L E !
16 */
17
18REAL4 KnotV2Iteration(REAL4 z, __constant sFractalCl *fractal, sExtendedAuxCl *aux)
19{
20	if (fractal->transformCommon.functionEnabledAxFalse) z.x = fabs(z.x);
21	if (fractal->transformCommon.functionEnabledAyFalse) z.y = fabs(z.y);
22	if (fractal->transformCommon.functionEnabledAzFalse) z.z = fabs(z.z);
23	z += fractal->transformCommon.offset000;
24
25	REAL4 zc = z;
26	REAL tempA = zc.y;
27	REAL tempB = zc.z;
28	if (fractal->transformCommon.functionEnabledJFalse)
29	{
30		REAL temp = tempA;
31		tempA = tempB;
32		tempB = temp;
33	}
34
35	zc.z *= fractal->transformCommon.scaleA1;
36	REAL rxz = native_sqrt(zc.x * zc.x + tempA * tempA);
37	REAL ang = atan2(tempA, zc.x);
38	REAL t = tempB;
39
40	REAL colorDist = 0.0f;
41	for (int n = 0; n < fractal->transformCommon.int3; n++)
42	{
43		zc = (REAL4){rxz, t, ang + M_PI_2x_F * n, 0.0f};
44
45		zc.x -= fractal->transformCommon.offsetA2;
46
47		REAL ra =
48			zc.z * ((REAL)fractal->transformCommon.int3X) / ((REAL)fractal->transformCommon.int3Z);
49		REAL raz =
50			zc.z * ((REAL)fractal->transformCommon.int8Y) / ((REAL)fractal->transformCommon.int3Z);
51
52		zc.x =
53			zc.x
54			- (fractal->transformCommon.offset1 * native_cos(ra) + fractal->transformCommon.offsetA2);
55		zc.y =
56			zc.y
57			- (fractal->transformCommon.offset1 * native_sin(raz) + fractal->transformCommon.offsetA2);
58
59		aux->DE0 = native_sqrt(zc.x * zc.x + zc.y * zc.y) - fractal->transformCommon.offset01;
60
61		if (fractal->transformCommon.functionEnabledKFalse) aux->DE0 /= aux->DE;
62
63		if (!fractal->transformCommon.functionEnabledDFalse)
64			aux->dist = min(aux->dist, aux->DE0);
65		else
66			aux->dist = aux->DE0;
67	}
68	if (fractal->transformCommon.functionEnabledEFalse) z = zc;
69
70	// aux->color
71	if (fractal->foldColor.auxColorEnabled)
72	{
73		REAL colorAdd = 0.0f;
74
75		if (fmod(ang, 2.0f) < 1.0f) colorAdd += fractal->foldColor.difs0000.x;
76		colorAdd += fractal->foldColor.difs0000.y * (zc.x);
77		colorAdd += fractal->foldColor.difs0000.z * (zc.y);
78		colorAdd += fractal->foldColor.difs0000.w * (zc.z);
79
80		colorAdd += fractal->foldColor.difs1;
81		if (fractal->foldColor.auxColorEnabledA)
82		{
83			if (colorDist != aux->dist) aux->color += colorAdd;
84		}
85		else
86			aux->color += colorAdd;
87	}
88
89	// DE tweak
90	if (fractal->analyticDE.enabledFalse) aux->dist = aux->dist * fractal->analyticDE.scale1;
91	return z;
92}