BlitzScript3D

Noel

Actually, there is no scripting language yet. Just a basic compiler that can parse some basic-like syntax into opcode.

It currently takes the basic program

let a=1
let b=2
let c=a*b+a/b
if a=b then print a else print b
end

and generates these opcodes

//tbasic startup...1
  sub  edx,edx
//let a=1 
  mov  eax,1
  mov  [_a],eax
//let b=2 
  mov  eax,2
  mov  [_b],eax
//let c=a*b+a/b 
  mov  eax,[_a]
  push eax
  mov  eax,[_b]
  pop  ecx
  imul eax,ecx
  push eax
  mov  eax,[_a]
  push eax
  mov  eax,[_b]
  mov  ecx,eax
  pop  ecx
  shl eax,ecx
  pop  ecx
  add  eax,ecx
  mov  [_c],eax
//if a<b then print a else print b 
  mov  eax,[_a]
  push eax
  mov  eax,[_b]
  pop  ecx
  cmp  ecx,eax
  slt  eax
  and  eax,255
  and  eax,eax
  jz  __1
  call print:64
  mov  eax,[_a]
  jmp  __2
__1:
  call print:64
  mov  eax,[_b]
__2:
//end 
  ret

_a:
  dd  0
_b:
  dd  0
_c:
  dd  0
Done!

Pcode is merely a numerical representation of these opcodes

;opcode
mov eax,2

;pcode equivalent
01 2

The VM simulate a cpu containing the necessary LIFO Stacks (Array), Registers/Stack Pointers(Variables), and Functions to process Pcode. Generating opcode may be optional.

Using 'compiled' Pcode files will provide greater performance than 'interpreting' the scripting language on the fly. Compilation is only required once.

This is a good start, lots to add.