Dessinateur de fractales
Contenu du snippet
Dessine la courbe de Mandelbrot. Code optimise, a compiler avec mingw32 ( ou DevCpp ). Les calculs sont faits en assembleurs. Cependant, la partie affichage ggnerait à être améliorée pour ne pas réafficher le fractale à chaque dessinage de la fenetre.
Pour zoomer, il faut appuyer le bouton de la souris en haut a gauche du rectangle que l'on veut voir et relacher le bouton de la souris en bas a droite.
N, c'est le nombre d'itérations, il faut l'augmenter si on zoome pas mal.
Source / Exemple :
#include <windows.h>
#include <stdio.h>
#include <math.h>
#define ID_BUTTON_DESSINER 100
#define ID_EDIT_CRMIN 101
#define ID_EDIT_CRMAX 102
#define ID_EDIT_CIMIN 103
#define ID_EDIT_CIMAX 104
#define ID_EDIT_N 105
#define ID_STATIC_CR 106
#define ID_STATIC_CI 107
/* Declare Windows procedure */
LRESULT CALLBACK WindowProcedure(HWND, UINT, WPARAM, LPARAM);
/* Make the class name into a global variable */
char szClassName[ ] = "WindowsApp";
COLORREF fractal[600][800];
double crmax,crmin, cimax,cimin, crpas,cipas;
HWND hwndmain, hbouton, hedit_crmin, hedit_crmax, hedit_cimin, hedit_cimax, hedit_n, hstatic_cr, hstatic_ci;
MSG messages; /* Here messages to the application are saved */
int WINAPI WinMain(HINSTANCE hThisInstance, HINSTANCE hPrevInstance, LPSTR lpszArgument, int nFunsterStil){
WNDCLASSEX wincl; /* Data structure for the windowclass */
/* The Window structure */
wincl.hInstance = hThisInstance;
wincl.lpszClassName = szClassName;
wincl.lpfnWndProc = WindowProcedure; /* This function is called by windows */
wincl.style = CS_DBLCLKS; /* Catch double-clicks */
wincl.cbSize = sizeof(WNDCLASSEX);
/* Use default icon and mouse-pointer */
wincl.hIcon = LoadIcon(NULL, IDI_APPLICATION);
wincl.hIconSm = LoadIcon(NULL, IDI_APPLICATION);
wincl.hCursor = LoadCursor(NULL, IDC_ARROW);
wincl.lpszMenuName = NULL; /* No menu */
wincl.cbClsExtra = 0; /* No extra bytes after the window class */
wincl.cbWndExtra = 0; /* structure or the window instance */
/* Use light-gray as the background of the window */
wincl.hbrBackground =(HBRUSH) GetStockObject(LTGRAY_BRUSH);
/* Register the window class, if fail quit the program */
if(!RegisterClassEx(&wincl)) return 0;
/* The class is registered, let's create the program*/
hwndmain = CreateWindowEx(
0, /* Extended possibilites for variation */
szClassName, /* Classname */
"Mandelbrot", /* Title Text */
WS_OVERLAPPEDWINDOW, /* default window */
CW_USEDEFAULT, /* Windows decides the position */
CW_USEDEFAULT, /* where the window ends up on the screen */
1015, /* The programs width */
627, /* and height in pixels */
HWND_DESKTOP, /* The window is a child-window to desktop */
NULL, /* No menu */
hThisInstance, /* Program Instance handler */
NULL /* No Window Creation data */
);
int i,j;
for(i=0;i<600;i++)
for(j=0;j<800;j++)
fractal[i][j]=RGB(0,0,0);
/* Make the window visible on the screen */
hbouton=CreateWindowEx (0,"BUTTON","dessiner",WS_CHILD|WS_VISIBLE|BS_DEFPUSHBUTTON,805,260,100,25,
hwndmain,(HMENU)ID_BUTTON_DESSINER,hThisInstance,NULL);
hedit_crmin=CreateWindowEx (0,"EDIT","-2.1",WS_CHILD|WS_VISIBLE|WS_BORDER ,805,30,200,20,
hwndmain,(HMENU)ID_EDIT_CRMIN,hThisInstance,NULL);
hedit_crmax=CreateWindowEx (0,"EDIT","0.9",WS_CHILD|WS_VISIBLE|WS_BORDER,805,80,200,20,
hwndmain,(HMENU)ID_EDIT_CRMAX,hThisInstance,NULL);
hedit_cimin=CreateWindowEx (0,"EDIT","-1.2",WS_CHILD|WS_VISIBLE|WS_BORDER,805,130,200,20,
hwndmain,(HMENU)ID_EDIT_CIMIN,hThisInstance,NULL);
hedit_cimax=CreateWindowEx (0,"EDIT","1.2",WS_CHILD|WS_VISIBLE|WS_BORDER,805,180,200,20,
hwndmain,(HMENU)ID_EDIT_CIMAX,hThisInstance,NULL);
hedit_n=CreateWindowEx (0,"EDIT","255",WS_CHILD|WS_VISIBLE|WS_BORDER,805,230,75,20,
hwndmain,(HMENU)ID_EDIT_N,hThisInstance,NULL);
CreateWindowEx (0,"STATIC","Cr min =",WS_CHILD|WS_VISIBLE,805,5,60,20,
hwndmain,(HMENU)0,hThisInstance,NULL);
CreateWindowEx (0,"STATIC","Cr max =",WS_CHILD|WS_VISIBLE,805,55,60,20,
hwndmain,(HMENU)0,hThisInstance,NULL);
CreateWindowEx (0,"STATIC","Ci min =",WS_CHILD|WS_VISIBLE,805,105,60,20,
hwndmain,(HMENU)0,hThisInstance,NULL);
CreateWindowEx (0,"STATIC","Ci max =",WS_CHILD|WS_VISIBLE,805,155,60,20,
hwndmain,(HMENU)0,hThisInstance,NULL);
CreateWindowEx (0,"STATIC","N =",WS_CHILD|WS_VISIBLE,805,205,30,20,
hwndmain,(HMENU)0,hThisInstance,NULL);
CreateWindowEx (0,"STATIC","cr =",WS_CHILD|WS_VISIBLE,805,500,30,20,
hwndmain,(HMENU)0,hThisInstance,NULL);
CreateWindowEx (0,"STATIC","ci =",WS_CHILD|WS_VISIBLE,805,550,30,20,
hwndmain,(HMENU)0,hThisInstance,NULL);
hstatic_cr= CreateWindowEx (0,"STATIC","",WS_CHILD|WS_VISIBLE,805,525,200,20,
hwndmain,(HMENU)ID_STATIC_CR,hThisInstance,NULL);
hstatic_ci= CreateWindowEx (0,"STATIC","",WS_CHILD|WS_VISIBLE,805,575,200,20,
hwndmain,(HMENU)ID_STATIC_CI,hThisInstance,NULL);
ShowWindow(hwndmain, nFunsterStil);
/* Run the message loop. It will run until GetMessage( ) returns 0 */
while(GetMessage(&messages, NULL, 0, 0))
{
/* Translate virtual-key messages into character messages */
TranslateMessage(&messages);
/* Send message to WindowProcedure */
DispatchMessage(&messages);
}
/* The program return-value is 0 - The value that PostQuitMessage( ) gave */
return messages.wParam;
}
COLORREF Palette(int e){
int k=((int)sqrt(e)*48)%768;
COLORREF r;
if(k<256) r=RGB(k,0,255-k);
if(k<512 && k>=256) r=RGB(511-k,k-256,0);
if(k>=512) r=RGB(0,767-k,k-512);
if(r==0){
char tampontxt[100];
sprintf(tampontxt,"k=%d m=%d",k,e);
MessageBox(hwndmain,tampontxt,"",MB_OK);
}
return r;
}
/* This function is called by the Windows function DispatchMessage( ) */
LRESULT CALLBACK WindowProcedure(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
HDC hdc;
PAINTSTRUCT ps;
int x,y,i,j;
switch (message) /* handle the messages */
{
case WM_DESTROY:
PostQuitMessage(0); /* send a WM_QUIT to the message queue */
break;
case WM_COMMAND:
if ((LOWORD(wParam) == ID_BUTTON_DESSINER) && (HIWORD(wParam) == BN_CLICKED)){
long double cr,ci;
char tampontxt[10000];
int Nmax;
GetDlgItemText(hwndmain,ID_EDIT_CRMIN,tampontxt,100);
sscanf(tampontxt,"%lf",&crmin);
GetDlgItemText(hwndmain,ID_EDIT_CRMAX,tampontxt,100);
sscanf(tampontxt,"%lf",&crmax);
GetDlgItemText(hwndmain,ID_EDIT_CIMIN,tampontxt,100);
sscanf(tampontxt,"%lf",&cimin);
GetDlgItemText(hwndmain,ID_EDIT_CIMAX,tampontxt,100);
sscanf(tampontxt,"%lf",&cimax);
Nmax=GetDlgItemInt(hwndmain,ID_EDIT_N,NULL,FALSE);
crpas=(crmax-crmin)/800;
cipas=(cimax-cimin)/600;
hdc=GetDC (hwnd);
for (x=0;x<800;x++){
cr=x*crpas+crmin;
for (y=0;y<600;y++){
ci=y*cipas+cimin;
char diverge=1;
asm volatile("fld1\n"
"fadd %%st(0)\n"
"fadd %%st(0)\n"//pour charger 4
"fldt %1\n"
"fldt %0\n"
"fldz\n"
"fldz"
:
: "m"(cr), "m"(ci)
);
int k;
for (k=0;k<Nmax && diverge;k++){
asm volatile( "movb $0,%0\n"
//calcul de zi
"fld %%st(0)\n"
"fmul %%st(2)\n"
"fadd %%st(0)\n" //multiplie par 2
"fadd %%st(4)\n"
//calcul de zr
"fld %%st(1)\n"
"fmul %%st(0)\n" //élève au carré
"fld %%st(3)\n"
"fmul %%st(0)\n"
"fsubrp\n"
"fadd %%st(4)\n"
//on remet les données a leur place
"fstp %%st(2)\n"
"fstp %%st(2)\n"
//comparaison de la valeur absolue pour voir si on sort
"fld %%st(0)\n"
"fmul %%st(0)\n" //élève au carré
"fld %%st(2)\n"
"fmul %%st(0)\n"
"faddp\n"
"fcomip %%st(5),%%st(0)\n"
"sbbb $0,%0"
:"=g" (diverge)
);
}
// on libère le FPU
asm volatile( "fstp %%st(0)\n"
"fstp %%st(0)\n"
"fstp %%st(0)\n"
"fstp %%st(0)\n"
"fstp %%st(0)\n":::"st");
if (diverge){
fractal[y][x]=RGB(0,0,0);
SetPixel(hdc,x,y,RGB(0,0,0));
} else {
fractal[y][x]=Palette(k);
SetPixel(hdc,x,y,Palette(k));
}
}
}
ReleaseDC(hwnd,hdc);
} else return DefWindowProc(hwnd, message, wParam, lParam);
break;
case WM_PAINT:
hdc=BeginPaint(hwndmain,&ps);
for (i=0;i<800;i++)
for (j=0;j<600;j++)
SetPixel(hdc,i,j,fractal[j][i]);
EndPaint(hwndmain,&ps);
break;
case WM_MOUSEMOVE:
x=LOWORD(lParam);
y=HIWORD(lParam);
if (x>0 && x<800 && y>0 && y<600){
char tampon[1000];
sprintf(tampon,"%.20lf",(double)(x*crpas+crmin) );
SetWindowText(hstatic_cr,tampon);
sprintf(tampon,"%.20lf",(double)(y*cipas+cimin) );
SetWindowText(hstatic_ci,tampon);
}
break;
case WM_LBUTTONDOWN:
x=LOWORD(lParam);
y=HIWORD(lParam);
if (x>0 && x<800 && y>0 && y<600){
char tampon[1000];
sprintf(tampon,"%.20lf",(double)(x*crpas+crmin) );
SetWindowText(hedit_crmin,tampon);
sprintf(tampon,"%.20lf",(double)(y*cipas+cimin) );
SetWindowText(hedit_cimin,tampon);
}
break;
case WM_LBUTTONUP:
x=LOWORD(lParam);
y=HIWORD(lParam);
if (x>0 && x<800 && y>0 && y<600){
char tampon[1000];
sprintf(tampon,"%.20lf",(double)(x*crpas+crmin) );
SetWindowText(hedit_crmax,tampon);
sprintf(tampon,"%.20lf",(double)(y*cipas+cimin) );
SetWindowText(hedit_cimax,tampon);
}
break;
default: /* for messages that we don't deal with */
return DefWindowProc(hwnd, message, wParam, lParam);
}
return 0;
}
Conclusion :
Pour zoomer, il faut appuyer le bouton de la souris en haut a gauche du rectangle que l'on veut voir et relacher le bouton de la souris en bas a droite.
N, c'est le nombre d'itérations, il faut l'augmenter si on zoome pas mal.
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