% Customising Syntax

[Charles Pegge]

% line glBegin GL_LINES : glVertex3f (%1) : glVertex3f (%3) : glEnd

line (0,0,-1) to (0,1,-1)

expands to:

glBegin GL_LINES : glVertex3f (0,0,-1) : glVertex3f (0,1,-1) : glEnd

[Mike Lobanovsky]

Can the same be done for Polygon, Circle, Arc, Point, etc. to obtain a standard set of BASIC-like graphics primitives? Noobs will be happy...

[Charles Pegge]

Possibly, Mike.

The underlying functions can be made poymorphic for additional flexibility:

for instance arcs (and fans) can be used for all arcs, circles and symmetrical polygons:

optional Radius, startAng, EndAng, step

Code: OxygenBasic

1.   sub arc(optional float r,a,b,s)
2.   ===============================
3.   float ar,br,c
4.   if not r then r=1.0
5.   if a=0. and b=0. then b=360
6.   if not s then s=5.0
7.   if s<0. then s=-s
8.   if b<a then c=a : a=b : b=c 'swap
9.  glBegin GL_LINE_STRIP
10.   do
11.     ar=rad(a)
12.     br=rad(b)
13.     glVertex2f r*cos(ar),r*sin(ar)
14.     a+=s
15.     if a>=b
16.       glVertex2f r*cos(br),r*sin(br)
17.       exit do
18.     end if
19.   end do
20.   glEnd
21.   end sub
22.