Rotating some points , seems slow

[slenkar]

im drawing lines between the points now (with DRAW )
but they seem to go up and right for some reason,

here is the code

triship arrays are two dimensional, one dimension for which ship it refers to
and the other dimension for the points

Code:

#include <FSin.bas>
#include <SP/Fill.bas>

Dim fsinarray(361) as Fixed
for iter=0 to 360
fsinarray(iter)=fSin(iter)
next

Dim fcosarray(361) as Fixed
for iter=0 to 360
fcosarray(iter)=fCos(iter)
next

Dim trishipx(2,12) as UByte
Dim trishipy(2,12) as UByte
Dim drawtrishipx(2,12) as UByte
dim drawtrishipy(2,12) as UByte
Dim fc, fs, tx, ty As Fixed


trishipx(0,0)=62
trishipy(0,0)=58

trishipx(0,1)=58
trishipy(0,1)=58

trishipx(0,2)=58
trishipy(0,2)=62

trishipx(0,3)=58
trishipy(0,3)=54

trishipx(0,4)=60
trishipy(0,4)=58

trishipx(0,5)=60
trishipy(0,5)=62


trishipx(1,0)=162
trishipy(1,0)=158

trishipx(1,1)=158
trishipy(1,1)=158

trishipx(1,2)=158
trishipy(1,2)=162

trishipx(1,3)=158
trishipy(1,3)=154

trishipx(1,4)=160
trishipy(1,4)=158

trishipx(1,5)=160
trishipy(1,5)=162


Dim trishipangle as Integer

Function rotate(degrees as Integer) as Integer
dim pointx as Ubyte
dim pointy as Ubyte

for trishipiter =0 to 1
if trishipiter=0 then
pointx=54
pointy=54
end if
if trishipiter=1 then
pointx=100
pointy=100
end if
if trishipiter=2 then
pointx=154
pointy=54
end if

  for  x=0 to 5
'Local theta:Float=1

fc = fcosarray(degrees)
fs = fsinarray(degrees)
tx = trishipx(trishipiter,x) - pointx
ty = trishipy(trishipiter,x) - pointy

drawtrishipx(trishipiter,x)= fc * tx - fs * ty + pointx
drawtrishipy(trishipiter,x)= fs * tx + fc * ty + pointy

'transformedX= fCos(degrees) * (trishipx(x)-pointx) - fSin(degrees) * (trishipy(x)-pointy) + pointx
'transformedY = fSin(degrees) * (trishipx(x)-pointx) + fCos(degrees) * (trishipy(x)-pointy) + pointy

Next
next
return 1
End Function

Function drawship() as Integer
for trishipiter=0 to 1
for x=0 to 5
'plotPoint(drawtrishipx(trishipiter,x),drawtrishipy(trishipiter,x))

if x<5 then
PLOT drawtrishipx(trishipiter,x), drawtrishipy(trishipiter,x)
DRAW drawtrishipx(trishipiter,x+1), drawtrishipy(trishipiter,x+1)
end if
if x=5 then
PLOT drawtrishipx(trishipiter,x), drawtrishipy(trishipiter,x)
DRAW drawtrishipx(trishipiter,0), drawtrishipy(trishipiter,0)
end if

next
next
return 1
End Function

While 1
CLS

trishipangle=trishipangle+1
if trishipangle>360 then
trishipangle=0
end if



'for x=0 to 5
'plotPoint(drawtrishipx(x),drawtrishipy(x))
'next

rotate(trishipangle)

drawship()

Wend



SUB plotPoint (x as uByte, y as uByte)
ASM
ld d,(IX+5) ;'X
ld e,(IX+7) ;'Y

    ld a, 191
   sub e  
   ret c  
   ld e, a  
   and a  
  
    rra      
   scf      
   rra      
   and a  
   rra      
   xor e        
   and 248
   xor e
   ld h, a
   ld a, d
   rlca
   rlca
   rlca
   xor e
   and 199
   xor e
   rlca
   rlca
   ld l, a
  
    ld a, d
   and 7
   ld b, a
   inc b
   ld a, 1
  
    plotPoint_loop:
        rrca
   djnz plotPoint_loop  
   ;cpl
    ld b, a  
   ld a, (hl)
   or b  
   ld (hl), a
  
END ASM


EDIT-
after drawing my own lines I could draw a rotating part of a spaceship
(featuring britlions fill routine)
http://www.4shared.com/file/DLgxB2PY/rotate_1.html

looks like it will have to be...turn based spaceship combat
END SUB