C++ to basic4gl

[wallypog]

Hi everyone; I am having problems translating from Cpp to basic4gl. Hereis what I came up with:


'globals
dim c# = 2.0
dim r# = 0.5
dim p = 6 ' Number of grid columns.
dim q = 4 ' Number of grid rows
dim pi# = m_pi
dim &vertices#() = NULL 'map sample to the torus.


'map sample to the torus.
function f#(i,j)
'dim f# '(i,j)
return ( ( c# + r# * cos( (-1 + 2* j/q) * PI# ) ) * cos( (-1 + 2* i/p) * PI# ) )
end function

function g#(i,j)
'dim g#(i,j)
return ( ( c# + r# * cos( (-1 + 2* j/q) * PI# ) ) * sin( (-1 + 2* i/p) * PI# ) )
end function

function h#(i,j)
'dim h#(i,j)
return ( r# * sin( (-1 + 2* j/q) * PI#) )
end function

' c#outine to fill the vertex array with
' co-ordinates of the mapped sample points.
function fillVertexArray()
k = 0
for j = 0 to q
for i = 0 to p


k = k+1 :&vertices(k) = f#(i,j)

k = k+1 :&vertices(k) = g#(i,j)

k = k+1 :&vertices(k) = h#(i,j)
next
next
end function

What am I doing wrong? John

[Adam]

It has been a long time since I have written code in basic4gl, but I noticed that you had a couple issues, like your array ( you can't use an array pointer like that I don't believe. here is a revised version, with issues I noticed, it will get you on the right path

'globals
dim c# = 2.0
dim r# = 0.5
dim p = 6 ' Number of grid columns.
dim q = 4 ' Number of grid rows
dim pi# = m_pi
dim vertices#(10000)'map sample to the torus.
dim k, j, i


'map sample to the torus.
function f#(i,j)
'dim f# '(i,j)
return ( ( c# + r# * cos( (-1 + 2* j/q) * PI# ) ) * cos( (-1 + 2* i/p) * PI# ) )
end function

function g#(i,j)
'dim g#(i,j)
return ( ( c# + r# * cos( (-1 + 2* j/q) * PI# ) ) * sin( (-1 + 2* i/p) * PI# ) )
end function

function h#(i,j)
'dim h#(i,j)
return ( r# * sin( (-1 + 2* j/q) * PI#) )
end function

' c#outine to fill the vertex array with
' co-ordinates of the mapped sample points.
sub fillVertexArray()
   k = 0
   for j = 0 to q
       for i = 0 to p
           k = k+1 :vertices#(k) = f#(i,j)
           k = k+1 :vertices#(k) = g#(i,j)
           k = k+1 :vertices#(k) = h#(i,j)
       next
   next
end sub

fillVertexArray()

[wallypog]

Thanks Adam. Silly me , I thought the problem was an array of pointers. Thanks again Adam, your help is much appreciated. Regards, John

[wallypog]

Since Basic4gl does not support "glVertxPointer" is there a work around for the following function? Cheers, John
' Drawing routine.
function drawScene()
'dim i,j
'*************************
'Dynamic array allocation with new value of p and q.
newfloat# = newfloat# + (3*(p+1)*(q+10))
vertices# = newfloat#
glVertexPointer(3, GL_FLOAT, 0, &vertices#)
glClear(GL_COLOR_BUFFER_BIT)
glLoadIdentity()
gluLookAt(0.0, 0.0, 6.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0)
glPolygonMode(GL_FRONT_AND_BACK, GL_LINE)
glColor3f(0.0, 0.0, 0.0)
' Rotate scene.
glRotatef(Zangle, 0.0, 0.0, 1.0)
glRotatef(Yangle, 0.0, 1.0, 0.0);
glRotatef(Xangle, 1.0, 0.0, 0.0)
end function

[matthew]

I believe that the OpenGLPlugin supports glVertexPointer. :-)

[wallypog]

Thanks Maththew, I'll check it out.