unit Main;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, direct3d9, d3dx9, dxhelp, ExtCtrls;

type
  TForm2 = class(TForm)
    Panel1: TPanel;
    procedure FormClose(Sender: TObject; var Action: TCloseAction);
    procedure FormCreate(Sender: TObject);
  private
    { Private-Deklarationen }
    procedure OnIdle(Sender: TObject; var done: boolean);
  public
    { Public-Deklarationen }
  end;

var
  Form2: TForm2;
  Direct3D9: IDirect3D9;
  D3DDev9: IDirect3DDevice9;
  Vertexbuffer: IDirect3DVertexBuffer9;
  vb_cylinder: IDirect3DVertexBuffer9;
  Timegap, Timestart: Cardinal;

type
  TD3DLVertex = record
    position: TD3DXVector3;
    diffuse: TD3DColor;
  end;

const
  D3DFVF_TD3DLVertex = D3DFVF_XYZ or D3DFVF_DIFFUSE;

implementation

{$R *.dfm}

function InitCylinder: HResult;
var
  Vertices: Array[0..99] of TD3DLVertex;
  CX: Integer;
  theta: Single;
  pVertices: Pointer;
begin
  // Dieser Zylinder wird über eine Schleife erstellt
  // in der jeweils der obere und untere Vertex definiert wird
  for cx := 0 to 49 do
  begin
    theta := ( 2 * D3DX_PI * CX ) / 49;
    Vertices[ 2 * CX ].position := D3DXVector3( cos( theta ), -1.0, sin( theta ) );
    Vertices[ 2 * CX ].diffuse := $FF00FF00;

    Vertices[ 2 * CX + 1 ].position := D3DXVector3( cos( theta ), 1.0, sin( theta ) );
    Vertices[ 2 * CX + 1 ].diffuse := $FFFF0000;
  end;

  // Erstellen des vb_Zylinders
  Result := D3DDev9.CreateVertexBuffer( sizeof( TD3DLVertex ) * 100,
                                        D3DUSAGE_WRITEONLY,
                                        D3DFVF_TD3DLVERTEX,
                                        D3DPOOL_DEFAULT,
                                        vb_cylinder, nil );
  if (Result <> D3D_OK) then
    Exit;
  Result := vb_cylinder.Lock( 0, Sizeof( Vertices ), pVertices, 0 );
  if (Result <> D3D_OK) then
    Exit;
  Move( Vertices, pVertices^, sizeof( Vertices ) );
  vb_cylinder.Unlock;

  Result := D3D_OK;
end;

procedure SetupTransformation;
var
  matRotZ: TD3DXMatrix;
  Rotation: Single;
begin
  Rotation := Rotation + TimeGap * 0.005;
  D3DXMatrixRotationZ( matRotZ, Rotation );
  D3DDev9.SetTransform( D3DTS_WORLDMATRIX(0), matRotZ);
end;

procedure SetupViewAndProjection;
var
  pos, dir, up: TD3DXVector3;
  matView, matProj: TD3DXMatrix;
begin
  // Position, Richtung und Ausrichtung festlegen
  pos := D3DXVector3( 1, 2, -5 );
  dir := D3DXVector3( 0, 0, 0 );
  up := D3DXVector3( 0.0, 1.0, 0.0 );

  // Viewmatrix festlegen
  D3DXMatrixLookAtLH( matView, pos, dir, up );
  D3DDev9.SetTransform( D3DTS_VIEW, matView );

  // Projektionsmatrix festlegen
  D3DXMatrixPerspectiveFovLH( matProj,
                              D3DX_PI / 4,
                              Form2.Width / Form2.Height,
                              1.0, 100 );
  D3DDev9.SetTransform( D3DTS_PROJECTION, matProj );
end;

// Dreieck erstellen
function InitGeometry: HResult;
var
  Vertices: Array[0..2] of TD3DLVertex;
  pVertices: Pointer;
begin
  // Vertices Eigenschaften
  Vertices[ 0 ].position := D3DXVector3( 1, 0, 0 );
  Vertices[ 0 ].diffuse := $FFFF0000;
  Vertices[ 1 ].position := D3DXVector3( -1, 0, 0 );
  Vertices[ 1 ].diffuse := $FF0000FF;
  Vertices[ 2 ].position := D3DXVector3( 0, 1, 0 );
  Vertices[ 2 ].diffuse := $FFFFFFFF;

  // Buffer erstellen
  Result := D3DDev9.CreateVertexBuffer( sizeof( TD3DLVertex ) * 3,
                                        D3DUSAGE_WRITEONLY,
                                        D3DFVF_TD3DLVERTEX, D3DPOOL_DEFAULT,
                                        Vertexbuffer, nil);
  // Gelungen?
  if (Result <> D3D_OK) then
    Exit;

  // Vertexbuffer schließen
  Result := VertexBuffer.Lock( 0, Sizeof( Vertices ), pVertices, 0 );
  // Gelungen?
  if (Result <> D3D_OK) then
    Exit;

  // Dann schieben wir die Vertices an die erlaubte Stelle
  Move( Vertices, pVertices^, Sizeof( Vertices ) );

  // Wieder aufschließen
  Result := Vertexbuffer.Unlock;

  // Kein Lichteinfall
  D3DDev9.SetRenderState( D3DRS_LIGHTING, LongWord( False ) );
end;

procedure TForm2.FormCreate(Sender: TObject);
begin
  // Interface erstellen
  DHInitDGFX( Panel1.Handle, False, 1280,1024,32, True, Direct3D9, D3DDev9 );
  InitGeometry;
  InitCylinder;
  Application.OnIdle := OnIdle;
end;

procedure TForm2.FormClose(Sender: TObject; var Action: TCloseAction);
begin
  DHCloseDGFX( Direct3D9, D3DDev9);
  Vertexbuffer := nil;
end;

procedure Render;
begin
  // Zeitdifferenz ermitteln
  TimeGap := GetTickCount - Timestart;
  Timestart := gettickcount;
  D3DDev9.BeginScene;
  D3DDev9.Clear( 0, nil, D3DCLEAR_TARGET, D3DCOLOR_ARGB(0,0,0,0), 10.0, 0);

  // Kameraeinstellung wählen
  SetupViewAndProjection;

  // Transformation einstellen
// SetupTransformation;

  // Streamsource setzen
  D3DDev9.SetStreamSource(0, vb_cylinder, 0, Sizeof( TD3DLVertex) );
  // FVF setzen
  D3DDev9.SetFVF( D3DFVF_TD3DLVertex );
  // DAS Dreieck rendern
  D3DDev9.DrawPrimitive( D3DPT_TRIANGLELIST, 0, 1 );

  D3DDev9.EndScene;
  D3DDev9.Present( nil, nil, 0, nil );
end;

procedure TForm2.OnIdle(Sender: TObject; var done: boolean);
begin
  done := false;
  Render;
end;

end.