Re: Multidimensional array member initialization

"Gert-Jan de Vos" <gert-jan.de.vos@onsneteindhoven.nl> ha scritto nel messaggio
news:4a41375a-4445-4ffb-bf67-ebd403d600fe@j5g2000yqm.googlegroups.com...
On Jan 7, 10:40 am, "olivier.scalb...@algosyn.com"
<olivier.scalb...@algosyn.com> wrote:


What about this?

---------------
; nasmw -fobj this.asm
; bcc32 -v that.cpp this.obj
section _DATA use32 public class=DATA

global @Image@fill2$qr7Color3d

section _TEXT use32 public class=CODE

;
; 0j, 4i, 8ra, 12&This_i, 16&Color3d_j
          align 4
@Image@fill2$qr7Color3d:
          push esi
          push edi
          mov esi, dword[esp+ 12]
          cmp esi, 0
          jne .1
..e: mov eax, 0
          stc
          jmp short .z
..1: mov eax, [esi]
          mov ecx, [esi+4] ;eax=h, ecx=w
          mul ecx
          cmp edx, 0
          jne .e
          cmp eax, 0
          jl .e
          mov ecx, eax ;ecx=h*w
          mov edi, [esi+8]
          cmp edi, 0
          je .e ;edi=pxs
          mov esi, dword[esp+ 16]
          mov eax, [esi]
          mov edx, [esi+4]
          mov esi, [esi+8]
..2: mov [edi], eax
          mov [edi+4], edx
          mov [edi+8], esi
          add edi, 12
          loop .2
          mov eax, 1
          clc
..z:
          pop edi
          pop esi
          ret
----------------------
#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;

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

class Image{
public:
  u32 height;
  u32 width;
  Color3d* pxs;

  Image(i32 h, i32 w)
  {i32 i, g;

   height=0; width=0; pxs=0;
   if(w<=0||h<=0) return;
   g =h*S(Color3d);
   if(g<=0) return;
   g*=w;
   if(g<=0) return;
   cout << "Size=" << g << "\n";
   pxs=(Color3d*) malloc(g);
   if(pxs==0) return;
   height=h; width=w;
  }

  ~Image(){free(pxs);}

  Color3d& v(int h, int w)
    {return *(pxs+w+h*width);}

  int fill (Color3d& 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(Color3d& color)
  {u32 x, end;
   Color3d *p;
   if(pxs==0) R 0;
   p=pxs;
   end=height*width;
   for(x=0; x<end; ++x, ++p)
           *p=color;
   R 1;
  }

int fill2(Color3d& color);

class Indexer{
  public:
  Color3d* data;
  Indexer(Color3d* dat) : data(dat){}
  Color3d& operator[](int x){return data[x];}
};

  // img[y] is Indexer
  // img[y][x] is *&Color3d
  Indexer operator[](int y)
    {return Indexer(pxs+y*width);}

};

int main(void)
{Color3d h={0.78373, 0.1383, 1-0.78373-0.1383};
 Image g(768, 1024);

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

 g.fill2(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;
}