#include <GL/freeglut.h>
#include <stdio.h>
#include <stdlib.h>
+#include <string.h>
#include <math.h>
+#define FGH_PI 3.14159265358979323846
typedef struct
{
AffineTrans ;
/* Number of levels to draw the fractal */
-static int num_levels = 0 ;
+static int num_levels = 4 ;
/* The definition of the fractal */
static int num_trans ;
static AffineTrans *affine ;
+/* Flag telling us to keep executing the main loop */
+static int continue_in_main_loop = 1;
+
/* the window title */
char window_title [ 80 ] ;
static void
Key(unsigned char key, int x, int y)
{
+ int need_redisplay = 1;
+
switch (key) {
case 27: /* Escape key */
- glutLeaveMainLoop () ;
+ continue_in_main_loop = 0 ;
break;
case '+' :
xwin = -1.0 ;
ywin = 0.0 ;
glTranslated ( xwin, ywin, -5.0 ) ;
-
break ;
- }
- glutPostRedisplay();
+ default:
+ need_redisplay = 0;
+ break;
+ }
+ if (need_redisplay)
+ glutPostRedisplay();
}
static void
Special(int key, int x, int y)
{
+ int need_redisplay = 1;
+
switch (key) {
case GLUT_KEY_UP :
glMatrixMode ( GL_MODELVIEW ) ;
glTranslated ( xwin, ywin, 0.0 ) ;
scale_factor *= 1.25 ;
break ;
+
+ default:
+ need_redisplay = 0;
+ break;
}
+ if (need_redisplay)
+ glutPostRedisplay();
+}
- glutPostRedisplay();
+
+static void
+checkedFGets ( char *s, int size, FILE *stream )
+{
+ if ( fgets ( s, size, stream ) == NULL ) {
+ fprintf ( stderr, "fgets failed\n");
+ exit ( EXIT_FAILURE );
+ }
}
+
void readConfigFile ( char *fnme )
{
FILE *fptr = fopen ( fnme, "rt" ) ;
int i ;
char inputline [ 256 ] ;
- /* Read a header line */
- fgets ( inputline, 256, fptr ) ;
+ if ( fptr )
+ {
+ /* Read a header line */
+ checkedFGets ( inputline, sizeof ( inputline ), fptr ) ;
- /* Read a comment line */
- fgets ( inputline, 256, fptr ) ;
+ /* Read a comment line */
+ checkedFGets ( inputline, sizeof ( inputline ), fptr ) ;
- /* Read the window title */
- fgets ( inputline, 256, fptr ) ;
- /* We assume here that this line will not exceed 79 characters plus a
- newline (window_title is 80 characters long). That'll cause a buffer
- overflow. For a simple program like this, though, we're letting it
- slide!
- */
- sscanf ( inputline, "%[a-zA-Z0-9!@#$%^&*()+=/\\_-\" ]", window_title ) ;
+ /* Read the window title */
+ checkedFGets ( inputline, sizeof ( inputline ), fptr ) ;
+ /* We assume here that this line will not exceed 79 characters plus a
+ newline (window_title is 80 characters long). That'll cause a buffer
+ overflow. For a simple program like this, though, we're letting it
+ slide!
+ */
+ sscanf ( inputline, "%[a-zA-Z0-9!@#$%^&*()+=/\\_-\" ]", window_title ) ;
- /* Read a comment line */
- fgets ( inputline, 256, fptr ) ;
+ /* Read a comment line */
+ checkedFGets ( inputline, sizeof ( inputline ), fptr ) ;
- /* Read the number of affine transformations */
- fgets ( inputline, 256, fptr ) ;
- sscanf ( inputline, "%d", &num_trans ) ;
+ /* Read the number of affine transformations */
+ checkedFGets ( inputline, sizeof ( inputline ), fptr ) ;
+ sscanf ( inputline, "%d", &num_trans ) ;
- affine = (AffineTrans *)malloc ( num_trans * sizeof(AffineTrans) ) ;
+ affine = (AffineTrans *)malloc ( num_trans * sizeof(AffineTrans) ) ;
- /* Read a comment line */
- fgets ( inputline, 256, fptr ) ;
+ /* Read a comment line */
+ checkedFGets ( inputline, sizeof ( inputline ), fptr ) ;
+
+ for ( i = 0; i < num_trans; i++ )
+ {
+ /* Read an affine transformation definition */
+ checkedFGets ( inputline, sizeof ( inputline ), fptr ) ;
+ sscanf ( inputline, "%lf %lf %lf %lf %lf %lf", &affine[i].a00, &affine[i].a01,
+ &affine[i].a10, &affine[i].a11, &affine[i].b0, &affine[i].b1 ) ;
+ }
+ }
+ else /* No data file, set a default */
+ {
+ printf ( "ERROR opening file <%s>\n", fnme ) ;
+ strcpy ( window_title, "Koch Snowflake" ) ;
+ num_trans = 4 ;
+ affine = (AffineTrans *)malloc ( num_trans * sizeof(AffineTrans) ) ;
+ affine[0].a00 = 1/3. ; affine[0].a01 = 0.00 ; affine[0].a10 = 0.00 ; affine[0].a11 = 1/3. ;
+ affine[0].b0 = 0.0 ; affine[0].b1 = 0.0 ;
+
+ affine[1].a00 = 1/6. ; affine[1].a01 = -1/3.*sin(FGH_PI/3.) ; affine[1].a10 = 1/3.*sin(FGH_PI/3.) ; affine[1].a11 = 1/6. ;
+ affine[1].b0 = 1/3. ; affine[1].b1 = 0.0 ;
+
+ affine[2].a00 = 1/6. ; affine[2].a01 = -1/3.*sin(-FGH_PI/3.) ; affine[2].a10 = 1/3.*sin(-FGH_PI/3.) ; affine[2].a11 = 1/6. ;
+ affine[2].b0 = 0.5 ; affine[2].b1 = sqrt(3)/6. ;
+
+ affine[3].a00 = 1/3. ; affine[3].a01 = 0.00 ; affine[3].a10 = 0.00 ; affine[3].a11 = 1/3. ;
+ affine[3].b0 = 2/3. ; affine[3].b1 = 0.0 ;
+ }
for ( i = 0; i < num_trans; i++ )
{
double m00, m01, m10, m11 ; /* Matrix "I" minus "A" */
double determ ; /* Determinant of this matrix */
- /* Read an affine transformation definition */
- fgets ( inputline, 256, fptr ) ;
- sscanf ( inputline, "%lf %lf %lf %lf %lf %lf", &affine[i].a00, &affine[i].a01,
- &affine[i].a10, &affine[i].a11, &affine[i].b0, &affine[i].b1 ) ;
-
/* Calculate the stationary point */
m00 = 1.0 - affine[i].a00 ;
int
main(int argc, char *argv[])
{
- int fractal_window ;
-
glutInitWindowSize(500, 250);
glutInitWindowPosition ( 140, 140 );
glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE );
else
readConfigFile ( "fractals.dat" ) ;
- fractal_window = glutCreateWindow( window_title );
+ glutCreateWindow( window_title );
glClearColor(1.0, 1.0, 1.0, 1.0);
glutSpecialFunc(Special);
glutDisplayFunc(Display);
- glutMainLoop();
+#ifdef WIN32
+#endif
+
+ while ( continue_in_main_loop )
+ glutMainLoopEvent();
printf ( "Back from the 'freeglut' main loop\n" ) ;
projects / freeglut / blobdiff