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/*
* $ProjectName$
* $ProjectRevision$
* -----------------------------------------------------------
* $Id$
* -----------------------------------------------------------
*
* $Author$
*
* Description:
*
* Copyright 2002-2003 Tor-Einar Jarnbjo
* -----------------------------------------------------------
*
* Change History
* -----------------------------------------------------------
* $Log$
* Revision 1.1 2005/07/11 15:42:36 hcl
* Songdb java version, source. only 1.5 compatible
*
* Revision 1.1.1.1 2004/04/04 22:09:12 shred
* First Import
*
* Revision 1.3 2003/04/10 19:49:04 jarnbjo
* no message
*
* Revision 1.2 2003/03/16 01:11:12 jarnbjo
* no message
*
*
*/
package de.jarnbjo.vorbis;
final public class Util {
public static final int ilog(int x) {
int res=0;
for(; x>0; x>>=1, res++);
return res;
}
public static final float float32unpack(int x) {
float mantissa=x&0x1fffff;
float e=(x&0x7fe00000)>>21;
if((x&0x80000000)!=0) {
mantissa=-mantissa;
}
return mantissa*(float)Math.pow(2.0, e-788.0);
}
public static final int lookup1Values(int a, int b) {
int res=(int)Math.pow(Math.E, Math.log(a)/b);
return intPow(res+1, b)<=a?res+1:res;
}
public static final int intPow(int base, int e) {
int res=1;
for(; e>0; e--, res*=base);
return res;
}
public static final boolean isBitSet(int value, int bit) {
return (value&(1<<bit))!=0;
}
public static final int icount(int value) {
int res=0;
while(value>0) {
res+=value&1;
value>>=1;
}
return res;
}
public static final int lowNeighbour(int[] v, int x) {
int max=-1, n=0;
for(int i=0; i<v.length && i<x; i++) {
if(v[i]>max && v[i]<v[x]) {
max=v[i];
n=i;
}
}
return n;
}
public static final int highNeighbour(int[] v, int x) {
int min=Integer.MAX_VALUE, n=0;
for(int i=0; i<v.length && i<x; i++) {
if(v[i]<min && v[i]>v[x]) {
min=v[i];
n=i;
}
}
return n;
}
public static final int renderPoint(int x0, int x1, int y0, int y1, int x) {
int dy=y1-y0;
int ady=dy<0?-dy:dy;
int off=(ady*(x-x0))/(x1-x0);
return dy<0?y0-off:y0+off;
}
public static final void renderLine(final int x0, final int y0, final int x1, final int y1, final float[] v) {
final int dy=y1-y0;
final int adx=x1-x0;
final int base=dy/adx;
final int sy=dy<0?base-1:base+1;
int x=x0;
int y=y0;
int err=0;
final int ady=(dy<0?-dy:dy)-(base>0?base*adx:-base*adx);
v[x]*=Floor.DB_STATIC_TABLE[y];
for(x=x0+1; x<x1; x++) {
err+=ady;
if(err>=adx) {
err-=adx;
v[x]*=Floor.DB_STATIC_TABLE[y+=sy];
}
else {
v[x]*=Floor.DB_STATIC_TABLE[y+=base];
}
}
}
}
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