#include <GL/freeglut.h>
#include <stdio.h>
#include <stdlib.h>
+#include <string.h>
#include <math.h>
-#ifdef WIN32
-#include <crtdbg.h> // DUMP MEMORY LEAKS
+#define FGH_PI 3.14159265358979323846
+#ifdef _MSC_VER
+/* DUMP MEMORY LEAKS */
+#include <crtdbg.h>
#endif
typedef struct
for ( i = 0; i < 10; i++ )
{
- int random = (rand() >> 10) % num_trans;
+ int random = ( rand( ) >> 10 ) % num_trans;
double new_x = affine[random].a00 * current_x + affine[random].a01 * current_y + affine[random].b0 ;
double new_y = affine[random].a10 * current_x + affine[random].a11 * current_y + affine[random].b1 ;
-
- glVertex2f ( new_x, new_y ) ;
+
+ glVertex2d ( new_x, new_y ) ;
current_x = new_x ;
current_y = new_y ;
}
}
+static int mouse_x = 0, mouse_y = 0 ;
+static int button_down = GLUT_DOWN ;
+
+static void
+Mouse ( int button, int updown, int x, int y )
+{
+ button_down = updown ;
+
+ if ( updown == GLUT_DOWN )
+ {
+ mouse_x = x ;
+ mouse_y = y ;
+ }
+}
+
+static void
+MouseMotion ( int x, int y )
+{
+ int window_width = glutGet ( GLUT_WINDOW_WIDTH ) ;
+ int window_height = glutGet ( GLUT_WINDOW_HEIGHT ) ;
+ int window_size = ( window_width < window_height ) ? window_width : window_height ;
+
+ double delta_x = 5.0 * (double)(x - mouse_x) / (double)(window_size) ;
+ double delta_y = 5.0 * (double)(y - mouse_y) / (double)(window_size) ;
+
+ xwin += delta_x * scale_factor ;
+ ywin -= delta_y * scale_factor ;
+ glMatrixMode ( GL_MODELVIEW ) ;
+ glTranslated ( delta_x * scale_factor, -delta_y * scale_factor, 0.0 ) ;
+
+ needClear = GL_TRUE;
+ glutPostRedisplay();
+
+ mouse_x = x ;
+ mouse_y = y ;
+}
+
+static void
+MouseWheel ( int wheel_number, int direction, int x, int y )
+{
+ double scale = ( direction > 0 ) ? 1.25 : 0.8 ;
+
+ glMatrixMode ( GL_MODELVIEW ) ;
+ glTranslated ( -xwin, -ywin, 0.0 ) ;
+ glScaled ( scale, scale, scale ) ;
+ glTranslated ( xwin, ywin, 0.0 ) ;
+ scale_factor /= scale ;
+
+ needClear = GL_TRUE;
+ 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" ) ;
if ( fptr )
{
/* Read a header line */
- fgets ( inputline, 256, fptr ) ;
+ checkedFGets ( inputline, sizeof ( inputline ), fptr ) ;
/* Read a comment line */
- fgets ( inputline, 256, fptr ) ;
+ checkedFGets ( inputline, sizeof ( inputline ), fptr ) ;
/* Read the window title */
- fgets ( inputline, 256, fptr ) ;
+ 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
sscanf ( inputline, "%[a-zA-Z0-9!@#$%^&*()+=/\\_-\" ]", window_title ) ;
/* Read a comment line */
- fgets ( inputline, 256, fptr ) ;
+ checkedFGets ( inputline, sizeof ( inputline ), fptr ) ;
/* Read the number of affine transformations */
- fgets ( inputline, 256, fptr ) ;
+ checkedFGets ( inputline, sizeof ( inputline ), fptr ) ;
sscanf ( inputline, "%d", &num_trans ) ;
affine = (AffineTrans *)malloc ( num_trans * sizeof(AffineTrans) ) ;
/* Read a comment line */
- fgets ( inputline, 256, fptr ) ;
+ checkedFGets ( inputline, sizeof ( inputline ), fptr ) ;
for ( i = 0; i < num_trans; i++ )
{
/* Read an affine transformation definition */
- fgets ( inputline, 256, fptr ) ;
+ 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, "Cantor Dust" ) ;
- num_trans = 2 ;
+ strcpy ( window_title, "Koch Snowflake" ) ;
+ num_trans = 4 ;
affine = (AffineTrans *)malloc ( num_trans * sizeof(AffineTrans) ) ;
- affine[0].a00 = 0.25 ; affine[0].a01 = 0.00 ; affine[0].a10 = 0.00 ; affine[0].a11 = 0.25 ;
+ 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 = 0.25 ; affine[1].a01 = 0.00 ; affine[1].a10 = 0.00 ; affine[1].a11 = 0.25 ;
- affine[1].b0 = 0.5 ; affine[1].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++ )
int
main(int argc, char *argv[])
{
- int fractal_window ;
-
glutInitDisplayMode( GLUT_RGB | GLUT_SINGLE );
glutInitWindowSize(500, 250);
else
readConfigFile ( "fractals.dat" ) ;
- fractal_window = glutCreateWindow( window_title );
+ glutCreateWindow( window_title );
glClearColor(1.0, 1.0, 1.0, 1.0);
glutKeyboardFunc(Key);
glutSpecialFunc(Special);
glutDisplayFunc(Display);
+ glutMouseFunc(Mouse);
+ glutMotionFunc(MouseMotion);
+ glutMouseWheelFunc(MouseWheel);
glutMainLoop();
free ( affine ) ;
-#ifdef WIN32
- _CrtDumpMemoryLeaks () ; // DUMP MEMORY LEAK INFORMATION
+#ifdef _MSC_VER
+ /* DUMP MEMORY LEAK INFORMATION */
+ _CrtDumpMemoryLeaks () ;
#endif
return 0; /* ANSI C requires main to return int. */
projects / freeglut / blobdiff