diff options
Diffstat (limited to 'src/colwheel.c')
| -rw-r--r-- | src/colwheel.c | 153 |
1 files changed, 153 insertions, 0 deletions
diff --git a/src/colwheel.c b/src/colwheel.c new file mode 100644 index 0000000..95f551c --- /dev/null +++ b/src/colwheel.c @@ -0,0 +1,153 @@ +/* + * colwheel.c + * + * Colour wheel definition and visualisation + * + * (c) 2006-2007 Thomas White <taw27@cam.ac.uk> + * + * Synth2D - two-dimensional Fourier synthesis + * + */ + +#ifdef HAVE_CONFIG_H +#include <config.h> +#endif + +#include <gtk/gtk.h> +#include <math.h> +#include <stdlib.h> +#include <fftw3.h> + +#include "displaywindow.h" + +#define COLWHEEL_WIDTH 256 +#define COLWHEEL_SIZE ((COLWHEEL_WIDTH)-1) +#define COLWHEEL_HALF ((COLWHEEL_WIDTH/2)-1) + +#define rad2deg(a) ((a)*180.0/M_PI) +#define deg2rad(a) ((a)*M_PI/180.0) + +gint colwheel_show(GtkWidget *widget, gpointer data) { + + GtkWidget *colwheel_window; + GdkPixbuf *colwheel_pixbuf; + GtkWidget *colwheel_pixmap_widget; + fftw_complex *colwheel; + + unsigned int x, y; + double am, ph; + + /* This isn't being transformed, so no need to use fftw_malloc() */ + colwheel = malloc(COLWHEEL_SIZE*COLWHEEL_SIZE*sizeof(fftw_complex)); + for ( x=0; x<COLWHEEL_SIZE; x++ ) { + for ( y=0; y<COLWHEEL_SIZE; y++ ) { + colwheel[y + COLWHEEL_SIZE*x][0] = 0; + colwheel[y + COLWHEEL_SIZE*x][1] = 0; + } + } + + /* Plot out a disc containing smoothly varying amplitude and phase */ + for ( am=0.0; am<1.0; am+=(1.0/COLWHEEL_SIZE) ) { + for ( ph=0.0; ph<2.0*M_PI; ph+=1.0/(2.0*M_PI*(double)COLWHEEL_SIZE) ) { + x = (unsigned int)(COLWHEEL_HALF + (COLWHEEL_HALF*am*cos(ph))); + y = (unsigned int)(COLWHEEL_HALF + (COLWHEEL_HALF*am*sin(ph))); + colwheel[(COLWHEEL_SIZE-1-y) + COLWHEEL_SIZE*(COLWHEEL_SIZE-1-x)][0] = am*cos(ph); + colwheel[(COLWHEEL_SIZE-1-y) + COLWHEEL_SIZE*(COLWHEEL_SIZE-1-x)][1] = am*sin(ph); + } + } + + /* Draw a line to remind the user where zero phase is */ + for ( x=COLWHEEL_HALF+1; x<COLWHEEL_SIZE; x++ ) { + colwheel[COLWHEEL_HALF + COLWHEEL_SIZE*(COLWHEEL_SIZE-1-x)][0] = 0; + colwheel[COLWHEEL_HALF + COLWHEEL_SIZE*(COLWHEEL_SIZE-1-x)][1] = 0; + } + + colwheel_window = gtk_window_new(GTK_WINDOW_TOPLEVEL); + gtk_window_set_title(GTK_WINDOW(colwheel_window), "Colour Wheel"); + colwheel_pixbuf = displaywindow_render_pixbuf(colwheel, 1, COLWHEEL_SIZE, COLWHEEL_SIZE, M_PI_2, 1, 1); + free(colwheel); + colwheel_pixmap_widget = gtk_image_new_from_pixbuf(colwheel_pixbuf); + gtk_container_add(GTK_CONTAINER(colwheel_window), colwheel_pixmap_widget); + gtk_widget_show_all(colwheel_window); + + return 0; + +} + +double colwheel_blue(double am, double ph) { + + double f; + unsigned int hi; + double d; + + ph = rad2deg(ph); /* Convert to degrees */ + ph += 180.0; /* Rotation of colour wheel */ + if ( ph >= 360.0 ) ph = 0.0; + d = ph / 60.0; + + hi = floor(d); /* Divide the colour wheel into six sections */ + f = d - hi; /* Distance into the current section of the colour wheel */ + if ( hi == 6 ) hi = 0; + switch ( hi ) { + case 0 : return am; + case 1 : return am; + case 2 : return am*(1.0-f); + case 3 : return 0.0; + case 4 : return am*f/2.0; + case 5 : return am/2.0+am*f/2.0; + default : return 0.0; + } + +} + +double colwheel_green(double am, double ph) { + + double f; + unsigned int hi; + double d; + + ph = rad2deg(ph); /* Convert to degrees */ + ph += 180.0; /* Rotation of colour wheel */ + if ( ph >= 360.0 ) ph = 0.0; + d = ph / 60.0; + + hi = floor(d); /* Divide the colour wheel into six sections */ + f = d - hi; /* Distance into the current section of the colour wheel */ + if ( hi == 6 ) hi = 0; + switch ( hi ) { + case 0 : return am*f/2.0; + case 1 : return am/2.0+am*f/2.0; + case 2 : return am; + case 3 : return am*(1.0-f); + case 4 : return 0.0; + case 5 : return 0.0; + default : return 0.0; + } + +} + +double colwheel_red(double am, double ph) { + + double f; + unsigned int hi; + double d; + + ph = rad2deg(ph); /* Convert to degrees */ + ph += 180.0; /* Rotation of colour wheel */ + if ( ph >= 360.0 ) ph = 0.0; + d = ph / 60.0; + + hi = floor(d); /* Divide the colour wheel into six sections */ + f = d - hi; /* Distance into the current section of the colour wheel */ + if ( hi == 6 ) hi = 0; + switch ( hi ) { + case 0 : return 0.0; + case 1 : return 0.0; + case 2 : return 0.0; + case 3 : return am*f; + case 4 : return am; + case 5 : return am*(1.0-f); + default : return 0.0; + } + +} |