From bddd5f2b98a56fc735d5687ecd0b43767aec8066 Mon Sep 17 00:00:00 2001
From: kwolekr <mirrorisim@gmail.com>
Date: Tue, 18 Dec 2012 16:45:50 -0500
Subject: [PATCH] Cleaned & enhanced noise object management

---
 src/noise.cpp | 89 ++++++++++++++++++++++++++++++++++-----------------
 src/noise.h   |  7 ++++
 2 files changed, 67 insertions(+), 29 deletions(-)

diff --git a/src/noise.cpp b/src/noise.cpp
index 3874848a..c038384d 100644
--- a/src/noise.cpp
+++ b/src/noise.cpp
@@ -270,45 +270,25 @@ float contour(float v)
 
 
 Noise::Noise(NoiseParams *np, int seed, int sx, int sy) {
-	int nlx, nly;
-	float ofactor;
-
-	//maximum possible spread value factor
-	ofactor = (float)(1 << (np->octaves - 1));
-
-	//noise lattice point count
-	//(int)(sz * spread * ofactor) is # of lattice points crossed due to length
-	// + 2 for the two initial endpoints
-	// + 1 for potentially crossing a boundary due to offset
-	nlx = (int)(sx * ofactor / np->spread.X) + 3;
-	nly = (int)(sy * ofactor / np->spread.Y) + 3;
-
-	this->np   = np;
-	this->seed = seed;
-	this->sx   = sx;
-	this->sy   = sy;
-	this->sz   = 1;
-	this->noisebuf = new float[nlx * nly];
-	this->buf      = new float[sx * sy];
-	this->result   = new float[sx * sy];
+	init(np, seed, sx, sy, 1);
 }
 
 
 Noise::Noise(NoiseParams *np, int seed, int sx, int sy, int sz) {
-	int nlx, nly, nlz;
-	float ofactor;
+	init(np, seed, sx, sy, sz);
+}
 
-	ofactor = (float)(1 << (np->octaves - 1));
-	nlx = (int)(sx * ofactor / np->spread.X) + 3;
-	nly = (int)(sy * ofactor / np->spread.Y) + 3;
-	nlz = (int)(sz * ofactor / np->spread.Z) + 3;
 
+void Noise::init(NoiseParams *np, int seed, int sx, int sy, int sz) {
 	this->np   = np;
 	this->seed = seed;
 	this->sx   = sx;
 	this->sy   = sy;
 	this->sz   = sz;
-	this->noisebuf = new float[nlx * nly * nlz];
+
+	this->noisebuf = NULL;
+	resizeNoiseBuf(sz > 1);
+
 	this->buf      = new float[sx * sy * sz];
 	this->result   = new float[sx * sy * sz];
 }
@@ -321,6 +301,58 @@ Noise::~Noise() {
 }
 
 
+void Noise::setSize(int sx, int sy) {
+	setSize(sx, sy, 1);
+}
+
+
+void Noise::setSize(int sx, int sy, int sz) {
+	this->sx = sx;
+	this->sy = sy;
+	this->sz = sz;
+
+	resizeNoiseBuf(sz > 1);
+
+	delete[] buf;
+	delete[] result;
+}
+
+
+void Noise::setSpreadFactor(v3f spread) {
+	this->np->spread = spread;
+
+	resizeNoiseBuf(sz > 1);
+}
+
+
+void Noise::setOctaves(int octaves) {
+	this->np->octaves = octaves;
+
+	resizeNoiseBuf(sz > 1);
+}
+
+
+void Noise::resizeNoiseBuf(bool is3d) {
+	int nlx, nly, nlz;
+	float ofactor;
+
+	//maximum possible spread value factor
+	ofactor = (float)(1 << (np->octaves - 1));
+
+	//noise lattice point count
+	//(int)(sz * spread * ofactor) is # of lattice points crossed due to length
+	// + 2 for the two initial endpoints
+	// + 1 for potentially crossing a boundary due to offset
+	nlx = (int)(sx * ofactor / np->spread.X) + 3;
+	nly = (int)(sy * ofactor / np->spread.Y) + 3;
+	nlz = is3d ? (int)(sz * ofactor / np->spread.Z) + 3 : 1;
+
+	if (noisebuf)
+		delete[] noisebuf;
+	noisebuf = new float[nlx * nly * nlz];
+}
+
+
 /*
  * NB:  This algorithm is not optimal in terms of space complexity.  The entire
  * integer lattice of noise points could be done as 2 lines instead, and for 3D,
@@ -344,7 +376,6 @@ void Noise::gradientMap2D(float x, float y, float step_x, float step_y, int seed
 	orig_u = u;
 
 	//calculate noise point lattice
-
 	nlx = (int)(u + sx * step_x) + 2;
 	nly = (int)(v + sy * step_y) + 2;
 	index = 0;
diff --git a/src/noise.h b/src/noise.h
index 0ab162b7..15df5c25 100644
--- a/src/noise.h
+++ b/src/noise.h
@@ -85,6 +85,13 @@ public:
 	Noise(NoiseParams *np, int seed, int sx, int sy, int sz);
 	~Noise();
 
+	void init(NoiseParams *np, int seed, int sx, int sy, int sz);
+	void setSize(int sx, int sy);
+	void setSize(int sx, int sy, int sz);
+	void setSpreadFactor(v3f spread);
+	void setOctaves(int octaves);
+	void resizeNoiseBuf(bool is3d);
+
 	void gradientMap2D(
 		float x, float y,
 		float step_x, float step_y,
-- 
2.30.2