SDK写的一个画树（花）程序

[img]C:\Documents and Settings\All Users\Documents\My Pictures\示例图片\Sunset.jpg[/img]从国外一个网站上抄来的，是用C+SDK写的，惭愧看不大懂，转成D版本先：

module flower;

import std.stdio;
import std.string;
import std.conv;
import std.math;
import std.algorithm;
import core.runtime;
//import core.stdc.math;

import win32.windows;

import samsTools.utils:toCstring;


const double Pi=3.1415926;

static TCHAR[256] szAppName=cast(char[256])"flower";
static const char[256] caption=cast(char[256])"SDK Flower Example";

int xo=320,yo=860;
int r=0,g=0,b=0;
HDC hddc;

float alfa0,beta0,gamma0,Riduzione;
struct elem2 { float x; float y; };
struct elem3 { float x; float y; float z; };

float sen (float r)
{ return sin(r); }

int Round (float nf)
{ int k;
  float t,f;

  k=cast(int)nf; t=cast(float)k;
  f=nf-t;
  if (f>0.50) k++;
  if (f<-0.50) k--;
  return k;
}

void putpixel (int x,int y)
{
	SetPixel(hddc,x,y,RGB(cast(ubyte)r,cast(ubyte)g,cast(ubyte)b));
}

void setcolor (int col)
{ if (col==15) {r=0;g=0;b=255;}
  if (col==14) {r=255;g=0;b=0;}
  if (col==13) {r=0;g=255;b=0;}
  if (col==12) {r=255;g=0;b=0;}
  if (col==11) {r=0;g=255;b=255;}
  if (col==10) {r=0;g=255;b=0;}
  if (col==9) {r=0;g=0;b=255;}
  if (col==8) {r=255;g=0;b=0;}
  if (col==7) {r=0;g=100;b=0;}
}

void swap(int *a, int *b)
{ int t;
  t=*b; *b=*a; *a=t;
}

void dasline (int x1,int y1,int x2,int y2)
{ int x,dx,incx;
  int y,dy,incy;
  int s,i,pxy,sw;

  dx=abs(x2-x1);
  dy=abs(y2-y1);

  if (x1>x2) incx=-1; else incx=1;
  if (y1>y2) incy=-1; else incy=1;

  if (dy>dx) { swap(&dx,&dy); swap(&incx,&incy); swap(&x1,&y1); sw=1; }
  else sw=0;

  pxy=dx;
  dx=dx-dy;
  s=dy;
  x=x1; y=y1;
  if (sw) putpixel(y,x); else  putpixel(x,y);
  for (i=0;i<pxy;i++)
  { x+=incx;
    if (s>0) {s-=dx; y+=incy;} else {s+=dy;}
    if (sw) putpixel(y,x); else putpixel(x,y);
  }
}

void RAss (elem3 *Vt, float xo,  float yo,  float zo,
			     float alfa,float beta,float gamma)
{ float x2,y2,z2,x1,y1,z1,x,y,z;

  x2=Vt.x ; y2=Vt.y ; z2=Vt.z ;
  x1=x2*cos(gamma)-z2*sen(gamma);
  z1=x2*sen(gamma)+z2*cos(gamma);
  z=z1*cos(beta)-y2*sen(beta)+zo;
  y1=z1*sen(beta)+y2*cos(beta);
  x=x1*cos(alfa)-y1*sen(alfa)+xo;
  y=x1*sen(alfa)+y1*cos(alfa)+yo;
  Vt.x=x; Vt.y=y; Vt.z=z;
}
void Rids (elem3 *vt3,elem2 *vt2)
{ float fi,yp;

  vt2.x=-vt3.z*sen(Pi/4)+vt3.x*cos(Pi/4);
  fi=0.5;
  yp=-vt3.x*sen(fi)+vt3.y*cos(fi);
  vt2.y=-vt3.z*sen(fi)+yp*cos(fi);
}
void Co(elem2 *vp, elem2 *vf)
{ int X1,X2,Y1,Y2;
  X1=xo+cast(int)(vp.x); Y1=yo-cast(int)(vp.y);
  X2=xo+cast(int)(vf.x); Y2=yo-cast(int)(vf.y);
  dasline(X1,Y1,X2,Y2);
}
void Disegna (float R,float Xo,float Yo,float Zo,
	      float alfa,float beta,float gamma)
{ int i;
  elem2 V2[3];
  elem3 V3[3];

  V3[1].x=0 ; V3[1].y=R ; V3[1].z=0 ;
  V3[2].x=0 ; V3[2].y=0 ; V3[2].z=0;
  for (i=1;i<3;i++) RAss (&V3[i],Xo,Yo,Zo,alfa,beta,gamma);
  for (i=1;i<3;i++) Rids (&V3[i],&V2[i]);
  Co (&V2[1],&V2[2]);
}
void Frattale (int n, float R,float Xrif,float Yrif,float Zrif,
		      float Rifa,float Rifb,float Rifg)
{ int rip;
  float R1,PasAlfa,PasBeta,PasGamma;
  elem3 pv;
  elem3 V3[3];

  if (n<9)
  { V3[1].x=0 ; V3[1].y=R ; V3[1].z=0 ;
    V3[2].x=R ; V3[2].y=0 ; V3[2].z=0;
    R1=R/Riduzione;
    for (rip=1;rip<4;rip++)
    { pv.x=V3[1].x; pv.y=V3[1].y; pv.z=V3[1].z;
      switch (rip)
      { case 1 : PasAlfa=Rifa+alfa0; PasBeta=Rifb+beta0;
		 PasGamma=Rifg+gamma0;
		 break;
	case 2 : PasAlfa=Rifa-alfa0; PasBeta=Rifb-beta0;
		 PasGamma=Rifg-gamma0;
		 break;
	case 3 : PasAlfa=Rifa+alfa0; PasBeta=Rifb-beta0;
		 PasGamma=Rifg-gamma0;
      }
      if (n<2) setcolor(10);
      if ((n>1) && (n<8)) setcolor(15);
      if (n==8) setcolor(12);
      RAss (&pv,Xrif,Yrif,Zrif,Rifa,Rifb,Rifg);
      Disegna(R1,pv.x,pv.y,pv.z,PasAlfa,PasBeta,PasGamma);
      Frattale(n+1,R1,pv.x,pv.y,pv.z,PasAlfa,PasBeta,PasGamma);
    }
  }
}

void fracto()
{
  setcolor(10);
  Riduzione=2.0; alfa0=-0.3; beta0=0.2; gamma0=0.1;
  Frattale(0,500,0,0,0,0,0,0);
}


extern(Windows)
int WinMain(HINSTANCE hInstance,HINSTANCE hPrevInstance,PSTR szCmdLine,int iCmdShow)
{
	//initialize D runtime
	Runtime.initialize;
	runModuleUnitTests;

	HWND hwnd;
	MSG msg;
	WNDCLASS wndclass;

	wndclass.style=CS_HREDRAW|CS_VREDRAW;
	wndclass.lpfnWndProc=&WndProc;
	wndclass.cbClsExtra=0;
	wndclass.cbWndExtra=0;
	wndclass.hInstance=hInstance;
	wndclass.hIcon=LoadIcon(null,IDI_APPLICATION);
	wndclass.hCursor=LoadCursor(null,IDC_ARROW);
	wndclass.hbrBackground=cast(HBRUSH)(COLOR_3DFACE+1);//GetStockObject(WHITE_BRUSH)
	wndclass.lpszMenuName=null;
	wndclass.lpszClassName=cast(const(char*))szAppName;

	if(! RegisterClass(&wndclass))
	{
		MessageBox(null,toCstring("Program requires Windows NT!"),
			cast(char*)szAppName,MB_ICONERROR);
		return 0;
	}

	hwnd=CreateWindow(szAppName.ptr,caption.ptr,
		WS_OVERLAPPEDWINDOW/*|WS_VSCROLL|WS_HSCROLL*/,
		CW_USEDEFAULT,CW_USEDEFAULT,
		CW_USEDEFAULT,CW_USEDEFAULT,
		null,null,hInstance,null);

	ShowWindow(hwnd,iCmdShow);
	UpdateWindow(hwnd);

	while(GetMessage(&msg,null,0,0)>0)
	{
		TranslateMessage(&msg);
		DispatchMessage(&msg);
	}

	//dispose D runtime:
	Runtime.terminate;

	
	return msg.wParam;
	
}

extern(Windows)
LRESULT WndProc(HWND hwnd,UINT message,WPARAM wParam,LPARAM lParam)
{
	HDC hdc;
	PAINTSTRUCT ps;
	RECT rect;
	
	switch(message)
	{
		case WM_CREATE:
		return 0;
		
		case WM_PAINT:
		hdc=BeginPaint(hwnd,&ps);
		GetClientRect(hwnd,&rect);
		hddc=hdc;
		fracto();
		EndPaint(hwnd,&ps);
		return 0;
		
		case WM_DESTROY:
		PostQuitMessage(0);
		break;
		case WM_CLOSE:
		PostMessage(null,WM_QUIT,0,0);
		break;
		default:
		break;
	}
	return DefWindowProc(hwnd,message,wParam,lParam);
}

运行时截图：