File talk:Color complex plot2.jpg

compiling errors

Dev-C++

Hi. Thx for nice image and src code. I'm trying to compile it under Dev-c++. Here is my compile log:

Compiler: Default compiler
Building Makefile: "D:\doc\programming\cpp\prog\complex\cp2\Makefile.win"
Executing  make clean
rm -f main.o  Project1.exe
g++.exe -c main.cpp -o main.o -I"lib/gcc/mingw32/3.4.2/include"  -I"include"   
main.cpp: In function `void SetHSV(double, double, double, unsigned char*)':
main.cpp:12: warning: converting to `int' from `double'
main.cpp: In function `int main()':
main.cpp:77: error: invalid conversion from `unsigned char*' to `const char*'
main.cpp:77: error:   initializing argument 1 of `std::basic_ostream<_CharT, _Traits>& std::basic_ostream<_CharT, _Traits>::write(const _CharT*, std::streamsize) 
[with _CharT = char, _Traits = std::char_traits<char>]'

What can I change to compile it ?

Regards

--Adam majewski (talk) 16:24, 18 May 2010 (UTC)

g++ & Linux

g++ c.cpp
c.cpp: In function ‘int main()’:
c.cpp:77: error: invalid conversion from ‘unsigned char*’ to ‘const char*’
c.cpp:77: error:   initializing argument 1 of ‘std::basic_ostream<_CharT, _Traits>& std::basic_ostream<_CharT, _Traits>::write(const _CharT*, std::streamsize) 
[with  _CharT  = char, _Traits = std::char_traits<char>]’

--Adam majewski (talk) 08:09, 7 May 2011 (UTC)

Src

This code works for me ( Dev-C++ ). Changes are marked by comment signs.

#include <complex>
#include <fstream>
 
using namespace std;

void SetHSV(double h, double s, double v,  char _color[3]) //
{
  double r=0, g=0, b=0;
  if(s==0)
    r = g = b = v;
  else {
    h /= 60;
    int i = (int) floor(h); /// 
    double f = h - i;
    double p = v*(1-s);
    double q = v*(1-s*f);
    double t = v*(1-s*(1-f));
    
    switch(i){
      case 0: r=v; g=t; b=p; break;
      case 1: r=q; g=v; b=p; break;
      case 2: r=p; g=v; b=t; break;
      case 3: r=p; g=q; b=v; break;
      case 4: r=t; g=p; b=v; break;
      case 5: r=v; g=p; b=q; break;
    }
  }
  int c;
  c = int(256*r); if(c>255) c = 255; _color[0] = c; //
  c = int(256*g); if(c>255) c = 255; _color[1] = c; //
  c = int(256*b); if(c>255) c = 255; _color[2] = c; //
}

complex<double> fun(complex<double>& c ){
  const complex<double> i(0., 1.);
  return (pow(c,2) - 1.) * pow(c -2. -i, 2) / (pow(c, 2) + 2. + 2. * i);
}
 
int main(){
  const int dimx = 800; const int dimy = 800;
  const double rmi = -3; const double rma =  3;
  const double imi = -3; const double ima =  3;

  ofstream f("complex.ppm", ios::binary);
  f << "P6" << endl
    << dimx << " " << dimy << endl
    << "255" << endl;

  for(int j=0; j < dimy; ++j){
    double im = ima - (ima -imi) *j /(dimy -1);
    for(int i=0; i < dimx; ++i){    
      double re = rmi +(rma -rmi) *i /(dimx -1);
      complex<double> c(re, im);
      complex<double> v = fun(c); 
      double a = arg(v)*180/M_PI;
      if(a < 0) a += 360;
      
      double m = abs(v);
      double ranges;
      double rangee = 1;

      while(m>rangee){
          ranges = rangee;
          rangee *= M_E;
      }

      double k   = (m-ranges)/(rangee-ranges);
      double sat = k < 0.5 ? 1-2.8*k : 2.8*k-1.1;
      if(sat < 0.3) sat = 0.3;
      else if(sat > 1) sat = 1;

      double val = k < 0.5 ? 1.4-1.6*k : 1.6*k-0.6;
      if(val < 0.6) val = 0.6;
      else if(val > 1) val = 1;

       char color[3]; //
      SetHSV(a,sat,val,color);
      f.write(color,3);
    }
  }
  return 0;
}