ZBar bar code reader . http://zbar.sourceforge.net/ ZBar is licensed under the GNU LGPL 2.1 to enable development of both open source and commercial projects.
Dependents: GR-PEACH_Camera_in_barcode levkov_ov7670
isaac.c
00001 /*Written by Timothy B. Terriberry (tterribe@xiph.org) 1999-2009 public domain. 00002 Based on the public domain implementation by Robert J. Jenkins Jr.*/ 00003 #include <float.h> 00004 #include <math.h> 00005 #include <string.h> 00006 #include "isaac.h" 00007 00008 00009 00010 #define ISAAC_MASK (0xFFFFFFFFU) 00011 00012 00013 00014 static void isaac_update(isaac_ctx *_ctx){ 00015 unsigned *m; 00016 unsigned *r; 00017 unsigned a; 00018 unsigned b; 00019 unsigned x; 00020 unsigned y; 00021 int i; 00022 m=_ctx->m; 00023 r=_ctx->r; 00024 a=_ctx->a; 00025 b=_ctx->b+(++_ctx->c)&ISAAC_MASK; 00026 for(i=0;i<ISAAC_SZ/2;i++){ 00027 x=m[i]; 00028 a=(a^a<<13)+m[i+ISAAC_SZ/2]&ISAAC_MASK; 00029 m[i]=y=m[(x&ISAAC_SZ-1<<2)>>2]+a+b&ISAAC_MASK; 00030 r[i]=b=m[y>>ISAAC_SZ_LOG+2&ISAAC_SZ-1]+x&ISAAC_MASK; 00031 x=m[++i]; 00032 a=(a^a>>6)+m[i+ISAAC_SZ/2]&ISAAC_MASK; 00033 m[i]=y=m[(x&ISAAC_SZ-1<<2)>>2]+a+b&ISAAC_MASK; 00034 r[i]=b=m[y>>ISAAC_SZ_LOG+2&ISAAC_SZ-1]+x&ISAAC_MASK; 00035 x=m[++i]; 00036 a=(a^a<<2)+m[i+ISAAC_SZ/2]&ISAAC_MASK; 00037 m[i]=y=m[(x&ISAAC_SZ-1<<2)>>2]+a+b&ISAAC_MASK; 00038 r[i]=b=m[y>>ISAAC_SZ_LOG+2&ISAAC_SZ-1]+x&ISAAC_MASK; 00039 x=m[++i]; 00040 a=(a^a>>16)+m[i+ISAAC_SZ/2]&ISAAC_MASK; 00041 m[i]=y=m[(x&ISAAC_SZ-1<<2)>>2]+a+b&ISAAC_MASK; 00042 r[i]=b=m[y>>ISAAC_SZ_LOG+2&ISAAC_SZ-1]+x&ISAAC_MASK; 00043 } 00044 for(i=ISAAC_SZ/2;i<ISAAC_SZ;i++){ 00045 x=m[i]; 00046 a=(a^a<<13)+m[i-ISAAC_SZ/2]&ISAAC_MASK; 00047 m[i]=y=m[(x&ISAAC_SZ-1<<2)>>2]+a+b&ISAAC_MASK; 00048 r[i]=b=m[y>>ISAAC_SZ_LOG+2&ISAAC_SZ-1]+x&ISAAC_MASK; 00049 x=m[++i]; 00050 a=(a^a>>6)+m[i-ISAAC_SZ/2]&ISAAC_MASK; 00051 m[i]=y=m[(x&ISAAC_SZ-1<<2)>>2]+a+b&ISAAC_MASK; 00052 r[i]=b=m[y>>ISAAC_SZ_LOG+2&ISAAC_SZ-1]+x&ISAAC_MASK; 00053 x=m[++i]; 00054 a=(a^a<<2)+m[i-ISAAC_SZ/2]&ISAAC_MASK; 00055 m[i]=y=m[(x&ISAAC_SZ-1<<2)>>2]+a+b&ISAAC_MASK; 00056 r[i]=b=m[y>>ISAAC_SZ_LOG+2&ISAAC_SZ-1]+x&ISAAC_MASK; 00057 x=m[++i]; 00058 a=(a^a>>16)+m[i-ISAAC_SZ/2]&ISAAC_MASK; 00059 m[i]=y=m[(x&ISAAC_SZ-1<<2)>>2]+a+b&ISAAC_MASK; 00060 r[i]=b=m[y>>ISAAC_SZ_LOG+2&ISAAC_SZ-1]+x&ISAAC_MASK; 00061 } 00062 _ctx->b=b; 00063 _ctx->a=a; 00064 _ctx->n=ISAAC_SZ; 00065 } 00066 00067 static void isaac_mix(unsigned _x[8]){ 00068 static const unsigned char SHIFT[8]={11,2,8,16,10,4,8,9}; 00069 int i; 00070 for(i=0;i<8;i++){ 00071 _x[i]^=_x[i+1&7]<<SHIFT[i]; 00072 _x[i+3&7]+=_x[i]; 00073 _x[i+1&7]+=_x[i+2&7]; 00074 i++; 00075 _x[i]^=_x[i+1&7]>>SHIFT[i]; 00076 _x[i+3&7]+=_x[i]; 00077 _x[i+1&7]+=_x[i+2&7]; 00078 } 00079 } 00080 00081 00082 void isaac_init(isaac_ctx *_ctx,const void *_seed,int _nseed){ 00083 const unsigned char *seed; 00084 unsigned *m; 00085 unsigned *r; 00086 unsigned x[8]; 00087 int i; 00088 int j; 00089 _ctx->a=_ctx->b=_ctx->c=0; 00090 m=_ctx->m; 00091 r=_ctx->r; 00092 x[0]=x[1]=x[2]=x[3]=x[4]=x[5]=x[6]=x[7]=0x9E3779B9; 00093 for(i=0;i<4;i++)isaac_mix(x); 00094 if(_nseed>ISAAC_SEED_SZ_MAX)_nseed=ISAAC_SEED_SZ_MAX; 00095 seed=(const unsigned char *)_seed; 00096 for(i=0;i<_nseed>>2;i++){ 00097 r[i]=seed[i<<2|3]<<24|seed[i<<2|2]<<16|seed[i<<2|1]<<8|seed[i<<2]; 00098 } 00099 if(_nseed&3){ 00100 r[i]=seed[i<<2]; 00101 for(j=1;j<(_nseed&3);j++)r[i]+=seed[i<<2|j]<<(j<<3); 00102 i++; 00103 } 00104 memset(r+i,0,(ISAAC_SZ-i)*sizeof(*r)); 00105 for(i=0;i<ISAAC_SZ;i+=8){ 00106 for(j=0;j<8;j++)x[j]+=r[i+j]; 00107 isaac_mix(x); 00108 memcpy(m+i,x,sizeof(x)); 00109 } 00110 for(i=0;i<ISAAC_SZ;i+=8){ 00111 for(j=0;j<8;j++)x[j]+=m[i+j]; 00112 isaac_mix(x); 00113 memcpy(m+i,x,sizeof(x)); 00114 } 00115 isaac_update(_ctx); 00116 } 00117 00118 unsigned isaac_next_uint32(isaac_ctx *_ctx){ 00119 if(!_ctx->n)isaac_update(_ctx); 00120 return _ctx->r[--_ctx->n]; 00121 } 00122 00123 /*Returns a uniform random integer less than the given maximum value. 00124 _n: The upper bound on the range of numbers returned (not inclusive). 00125 This must be strictly less than 2**32. 00126 Return: An integer uniformly distributed between 0 (inclusive) and _n 00127 (exclusive).*/ 00128 unsigned isaac_next_uint(isaac_ctx *_ctx,unsigned _n){ 00129 unsigned r; 00130 unsigned v; 00131 unsigned d; 00132 do{ 00133 r=isaac_next_uint32(_ctx); 00134 v=r%_n; 00135 d=r-v; 00136 } 00137 while((d+_n-1&ISAAC_MASK)<d); 00138 return v; 00139 } 00140
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