//
// The graphics engine GXScene https://github.com/glscene
//
unit FRxMaterialPreview;

(* Material Preview frame *)

interface

uses
  System.SysUtils,
  System.Types,
  System.UITypes,
  System.Classes,
  System.Variants,
  System.Math.Vectors,
  FMX.Types,
  FMX.Graphics,
  FMX.Controls,
  FMX.Forms,
  FMX.Dialogs,
  FMX.StdCtrls,
  FMX.Media,
  FMX.Viewport3D,
  FMX.ListBox,
  FMX.Types3D,
  FMX.Controls3D,
  FMX.Objects3D,
  FMX.MaterialSources,
  FMX.Layers3D,

  GXS.BaseClasses,
  GXS.Scene,
//  GXS.SceneViewer,
  GXS.Material,
  GXS.HUDObjects,
  GXS.GeomObjects,
  GXS.Color,
  GXS.Coordinates;

type
  TMaterialPreviewFrame = class(TFrame)
    CBObject: TComboBox;
    Camera: TCamera;
    Cube: TCube;
    Sphere: TSphere;
    LightSource: TLight;
    CBBackground: TComboBox;
    BackGroundSprite: TImage3D;
    LightMaterialSource: TLightMaterialSource;
    Cone: TCone;
    Teapot: TModel3D;
    World: TDummy;
    Light: TDummy;
    FireSphere: TSphere;
    GLSViewer: TViewport3D;
    procedure CBObjectChange(Sender: TObject);
    procedure CBBackgroundChange(Sender: TObject);
    procedure GLSViewerMouseMove(Sender: TObject; Shift: TShiftState; X,
      Y: Single);
    procedure GLSViewerMouseDown(Sender: TObject; Button: TMouseButton;
      Shift: TShiftState; X, Y: Single);
    procedure GLSViewerMouseWheel(Sender: TObject; Shift: TShiftState;
      WheelDelta: Integer; var Handled: Boolean);
    procedure GLSViewerMouseUp(Sender: TObject; Button: TMouseButton;
      Shift: TShiftState; X, Y: Single);
  private
    FLibMaterial: TgxAbstractLibMaterial;
    function GetMaterial: TgxMaterial;
    procedure SetMaterial(const Value: TgxMaterial);
    function GetLibMaterial: TgxAbstractLibMaterial;
    procedure SetLibMaterial(const Value: TgxAbstractLibMaterial);
  public
    IsMouseUp : Boolean;
    Down : TPointF;
    GLMaterialLibrary: TgxMaterialLibrary;
    constructor Create(AOwner : TComponent); override;
    property Material : TgxMaterial read GetMaterial
      write SetMaterial;
    property LibMaterial : TgxAbstractLibMaterial read GetLibMaterial
      write SetLibMaterial;
  end;

//=======================================================================
implementation
//=======================================================================

{$R *.fmx}

var
  MX, MY: Integer;

//--------------------------------------------------------------
// TRMaterialPreview
//--------------------------------------------------------------

constructor TMaterialPreviewFrame.Create(AOwner: TComponent);
begin
  inherited;
   BackGroundSprite.Position.X := GLSViewer.Width/2;
   BackGroundSprite.Position.Y := GLSViewer.Height/2;
   BackGroundSprite.Width := GLSViewer.Width;
   BackGroundSprite.Height := GLSViewer.Height;

   CBObject.ItemIndex:=0;       CBObjectChange(Self);
   CBBackground.ItemIndex:=0;   CBBackgroundChange(Self);
end;

procedure TMaterialPreviewFrame.CBObjectChange(Sender: TObject);
var
   i : Integer;
begin
   i:=CBObject.ItemIndex;
   Cube.Visible   := I = 0;
   Sphere.Visible := I = 1;
   Cone.Visible   := I = 2;
   Teapot.Visible := I = 3;
end;

procedure TMaterialPreviewFrame.CBBackgroundChange(Sender: TObject);
var
   bgColor : TColor;
begin
   case CBBackground.ItemIndex of
      1 : bgColor := TColors.White;
      2 : bgColor := TColors.Black;
      3 : bgColor := TColors.Blue;
      4 : bgColor := TColors.Red;
      5 : bgColor := TColors.Green;
   else
      bgColor := TColors.SysNone;
   end;
   if (bgColor<>TColors.SysNone) then
     BackGroundSprite.Bitmap.Canvas.Fill.Color := bgColor;
end;

procedure TMaterialPreviewFrame.GLSViewerMouseMove(Sender: TObject;
  Shift: TShiftState; X, Y: Single);
begin
  if (ssLeft in Shift) and (ssLeft in Shift) then
  begin
    World.RotationAngle.X := World.RotationAngle.X - ((Y - Down.Y) * 0.3);
    World.RotationAngle.Y := World.RotationAngle.Y + ((X - Down.X) * 0.3);
    Down := PointF(X, Y);
  end;
end;

procedure TMaterialPreviewFrame.GLSViewerMouseUp(Sender: TObject;
  Button: TMouseButton; Shift: TShiftState; X, Y: Single);
begin
  IsMouseUp := False;
end;

procedure TMaterialPreviewFrame.GLSViewerMouseDown(Sender: TObject;
  Button: TMouseButton; Shift: TShiftState; X, Y: Single);
begin
  Down := PointF(X, Y);
  IsMouseUp := True;
end;

procedure TMaterialPreviewFrame.GLSViewerMouseWheel(Sender: TObject;
  Shift: TShiftState; WheelDelta: Integer; var Handled: Boolean);
var
  AVector: TVector3D;
begin
  AVector := Vector3D(0, 0, 1);
  Camera.Position.Vector := Camera.Position.Vector + AVector * (WheelDelta / 120) * 0.3;
end;

function TMaterialPreviewFrame.GetMaterial: TgxMaterial;
begin
  Result := GLMaterialLibrary.Materials[0].Material;
end;

procedure TMaterialPreviewFrame.SetMaterial(const Value: TgxMaterial);
begin
  GLMaterialLibrary.Materials[0].Material.Assign(Value.GetActualPrimaryMaterial);
end;

function TMaterialPreviewFrame.GetLibMaterial: TgxAbstractLibMaterial;
begin
  Result := FLibMaterial;
end;

procedure TMaterialPreviewFrame.SetLibMaterial(const Value: TgxAbstractLibMaterial);
begin
  FLibMaterial := Value;
  if Assigned(FLibMaterial) then
  begin
    with GLMaterialLibrary.Materials[0] do
    begin
      Material.MaterialLibrary := FLibMaterial.MaterialLibrary;
      Material.LibMaterialName := FLibMaterial.Name
    end;
  end
  else
  with GLMaterialLibrary.Materials[0] do
  begin
    Material.MaterialLibrary := nil;
    Material.LibMaterialName := '';
  end;
end;

end.