FMudanyali/FreeGLUT-Vita
Archived
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Lorenz attractor demo (John Fay)

Browse Source 
git-svn-id: https://svn.code.sf.net/p/freeglut/code/trunk@111 7f0cb862-5218-0410-a997-914c9d46530a
This commit is contained in:
brianp 2003-06-30 17:09:12 +00:00
parent 1f95108eca
commit 8cce55439e
3 changed files with 447 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
.gitattributes vendored
View File

@ -77,6 +77,8 @@ freeglut/freeglut/progs/demos/Fractals/fractals.dat svn_keywords=Author+Date+Id+
freeglut/freeglut/progs/demos/Fractals_random/Fractals_random.dsp svn_keywords=Author+Date+Id+Revision freeglut/freeglut/progs/demos/Fractals_random/Fractals_random.dsp svn_keywords=Author+Date+Id+Revision
freeglut/freeglut/progs/demos/Fractals_random/fractals.dat svn_keywords=Author+Date+Id+Revision freeglut/freeglut/progs/demos/Fractals_random/fractals.dat svn_keywords=Author+Date+Id+Revision
freeglut/freeglut/progs/demos/Fractals_random/fractals_random.c svn_keywords=Author+Date+Id+Revision freeglut/freeglut/progs/demos/Fractals_random/fractals_random.c svn_keywords=Author+Date+Id+Revision
freeglut/freeglut/progs/demos/Lorenz/lorenz.c svn_keywords=Author+Date+Id+Revision
freeglut/freeglut/progs/demos/Lorenz/lorenz.dsp svn_keywords=Author+Date+Id+Revision
freeglut/freeglut/src/Makefile.am svn_keywords=Author+Date+Id+Revision freeglut/freeglut/src/Makefile.am svn_keywords=Author+Date+Id+Revision
freeglut/freeglut/src/freeglut_callbacks.c svn_keywords=Author+Date+Id+Revision freeglut/freeglut/src/freeglut_callbacks.c svn_keywords=Author+Date+Id+Revision
freeglut/freeglut/src/freeglut_cursor.c svn_keywords=Author+Date+Id+Revision freeglut/freeglut/src/freeglut_cursor.c svn_keywords=Author+Date+Id+Revision

344
freeglut/freeglut/progs/demos/Lorenz/lorenz.c Normal file
View File

@ -0,0 +1,344 @@
/*
* Lorenz Strange Attractor
*
* Written by John F. Fay in honor of the "freeglut" 2.0.0 release in July 2003
*
* What it does:
* This program starts with two particles right next to each other. The particles
* move through a three-dimensional phase space governed by the following equations:
* dx/dt = sigma * ( y - x )
* dy/dt = r * x - y + x * z
* dz/dt = x * y + b * z
* These are the Lorenz equations and define the "Lorenz Attractor." Any two particles
* arbitrarily close together will move apart as time increases, but their tracks are
* confined within a region of the space.
*
* Commands:
* Arrow keys: Rotate the view
* PgUp, PgDn: Zoom in and out
* Mouse click: Center on the nearest point on a particle trajectory
*
* 'r'/'R': Reset the simulation
* 'm'/'M': Modify the Lorenz parameters (in the text window)
* 's'/'S': Stop (the advancement in time)
* 'g'/'G': Go
* <spacebar>: Single-step
* <Escape>: Quit
*/
/* Include Files */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include <time.h>
#include <GL/freeglut.h>
/************************************** Defined Constants ***************************************/
/* Number of points to draw in the curves */
#define NUM_POINTS 512
/* Angle to rotate when the user presses an arrow key */
#define ROTATION_ANGLE 5.0
/* Amount to scale bu when the user presses PgUp or PgDn */
#define SCALE_FACTOR 0.8
/*************************************** Global Variables ***************************************/
/* Lorenz Attractor variables */
double s0 = 10.0, r0 = 28.0, b0 = 8.0/3.0 ; /* Default Lorenz attactor parameters */
double time_step = 0.03 ; /* Time step in the simulation */
double sigma = 10.0, r = 28.0, b = 8.0/3.0 ; /* Lorenz attactor parameters */
double red_position[NUM_POINTS][3] ; /* Path of the red point */
double grn_position[NUM_POINTS][3] ; /* Path of the green point */
int array_index ; /* Position in *_position arrays of most recent point */
double distance = 0.0 ; /* Distance between the two points */
/* GLUT variables */
double yaw = 0.0, pit = 0.0 ; /* Euler angles of the viewing rotation */
double scale = 1.0 ; /* Scale factor */
double xcen = 0.0, ycen = 0.0, zcen = 0.0 ; /* Coordinates of the point looked at */
int animate = 1 ; /* 0 - stop, 1 = go, 2 = single-step */
/******************************************* Functions ******************************************/
/* The Lorenz Attractor */
void calc_deriv ( double position[3], double deriv[3] )
{
/* Calculate the Lorenz attractor derivatives */
deriv[0] = sigma * ( position[1] - position[0] ) ;
deriv[1] = ( r + position[2] ) * position[0] - position[1] ;
deriv[2] = -position[0] * position[1] - b * position[2] ;
}
void advance_in_time ( double time_step, double position[3], double new_position[3] )
{
/* Move a point along the Lorenz attractor */
double deriv0[3], deriv1[3], deriv2[3], deriv3[3] ;
int i ;
memcpy ( new_position, position, 3 * sizeof(double) ) ; /* Save the present values */
/* First pass in a Fourth-Order Runge-Kutta integration method */
calc_deriv ( position, deriv0 ) ;
for ( i = 0; i < 3; i++ )
new_position[i] = position[i] + 0.5 * time_step * deriv0[i] ;
/* Second pass */
calc_deriv ( new_position, deriv1 ) ;
for ( i = 0; i < 3; i++ )
new_position[i] = position[i] + 0.5 * time_step * deriv1[i] ;
/* Third pass */
calc_deriv ( position, deriv2 ) ;
for ( i = 0; i < 3; i++ )
new_position[i] = position[i] + time_step * deriv2[i] ;
/* Second pass */
calc_deriv ( new_position, deriv3 ) ;
for ( i = 0; i < 3; i++ )
new_position[i] = position[i] + 0.1666666666666666667 * time_step *
( deriv0[i] + 2.0 * ( deriv1[i] + deriv2[i] ) + deriv3[i] ) ;
}
/* GLUT callbacks */
void key_cb ( unsigned char key, int x, int y )
{
int i ;
char inputline [ 80 ] ;
switch ( key )
{
case 'r' : case 'R' : /* Reset the simulation */
/* Reset the Lorenz parameters */
sigma = s0 ;
b = b0 ;
r = r0 ;
/* Set an initial position */
red_position[0][0] = (double)rand() / (double)RAND_MAX ;
red_position[0][1] = (double)rand() / (double)RAND_MAX ;
red_position[0][2] = (double)rand() / (double)RAND_MAX ;
grn_position[0][0] = (double)rand() / (double)RAND_MAX ;
grn_position[0][1] = (double)rand() / (double)RAND_MAX ;
grn_position[0][2] = (double)rand() / (double)RAND_MAX ;
array_index = 0 ;
/* Initialize the arrays */
for ( i = 1; i < NUM_POINTS; i++ )
{
memcpy ( red_position[i], red_position[0], 3 * sizeof(double) ) ;
memcpy ( grn_position[i], grn_position[0], 3 * sizeof(double) ) ;
}
break ;
case 'm' : case 'M' : /* Modify the Lorenz parameters */
printf ( "Please enter new value for <sigma> (default %lf, currently %lf): ", s0, sigma ) ;
fgets ( inputline, 79, stdin ) ;
sscanf ( inputline, "%lf", &sigma ) ;
printf ( "Please enter new value for <b> (default %lf, currently %lf): ", b0, b ) ;
fgets ( inputline, 79, stdin ) ;
sscanf ( inputline, "%lf", &b ) ;
printf ( "Please enter new value for <r> (default %lf, currently %lf): ", r0, r ) ;
fgets ( inputline, 79, stdin ) ;
sscanf ( inputline, "%lf", &r ) ;
break ;
case 's' : case 'S' : /* Stop the animation */
animate = 0 ;
break ;
case 'g' : case 'G' : /* Start the animation */
animate = 1 ;
break ;
case ' ' : /* Spacebar: Single step */
animate = 2 ;
break ;
case 27 : /* Escape key */
glutLeaveMainLoop () ;
break ;
}
}
void special_cb ( int key, int x, int y )
{
switch ( key )
{
case GLUT_KEY_UP : /* Rotate up a little */
glRotated ( ROTATION_ANGLE, 0.0, 1.0, 0.0 ) ;
break ;
case GLUT_KEY_DOWN : /* Rotate down a little */
glRotated ( -ROTATION_ANGLE, 0.0, 1.0, 0.0 ) ;
break ;
case GLUT_KEY_LEFT : /* Rotate left a little */
glRotated ( ROTATION_ANGLE, 0.0, 0.0, 1.0 ) ;
break ;
case GLUT_KEY_RIGHT : /* Rotate right a little */
glRotated ( -ROTATION_ANGLE, 0.0, 0.0, 1.0 ) ;
break ;
case GLUT_KEY_PAGE_UP : /* Zoom in a little */
glScaled ( 1.0 / SCALE_FACTOR, 1.0 / SCALE_FACTOR, 1.0 / SCALE_FACTOR ) ;
break ;
case GLUT_KEY_PAGE_DOWN : /* Zoom out a little */
glScaled ( SCALE_FACTOR, SCALE_FACTOR, SCALE_FACTOR ) ;
break ;
}
glutPostRedisplay () ;
}
void mouse_cb ( int button, int updown, int x, int y )
{
if ( updown == GLUT_DOWN )
{
double dist = 1.0e20 ; /* A very large number */
(void) dist; /* what's this all about? */
}
}
void draw_curve ( int index, double position [ NUM_POINTS ][3] )
{
int i = index ;
glBegin ( GL_LINE_STRIP ) ;
do
{
i = ( i == NUM_POINTS-1 ) ? 0 : i + 1 ;
glVertex3dv ( position[i] ) ;
}
while ( i != index ) ;
glEnd () ;
}
void display_cb ( void )
{
char string [ 80 ] ;
glClear ( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT ) ;
glColor3d ( 1.0, 1.0, 1.0 ) ; /* White */
/* Draw some axes */
glBegin ( GL_LINES ) ;
glVertex3d ( 0.0, 0.0, 0.0 ) ;
glVertex3d ( 2.0, 0.0, 0.0 ) ;
glVertex3d ( 0.0, 0.0, 0.0 ) ;
glVertex3d ( 0.0, 1.0, 0.0 ) ;
glVertex3d ( 0.0, 0.0, 0.0 ) ;
glVertex3d ( 0.0, 0.0, 1.0 ) ;
glEnd () ;
glColor3d ( 1.0, 0.0, 0.0 ) ; /* Red */
draw_curve ( array_index, red_position ) ;
glColor3d ( 0.0, 1.0, 0.0 ) ; /* Green */
draw_curve ( array_index, grn_position ) ;
/* Print the distance between the two points */
glColor3d ( 1.0, 1.0, 1.0 ) ; /* White */
sprintf ( string, "Distance: %10.6lf", distance ) ;
glRasterPos2i ( 10, 10 ) ;
glutBitmapString ( GLUT_BITMAP_HELVETICA_12, string ) ;
glutSwapBuffers();
}
void reshape_cb ( int width, int height )
{
float ar;
glViewport ( 0, 0, width, height ) ;
glMatrixMode ( GL_PROJECTION ) ;
glLoadIdentity () ;
ar = (float) width / (float) height ;
glFrustum ( -ar, ar, -1.0, 1.0, 10.0, 100.0 ) ;
glMatrixMode ( GL_MODELVIEW ) ;
glLoadIdentity () ;
xcen = 0.0 ;
ycen = 0.0 ;
zcen = 0.0 ;
glTranslated ( xcen, ycen, zcen - 50.0 ) ;
}
void timer_cb ( int value )
{
/* Function called at regular intervals to update the positions of the points */
double deltax, deltay, deltaz ;
int new_index = array_index + 1 ;
/* Set the next timed callback */
glutTimerFunc ( 30, timer_cb, 0 ) ;
if ( animate > 0 )
{
if ( new_index == NUM_POINTS ) new_index = 0 ;
advance_in_time ( time_step, red_position[array_index], red_position[new_index] ) ;
advance_in_time ( time_step, grn_position[array_index], grn_position[new_index] ) ;
array_index = new_index ;
deltax = red_position[array_index][0] - grn_position[array_index][0] ;
deltay = red_position[array_index][1] - grn_position[array_index][1] ;
deltaz = red_position[array_index][2] - grn_position[array_index][2] ;
distance = sqrt ( deltax * deltax + deltay * deltay + deltaz * deltaz ) ;
if ( animate == 2 ) animate = 0 ;
}
glutPostRedisplay () ;
}
/* The Main Program */
int main ( int argc, char *argv[] )
{
int pargc = argc ;
/* Initialize the random number generator */
srand ( 1023 ) ;
/* Set up the OpenGL parameters */
/* glDrawBuffer ( GL_BACK ) ;*/
glEnable ( GL_DEPTH_TEST ) ;
glClearColor ( 0.0, 0.0, 0.0, 0.0 ) ;
glClearDepth ( 1.0 ) ;
/* Initialize GLUT */
glutInitWindowSize ( 600, 600 ) ;
glutInit ( &pargc, argv ) ;
glutInitDisplayMode ( GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH ) ;
/* Create the window */
glutCreateWindow ( "Lorenz Attractor" ) ;
glutKeyboardFunc ( key_cb ) ;
glutMouseFunc ( mouse_cb ) ;
glutSpecialFunc ( special_cb ) ;
glutDisplayFunc ( display_cb ) ;
glutReshapeFunc ( reshape_cb ) ;
glutTimerFunc ( 30, timer_cb, 0 ) ;
/* Initialize the attractor: The easiest way is to call the keyboard callback with an
* argument of 'r' for Reset.
*/
key_cb ( 'r', 0, 0 ) ;
/* Enter the GLUT main loop */
glutMainLoop () ;
return 0;
}

101
freeglut/freeglut/progs/demos/Lorenz/lorenz.dsp Normal file
View File

@ -0,0 +1,101 @@
# Microsoft Developer Studio Project File - Name="lorenz" - Package Owner=<4>
# Microsoft Developer Studio Generated Build File, Format Version 6.00
# ** DO NOT EDIT **
# TARGTYPE "Win32 (x86) Console Application" 0x0103
CFG=lorenz - Win32 Debug
!MESSAGE This is not a valid makefile. To build this project using NMAKE,
!MESSAGE use the Export Makefile command and run
!MESSAGE
!MESSAGE NMAKE /f "lorenz.mak".
!MESSAGE
!MESSAGE You can specify a configuration when running NMAKE
!MESSAGE by defining the macro CFG on the command line. For example:
!MESSAGE
!MESSAGE NMAKE /f "lorenz.mak" CFG="lorenz - Win32 Debug"
!MESSAGE
!MESSAGE Possible choices for configuration are:
!MESSAGE
!MESSAGE "lorenz - Win32 Release" (based on "Win32 (x86) Console Application")
!MESSAGE "lorenz - Win32 Debug" (based on "Win32 (x86) Console Application")
!MESSAGE
# Begin Project
# PROP AllowPerConfigDependencies 0
# PROP Scc_ProjName ""
# PROP Scc_LocalPath ""
CPP=cl.exe
RSC=rc.exe
!IF "$(CFG)" == "lorenz - Win32 Release"
# PROP BASE Use_MFC 0
# PROP BASE Use_Debug_Libraries 0
# PROP BASE Output_Dir "Release"
# PROP BASE Intermediate_Dir "Release"
# PROP BASE Target_Dir ""
# PROP Use_MFC 0
# PROP Use_Debug_Libraries 0
# PROP Output_Dir "Release"
# PROP Intermediate_Dir "Release"
# PROP Target_Dir ""
# ADD BASE CPP /nologo /W3 /GX /O2 /D "WIN32" /D "NDEBUG" /D "_CONSOLE" /D "_MBCS" /YX /FD /c
# ADD CPP /nologo /W3 /GX /O2 /D "WIN32" /D "NDEBUG" /D "_CONSOLE" /D "_MBCS" /YX /FD /c
# ADD BASE RSC /l 0x409 /d "NDEBUG"
# ADD RSC /l 0x409 /d "NDEBUG"
BSC32=bscmake.exe
# ADD BASE BSC32 /nologo
# ADD BSC32 /nologo
LINK32=link.exe
# ADD BASE LINK32 kernel32.lib user32.lib gdi32.lib winspool.lib comdlg32.lib advapi32.lib shell32.lib ole32.lib oleaut32.lib uuid.lib odbc32.lib odbccp32.lib kernel32.lib user32.lib gdi32.lib winspool.lib comdlg32.lib advapi32.lib shell32.lib ole32.lib oleaut32.lib uuid.lib odbc32.lib odbccp32.lib /nologo /subsystem:console /machine:I386
# ADD LINK32 kernel32.lib user32.lib gdi32.lib winspool.lib comdlg32.lib advapi32.lib shell32.lib ole32.lib oleaut32.lib uuid.lib odbc32.lib odbccp32.lib kernel32.lib user32.lib gdi32.lib winspool.lib comdlg32.lib advapi32.lib shell32.lib ole32.lib oleaut32.lib uuid.lib odbc32.lib odbccp32.lib /nologo /subsystem:console /machine:I386
!ELSEIF "$(CFG)" == "lorenz - Win32 Debug"
# PROP BASE Use_MFC 0
# PROP BASE Use_Debug_Libraries 1
# PROP BASE Output_Dir "Debug"
# PROP BASE Intermediate_Dir "Debug"
# PROP BASE Target_Dir ""
# PROP Use_MFC 0
# PROP Use_Debug_Libraries 1
# PROP Output_Dir "Debug"
# PROP Intermediate_Dir "Debug"
# PROP Ignore_Export_Lib 0
# PROP Target_Dir ""
# ADD BASE CPP /nologo /W3 /Gm /GX /ZI /Od /D "WIN32" /D "_DEBUG" /D "_CONSOLE" /D "_MBCS" /YX /FD /GZ /c
# ADD CPP /nologo /W3 /Gm /GX /ZI /Od /I "C:\OpenGL\freeglut\include" /D "WIN32" /D "_DEBUG" /D "_CONSOLE" /D "_MBCS" /D "FREEGLUT_STATIC" /YX /FD /GZ /c
# ADD BASE RSC /l 0x409 /d "_DEBUG"
# ADD RSC /l 0x409 /d "_DEBUG"
BSC32=bscmake.exe
# ADD BASE BSC32 /nologo
# ADD BSC32 /nologo
LINK32=link.exe
# ADD BASE LINK32 kernel32.lib user32.lib gdi32.lib winspool.lib comdlg32.lib advapi32.lib shell32.lib ole32.lib oleaut32.lib uuid.lib odbc32.lib odbccp32.lib kernel32.lib user32.lib gdi32.lib winspool.lib comdlg32.lib advapi32.lib shell32.lib ole32.lib oleaut32.lib uuid.lib odbc32.lib odbccp32.lib /nologo /subsystem:console /debug /machine:I386 /pdbtype:sept
# ADD LINK32 kernel32.lib user32.lib gdi32.lib winspool.lib comdlg32.lib advapi32.lib shell32.lib ole32.lib oleaut32.lib uuid.lib odbc32.lib odbccp32.lib kernel32.lib user32.lib gdi32.lib winspool.lib comdlg32.lib advapi32.lib shell32.lib ole32.lib oleaut32.lib uuid.lib odbc32.lib odbccp32.lib /nologo /subsystem:console /debug /machine:I386 /pdbtype:sept /libpath:"C:\OpenGL\freeglut\freeglut_static___Win32_Debug"
!ENDIF
# Begin Target
# Name "lorenz - Win32 Release"
# Name "lorenz - Win32 Debug"
# Begin Group "Source Files"
# PROP Default_Filter "cpp;c;cxx;rc;def;r;odl;idl;hpj;bat"
# Begin Source File
SOURCE=.\lorenz.c
# End Source File
# End Group
# Begin Group "Header Files"
# PROP Default_Filter "h;hpp;hxx;hm;inl"
# End Group
# Begin Group "Resource Files"
# PROP Default_Filter "ico;cur;bmp;dlg;rc2;rct;bin;rgs;gif;jpg;jpeg;jpe"
# End Group
# End Target
# End Project