program ModelLoader;

uses
  SysUtils, Classes, crt, Math;

const
  cScale = 1/20;

type
  TPartStruct = record
    wColour: LongInt;
    bType: LongInt;
  end;

  TModelList = array of TPartStruct;

  PDATFile = ^TDATFile;
  TDATFile = record
    tParts: array of TPartStruct;
    iPartCount: LongInt;
  end;

var
  g_sFilenames: string;
  g_sFilesToLoad: string;
  g_ModelCount: LongInt;
  g_tModels: array of TModelList;

function LoadModel(pFile: PChar; sFilename: string = ''; iModelIndex: LongInt = -1; iLoadDependencies: Byte = 1): PDATFile;
var
  iLastPart, iLimitParts, iFailed, iLineNum, iType, iColour, iResu: LongInt;
  pT: PDATFile;
  RecursionLevel, iTotalLines, iTotalParts: LongInt;
  pNew: Pointer;
begin
  iLastPart := 0;
  iLimitParts := -1;
  iFailed := 0;
  iLineNum := 1;
  pT := nil;
  RecursionLevel := 0;
  iTotalLines := 0;
  iTotalParts := 0;
  Inc(RecursionLevel);

  if iModelIndex < 0 then
  begin
    iModelIndex := g_ModelCount;
    SetLength(g_tModels, g_ModelCount + 1);
    Inc(g_ModelCount);
  end;

  repeat
    if iLastPart > iLimitParts then
    begin
      Inc(iLimitParts, 4096);
      ReallocMem(pT, SizeOf(TDATFile) + (iLimitParts + 1) * SizeOf(TPartStruct));
      if pT = nil then
      begin
        WriteLn('Failed to allocate memory to load file');
        iFailed := 1;
        Break;
      end;
    end;

    // Simulate reading and processing model file
    iResu := Random(10);  // Placeholder for actual reading function
    if iResu = 0 then
      Continue;

    // Simulate checking for model type and color
    iType := Random(3);  // Random value to simulate the process
    if iType <> 0 then
    begin
      iColour := Random(16);
      pT^.tParts[iLastPart].wColour := iColour;
      pT^.tParts[iLastPart].bType := iType;
    end;

    Inc(iLastPart);
  until False;

  Dec(RecursionLevel);

  if iFailed = 1 then
  begin
    WriteLn('Failure during file loading');
    Exit(nil);
  end;

  pT^.iPartCount := iLastPart;
  Result := pT;
end;

begin
  Randomize;

  g_sFilenames := '';
  g_sFilesToLoad := '';
  g_ModelCount := 0;
  SetLength(g_tModels, 1);

  WriteLn('Loading model...');
  LoadModel(nil, 'testfile.dat');
end.
uses crt, sysutils, math;

type
  SinglePtr = ^Single;
  LineType2Struct = record
    fX1, fY1, fZ1: Single;
    fX2, fY2, fZ2: Single;
  end;
  LineType4Struct = record
    fX1, fY1, fZ1: Single;
    fX2, fY2, fZ2: Single;
    fX3, fY3, fZ3: Single;
    fX4, fY4, fZ4: Single;
  end;

procedure CrossProduct(v1, v2, result: SinglePtr);
begin
  result^[0] := v1^[1] * v2^[2] - v1^[2] * v2^[1];
  result^[1] := v1^[2] * v2^[0] - v1^[0] * v2^[2];
  result^[2] := v1^[0] * v2^[1] - v1^[1] * v2^[0];
end;

procedure Normalize(v: SinglePtr);
var
  length: Single;
begin
  length := Sqrt(v^[0] * v^[0] + v^[1] * v^[1] + v^[2] * v^[2]);
  if length <> 0.0 then
  begin
    v^[0] := v^[0] / length;
    v^[1] := v^[1] / length;
    v^[2] := v^[2] / length;
  end;
end;

procedure SetLineNormal(var tLine: LineType2Struct);
var
  direction, ref, normal: array[0..2] of Single;
  normalScale: Single;
begin
  direction[0] := tLine.fX2 - tLine.fX1;
  direction[1] := tLine.fY2 - tLine.fY1;
  direction[2] := tLine.fZ2 - tLine.fZ1;

  ref[0] := 0.0;
  ref[1] := 1.0;
  ref[2] := 0.0;

  CrossProduct(@direction[0], @ref[0], @normal[0]);
  Normalize(@normal[0]);

  normalScale := 0.5;
  normal[0] := normal[0] * normalScale;
  normal[1] := normal[1] * normalScale;
  normal[2] := normal[2] * normalScale;

  // In Pascal, you can use OpenGL to set the normal vector like this
  // but this would require the OpenGL unit.
  // glNormal3fv(@normal[0]);
end;

procedure SetQuadNormal(var tQuad: LineType4Struct);
var
  edge1, edge2, normal: array[0..2] of Single;
begin
  edge1[0] := tQuad.fX2 - tQuad.fX1;
  edge1[1] := tQuad.fY2 - tQuad.fY1;
  edge1[2] := tQuad.fZ2 - tQuad.fZ1;

  edge2[0] := tQuad.fX3 - tQuad.fX1;
  edge2[1] := tQuad.fY3 - tQuad.fY1;
  edge2[2] := tQuad.fZ3 - tQuad.fZ1;

  // Compute normal for the first triangle
  CrossProduct(@edge1[0], @edge2[0], @normal[0]);

  // Normalize the normal
  Normalize(@normal[0]);

  // Set normal for the quad
  // glNormal3fv(@normal[0]);
end;
procedure DrawLine2D(x1, y1, x2, y2: Single);
begin
  // OpenGL-like drawing a 2D line
  // This is a placeholder for OpenGL drawing code
  // glBegin(GL_LINES);
  // glVertex2f(x1, y1);
  // glVertex2f(x2, y2);
  // glEnd;
end;

procedure DrawQuad3D(var tQuad: LineType4Struct);
begin
  // OpenGL-like drawing a 3D quad
  // glBegin(GL_QUADS);
  // glVertex3f(tQuad.fX1, tQuad.fY1, tQuad.fZ1);
  // glVertex3f(tQuad.fX2, tQuad.fY2, tQuad.fZ2);
  // glVertex3f(tQuad.fX3, tQuad.fY3, tQuad.fZ3);
  // glVertex3f(tQuad.fX4, tQuad.fY4, tQuad.fZ4);
  // glEnd;
end;

procedure DrawQuadTextured3D(var tQuad: LineType4Struct);
begin
  // OpenGL-like drawing a 3D textured quad
  // glBegin(GL_QUADS);
  // glTexCoord2f(0.0, 0.0);
  // glVertex3f(tQuad.fX1, tQuad.fY1, tQuad.fZ1);

  // glTexCoord2f(1.0, 0.0);
  // glVertex3f(tQuad.fX2, tQuad.fY2, tQuad.fZ2);

  // glTexCoord2f(1.0, 1.0);
  // glVertex3f(tQuad.fX3, tQuad.fY3, tQuad.fZ3);

  // glTexCoord2f(0.0, 1.0);
  // glVertex3f(tQuad.fX4, tQuad.fY4, tQuad.fZ4);

  // glEnd;
end;

procedure DrawTriangle3D(x1, y1, z1, x2, y2, z2, x3, y3, z3: Single);
begin
  // OpenGL-like drawing a 3D triangle
  // glBegin(GL_TRIANGLES);
  // glVertex3f(x1, y1, z1);
  // glVertex3f(x2, y2, z2);
  // glVertex3f(x3, y3, z3);
  // glEnd;
end;

procedure DrawCube(x, y, z, size: Single);
var
  halfSize: Single;
  quad: LineType4Struct;
begin
  halfSize := size / 2.0;

  // Front face
  quad.fX1 := x - halfSize; quad.fY1 := y - halfSize; quad.fZ1 := z + halfSize;
  quad.fX2 := x + halfSize; quad.fY2 := y - halfSize; quad.fZ2 := z + halfSize;
  quad.fX3 := x + halfSize; quad.fY3 := y + halfSize; quad.fZ3 := z + halfSize;
  quad.fX4 := x - halfSize; quad.fY4 := y + halfSize; quad.fZ4 := z + halfSize;
  DrawQuad3D(quad);

  // Back face
  quad.fX1 := x - halfSize; quad.fY1 := y - halfSize; quad.fZ1 := z - halfSize;
  quad.fX2 := x + halfSize; quad.fY2 := y - halfSize; quad.fZ2 := z - halfSize;
  quad.fX3 := x + halfSize; quad.fY3 := y + halfSize; quad.fZ3 := z - halfSize;
  quad.fX4 := x - halfSize; quad.fY4 := y + halfSize; quad.fZ4 := z - halfSize;
  DrawQuad3D(quad);

  // Other faces (left, right, top, bottom) follow the same approach
  // ...
end;
procedure DrawCube(x, y, z, size: Single);
var
  halfSize: Single;
  quad: LineType4Struct;
begin
  halfSize := size / 2.0;

  // Front face
  quad.fX1 := x - halfSize; quad.fY1 := y - halfSize; quad.fZ1 := z + halfSize;
  quad.fX2 := x + halfSize; quad.fY2 := y - halfSize; quad.fZ2 := z + halfSize;
  quad.fX3 := x + halfSize; quad.fY3 := y + halfSize; quad.fZ3 := z + halfSize;
  quad.fX4 := x - halfSize; quad.fY4 := y + halfSize; quad.fZ4 := z + halfSize;
  DrawQuad3D(quad);

  // Back face
  quad.fX1 := x - halfSize; quad.fY1 := y - halfSize; quad.fZ1 := z - halfSize;
  quad.fX2 := x + halfSize; quad.fY2 := y - halfSize; quad.fZ2 := z - halfSize;
  quad.fX3 := x + halfSize; quad.fY3 := y + halfSize; quad.fZ3 := z - halfSize;
  quad.fX4 := x - halfSize; quad.fY4 := y + halfSize; quad.fZ4 := z - halfSize;
  DrawQuad3D(quad);

  // Left face
  quad.fX1 := x - halfSize; quad.fY1 := y - halfSize; quad.fZ1 := z - halfSize;
  quad.fX2 := x - halfSize; quad.fY2 := y - halfSize; quad.fZ2 := z + halfSize;
  quad.fX3 := x - halfSize; quad.fY3 := y + halfSize; quad.fZ3 := z + halfSize;
  quad.fX4 := x - halfSize; quad.fY4 := y + halfSize; quad.fZ4 := z - halfSize;
  DrawQuad3D(quad);

  // Right face
  quad.fX1 := x + halfSize; quad.fY1 := y - halfSize; quad.fZ1 := z - halfSize;
  quad.fX2 := x + halfSize; quad.fY2 := y - halfSize; quad.fZ2 := z + halfSize;
  quad.fX3 := x + halfSize; quad.fY3 := y + halfSize; quad.fZ3 := z + halfSize;
  quad.fX4 := x + halfSize; quad.fY4 := y + halfSize; quad.fZ4 := z - halfSize;
  DrawQuad3D(quad);

  // Top face
  quad.fX1 := x - halfSize; quad.fY1 := y + halfSize; quad.fZ1 := z - halfSize;
  quad.fX2 := x + halfSize; quad.fY2 := y + halfSize; quad.fZ2 := z - halfSize;
  quad.fX3 := x + halfSize; quad.fY3 := y + halfSize; quad.fZ3 := z + halfSize;
  quad.fX4 := x - halfSize; quad.fY4 := y + halfSize; quad.fZ4 := z + halfSize;
  DrawQuad3D(quad);

  // Bottom face
  quad.fX1 := x - halfSize; quad.fY1 := y - halfSize; quad.fZ1 := z - halfSize;
  quad.fX2 := x + halfSize; quad.fY2 := y - halfSize; quad.fZ2 := z - halfSize;
  quad.fX3 := x + halfSize; quad.fY3 := y - halfSize; quad.fZ3 := z + halfSize;
  quad.fX4 := x - halfSize; quad.fY4 := y - halfSize; quad.fZ4 := z + halfSize;
  DrawQuad3D(quad);
end;
procedure DrawCubeTextured(x, y, z, size: Single);
var
  halfSize: Single;
  quad: LineType4Struct;
begin
  halfSize := size / 2.0;

  // Front face
  quad.fX1 := x - halfSize; quad.fY1 := y - halfSize; quad.fZ1 := z + halfSize;
  quad.fX2 := x + halfSize; quad.fY2 := y - halfSize; quad.fZ2 := z + halfSize;
  quad.fX3 := x + halfSize; quad.fY3 := y + halfSize; quad.fZ3 := z + halfSize;
  quad.fX4 := x - halfSize; quad.fY4 := y + halfSize; quad.fZ4 := z + halfSize;
  DrawQuadTextured3D(quad);

  // Back face (similarly for the rest of the cube)
  quad.fX1 := x - halfSize; quad.fY1 := y - halfSize; quad.fZ1 := z - halfSize;
  quad.fX2 := x + halfSize; quad.fY2 := y - halfSize; quad.fZ2 := z - halfSize;
  quad.fX3 := x + halfSize; quad.fY3 := y + halfSize; quad.fZ3 := z - halfSize;
  quad.fX4 := x - halfSize; quad.fY4 := y + halfSize; quad.fZ4 := z - halfSize;
  DrawQuadTextured3D(quad);

  // Left, right, top, bottom faces would follow in the same fashion
  // ...
end;