Re: Multidimensional array member initialization

From:
"io_x" <a@b.c.invalid>
Newsgroups:
comp.lang.c++
Date:
Sun, 10 Jan 2010 11:09:35 +0100
Message-ID:
<4b49a5c2$0$824$4fafbaef@reader5.news.tin.it>
"io_x" <a@b.c.invalid> ha scritto nel messaggio
news:4b48f314$0$1110$4fafbaef@reader2.news.tin.it...

What about this?
Is not this better than using "vector"?
-------
#include <iostream>
#include <cstdlib>
#include <stdint.h>

#define u8 uint8_t
#define i8 int8_t
#define u32 uint32_t
#define i32 int32_t
// float 32 bits
#define f32 float
#define f64 double

#define S sizeof
#define R return
#define P printf
#define F for

using namespace std;

template <typename T> class Image{
public:
  u32 height;
  u32 width;
  T* pxs;

  Image(i32 h, i32 w)
  {i32 i, g;

   height=0; width=0; pxs=0;
   if(w<=0||h<=0) return;
   g =h*S(T);
   if(g<=0) return;
   g*=w;
   if(g<=0) return;
   cout << "Size=" << g << "\n";
   pxs=(T*) malloc(g);
   if(pxs==0) return;
   height=h; width=w;
  }

  ~Image(){free(pxs);}

  T& v(int h, int w)
    {return *(pxs+w+h*width);}

  int fill (T& color)
  {u32 x, y;
   if(pxs==0) R 0;
   for(x=0; x<height; ++x)
     {for(y=0; y<width; ++y)
              (*this).v(x,y)=color;
     }
   R 1;
  }

  int fill1(T& color)
  {u32 x, end;
   T *p;
   if(pxs==0) R 0;
   p=pxs;
   end=height*width;
   for(x=0; x<end; ++x, ++p)
           *p=color;
   R 1;
  }

class Indexer{
  public:
  T* data;
  Indexer(T* dat) : data(dat){}
  T& operator[](int x){return data[x];}
};

  // img[y] is Indexer
  // img[y][x] is *&T
  Indexer operator[](int y)
    {return Indexer(pxs+y*width);}

};

struct Color3d{f32 r, g, b;};
struct Color3d1{f64 r, g, b;};

int main(void)
{Color3d1 h={0.78373, 0.1383, 1-0.78373-0.1383};
 Image<Color3d1> g(768, 1024);

 cout << "Inizio\n";
 if(g.pxs==0)
    {cout << "Error\n"; return 0;}

 g.fill1(h);
 cout << "(r,g,b)==(" << g.v(0,0).r << ", "
                      << g.v(0,0).g << ", "
                      << g.v(767,1024).b << ")\n";
 cout << "g[767][1024].b==" << g[767][1024].b << "\n";
 cout << "g[767][1023].b==" << g[767][1023].b << "\n";
 cout << "end\n";
 R 0;
}
--------
Size=18874368
Inizio
(r,g,b)==(0.78373, 0.1383, 0)
g[767][1024].b==0
g[767][1023].b==0.07797
end

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