better animate rate (Marcelo Magallon)
diff --git a/progs/demos/bounce.c b/progs/demos/bounce.c
index c0f739e..2f3fa9f 100644
--- a/progs/demos/bounce.c
+++ b/progs/demos/bounce.c
@@ -14,6 +14,8 @@
#include <stdlib.h>
#include <string.h>
#include <GL/glut.h>
+#include <sys/time.h>
+#include <time.h>
#define COS(X) cos( (X) * 3.14159/180.0 )
#define SIN(X) sin( (X) * 3.14159/180.0 )
@@ -25,12 +27,12 @@
GLboolean IndexMode = GL_FALSE;
GLuint Ball;
GLenum Mode;
-GLfloat Zrot = 0.0, Zstep = 6.0;
+GLfloat Zrot = 0.0, Zstep = 180.0;
GLfloat Xpos = 0.0, Ypos = 1.0;
-GLfloat Xvel = 0.2, Yvel = 0.0;
+GLfloat Xvel = 2.0, Yvel = 0.0;
GLfloat Xmin = -4.0, Xmax = 4.0;
GLfloat Ymin = -3.8, Ymax = 4.0;
-GLfloat G = -0.1;
+GLfloat G = -9.8;
static GLuint
make_ball(void)
@@ -149,10 +151,17 @@
idle(void)
{
static float vel0 = -100.0;
+ static double t0 = -1.;
+ double t, dt;
+ t = glutGet(GLUT_ELAPSED_TIME) / 1000.;
+ if (t0 < 0.)
+ t0 = t;
+ dt = t - t0;
+ t0 = t;
- Zrot += Zstep;
+ Zrot += Zstep*dt;
- Xpos += Xvel;
+ Xpos += Xvel*dt;
if (Xpos >= Xmax) {
Xpos = Xmax;
Xvel = -Xvel;
@@ -163,8 +172,8 @@
Xvel = -Xvel;
Zstep = -Zstep;
}
- Ypos += Yvel;
- Yvel += G;
+ Ypos += Yvel*dt;
+ Yvel += G*dt;
if (Ypos < Ymin) {
Ypos = Ymin;
if (vel0 == -100.0)