[C++] 几行代码生成漂亮图片，数学家就是牛！

信息获得处：http://news.cnblogs.com/n/501488/

分形：http://baike.baidu.com/subview/83243/11213590.htm?fr=aladdin

代码：[采用宏定义的来选择绘制不同的图，所以把最后两个给注释掉了，因为宏冲突，想自己试试可以单独编译运行]

PS:生成的图片是ppm格式的要用格式工厂之类的软件进行转换，也可以自己在程序里直接把图片生成bmp或者其他格式的~

 // NOTE: compile with g++ filename.cpp -std=c++11
 #include <iostream>
 #include <cmath>
 #include <cstdlib>
 #define DIM 1024
 #define DM1 (DIM-1)
 #define _sq(x) ((x)*(x)) // square
 #define _cb(x) abs((x)*(x)*(x)) // absolute value of cube
 #define _cr(x) (unsigned char)(pow ((x),1.0/3.0)) // cube root
 #define F

 unsigned char GR (int,int);
 unsigned char BL (int,int);

 unsigned char RD (int i,int j){
     #ifdef A
     return (char)(_sq(cos(atan2(j-,i-)/))*);
     #endif

     #ifdef B
     #define r(n) (rand ()%n)
     static char c[][];
     return!c[i][j]?c[i][j]=!r()?r():RD ((i+r())%,(j+r())%):c[i][j];
     #endif

     #ifdef C
     float x=,y=;
     int k;
     for(k=;k++<;){
         float a=x*x-y*y+ (i-768.0)/;
         y=*x*y+ (j-512.0)/;
         x=a;
         if(x*x+y*y>)break;
     }
     return log (k)*;
     #endif

     #ifdef D
     double a=,b=,c,d,n=;
     while((c=a*a)+(d=b*b)<&&n++<){
         b=*a*b+j*8e--.;
         a=c-d+i*8e-+.;
     }
     return *pow ((n-)/,.);
     #endif

     #ifdef E
     static double k;
     k+=rand ()/./RAND_MAX;
     int l=k;
     l%=;
     return l>?-l:l;
     #endif

     #ifdef F
     float s=./(j+);
     float y=(j+sin ((i*i+_sq (j-)*)/./DIM)*)*s;
     return (int((i+DIM)*s+y)%+int((DIM*-i)*s+y)%)*;
     #endif
 /*
     #ifdef G
     #define D DIM
     #define M m[(x+D+ (d==0)-(d==2))%D][(y+D+ (d==1)-(d==3))%D]
     #define R rand ()%D
     #define B m[x][y]
     return(i+j)?256-(BL (i,j))/2:0;
     #endif
 */
 /*
     #ifdef H
     #define A float a=0,b,k,r,x
     #define B int e,o
     #define C (x) x>255?255:x
     #define R return #define D DIM
     R BL (i,j)*(D-i)/D;
     #endif
 */
     return ;
 }
 unsigned char GR (int i,int j){
     #ifdef A
     return (char)(_sq (cos (atan2(j-,i-)/-*acos (-)/))*);
     #endif

     #ifdef B
     static char c[][];
     return!c[i][j]?c[i][j]=!r()?r():GR ((i+r())%,(j+r())%):c[i][j];
     #endif

     #ifdef C
     float x=,y=;
     int k;
     for(k=;k++<;){
         float a=x*x-y*y+ (i-768.0)/;
         y=*x*y+ (j-512.0)/;
         x=a;
         if(x*x+y*y>)break;
     }
     return log (k)*;
     #endif

     #ifdef D
     double a=,b=,c,d,n=;
     while((c=a*a)+(d=b*b)<&&n++<){
         b=*a*b+j*8e--.;
         a=c-d+i*8e-+.;
     }
     return *pow ((n-)/,.);
     #endif

     #ifdef E
     static double k;
     k+=rand ()/./RAND_MAX;
     int l=k;
     l%=;
     return l>?-l:l;
     #endif

     #ifdef F
     float s=./(j+);
     float y=(j+sin ((i*i+_sq (j-)*)/./DIM)*)*s;
     return (int(*((i+DIM)*s+y))%+int(*((DIM*-i)*s+y))%)*;
     #endif
 /*
     #ifdef G
     #define A
     static int m[D][D],e,x,y,d,c[4],f,n;
     if (i+j<1){
         for (d=D*D;d;d--){
             m[d%D][d/D]=d%6?0:rand ()%2000?1:255;
         }
         for (n=1 return RD (i,j);
     #endif
 */
 /*
     #ifdef H
     #define E DM1
     #define F static float
     #define G for (
     #define H r=a*1.6/D+2.4;x=1.0001*b/D
     R BL (i,j)*(D-j/2)/D;
     #endif
 */
     return ;
 }
 unsigned char BL (int i,int j){
     #ifdef A
     return (char)(_sq (cos (atan2(j-,i-)/+*acos (-)/))*);
     #endif

     #ifdef B
     static char c[][];
     return!c[i][j]?c[i][j]=!r()?r():BL((i+r())%,(j+r())%):c[i][j];
     #endif

     #ifdef C
     float x=,y=;
     int k;
     for(k=;k++<;){
         float a=x*x-y*y+ (i-768.0)/;
         y=*x*y+ (j-512.0)/;
         x=a;
         if(x*x+y*y>)break;
     }
     return -log (k)*;
     #endif

     #ifdef D
     double a=,b=,c,d,n=;
     while((c=a*a)+(d=b*b)<&&n++<){
         b=*a*b+j*8e--.;
         a=c-d+i*8e-+.;
     }
     return *pow ((n-)/,.);
     #endif

     #ifdef E
         static double k;
         k+=rand ()/./RAND_MAX;
         int l=k;
         l%=;
         return l>?-l:l;
     #endif    

     #ifdef F
     float s=./(j+);
     float y=(j+sin ((i*i+_sq (j-)*)/./DIM)*)*s;
     return (int(*((i+DIM)*s+y))%+int(*((DIM*-i)*s+y))%)*;
     #endif
 /*
     #ifdef G
     A;n;n++){
         x=R;y=R;
         if(B==1){
             f=1;
             for(d=0;d<4;d++){
                 c[d]=M;
                 f=f<c[d]?c[d]:f;
             }
             if(f>2){B=f-1;}
             else{
                 ++e%=4;
                 d=e;
                 if(!c[e]){
                     B=0;M=1;
                 }}}}}
     return m[i][j];
     #endif
 */
 /*
     #ifdef H
     F c[D][D];
     if(i+j<1){A;B;G;a<D;a+=0.1){G b=0;b<D;b++){H;G k=0;k<D;k++){x=r*x*(1-x);
     if(k>D/2){e=a;o=(E*x);c[e][o]+=0.01;}}}}}
     R C (c[j][i])*i/D;
     #endif
 */

     return ;
 }

 void pixel_write (int,int);
 FILE *fp;
 int main (){
     fp = fopen ("MathPic.ppm","wb");
     fprintf (fp, "P6\n%d %d\n255\n", DIM, DIM);
     for(int j=;j<DIM;j++)
         for(int i=;i<DIM;i++)
             pixel_write (i,j);
     fclose (fp);
     return ;
 }
 void pixel_write (int i, int j){
     static unsigned char color[];
     color[] = RD (i,j)&;
     color[] = GR (i,j)&;
     color[] = BL (i,j)&;
     fwrite (color, , , fp);
 }