//
// The graphics engine GLXEngine. The unit of GXScene for Delphi
//
unit FRxColorEditor;

(* RGB+Alpha color editor *)

interface

uses
  System.SysUtils,
  System.Types,
  System.UITypes,
  System.Classes,
  System.Variants,
  FMX.Types,
  FMX.Graphics,
  FMX.Controls,
  FMX.Forms,
  FMX.Dialogs,
  FMX.StdCtrls,
  FMX.Colors,
  FMX.Edit,
  FMX.Controls.Presentation,
  FMX.Objects,

  Stage.VectorTypes,
  Stage.VectorGeometry,
  GXS.Color,
  GXS.Texture;

type
  TColorEditorFrame = class(TFrame)
    Label1: TLabel;
    Label2: TLabel;
    Label3: TLabel;
    Label4: TLabel;
    Panel1: TPanel;
    ColorEditorPaintBox: TPaintBox;
    RedEdit: TEdit;
    GreenEdit: TEdit;
    BlueEdit: TEdit;
    AlphaEdit: TEdit;
    PAPreview: TColorPanel;
    procedure TBEChange(Sender: TObject);
    procedure ColorEditorPaintBoxPaint(Sender: TObject; Canvas: TCanvas);
    procedure FrameResize(Sender: TObject);
    procedure ColorEditorPaintBoxMouseDown(Sender: TObject;
      Button: TMouseButton; Shift: TShiftState; X, Y: Single);
    procedure ColorEditorPaintBoxMouseMove(Sender: TObject; Shift: TShiftState;
      X, Y: Single);
    procedure ColorEditorPaintBoxMouseUp(Sender: TObject; Button: TMouseButton;
      Shift: TShiftState; X, Y: Single);
    procedure RedEditChange(Sender: TObject);
    procedure GreenEditChange(Sender: TObject);
    procedure BlueEditChange(Sender: TObject);
    procedure AlphaEditChange(Sender: TObject);
    procedure PAPreviewDblClick(Sender: TObject);
  private
    FOnChange: TNotifyEvent;
    Updating: Boolean;
    WorkBitmap: TBitmap;
    RedValue: Integer;
    GreenValue: Integer;
    BlueValue: Integer;
    AlphaVAlue: Integer;
    DraggingValue: (None, Red, Green, Blue, Alpha);
    procedure SetColor(const val: THomogeneousFltVector);
    function GetColor: THomogeneousFltVector;
    procedure DrawContents;
    procedure DragColorSliderToPosition(XPos: Integer);
    procedure ContentsChanged;
  public
    constructor Create(AOwner: TComponent); override;
    destructor Destroy; override;
    property Color: THomogeneousFltVector read GetColor write SetColor;
  published
    property OnChange: TNotifyEvent read FOnChange write FOnChange;
  end;

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

// =====================================================================

{$R *.fmx}

const
  MaxColorValue = 255;
  MaxAlphaValue = 1000;

  ColorSliderLeft = 40;
  ColorSliderWidth = 128;
  ColorSliderHeight = 16;
  ColorViewHeight = 7;
  ColorSliderMaxValue = ColorSliderWidth - 2;

  RTop = 8;
  GTop = 30;
  BTop = 52;
  ATop = 74;

  PreviewPanelLeft = 216;
  PreviewPanelTop = 10;
  PreviewPanelWidth = 65;
  PreviewPanelHeight = 74;

  AlphaCheckSize = 9;
  AlphaChecksHigh = 4;
  AlphaChecksWide = 7;

procedure TColorEditorFrame.TBEChange(Sender: TObject);
begin
  PAPreview.Color := RedValue + (GreenValue Shl 8) + (BlueValue Shl 16); //RGB(RedValue, GreenValue, BlueValue);
  if (not Updating) and Assigned(FOnChange) then
    FOnChange(Self);
end;

procedure TColorEditorFrame.SetColor(const val: THomogeneousFltVector);
begin
  RedValue := Round(val.X * 255);
  GreenValue := Round(val.Y * 255);
  BlueValue := Round(val.Z * 255);
  AlphaVAlue := Round(val.W * 1000);

  ContentsChanged;
end;

function TColorEditorFrame.GetColor: THomogeneousFltVector;
begin
  Result := VectorMake(RedValue / 255, GreenValue / 255, BlueValue / 255,
    AlphaVAlue / 1000);
end;

procedure TColorEditorFrame.ColorEditorPaintBoxPaint(Sender: TObject;
  Canvas: TCanvas);
begin
  ColorEditorPaintBox.Canvas.Bitmap.Assign(WorkBitmap);
  RedEdit.Height := 16;
  GreenEdit.Height := 16;
  BlueEdit.Height := 16;
  AlphaEdit.Height := 16;
end;

constructor TColorEditorFrame.Create(AOwner: TComponent);
begin
  inherited;
  WorkBitmap := TBitmap.Create;
  (* in VCL
    WorkBitmap.PixelFormat := glpf24bit;
    WorkBitmap.Handle := TBitmapHandleType.bmDib;
  *)
  RedValue := 200;
  GreenValue := 120;
  BlueValue := 60;
  AlphaVAlue := 450;
end;

destructor TColorEditorFrame.Destroy;
begin
  inherited;
  WorkBitmap.Free;
end;

procedure TColorEditorFrame.FrameResize(Sender: TObject);
begin
  WorkBitmap.Width := Round(ColorEditorPaintBox.Width);
  WorkBitmap.Height := Round(ColorEditorPaintBox.Height);
  with WorkBitmap.Canvas do
  begin
    { TODO : rewright to use TPath and SVG drawing }
    (*
      Pen.Color := TColors.Lime;
      MoveTo(0,0);
      LineTo(Width-1,Height-1);
      MoveTo(Width-1,0);
      LineTo(0,Height-1);
    *)
  end;
  DrawContents;

  // Edits have an annoying habit of forgetting their height if they are small
  RedEdit.Height := 18;
  GreenEdit.Height := 18;
  BlueEdit.Height := 18;
  AlphaEdit.Height := 18;
end;

function ColorValueToColorViewPosition(ColorValue: Integer): Integer;
begin
  Result := Round((ColorSliderMaxValue / (MaxColorValue + 1)) * ColorValue);
end;

function AlphaValueToColorViewPosition(AlphaVAlue: Integer): Integer;
begin
  Result := Round((ColorSliderMaxValue / (MaxAlphaValue + 1)) * AlphaVAlue);
end;

function ColorViewPositionToColorValue(ColorViewPosition: Integer): Integer;
begin
  if ColorViewPosition < 0 then
    ColorViewPosition := 0;
  if ColorViewPosition > ColorSliderMaxValue then
    ColorViewPosition := ColorSliderMaxValue;

  Result := Round(ColorViewPosition / (ColorSliderMaxValue / (MaxColorValue)));
end;

function ColorViewPositionToAlphaValue(ColorViewPosition: Integer): Integer;
begin
  if ColorViewPosition < 0 then
    ColorViewPosition := 0;
  if ColorViewPosition > ColorSliderMaxValue then
    ColorViewPosition := ColorSliderMaxValue;
  Result := Round(ColorViewPosition / (ColorSliderMaxValue / (MaxAlphaValue)));
end;

procedure TColorEditorFrame.DrawContents;
var
  Position: Integer;
  tx, ty: Integer;
  RViewColor: TColor;
  GViewColor: TColor;
  BViewColor: TColor;
  AViewColor: TColor;
  ViewLevel: Integer;
  WhiteCheckColor: TColor;
  BlackCheckColor: TColor;
  AValue: Single;
  ARect: TRectF;
begin
  WorkBitmap.Canvas.Fill.Color := TColors.cBTNFACE;
  ARect := TRectF.Create(0, 0, WorkBitmap.Width, WorkBitmap.Height);
  WorkBitmap.Canvas.BeginScene;
  WorkBitmap.Canvas.FillRect(ARect, 20, 40, AllCorners, 100);
  WorkBitmap.Canvas.EndScene;
  { TODO : must be replaced with fmx font, brush and textout }
  (*
    Font.Color := TColors.Black;
    Font.Name := 'Arial';
    Font.Height := 14;

    TextOut(6,5,'Red');
    TextOut(6,26,'Green');
    TextOut(6,48,'Blue');
    TextOut(6,70,'Alpha');

    Brush.Color := TColors.Black;
    FrameRect(Rect(ColorSliderLeft,RTop,ColorSliderLeft+ColorSliderWidth,RTop+ColorViewHeight));
    FrameRect(Rect(ColorSliderLeft,GTop,ColorSliderLeft+ColorSliderWidth,GTop+ColorViewHeight));
    FrameRect(Rect(ColorSliderLeft,BTop,ColorSliderLeft+ColorSliderWidth,BTop+ColorViewHeight));
    FrameRect(Rect(ColorSliderLeft,ATop,ColorSliderLeft+ColorSliderWidth,ATop+ColorViewHeight));

    // Color View Frames
    Pen.Color := TColors.cBTNSHADOW;
    PolyLine([  Point(ColorSliderLeft-1,RTop+ColorViewHeight),
    Point(ColorSliderLeft-1,RTop-1),
    Point(ColorSliderLeft+ColorSliderWidth+1,RTop-1)  ]);

    PolyLine([  Point(ColorSliderLeft-1,GTop+ColorViewHeight),
    Point(ColorSliderLeft-1,GTop-1),
    Point(ColorSliderLeft+ColorSliderWidth+1,GTop-1)  ]);

    PolyLine([  Point(ColorSliderLeft-1,BTop+ColorViewHeight),
    Point(ColorSliderLeft-1,BTop-1),
    Point(ColorSliderLeft+ColorSliderWidth+1,BTop-1)  ]);

    PolyLine([  Point(ColorSliderLeft-1,ATop+ColorViewHeight),
    Point(ColorSliderLeft-1,ATop-1),
    Point(ColorSliderLeft+ColorSliderWidth+1,ATop-1)  ]);

    Pen.Color := TColors.cBTNHIGHLIGHT;

    PolyLine([  Point(ColorSliderLeft,RTop+ColorViewHeight),
    Point(ColorSliderLeft+ColorSliderWidth,RTop+ColorViewHeight),
    Point(ColorSliderLeft+ColorSliderWidth,RTop) ]);

    PolyLine([  Point(ColorSliderLeft,GTop+ColorViewHeight),
    Point(ColorSliderLeft+ColorSliderWidth,GTop+ColorViewHeight),
    Point(ColorSliderLeft+ColorSliderWidth,GTop) ]);

    PolyLine([  Point(ColorSliderLeft,BTop+ColorViewHeight),
    Point(ColorSliderLeft+ColorSliderWidth,BTop+ColorViewHeight),
    Point(ColorSliderLeft+ColorSliderWidth,BTop) ]);

    PolyLine([  Point(ColorSliderLeft,ATop+ColorViewHeight),
    Point(ColorSliderLeft+ColorSliderWidth,ATop+ColorViewHeight),
    Point(ColorSliderLeft+ColorSliderWidth,ATop) ]);

    // Color pointer triangles

    Pen.Color := clBlack;
    Position:=ColorValueToColorViewPosition(RedValue) + ColorSliderLeft;
    PolyLine([ Point(Position,RTop+ColorViewHeight+2),
    Point(Position+6,RTop+ColorViewHeight+8),
    Point(Position-6,RTop+ColorViewHeight+8),
    Point(Position,RTop+ColorViewHeight+2)]);

    Position:=ColorValueToColorViewPosition(GreenValue) + ColorSliderLeft;
    PolyLine([ Point(Position,GTop+ColorViewHeight+2),
    Point(Position+6,GTop+ColorViewHeight+8),
    Point(Position-6,GTop+ColorViewHeight+8),
    Point(Position,GTop+ColorViewHeight+2)]);

    Position:=ColorValueToColorViewPosition(BlueValue) + ColorSliderLeft;
    PolyLine([ Point(Position,BTop+ColorViewHeight+2),
    Point(Position+6,BTop+ColorViewHeight+8),
    Point(Position-6,BTop+ColorViewHeight+8),
    Point(Position,BTop+ColorViewHeight+2)]);

    Position:=AlphaValueToColorViewPosition(AlphaValue) + ColorSliderLeft;
    PolyLine([ Point(Position,ATop+ColorViewHeight+2),
    Point(Position+6,ATop+ColorViewHeight+8),
    Point(Position-6,ATop+ColorViewHeight+8),
    Point(Position,ATop+ColorViewHeight+2)]);

    // Color view spectrums
    For tx := 1 to ColorSliderWidth - 2 do
    begin
    ViewLevel := (tx * 256) div ColorSliderWidth;
    AViewColor := (ViewLevel) + (ViewLevel shl 8) + (viewLevel shl 16);
    RViewColor := (ViewLevel) + (GreenValue Shl 8) + (BlueValue Shl 16);
    GViewColor := (RedValue) + (ViewLevel shl 8) + (BlueValue Shl 16);
    BViewColor := (RedValue) + (GreenValue Shl 8) + (ViewLevel Shl 16);
    For ty := 1 to ColorViewHeight -2 do
    begin
    Pixels[ColorSliderLeft+tx,Rtop+Ty]:=RViewCOlor;
    Pixels[ColorSliderLeft+tx,Gtop+Ty]:=GViewColor;
    Pixels[ColorSliderLeft+tx,Btop+Ty]:=BViewColor;
    Pixels[ColorSliderLeft+tx,Atop+Ty]:=AViewColor;
    end;
    end;

    // Color preview panel
    Pen.Color := clBtnShadow;
    PolyLine([  Point(PreviewPanelLeft-1,PreviewPanelTop+PreviewPanelHeight),
    Point(PreviewPanelLeft-1,PreviewPanelTop-1),
    Point(PreviewPanelLeft+PreviewPanelWidth,PreviewPanelTop-1) ]);
    Pen.Color := clBtnHighlight;
    PolyLine([  Point(PreviewPanelLeft,PreviewPanelTop+PreviewPanelHeight),
    Point(PreviewPanelLeft+PreviewPanelWidth,PreviewPanelTop+PreviewPanelHeight),
    Point(PreviewPanelLeft+PreviewPanelWidth,PreviewPanelTop) ]);

    Brush.Color := (RedValue) + (GreenValue Shl 8) + (BlueValue Shl 16);
    Pen.Color := clBlack;
    Rectangle(Rect(PreviewPanelLeft,PreviewPanelTop,PreviewPanelLeft+PreviewPanelWidth,PreviewPanelTop+PreviewPanelHeight div 2 ) );
    PolyLine([  Point(PreviewPanelLeft,PreviewPanelTop+PreviewPanelHeight div 2 -1),
    Point(PreviewPanelLeft,PreviewPanelTop+PreviewPanelHeight -1),
    Point(PreviewPanelLeft+PreviewPanelWidth-1,PreviewPanelTop+PreviewPanelHeight-1),
    Point(PreviewPanelLeft+PreviewPanelWidth-1,PreviewPanelTop+PreviewPanelHeight div 2-1)
    ]);

    AValue := AlphaValue / MaxAlphaValue;
    BlackCheckColor := Round(RedValue * Avalue) + Round(GreenValue*AValue) shl 8 + Round(BlueValue*AValue) shl 16;
    WhiteCheckColor := Round(RedValue * Avalue + (255 * (1-AValue))) + Round(GreenValue*AValue + (255 * (1-AValue))) shl 8 +  Round(BlueValue*AValue + (255 * (1-AValue))) shl 16;
    For ty := 0 to AlphaChecksHigh - 1 do
    begin
    For tx := 0 to AlphaChecksWide - 1 do
    begin
    if (tx+ty) and 1 = 0 then Brush.Color := BlackCheckColor else Brush.Color := WhiteCheckColor;
    FillRect(Rect(  PreviewPanelLeft+1 + tx*AlphaCheckSize,
    PreviewPanelTop+PreviewPanelHeight Div 2 + ty*AlphaCheckSize,
    PreviewPanelLeft+1 + (tx+1)*AlphaCheckSize,
    PreviewPanelTop+PreviewPanelHeight Div 2 + (ty+1)*AlphaCheckSize
    ));
    end;
    end;
  *)
end;

procedure TColorEditorFrame.ColorEditorPaintBoxMouseDown(Sender: TObject;
  Button: TMouseButton; Shift: TShiftState; X, Y: Single);
begin
  DraggingValue := None;
  if Button = TMouseButton.mbLeft then
  begin
    if (X > ColorSliderLeft - 5) and
      (X < (ColorSliderLeft + ColorSliderMaxValue + 5)) then
    begin
      // In X range For Color Sliders
      If (Y > RTop) and ((RTop + ColorSliderHeight) > Y) then
        DraggingValue := Red;
      If (Y > GTop) and ((GTop + ColorSliderHeight) > Y) then
        DraggingValue := Green;
      If (Y > BTop) and ((BTop + ColorSliderHeight) > Y) then
        DraggingValue := Blue;
      If (Y > ATop) and ((ATop + ColorSliderHeight) > Y) then
        DraggingValue := Alpha;

      If DraggingValue <> None then
        DragColorSliderToPosition(Round(X) - ColorSliderLeft - 1);
    end
  end;
end;

procedure TColorEditorFrame.DragColorSliderToPosition(XPos: Integer);
begin
  case DraggingValue of
    Red:
      RedValue := ColorViewPositionToColorValue(XPos);
    Green:
      GreenValue := ColorViewPositionToColorValue(XPos);
    Blue:
      BlueValue := ColorViewPositionToColorValue(XPos);
    Alpha:
      AlphaVAlue := ColorViewPositionToAlphaValue(XPos);
  end;
  ContentsChanged;
end;

procedure TColorEditorFrame.ContentsChanged;
var
  ARect: TRectF;
begin
  if Not Updating then
  begin
    Updating := True;
    DrawContents;
    ARect := TRectF.Create(0, 0, WorkBitmap.Width, WorkBitmap.Height);
    WorkBitmap.Canvas.BeginScene();
    ColorEditorPaintBox.Canvas.DrawBitmap(WorkBitmap, ARect, ARect, 50);
    WorkBitmap.Canvas.EndScene();

    RedEdit.Text := IntToStr(RedValue);
    GreenEdit.Text := IntToStr(GreenValue);
    BlueEdit.Text := IntToStr(BlueValue);
    AlphaEdit.Text := IntToStr(AlphaVAlue);

    PAPreview.Color := RedValue + (GreenValue Shl 8) + (BlueValue Shl 16);
    Updating := False;

    TBEChange(Self);
  end;
end;

procedure TColorEditorFrame.ColorEditorPaintBoxMouseMove(Sender: TObject;
  Shift: TShiftState; X, Y: Single);
begin
  if DraggingValue <> None then
    DragColorSliderToPosition(Round(X) - ColorSliderLeft - 1);
end;

procedure TColorEditorFrame.ColorEditorPaintBoxMouseUp(Sender: TObject;
  Button: TMouseButton; Shift: TShiftState; X, Y: Single);
begin
  if Button = TMouseButton.mbLeft then
    DraggingValue := None;
end;

procedure TColorEditorFrame.RedEditChange(Sender: TObject);
var
  IntValue: Integer;
begin
  IntValue := StrToIntDef(RedEdit.Text, -1);

  If (IntValue < 0) or (IntValue > MaxColorValue) then
  begin
    RedEdit.TextSettings.FontColor := TColors.Red;
  end
  else
  begin
    RedEdit.TextSettings.FontColor := TColors.cWINDOW;
    RedValue := IntValue;
    ContentsChanged;
  end;
end;

procedure TColorEditorFrame.GreenEditChange(Sender: TObject);
var
  IntValue: Integer;
begin
  IntValue := StrToIntDef(GreenEdit.Text, -1);

  If (IntValue < 0) or (IntValue > MaxColorValue) then
  begin
    GreenEdit.TextSettings.FontColor := TColors.Red;
  end
  else
  begin
    GreenEdit.TextSettings.FontColor := TColors.cWINDOW;
    GreenValue := IntValue;
    ContentsChanged;
  end;
end;

procedure TColorEditorFrame.PAPreviewDblClick(Sender: TObject);
begin
  SetColor(ConvertWinColor(PAPreview.Color));
end;

procedure TColorEditorFrame.BlueEditChange(Sender: TObject);
var
  IntValue: Integer;
begin
  IntValue := StrToIntDef(BlueEdit.Text, -1);

  If (IntValue < 0) or (IntValue > MaxColorValue) then
  begin
    BlueEdit.TextSettings.FontColor := TColors.Red;
  end
  else
  begin
    BlueEdit.TextSettings.FontColor := TColors.cWINDOW;
    BlueValue := IntValue;
    ContentsChanged;
  end;
end;

procedure TColorEditorFrame.AlphaEditChange(Sender: TObject);
var
  IntValue: Integer;
begin
  IntValue := StrToIntDef(AlphaEdit.Text, -1);

  If (IntValue < 0) or (IntValue > MaxAlphaValue) then
  begin
    AlphaEdit.TextSettings.FontColor := TColors.Red;
  end
  else
  begin
    AlphaEdit.TextSettings.FontColor := TColors.cWINDOW;
    AlphaVAlue := IntValue;
    ContentsChanged;
  end;
end;

end.