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move some stuff out of MapGenerator.h
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@UnknownShadow200
UnknownShadow200 committed Feb 1, 2019
1 parent 4655f41 commit 01340e8
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Showing 2 changed files with 94 additions and 107 deletions.
185 changes: 94 additions & 91 deletions src/MapGenerator.c
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Expand Up @@ -56,6 +56,100 @@ void FlatgrassGen_Generate(void) {
}


/*########################################################################################################################*
*---------------------------------------------------Noise generation------------------------------------------------------*
*#########################################################################################################################*/
#define NOISE_TABLE_SIZE 512
static void ImprovedNoise_Init(uint8_t* p, RNGState* rnd) {
uint8_t tmp;
int i, j;
for (i = 0; i < 256; i++) { p[i] = i; }

/* shuffle randomly using fisher-yates */
for (i = 0; i < 256; i++) {
j = Random_Range(rnd, i, 256);
tmp = p[i]; p[i] = p[j]; p[j] = tmp;
}

for (i = 0; i < 256; i++) {
p[i + 256] = p[i];
}
}

static float ImprovedNoise_Calc(uint8_t* p, float x, float y) {
int xFloor, yFloor, X, Y;
float u, v;
int A, B, hash;
float g22, g12, c1;
float g21, g11, c2;

xFloor = x >= 0 ? (int)x : (int)x - 1;
yFloor = y >= 0 ? (int)y : (int)y - 1;
X = xFloor & 0xFF; Y = yFloor & 0xFF;
x -= xFloor; y -= yFloor;

u = x * x * x * (x * (x * 6 - 15) + 10); /* Fade(x) */
v = y * y * y * (y * (y * 6 - 15) + 10); /* Fade(y) */
A = p[X] + Y; B = p[X + 1] + Y;

/* Normally, calculating Grad involves a function call. However, we can directly pack this table
(since each value indicates either -1, 0 1) into a set of bit flags. This way we avoid needing
to call another function that performs branching */
#define xFlags 0x46552222
#define yFlags 0x2222550A

hash = (p[p[A]] & 0xF) << 1;
g22 = (((xFlags >> hash) & 3) - 1) * x + (((yFlags >> hash) & 3) - 1) * y; /* Grad(p[p[A], x, y) */
hash = (p[p[B]] & 0xF) << 1;
g12 = (((xFlags >> hash) & 3) - 1) * (x - 1) + (((yFlags >> hash) & 3) - 1) * y; /* Grad(p[p[B], x - 1, y) */
c1 = g22 + u * (g12 - g22);

hash = (p[p[A + 1]] & 0xF) << 1;
g21 = (((xFlags >> hash) & 3) - 1) * x + (((yFlags >> hash) & 3) - 1) * (y - 1); /* Grad(p[p[A + 1], x, y - 1) */
hash = (p[p[B + 1]] & 0xF) << 1;
g11 = (((xFlags >> hash) & 3) - 1) * (x - 1) + (((yFlags >> hash) & 3) - 1) * (y - 1); /* Grad(p[p[B + 1], x - 1, y - 1) */
c2 = g21 + u * (g11 - g21);

return c1 + v * (c2 - c1);
}


struct OctaveNoise { uint8_t p[8][NOISE_TABLE_SIZE]; int octaves; };
static void OctaveNoise_Init(struct OctaveNoise* n, RNGState* rnd, int octaves) {
int i;
n->octaves = octaves;

for (i = 0; i < octaves; i++) {
ImprovedNoise_Init(n->p[i], rnd);
}
}

static float OctaveNoise_Calc(struct OctaveNoise* n, float x, float y) {
float amplitude = 1, freq = 1;
float sum = 0;
int i;

for (i = 0; i < n->octaves; i++) {
sum += ImprovedNoise_Calc(n->p[i], x * freq, y * freq) * amplitude;
amplitude *= 2.0f;
freq *= 0.5f;
}
return sum;
}


struct CombinedNoise { struct OctaveNoise noise1, noise2; };
static void CombinedNoise_Init(struct CombinedNoise* n, RNGState* rnd, int octaves1, int octaves2) {
OctaveNoise_Init(&n->noise1, rnd, octaves1);
OctaveNoise_Init(&n->noise2, rnd, octaves2);
}

static float CombinedNoise_Calc(struct CombinedNoise* n, float x, float y) {
float offset = OctaveNoise_Calc(&n->noise2, x, y);
return OctaveNoise_Calc(&n->noise1, x + offset, y);
}


/*########################################################################################################################*
*----------------------------------------------------Notchy map gen-------------------------------------------------------*
*#########################################################################################################################*/
Expand Down Expand Up @@ -542,97 +636,6 @@ void NotchyGen_Generate(void) {
}


/*########################################################################################################################*
*---------------------------------------------------Noise generation------------------------------------------------------*
*#########################################################################################################################*/
void ImprovedNoise_Init(uint8_t* p, RNGState* rnd) {
uint8_t tmp;
int i, j;
for (i = 0; i < 256; i++) { p[i] = i; }

/* shuffle randomly using fisher-yates */
for (i = 0; i < 256; i++) {
j = Random_Range(rnd, i, 256);
tmp = p[i]; p[i] = p[j]; p[j] = tmp;
}

for (i = 0; i < 256; i++) {
p[i + 256] = p[i];
}
}

float ImprovedNoise_Calc(uint8_t* p, float x, float y) {
int xFloor, yFloor, X, Y;
float u, v;
int A, B, hash;
float g22, g12, c1;
float g21, g11, c2;

xFloor = x >= 0 ? (int)x : (int)x - 1;
yFloor = y >= 0 ? (int)y : (int)y - 1;
X = xFloor & 0xFF; Y = yFloor & 0xFF;
x -= xFloor; y -= yFloor;

u = x * x * x * (x * (x * 6 - 15) + 10); /* Fade(x) */
v = y * y * y * (y * (y * 6 - 15) + 10); /* Fade(y) */
A = p[X] + Y; B = p[X + 1] + Y;

/* Normally, calculating Grad involves a function call. However, we can directly pack this table
(since each value indicates either -1, 0 1) into a set of bit flags. This way we avoid needing
to call another function that performs branching */
#define xFlags 0x46552222
#define yFlags 0x2222550A

hash = (p[p[A]] & 0xF) << 1;
g22 = (((xFlags >> hash) & 3) - 1) * x + (((yFlags >> hash) & 3) - 1) * y; /* Grad(p[p[A], x, y) */
hash = (p[p[B]] & 0xF) << 1;
g12 = (((xFlags >> hash) & 3) - 1) * (x - 1) + (((yFlags >> hash) & 3) - 1) * y; /* Grad(p[p[B], x - 1, y) */
c1 = g22 + u * (g12 - g22);

hash = (p[p[A + 1]] & 0xF) << 1;
g21 = (((xFlags >> hash) & 3) - 1) * x + (((yFlags >> hash) & 3) - 1) * (y - 1); /* Grad(p[p[A + 1], x, y - 1) */
hash = (p[p[B + 1]] & 0xF) << 1;
g11 = (((xFlags >> hash) & 3) - 1) * (x - 1) + (((yFlags >> hash) & 3) - 1) * (y - 1); /* Grad(p[p[B + 1], x - 1, y - 1) */
c2 = g21 + u * (g11 - g21);

return c1 + v * (c2 - c1);
}


void OctaveNoise_Init(struct OctaveNoise* n, RNGState* rnd, int octaves) {
int i;
n->octaves = octaves;

for (i = 0; i < octaves; i++) {
ImprovedNoise_Init(n->p[i], rnd);
}
}

float OctaveNoise_Calc(struct OctaveNoise* n, float x, float y) {
float amplitude = 1, freq = 1;
float sum = 0;
int i;

for (i = 0; i < n->octaves; i++) {
sum += ImprovedNoise_Calc(n->p[i], x * freq, y * freq) * amplitude;
amplitude *= 2.0f;
freq *= 0.5f;
}
return sum;
}


void CombinedNoise_Init(struct CombinedNoise* n, RNGState* rnd, int octaves1, int octaves2) {
OctaveNoise_Init(&n->noise1, rnd, octaves1);
OctaveNoise_Init(&n->noise2, rnd, octaves2);
}

float CombinedNoise_Calc(struct CombinedNoise* n, float x, float y) {
float offset = OctaveNoise_Calc(&n->noise2, x, y);
return OctaveNoise_Calc(&n->noise1, x + offset, y);
}


/*########################################################################################################################*
*----------------------------------------------------Tree generation------------------------------------------------------*
*#########################################################################################################################*/
Expand Down
16 changes: 0 additions & 16 deletions src/MapGenerator.h
View file
Expand Up @@ -16,22 +16,6 @@ extern int Gen_Seed;
extern bool Gen_Vanilla;
extern BlockRaw* Gen_Blocks;

void FlatgrassGen_Generate(void);
void NotchyGen_Generate(void);

#define NOISE_TABLE_SIZE 512
void ImprovedNoise_Init(uint8_t* p, RNGState* rnd);
float ImprovedNoise_Calc(uint8_t* p, float x, float y);

struct OctaveNoise { uint8_t p[8][NOISE_TABLE_SIZE]; int octaves; };
void OctaveNoise_Init(struct OctaveNoise* n, RNGState* rnd, int octaves);
float OctaveNoise_Calc(struct OctaveNoise* n, float x, float y);

struct CombinedNoise { struct OctaveNoise noise1, noise2; };
void CombinedNoise_Init(struct CombinedNoise* n, RNGState* rnd, int octaves1, int octaves2);
float CombinedNoise_Calc(struct CombinedNoise* n, float x, float y);


extern BlockRaw* Tree_Blocks;
extern RNGState* Tree_Rnd;
/* Appropriate buffer size to hold positions and blocks generated by the tree generator. */
Expand Down

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