oss/luanti
oss/luanti
1
0
Fork 0
mirror of https://github.com/luanti-org/luanti.git synced 2025-06-27 16:36:03 +00:00
Code Wiki Activity

Mgfractal: Add 3D and 4D fractals

Browse source 
3D Mandelbrot/Mandelbar
3D Christmas Tree
3D Mandelbulb
3D Cosine Mandelbulb
4D Mandelbulb
Plus corresponding julia set for each
Add credits for formulas
Rename parameter 'formula' to 'fractal'
Speed optimisations
This commit is contained in:
paramat 2015-12-08 05:40:36 +00:00
parent aed10765f2
commit c26eb87aec
4 changed files with 145 additions and 59 deletions
Download patch file Download diff file Expand all files Collapse all files

88
src/mapgen_fractal.cpp
View file

@ -66,7 +66,7 @@ MapgenFractal::MapgenFractal(int mapgenid, MapgenParams *params, EmergeManager *
MapgenFractalParams *sp = (MapgenFractalParams *)params->sparams;
this->spflags = sp->spflags;
this->formula = sp->formula;
this->fractal = sp->fractal;
this->iterations = sp->iterations;
this->scale = sp->scale;
this->offset = sp->offset;
@ -77,6 +77,9 @@ MapgenFractal::MapgenFractal(int mapgenid, MapgenParams *params, EmergeManager *
this->julia_z = sp->julia_z;
this->julia_w = sp->julia_w;
this->formula = fractal / 2 + fractal % 2;
this->julia = fractal % 2 == 0;
//// 2D terrain noise
noise_seabed = new Noise(&sp->np_seabed, seed, csize.X, csize.Z);
noise_filler_depth = new Noise(&sp->np_filler_depth, seed, csize.X, csize.Z);
@ -141,7 +144,7 @@ MapgenFractalParams::MapgenFractalParams()
{
spflags = 0;
formula = 1;
fractal = 1;
iterations = 11;
scale = v3f(4096.0, 1024.0, 4096.0);
offset = v3f(1.79, 0.0, 0.0);
@ -163,7 +166,7 @@ void MapgenFractalParams::readParams(const Settings *settings)
{
settings->getFlagStrNoEx("mgfractal_spflags", spflags, flagdesc_mapgen_fractal);
settings->getU16NoEx("mgfractal_formula", formula);
settings->getU16NoEx("mgfractal_fractal", fractal);
settings->getU16NoEx("mgfractal_iterations", iterations);
settings->getV3FNoEx("mgfractal_scale", scale);
settings->getV3FNoEx("mgfractal_offset", offset);
@ -185,7 +188,7 @@ void MapgenFractalParams::writeParams(Settings *settings) const
{
settings->setFlagStr("mgfractal_spflags", spflags, flagdesc_mapgen_fractal, U32_MAX);
settings->setU16("mgfractal_formula", formula);
settings->setU16("mgfractal_fractal", fractal);
settings->setU16("mgfractal_iterations", iterations);
settings->setV3F("mgfractal_scale", scale);
settings->setV3F("mgfractal_offset", offset);
@ -368,7 +371,7 @@ bool MapgenFractal::getFractalAtPoint(s16 x, s16 y, s16 z)
{
float cx, cy, cz, cw, ox, oy, oz, ow;
if (formula % 2 == 0) { // Julia sets, formula = 2, 4, 6, 8
if (julia) { // Julia set
cx = julia_x;
cy = julia_y;
cz = julia_z;
@ -377,7 +380,7 @@ bool MapgenFractal::getFractalAtPoint(s16 x, s16 y, s16 z)
oy = (float)y / scale.Y - offset.Y;
oz = (float)z / scale.Z - offset.Z;
ow = slice_w;
} else { // Mandelbrot sets, formula = 1, 3, 5, 7
} else { // Mandelbrot set
cx = (float)x / scale.X - offset.X;
cy = (float)y / scale.Y - offset.Y;
cz = (float)z / scale.Z - offset.Z;
@ -388,32 +391,87 @@ bool MapgenFractal::getFractalAtPoint(s16 x, s16 y, s16 z)
ow = 0.0f;
}
for (u16 iter = 0; iter < iterations; iter++) {
float nx = 0.0f;
float ny = 0.0f;
float nz = 0.0f;
float nw = 0.0f;
float nx = 0.0f;
float ny = 0.0f;
float nz = 0.0f;
float nw = 0.0f;
if (formula == 1 || formula == 2) { // 4D "Roundy" Mandelbrot/Julia Set
for (u16 iter = 0; iter < iterations; iter++) {
if (formula == 1) { // 4D "Roundy"
nx = ox * ox - oy * oy - oz * oz - ow * ow + cx;
ny = 2.0f * (ox * oy + oz * ow) + cy;
nz = 2.0f * (ox * oz + oy * ow) + cz;
nw = 2.0f * (ox * ow + oy * oz) + cw;
} else if (formula == 3 || formula == 4) { // 4D "Squarry" Mandelbrot/Julia Set
} else if (formula == 2) { // 4D "Squarry"
nx = ox * ox - oy * oy - oz * oz - ow * ow + cx;
ny = 2.0f * (ox * oy + oz * ow) + cy;
nz = 2.0f * (ox * oz + oy * ow) + cz;
nw = 2.0f * (ox * ow - oy * oz) + cw;
} else if (formula == 5 || formula == 6) { // 4D "Mandy Cousin" Mandelbrot/Julia Set
} else if (formula == 3) { // 4D "Mandy Cousin"
nx = ox * ox - oy * oy - oz * oz + ow * ow + cx;
ny = 2.0f * (ox * oy + oz * ow) + cy;
nz = 2.0f * (ox * oz + oy * ow) + cz;
nw = 2.0f * (ox * ow + oy * oz) + cw;
} else if (formula == 7 || formula == 8) { // 4D "Variation" Mandelbrot/Julia Set
} else if (formula == 4) { // 4D "Variation"
nx = ox * ox - oy * oy - oz * oz - ow * ow + cx;
ny = 2.0f * (ox * oy + oz * ow) + cy;
nz = 2.0f * (ox * oz - oy * ow) + cz;
nw = 2.0f * (ox * ow + oy * oz) + cw;
} else if (formula == 5) { // 3D "Mandelbrot/Mandelbar"
nx = ox * ox - oy * oy - oz * oz + cx;
ny = 2.0f * ox * oy + cy;
nz = -2.0f * ox * oz + cz;
} else if (formula == 6) { // 3D "Christmas Tree"
// Altering the formula here is necessary to avoid division by zero
if (fabs(oz) < 0.000000001f) {
nx = ox * ox - oy * oy - oz * oz + cx;
ny = 2.0f * oy * ox + cy;
nz = 4.0f * oz * ox + cz;
} else {
float a = (2.0f * ox) / (sqrt(oy * oy + oz * oz));
nx = ox * ox - oy * oy - oz * oz + cx;
ny = a * (oy * oy - oz * oz) + cy;
nz = a * 2.0f * oy * oz + cz;
}
} else if (formula == 7) { // 3D "Mandelbulb"
if (fabs(oy) < 0.000000001f) {
nx = ox * ox - oz * oz + cx;
ny = cy;
nz = -2.0f * oz * sqrt(ox * ox) + cz;
} else {
float a = 1.0f - (oz * oz) / (ox * ox + oy * oy);
nx = (ox * ox - oy * oy) * a + cx;
ny = 2.0f * ox * oy * a + cy;
nz = -2.0f * oz * sqrt(ox * ox + oy * oy) + cz;
}
} else if (formula == 8) { // 3D "Cosine Mandelbulb"
if (fabs(oy) < 0.000000001f) {
nx = 2.0f * ox * oz + cx;
ny = 4.0f * oy * oz + cy;
nz = oz * oz - ox * ox - oy * oy + cz;
} else {
float a = (2.0f * oz) / sqrt(ox * ox + oy * oy);
nx = (ox * ox - oy * oy) * a + cx;
ny = 2.0f * ox * oy * a + cy;
nz = oz * oz - ox * ox - oy * oy + cz;
}
} else if (formula == 9) { // 4D "Mandelbulb"
float rxy = sqrt(ox * ox + oy * oy);
float rxyz = sqrt(ox * ox + oy * oy + oz * oz);
if (fabs(ow) < 0.000000001f && fabs(oz) < 0.000000001f) {
nx = (ox * ox - oy * oy) + cx;
ny = 2.0f * ox * oy + cy;
nz = -2.0f * rxy * oz + cz;
nw = 2.0f * rxyz * ow + cw;
} else {
float a = 1.0f - (ow * ow) / (rxyz * rxyz);
float b = a * (1.0f - (oz * oz) / (rxy * rxy));
nx = (ox * ox - oy * oy) * b + cx;
ny = 2.0f * ox * oy * b + cy;
nz = -2.0f * rxy * oz * a + cz;
nw = 2.0f * rxyz * ow + cw;
}
}
if (nx * nx + ny * ny + nz * nz + nw * nw > 4.0f)