If two parameters are given to "_NEWIMAGE()" and any graphics command is called (in the program below "PSET") the program gives an error box which, if not taken seriously, the program hangs for a moment then terminates, writing on the terminal "killed". The source code was something I found from the "dot-com" forum that was meant for "QBJS" and not on Linux.
My other addition to the original program was "_DISPLAY" just above "_LIMIT" so this was more tolerable.
Code: (Select All)
''by "mikesharpe" from qb64-dot-com forum
dim shared pi, p, q, d, z0, t, f, sw, sh
sw = 800
sh = 600
d = 700
z0 = 1500
pi = 4*atn(1)
screen _newimage(sw, sh, 12)
sv = 2*pi/30
su = 2*pi/10
for t = 0 to 2*pi step 0.01
cls
u = 0
for v=0 to 2*pi+sv step sv
x = cos(u)
y = sin(u)
z = cos(v)
w = sin(v)
proj x, y, z, w
pset (p, q)
for u=0 to 2*pi+su step su
x = cos(u)
y = sin(u)
z = cos(v)
w = sin(v)
proj x, y, z, w
line -(p, q)
next
next
for u=0 to 2*pi+su step su
x = cos(u)
y = sin(u)
z = cos(v)
w = sin(v)
proj x, y, z, w
pset (p, q), _rgb(255,0,0)
for v=0 to 2*pi+sv step sv
x = cos(u)
y = sin(u)
z = cos(v)
w = sin(v)
proj x, y, z, w
line -(p, q), _rgb(255,0,0)
next
next
_display
_limit 50
next
_autodisplay
system
sub proj(x, y, z, w)
xx = x
yy = y*cos(t) - w*sin(t)
zz = z
ww = y*sin(t) + w*cos(t)
d2 = 3
w0 = 3
xx = xx*d2/(w0 + ww)
yy = yy*d2/(w0 + ww)
zz = zz*d2/(w0 + ww)
xxx = xx*cos(t) - zz*sin(t)
zzz = xx*sin(t) + zz*cos(t)
xx = xxx
zz = zzz
a = pi/12
b = pi/3
xxx = xx*cos(a) - yy*sin(a)
yyy = xx*sin(a) + yy*cos(a)
xx = xxx
yy = yyy
yyy = yy*cos(b) - zz*sin(b)
zzz = yy*sin(b) + zz*cos(b)
yy = yyy
zz = zzz
xx = 200*xx
yy = 200*yy
zz = 200*zz
p = sw/2 + 2*xx*d/(yy + z0)
q = sh/2 - 2*zz*d/(yy + z0)
end subMy other addition to the original program was "_DISPLAY" just above "_LIMIT" so this was more tolerable.