Rest of commit...

qw/source/noisetextures.c

@@ -0,0 +1,121 @@
+/*
+	noisetextures.c
+
+	Noise texture generators
+
+	noise_plasma
+	Copyright (C) 2001 Ragnvald `Despair` Maartmann-Moe IV.
+
+	noise_diamondsquare (originally fractalnoise)
+	Copyright (C) 2000 Forest `LordHavoc` Hale.
+
+	This program is free software; you can redistribute it and/or
+	modify it under the terms of the GNU General Public License
+	as published by the Free Software Foundation; either version 2
+	of the License, or (at your option) any later version.
+
+	This program is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY; without even the implied warranty of
+	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+
+	See the GNU General Public License for more details.
+
+	You should have received a copy of the GNU General Public License
+	along with this program; if not, write to:
+
+		Free Software Foundation, Inc.
+		59 Temple Place - Suite 330
+		Boston, MA  02111-1307, USA
+
+	$Id$
+*/
+
+#include <stdlib.h>
+
+#include "QF/mathlib.h"
+
+void
+noise_diamondsquare (unsigned char *noise, int size)
+{
+	int         x, y, g, g2, amplitude, min, max, size1 = size - 1;
+	int        *noisebuf;
+
+#define n(x,y) noisebuf[((y)&size1)*size+((x)&size1)]
+	noisebuf = calloc (size * size, sizeof (int));
+
+	amplitude = 32767;
+	g2 = size;
+	n (0, 0) = 0;
+	for (; (g = g2 >> 1) >= 1; g2 >>= 1) {
+		// subdivide, diamond-square algorythm (really this has little
+		// to do with squares)
+		// diamond
+		for (y = 0; y < size; y += g2)
+			for (x = 0; x < size; x += g2)
+				n (x + g, y + g) =
+					(n (x, y) + n (x + g2, y) + n (x, y + g2) +
+					 n (x + g2, y + g2)) >> 2;
+		// square
+		for (y = 0; y < size; y += g2)
+			for (x = 0; x < size; x += g2) {
+				n (x + g, y) =
+					(n (x, y) + n (x + g2, y) + n (x + g, y - g) +
+					 n (x + g, y + g)) >> 2;
+				n (x, y + g) =
+					(n (x, y) + n (x, y + g2) + n (x - g, y + g) +
+					 n (x + g, y + g)) >> 2;
+			}
+		// Brownian motion ( at every smaller level, random behavior )
+		amplitude >>= 1;
+		for (y = 0; y < size; y += g)
+			for (x = 0; x < size; x += g)
+				n (x, y) += (rand () & amplitude);
+	}
+	// find range of noise values
+	min = max = 0;
+	for (y = 0; y < size; y++)
+		for (x = 0; x < size; x++) {
+			if (n (x, y) < min)
+				min = n (x, y);
+			if (n (x, y) > max)
+				max = n (x, y);
+		}
+	max -= min;
+	// normalize noise and copy to output
+	for (y = 0; y < size; y++)
+		for (x = 0; x < size; x++)
+			*noise++ = (n (x, y) - min) * 255 / max;
+	free (noisebuf);
+	#undef n
+}
+
+
+void
+noise_plasma (unsigned char *noise, int size)
+{
+	int a, b, c, d, i, j, k;
+
+	if (128 >= size)
+		d = 64 / size;
+	else
+		d = -size / 64;
+
+	memset(noise, 128, sizeof (*noise));
+
+	for (i=size; i > 0; i/=2) {
+		for (j=0; j < size; j+=i) {
+			for (k=0; k < size; k+=i) {
+				if (d>=0)
+				        c = i * d;
+				else
+					c = -i / d;
+
+				c=lhrandom(-c, c);
+
+				for (a=j; a < j+i; a++)
+					for (b=k; b < k+i; b++)
+						noise[a*size+b] += c;
+			}
+		}
+	}
+}