static void
linear_arc(int x0, int y0, int radius, double theta, double delta_theta)
/* x coordinate of center */
/* y coordinate of center */
/* radius of arc */
/* initial angle ( +x axis = 0 rad ) */
/* delta angle */
/*
* Notes:
* Draws an arc of radius and center at (x0,y0) beginning at
* angle theta (in rad) and ending at theta + delta_theta
*/
{
int x1, y1, x2, y2;
int i, s = 60;
double dphi;
x2 = x0 + (int) (radius * cos(theta));
y2 = y0 + (int) (radius * sin(theta));
dphi = delta_theta / s;
for (i = 1; i <= s; i++) {
x1 = x2;
y1 = y2;
x2 = x0 + (int)(radius * cos(theta + i*dphi));
y2 = y0 + (int)(radius * sin(theta + i*dphi));
X11_DrawLine(x1, y1, x2, y2);
}
}
static void
linear_arc(int x0, int y0, int radius, double theta1, double theta2)
/* x coordinate of center */
/* y coordinate of center */
/* radius of arc */
/* initial angle ( +x axis = 0 rad ) */
/* final angle ( +x axis = 0 rad ) */
/*
* Notes:
* Draws an arc of radius and center at (x0,y0) beginning at
* angle theta1 (in rad) and ending at theta2
*/
{
int x1, y1, x2, y2;
int s = 60;
double dphi, phi;
x2 = x0 + (int) (radius * cos(theta1));
y2 = y0 + (int) (radius * sin(theta1));
while(theta1 >= theta2)
theta2 += 2 * M_PI;
dphi = (theta2 - theta1) / s;
if ((theta1 + dphi) == theta1) {
theta2 += 2 * M_PI;
dphi = (theta2 - theta1) / s;
}
for(phi = theta1 + dphi; phi < theta2; phi += dphi) {
x1 = x2;
y1 = y2;
x2 = x0 + (int)(radius * cos(phi));
y2 = y0 + (int)(radius * sin(phi));
X11_DrawLine(x1,y1,x2,y2);
}
x1 = x2;
y1 = y2;
x2 = x0 + (int)(radius * cos(theta2));
y2 = y0 + (int)(radius * sin(theta2));
X11_DrawLine(x1,y1,x2,y2);
}
