Tiny 3DS loader

[virtual]

hi
a tiny 3ds warpper draw 1 object wih 1 texture
in fact this is my translation of a c++ code has been found in www.codesampler.com

Unit Mini3ds;

interface

uses windows,opengl;


const
   MAX_GEO = 10000;
type

// Vertex
   Vertex  = record
        x,
        y,
        z : single;
        end;

// texture
   mapcoord = record
        u,
        v : single;
        end;

// index
   polygon = record
        a,
        b,
        c : integer;
        end;

// 3d object structure
   _object = record
        name : array[0..21] of char;
        numVerts : integer;
        numPolys : integer;
        v : array [0..MAX_GEO] of vertex;
        p : array [0..MAX_GEO] of polygon;
        m : array [0..MAX_GEO] of mapcoord;
        end;

// 3ds object
  T3DS = object
   public
    procedure Load(_fn : string);
    procedure Draw();
    procedure free();
   public
    obj : _object;
   end;


implementation

{ T3DS }

procedure T3DS.Load(_fn: string);
var
_file : file of byte;
 i  : integer;
 chunkID : short;
 chunkLength  : integer;
 tmp       : char;
 useless  : short;
 from      : integer;
_fsize     : integer;
 label begincase;
begin

    AssignFile(_file,_fn);
    Reset(_file);
  _fsize := filesize(_file);

  while ( filepos(_file) < _fsize) do
  begin
     begincase:
     BlockRead(_file,chunkID,2);
     BlockRead(_file,chunkLength,4);

    case chunkID of

     $4d4d : begin end;
     $3d3d : begin end;
     $4000 :
  	for i:=0 to 20-1 do
	 begin
	       Blockread (_file,tmp, 1);
                       obj.name[i]:=tmp;
                if pointer(tmp) = NIL then
              goto begincase;
      end;

     $3f80 :begin end;
     $4100 :begin end;
     $4110 :
         begin
   	BlockRead(_file,obj.numVerts,2);
    	for i:=0 to obj.numVerts - 1 do
                    begin
	         BlockRead (_file, obj.v[i].x,4);
                         BlockRead (_file, obj.v[i].y,4);
    	         BlockRead (_file, obj.v[i].z,4);
 	    end;
        end;

     $4120 :
      begin
	BlockRead (_file,obj.numPolys, 2);
                  for i:=0 to obj.numPolys - 1 do
                     begin
	        BlockRead (_file,obj.p[i].a, 2);
    	        BlockRead (_file,obj.p[i].b, 2);
	        BlockRead (_file,obj.p[i].c, 2);
	        BlockRead (_file,useless, 2);
	     end;
      end;

     $4140 :
      begin
   	BlockRead (_file , useless, 2);
    	  for i:=0 to obj.numVerts - 1 do
	     begin
	         BlockRead (_file , obj.m[i].u , 4);
                         BlockRead (_file , obj.m[i].v , 4);
	     end;
      end;
    else
    begin
         from := filePos(_file);
         seek(_file,from + chunkLength-6);
     end;
    end;
  end;
 closefile(_file);
end;

procedure T3DS.Draw();
var i : integer;
begin

   glBegin(GL_TRIANGLES);
     for i:=0 to obj.numPolys - 1 do
        begin
             glTexCoord2f( obj.m[ obj.p[i].a ].u,obj.m[ obj.p[i].a ].v);
             glVertex3f( obj.v[ obj.p[i].a ].x,
                              obj.v[ obj.p[i].a ].y,
                              obj.v[ obj.p[i].a ].z);

             glTexCoord2f( obj.m[ obj.p[i].b ].u,obj.m[ obj.p[i].b ].v);
             glVertex3f( obj.v[ obj.p[i].b ].x,
                              obj.v[ obj.p[i].b ].y,
                              obj.v[ obj.p[i].b ].z);

             glTexCoord2f( obj.m[ obj.p[i].c ].u,obj.m[ obj.p[i].c ].v);
             glVertex3f( obj.v[ obj.p[i].c ].x,
                              obj.v[ obj.p[i].c ].y,
                              obj.v[ obj.p[i].c ].z);
        end;

 glEnd();

end;

procedure T3DS.free;
begin
 //
end.

virtual

[WILL]

Cool. Is this something that you will be continually updating?

[virtual]

this way we don't need to update

[User137]

I was hoping it'd have bone structure i could learn from Useful regardless.

[noeska]

Oh another 3ds loader for pascal and opengl :-)

Have a look at mine too: http://www.noeska.com/dogl/glmodel.aspx . That also does bone animation for milkshape ascii files. But afaik mine might have lost its tinyness...

[WILL]

Wow, I just realized just how tiny this little loader really is. Now you called it a wrapper, but in reality it's just a mini library for use with OpenGL, right? From the source code above it doesn't seem to need an extra API file to work.

[Brainer]

Don't take it as a criticism, but I'd really love to see the code more Delphi-like ("objects" were deprecated a long time ago). Plus, just like User137 said, animations would be most welcome, too. Also, some normal calculation code can fit in too, if you ask me.

Enough bitchin, nice piece of work, virtual. Keep up the great work, hope you can expand the code.

[virtual]

glad that you like it

i think this is the most minimal 3ds loader , i used it to draw low res objects. ( i use another loader for other purposes)
another thing can benefit is to write your own simple 3d file format based on the previous data structure

[Ingemar]

Can you point me to a 3ds file for which this loader works? I have tried it on some, but they seem to include multiple sets of vertices, which overwrite each other in this loader. I suppose these are complex shapes, unsupported by this code, right?

[Ingemar]

Can you point me to a 3ds file for which this loader works? I have tried it on some, but they seem to include multiple sets of vertices, which overwrite each other in this loader. I suppose these are complex shapes, unsupported by this code, right?

I found one answer in my own notes (after trying the C++ original of this code):

"62standing-woman.3ds"

I don't know where I got that, but that one works - but most others I have tried fail. That limits the usage quite a bit.