using struct?

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dosin

Joined: 24 Aug 2007
Posts: 337

dosin 11 Dec 2007, 04:50

I ran across this is the manual..

Code:

struc point x,y
     {
  .x dw x
     .y dw y
     }

would it be possible to:

Code:

struct 3d
{

.x dd 0
.y dd 0
.z dd 0

}3d_points

and how to use a struct with the regs..

mov eax,[3d_points.x]?

11 Dec 2007, 04:50

edfed

Joined: 20 Feb 2006
Posts: 4353
Location: Now

edfed 11 Dec 2007, 05:52

when building a dot, you know the structure, X,Y
when building a box, you know the structure X,Y,XL,YL,color
when building a 3D poligon, you know the structure P1,P2,P3
etc etc...
i don't use the struct macro.
structure can be done with memory directive and a related equate ??.

Code:

point:     ;related equate
X=0
Y=4
points:   ;structure
.1 dd 0,0 ;one point
.2 dd 4,8 
onedot dd 10,10

mov esi,points
mov eax,[esi+point.X]
add esi,8
mov ebx,[esi+point.Y]
mov esi,onedot
mov ecx,[esi+point.Y]

there are frequent bugs when structure is not clear
but with this i don't need the struct directive... Smile

11 Dec 2007, 05:52

revolution
When all else fails, read the source

Joined: 24 Aug 2004
Posts: 20451
Location: In your JS exploiting you and your system

revolution 11 Dec 2007, 07:21

dosin: struc and struct are entirely different things. you have mixed them together in your post.

struc is an assembler preprocessor directive. It is similar to 'macro' with one minor difference that the expanded structure must have a naming label.

struct (with the extra 't') is a macro if you include the standard fasm file 'struct.inc'. If you don't include this file then struct is undefined. Also the struct macro as used in the fasm include file does not use the curly braces {}, you should terminate it with 'ends' and don't use the dots for the internal labels.

Code:

;define the macro structure
struct THREE_D
 x dd ?
 y dd ?
 z dd ?
ends

;instantiate it
my_point THREE_D

;access a value
mov rax,[my_point.x]

11 Dec 2007, 07:21

dosin

Joined: 24 Aug 2007
Posts: 337

dosin 11 Dec 2007, 08:04

lol! struct from programming C/C++... from typing it so much I added the t.

I just have never used the struct in asm I have seen it a few times but not known how to use it!

Well I can't use macros.. I am thinking I have a way around not using it!

Thanks for both the post!

11 Dec 2007, 08:04

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