Skip to content

Commit

Permalink
Mgfractal: Use 'switch case' instead of 'if else' (#6314)
Browse files Browse the repository at this point in the history
  • Loading branch information
@paramat @nerzhul
paramat authored and nerzhul committed Aug 26, 2017
1 parent 096ea03 commit e55aeec
Showing 1 changed file with 20 additions and 10 deletions.
30 changes: 20 additions & 10 deletions src/mapgen_fractal.cpp
View file
Expand Up @@ -268,32 +268,38 @@ bool MapgenFractal::getFractalAtPoint(s16 x, s16 y, s16 z)
float nw = 0.0f;

for (u16 iter = 0; iter < iterations; iter++) {

if (formula == 1) { // 4D "Roundy"
switch (formula) {
default:
case 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 == 2) { // 4D "Squarry"
break;
case 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 == 3) { // 4D "Mandy Cousin"
break;
case 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 == 4) { // 4D "Variation"
break;
case 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"
break;
case 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"
break;
case 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;
Expand All @@ -305,7 +311,8 @@ bool MapgenFractal::getFractalAtPoint(s16 x, s16 y, s16 z)
ny = a * (oy * oy - oz * oz) + cy;
nz = a * 2.0f * oy * oz + cz;
}
} else if (formula == 7) { // 3D "Mandelbulb"
break;
case 7: // 3D "Mandelbulb"
if (fabs(oy) < 0.000000001f) {
nx = ox * ox - oz * oz + cx;
ny = cy;
Expand All @@ -316,7 +323,8 @@ bool MapgenFractal::getFractalAtPoint(s16 x, s16 y, s16 z)
ny = 2.0f * ox * oy * a + cy;
nz = -2.0f * oz * sqrt(ox * ox + oy * oy) + cz;
}
} else if (formula == 8) { // 3D "Cosine Mandelbulb"
break;
case 8: // 3D "Cosine Mandelbulb"
if (fabs(oy) < 0.000000001f) {
nx = 2.0f * ox * oz + cx;
ny = 4.0f * oy * oz + cy;
Expand All @@ -327,7 +335,8 @@ bool MapgenFractal::getFractalAtPoint(s16 x, s16 y, s16 z)
ny = 2.0f * ox * oy * a + cy;
nz = oz * oz - ox * ox - oy * oy + cz;
}
} else if (formula == 9) { // 4D "Mandelbulb"
break;
case 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) {
Expand All @@ -343,6 +352,7 @@ bool MapgenFractal::getFractalAtPoint(s16 x, s16 y, s16 z)
nz = -2.0f * rxy * oz * a + cz;
nw = 2.0f * rxyz * ow + cw;
}
break;
}

if (nx * nx + ny * ny + nz * nz + nw * nw > 4.0f)
Expand Down

0 comments on commit e55aeec

Please sign in to comment.