/*******************************************************
*    This small program draws an arttistic bundle      *
*    of geometrical lines                              *
* ---------------------------------------------------- *
*                                                      *
*       Visual C++ in API style Release By J-P Moreau. *
*******************************************************/
#include <windows.h>
#include <stdio.h>
#include <math.h>

HDC  hdc;
RECT rect;

//Functions used here of module Gr2D.cpp
void Fenetre(double,double,double,double); 
void Cloture(int,int,int,int); 
void Bordure();
void MoveXY(double,double);
void LineXY(double,double);


//"home made" graphic commands for hdc environment used by above functions
void DrawPixel(int ix,int iy) {
  //sorry, no other available command found
  Rectangle(hdc,rect.left+ix,rect.top+iy,
	            rect.left+ix+2,rect.top+iy+1);
}

void Swap(int *i1,int *i2) {
  int it;
  it=*i1; *i1=*i2; *i2=it;
}

void DrawLine(int ix1,int iy1,int ix2,int iy2) {
  int i,il,ix,iy;
  double dx,dy;
  if (ix2<ix1) {
	Swap(&ix1,&ix2); Swap(&iy1,&iy2);
  }
  il=(int) sqrt((ix2-ix1)*(ix2-ix1)+(iy2-iy1)*(iy2-iy1));
  dx=(double) (ix2-ix1)/il; 
  dy=(double) (iy2-iy1)/il;
  ix=ix1; iy=iy1;
  for (i=1;i<il+1; i++) {
	DrawPixel(ix,iy);
	ix=(int) (ix1+i*dx); 
	iy=(int) (iy1+i*dy);
  }
}

void OutText(int ix,int iy,char *s) {
  RECT rct;
  rct.left=ix; rct.right=ix+10*strlen(s);
  rct.top=iy; rct.bottom=iy+10;
  DrawText(hdc, s, -1, &rct,
                DT_SINGLELINE | DT_CENTER | DT_VCENTER);
}

// begin specific section

int    bord = 10;
double Min_X = -1.3,
	   Min_Y = -1.3,
	   Max_X =  1.3,
	   Max_Y =  1.3,
	   infT = 0.0,
	   supT = 6.2832;

typedef double Point2D[3];

 int  nbpas;  //number of steps
 char s[20];

extern MaxX, MaxY;

 void Equations (Point2D A, Point2D B, double t) {
   A[1] = cos(t) + 0.25*cos(5*t);
   A[2] = sin(t) + 0.25*sin(5*t);
   B[1] = -cos(5*t);
   B[2] = 0.0;
 }

 void TraceFaisceau() {
   double t,dt;
   Point2D A,B;
   dt=(supT-infT)/nbpas;
   t=infT;
   while(t <=supT) {
     Equations(A,B,t);
     t += dt;
     MoveXY(A[1],A[2]);
     LineXY(B[1],B[2]);
   }
 }

 void Initialise() {
   MaxX=(rect.right-rect.left);
   MaxY=(rect.bottom-rect.top);
   Fenetre(Min_X,Max_X,Min_Y,Max_Y);
   Cloture(2*bord,MaxX-2*bord,8*bord,MaxY-5*bord);
 }


//  main subroutine
void Exec_Faisceaux() {
  
  Initialise();
  nbpas=300;
  Bordure();
  TraceFaisceau();
  sprintf(s," N = %d", nbpas);
  OutText(MaxX/2-4*bord,20,s); 

}

// end specific section

//Handle window Paint and Destroy messages
long FAR PASCAL /*_export*/ WndProc(HWND hwnd,
    UINT message, UINT wParam, LONG lParam) 
{
    HPEN        hpen, hpenOld;
    PAINTSTRUCT ps;

    switch (message) {
        case WM_PAINT:
	    hdc = BeginPaint(hwnd, &ps);
	    GetClientRect(hwnd, &rect);
            hpen = CreatePen(PS_SOLID, 1, RGB(0, 0, 255));
            hpenOld = SelectObject(hdc,hpen);

            Exec_Faisceaux();
               
            SelectObject(hdc,hpenOld);
            DeleteObject(hpen);
            EndPaint(hwnd, &ps);
            return 0;
        case WM_DESTROY:
            PostQuitMessage(0);
            return 0;
    }
    return DefWindowProc(hwnd, message, wParam, lParam);
}

// main program
int PASCAL WinMain(HANDLE hInstance, HANDLE hPrevInstance,
    LPSTR lpszCmdParam, int nCmdShow)
{
    static char szAppName[] = "Faisceaux";
    HWND        hwnd;
    MSG         msg;
    WNDCLASS    wndclass;

    if (!hPrevInstance) {
        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 = GetStockObject(WHITE_BRUSH);
        wndclass.lpszMenuName  = NULL;
        wndclass.lpszClassName = szAppName;

        RegisterClass(&wndclass);
    }

    hwnd = CreateWindow(szAppName,  // window class name
        " FAISCEAUX",               // window caption
        WS_OVERLAPPEDWINDOW,        // window style                       
        CW_USEDEFAULT,              // initial x position
        CW_USEDEFAULT,              // initial y position
        CW_USEDEFAULT,              // initial x size
        CW_USEDEFAULT,              // initial y size
        NULL,                       // parent window handle
        NULL,                       // window menu handle
        hInstance,                  // program instance handle
        NULL);                      // creation parameters

   ShowWindow(hwnd, nCmdShow);
   UpdateWindow(hwnd);

   while (GetMessage(&msg, NULL, 0, 0)) {
       TranslateMessage(&msg);
       DispatchMessage(&msg);
   }
   return msg.wParam;
}

//end of file faisceaux.cpp