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/*
* example2.c: oscillating mesh with FORMS control panel
*
* This example module is distributed with the geomview manual.
* If you are not reading this in the manual, see the "External
* Modules" chapter of the manual for an explanation.
*
* This module creates an oscillating mesh and has a FORMS control
* panel that lets you change the speed of the oscillation with a
* slider.
*/
#include <math.h>
#include <stdio.h>
#include <sys/time.h> /* for struct timeval below */
#include "forms.h" /* for FORMS library */
FL_FORM *OurForm;
FL_OBJECT *VelocitySlider;
float dt;
/* F is the function that we plot
*/
float F(x,y,t)
float x,y,t;
{
float r = sqrt(x*x+y*y);
return(sin(r + t)*sqrt(r));
}
/* SetVelocity is the slider callback procedure; FORMS calls this
* when the user moves the slider bar.
*/
void SetVelocity(FL_OBJECT *obj, long val)
{
dt = fl_get_slider_value(VelocitySlider);
}
/* Quit is the "Quit" button callback procedure; FORMS calls this
* when the user clicks the "Quit" button.
*/
void Quit(FL_OBJECT *obj, long val)
{
exit(0);
}
/* create_form_OurForm() creates the FORMS panel by calling a bunch of
* procedures in the FORMS library. This code was generated
* automatically by the FORMS designer program; normally this code
* would be in a separate file which you would not edit by hand. For
* simplicity of this example, however, we include this code here.
*/
create_form_OurForm()
{
FL_OBJECT *obj;
FL_FORM *form;
OurForm = form = fl_bgn_form(FL_NO_BOX,380.0,120.0);
obj = fl_add_box(FL_UP_BOX,0.0,0.0,380.0,120.0,"");
VelocitySlider = obj = fl_add_valslider(FL_HOR_SLIDER,20.0,30.0,
340.0,40.0,"Velocity");
fl_set_object_lsize(obj,FL_LARGE_FONT);
fl_set_object_align(obj,FL_ALIGN_TOP);
fl_set_call_back(obj,SetVelocity,0);
obj = fl_add_button(FL_NORMAL_BUTTON,290.0,75.0,70.0,35.0,"Quit");
fl_set_object_lsize(obj,FL_LARGE_FONT);
fl_set_call_back(obj,Quit,0);
fl_end_form();
}
main(argc, argv)
char **argv;
{
int xdim, ydim;
float xmin, xmax, ymin, ymax, dx, dy, t;
int fdmask;
static struct timeval timeout = {0, 200000};
xmin = ymin = -5; /* Set x and y */
xmax = ymax = 5; /* plot ranges */
xdim = ydim = 24; /* Set x and y resolution */
dt = 0.1; /* Time increment is 0.1 */
/* Forms panel setup.
*/
foreground();
create_form_OurForm();
fl_set_slider_bounds(VelocitySlider, 0.0, 1.0);
fl_set_slider_value(VelocitySlider, dt);
fl_show_form(OurForm, FL_PLACE_SIZE, TRUE, "Example 2");
/* Geomview setup.
*/
printf("(geometry example { : foo })\n");
fflush(stdout);
/* Loop until killed.
*/
for (t=0; ; t+=dt) {
fdmask = (1 << fileno(stdin)) | (1 << qgetfd());
select(qgetfd()+1, &fdmask, NULL, NULL, &timeout);
fl_check_forms();
UpdateMesh(xmin, xmax, ymin, ymax, xdim, ydim, t);
}
}
/* UpdateMesh sends one mesh iteration to geomview
*/
UpdateMesh(xmin, xmax, ymin, ymax, xdim, ydim, t)
float xmin, xmax, ymin, ymax, t;
int xdim, ydim;
{
int i,j;
float x,y, dx,dy;
dx = (xmax-xmin)/(xdim-1);
dy = (ymax-ymin)/(ydim-1);
printf("(read geometry { define foo \n");
printf("MESH\n");
printf("%1d %1d\n", xdim, ydim);
for (j=0, y = ymin; j<ydim; ++j, y += dy) {
for (i=0, x = xmin; i<xdim; ++i, x += dx) {
printf("%f %f %f\t", x, y, F(x,y,t));
}
printf("\n");
}
printf("})\n");
fflush(stdout);
}
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