unit WaterfallView;

{
  WaterfallView.pas — рендеринг водопада.
  TWaterfallView — изолированный класс, не зависит от SpectrumView.
}

{$IFDEF FPC}
  {$MODE Delphi}
{$ENDIF}

interface

uses
  Classes, SysUtils, Graphics, ExtCtrls, Controls, Math,
  LCLIntf, LCLType, AppTheme;

type
  TWaterfallView = class
  protected
    FWaterfallBitmap:   TBitmap;
    FWfBitmap:          TBitmap;
    FWfBitmapW:         Integer;
    FWfBitmapH:         Integer;
    FWfRowBuf:          array of LongWord;   // одна строка (новейшая), нативный порядок
    FWfHead:            Integer;             // физ. строка bitmap с новейшей линией
    FWfLut:             array[0..511] of LongWord;
    FWfLutLow:          Double;
    FWfLutHigh:         Double;
    FWfLutLight:        Boolean;
    FWaterfallBuf:      array[0..1023] of Single;
    FWaterfallBufCount: Integer;
    FWaterfallDirty:    Boolean;
    FWfFrameCounter:    Integer;
    FWfFrameInterval:   Integer;
    FWfAGCEnabled:      Boolean;
    FWfNFEnabled:       Boolean;
    FWfManualHigh:      Double;
    FWfManualLow:       Double;
    FWfAGCOffset:       Double;
    FWfHigh:            Double;
    FWfLow:             Double;
    FCenterFreq:        Double;
    FSpanHz:            Double;
    FTXMode:            Boolean;
    FTXFreq:            Double;
    FTXSpanHz:          Double;
    FMarkerActive:      Boolean;
    FMarkerX:           Integer;
    FTheme:             TAppTheme;
    FLightTheme:        Boolean;
    FPbWaterfall:       TControl;

    procedure DrawMarkerLine(C: TCanvas; W, H: Integer);
    procedure BuildWfLut(WfLow, WfHigh: Double);
  public
    constructor Create;
    destructor  Destroy; override;

    property CenterFreq:     Double  read FCenterFreq    write FCenterFreq;
    property SpanHz:         Double  read FSpanHz        write FSpanHz;
    property TXMode:         Boolean read FTXMode        write FTXMode;
    property TXFreq:         Double  read FTXFreq        write FTXFreq;
    property TXSpanHz:       Double  read FTXSpanHz      write FTXSpanHz;
    property WfAGCEnabled:   Boolean read FWfAGCEnabled  write FWfAGCEnabled;
    property WfNFEnabled:    Boolean read FWfNFEnabled   write FWfNFEnabled;
    property WfManualHigh:   Double  read FWfManualHigh  write FWfManualHigh;
    property WfManualLow:    Double  read FWfManualLow   write FWfManualLow;
    property WfAGCOffset:    Double  read FWfAGCOffset   write FWfAGCOffset;
    property WaterfallDirty: Boolean read FWaterfallDirty write FWaterfallDirty;
    property WfFrameInterval: Integer read FWfFrameInterval write FWfFrameInterval;
    property MarkerActive:   Boolean read FMarkerActive  write FMarkerActive;
    property MarkerX:        Integer read FMarkerX       write FMarkerX;
    property PbWaterfall:    TControl write FPbWaterfall;

    procedure SetWaterfallData(const Pixels: array of Single; Count: Integer); virtual;
    procedure DrawWaterfall; virtual;
    procedure PaintWaterfall(Sender: TObject); virtual;
    procedure SetWaterfallBitmapSize(W, H: Integer); virtual;
    procedure ResetWfAvgBuf; virtual;
    procedure ResetWfBuf; virtual;
    procedure SetTheme(const T: TAppTheme); virtual;
  end;

implementation

// ════════════════════════════════════════════════════════════════════════════
// Вспомогательные функции
// ════════════════════════════════════════════════════════════════════════════

function FormatFreqWF(Hz: Double): string;
var Mhz: Int64; KHz, Rest: Integer;
begin
  Mhz  := Trunc(Hz / 1000000);
  KHz  := Trunc((Hz - Mhz * 1000000) / 1000);
  Rest := Trunc(Hz) mod 1000;
  Result := Format('%d.%3.3d.%3.3d', [Mhz, KHz, Rest]);
end;

function WaterfallEnhancedColorThetis(ValueDB, LowDB, HighDB: Double): LongWord;
var
  Overall, Local: Double;
  R, G, B: Integer;
begin
  if ValueDB <= LowDB then begin Result := $FF000000; Exit; end;
  if ValueDB >= HighDB then begin Result := ($FF shl 24) or (255 shl 16) or (124 shl 8) or 192; Exit; end;
  Overall := (ValueDB - LowDB) / Max(1E-9, HighDB - LowDB);
  if Overall < (2.0 / 9.0) then
  begin Local := Overall / (2.0/9.0); R := 0; G := 0; B := Round(Local * 255.0); end
  else if Overall < (3.0 / 9.0) then
  begin Local := (Overall - 2.0/9.0) / (1.0/9.0); R := 0; G := Round(Local*255.0); B := 255; end
  else if Overall < (4.0 / 9.0) then
  begin Local := (Overall - 3.0/9.0) / (1.0/9.0); R := 0; G := 255; B := Round((1.0-Local)*255.0); end
  else if Overall < (5.0 / 9.0) then
  begin Local := (Overall - 4.0/9.0) / (1.0/9.0); R := Round(Local*255.0); G := 255; B := 0; end
  else if Overall < (7.0 / 9.0) then
  begin Local := (Overall - 5.0/9.0) / (2.0/9.0); R := 255; G := Round((1.0-Local)*255.0); B := 0; end
  else if Overall < (8.0 / 9.0) then
  begin Local := (Overall - 7.0/9.0) / (1.0/9.0); R := 255; G := 0; B := Round(Local*255.0); end
  else
  begin
    Local := (Overall - 8.0/9.0) / (1.0/9.0);
    R := Round((0.75 + 0.25 * (1.0 - Local)) * 255.0);
    G := Round(Local * 255.0 * 0.5);
    B := 255;
  end;
  R := EnsureRange(R, 0, 255);
  G := EnsureRange(G, 0, 255);
  B := EnsureRange(B, 0, 255);
  Result := ($FF shl 24) or (R shl 16) or (G shl 8) or B;
end;

function WaterfallLightTheme(ValueDB, LowDB, HighDB: Double): LongWord;
const
  NSTOPS = 8;
  SR: array[0..NSTOPS-1] of Integer = (224, 160,  20,   0,   0, 220, 255, 255);
  SG: array[0..NSTOPS-1] of Integer = (230, 185,  80, 185, 200, 210,  90,  20);
  SB: array[0..NSTOPS-1] of Integer = (232, 210, 200, 210,  80,   0,   0,  20);
var
  T: Double;
  Seg: Integer;
  R, G, B: Integer;
begin
  if ValueDB <= LowDB  then begin Result := $FFE0E6E8; Exit; end;
  if ValueDB >= HighDB then begin Result := ($FF shl 24) or (SR[NSTOPS-1] shl 16) or (SG[NSTOPS-1] shl 8) or SB[NSTOPS-1]; Exit; end;
  T   := (ValueDB - LowDB) / Max(1E-9, HighDB - LowDB) * (NSTOPS - 1);
  Seg := Min(NSTOPS - 2, Trunc(T));
  T   := T - Seg;
  R := EnsureRange(Round(SR[Seg] * (1.0 - T) + SR[Seg+1] * T), 0, 255);
  G := EnsureRange(Round(SG[Seg] * (1.0 - T) + SG[Seg+1] * T), 0, 255);
  B := EnsureRange(Round(SB[Seg] * (1.0 - T) + SB[Seg+1] * T), 0, 255);
  Result := ($FF shl 24) or (R shl 16) or (G shl 8) or B;
end;

// Преобразует логический $AARRGGBB в нативный для ScanLine порядок байт.
// DARWIN (Cocoa): в памяти [A,R,G,B]; прочие (Qt6/Win32): [B,G,R,A].
// Платформы little-endian, поэтому байт 0 — младший байт LongWord.
function NativePixel(ARGB: LongWord): LongWord; inline;
{$IFDEF DARWIN}
begin
  Result :=  (ARGB shr 24)                    // A → байт 0
         or (((ARGB shr 16) and $FF) shl 8)   // R → байт 1
         or (((ARGB shr 8)  and $FF) shl 16)  // G → байт 2
         or  ((ARGB and $FF)        shl 24);  // B → байт 3
end;
{$ELSE}
begin
  Result := ARGB;   // $AARRGGBB на LE уже даёт в памяти [B,G,R,A]
end;
{$ENDIF}

// ════════════════════════════════════════════════════════════════════════════
// TWaterfallView
// ════════════════════════════════════════════════════════════════════════════

constructor TWaterfallView.Create;
begin
  inherited Create;
  FWaterfallBitmap   := TBitmap.Create;
  FWfBitmap          := TBitmap.Create;
  FWfBitmap.PixelFormat := pf32bit;
  FWfBitmapW         := 0;
  FWfBitmapH         := 0;
  FWfManualHigh      := -80.0;
  FWfManualLow       := -130.0;
  FWfAGCOffset       := 0.0;
  FWfHigh            := -80.0;
  FWfLow             := -130.0;
  FWfAGCEnabled      := True;
  FWfNFEnabled       := False;
  FWaterfallBufCount := 1024;
  FWfFrameInterval   := 2;
  FWfFrameCounter    := 0;
  FWaterfallDirty    := True;
  FTheme             := DarkTheme;
  FLightTheme        := False;
  FSpanHz            := 192000;
  FWfLutLow          := 1.0;   // невалидно → LUT перестроится при первом кадре
  FWfLutHigh         := 0.0;
  FWfLutLight        := False;
  ResetWfBuf;
end;

destructor TWaterfallView.Destroy;
begin
  FWaterfallBitmap.Free;
  FWfBitmap.Free;
  inherited;
end;

procedure TWaterfallView.SetTheme(const T: TAppTheme);
begin
  FTheme      := T;
  FLightTheme := T.BG > TColor($00808080);
  FWaterfallDirty := True;
  // Сброс размера — чтобы следующий кадр перезаполнил фон новой темой
  FWfBitmapW := 0;
  FWfBitmapH := 0;
  FWfLutLow  := 1.0;   // невалидно → LUT перестроится
  FWfLutHigh := 0.0;
  SetLength(FWfRowBuf, 0);
  FWfHead := 0;
end;

procedure TWaterfallView.ResetWfAvgBuf;
begin
  FWfHigh := FWfManualHigh;
  FWfLow  := FWfManualLow;
  FWaterfallDirty := True;
end;

procedure TWaterfallView.ResetWfBuf;
var i: Integer;
begin
  for i := 0 to 1023 do FWaterfallBuf[i] := -130.0;
  FWfHigh := FWfManualHigh;
  FWfLow  := FWfManualLow;
  FWaterfallDirty := True;
end;

procedure TWaterfallView.SetWaterfallData(const Pixels: array of Single; Count: Integer);
var i, N: Integer;
begin
  N := Min(Count, 1024);
  for i := 0 to N - 1 do FWaterfallBuf[i] := Pixels[i];
  FWaterfallBufCount := N;
  Inc(FWfFrameCounter);
  if FWfFrameCounter >= Max(1, FWfFrameInterval) then
  begin
    FWfFrameCounter := 0;
    FWaterfallDirty := True;
  end;
end;

procedure TWaterfallView.SetWaterfallBitmapSize(W, H: Integer);
begin
  FWaterfallBitmap.SetSize(W, H);
  FWfBitmapW := 0;
  FWfBitmapH := 0;
  SetLength(FWfRowBuf, 0);
  FWfHead := 0;
end;

procedure TWaterfallView.DrawMarkerLine(C: TCanvas; W, H: Integer);
var MX: Integer; MarkerFreq: Double; MarkerLbl: string;
begin
  MX := Round(FMarkerX / 1000.0 * W);
  if (MX < 0) or (MX >= W) then Exit;
  MarkerFreq := (FCenterFreq - FSpanHz / 2) + FMarkerX / 1000.0 * FSpanHz;
  MarkerLbl  := FormatFreqWF(Round(MarkerFreq));
  C.Pen.Color := TColor($004444FF);
  C.Pen.Width := 1; C.Pen.Style := psSolid;
  C.MoveTo(MX, 0); C.LineTo(MX, H);
  C.Font.Color := TColor($004444FF);
  C.Font.Size  := 7; C.Font.Name := 'Courier New';
  if MX + 4 + C.TextWidth(MarkerLbl) < W then
    C.TextOut(MX + 4, 4, MarkerLbl)
  else
    C.TextOut(MX - 4 - C.TextWidth(MarkerLbl), 4, MarkerLbl);
end;

// Перестраивает палитру dB→цвет (512 точек) один раз на кадр вместо
// вычисления цвета с плавающей точкой на каждый пиксель.
procedure TWaterfallView.BuildWfLut(WfLow, WfHigh: Double);
var
  i: Integer;
  dB, Range: Double;
  C: LongWord;
begin
  Range := WfHigh - WfLow;
  if Range < 1E-6 then Range := 1E-6;
  for i := 0 to High(FWfLut) do
  begin
    dB := WfLow + (i / High(FWfLut)) * Range;
    if FLightTheme then
      C := WaterfallLightTheme(dB, WfLow, WfHigh)
    else
      C := WaterfallEnhancedColorThetis(dB, WfLow, WfHigh);
    FWfLut[i] := NativePixel(C);
  end;
  FWfLutLow   := WfLow;
  FWfLutHigh  := WfHigh;
  FWfLutLight := FLightTheme;
end;

// ────────────────────────────────────────────────────────────────────────────
// DrawWaterfall
// ────────────────────────────────────────────────────────────────────────────

procedure TWaterfallView.DrawWaterfall;
var
  W, H, X: Integer;
  dB, frac, WatSrcF: Double;
  WatS0, WatS1: Integer;
  TargetLow, TargetHigh: Double;
  HistMinDB, HistMaxDB, HistStepDB: Double;
  NoiseFloorDB, SignalTopDB: Double;
  CumCount, LowTargetCount, HighTargetCount, HistIdx: Integer;
  WfHigh, WfLow, LutScale, Step: Double;
  Row, Idx: Integer; RowPtr: PByte;
  Pal: LongWord; Hist: array[0..191] of Integer; SrcCount: Integer;
const
  ALPHA_HIGH = 0.10; ALPHA_LOW = 0.08;
  WF_AUTO_OFFSET = -4.0; WF_MIN_RANGE = 48.0; WF_MAX_RANGE = 62.0;
begin
  if FWaterfallBitmap = nil then Exit;
  W := FWaterfallBitmap.Width; H := FWaterfallBitmap.Height;
  if (W <= 0) or (H <= 0) then Exit;
  SrcCount := EnsureRange(FWaterfallBufCount, 2, 1024);

  FillChar(Hist, SizeOf(Hist), 0);
  HistMinDB := -170.0; HistMaxDB := 22.0;
  HistStepDB := (HistMaxDB - HistMinDB) / Length(Hist);
  for X := 0 to SrcCount - 1 do
  begin
    HistIdx := EnsureRange(Trunc((FWaterfallBuf[X] - HistMinDB) / HistStepDB), 0, High(Hist));
    Inc(Hist[HistIdx]);
  end;

  LowTargetCount  := Round(SrcCount * 0.30);
  HighTargetCount := Round(SrcCount * 0.98);
  CumCount := 0; NoiseFloorDB := FWfLow; SignalTopDB := FWfHigh;
  for HistIdx := 0 to High(Hist) do
  begin
    CumCount := CumCount + Hist[HistIdx];
    if CumCount >= LowTargetCount then
    begin NoiseFloorDB := HistMinDB + (HistIdx + 0.5) * HistStepDB; Break; end;
  end;
  CumCount := 0;
  for HistIdx := 0 to High(Hist) do
  begin
    CumCount := CumCount + Hist[HistIdx];
    if CumCount >= HighTargetCount then
    begin SignalTopDB := HistMinDB + (HistIdx + 0.5) * HistStepDB; Break; end;
  end;

  if FWfAGCEnabled then
  begin
    TargetLow := NoiseFloorDB + WF_AUTO_OFFSET + FWfAGCOffset;
    if FWfNFEnabled then
      TargetHigh := Max(TargetLow + WF_MIN_RANGE, SignalTopDB + 6.0)
    else
      TargetHigh := TargetLow + 52.0;
    if TargetHigh > TargetLow + WF_MAX_RANGE then TargetHigh := TargetLow + WF_MAX_RANGE;
    FWfLow  := FWfLow  + ALPHA_LOW  * (TargetLow  - FWfLow);
    FWfHigh := FWfHigh + ALPHA_HIGH * (TargetHigh - FWfHigh);
  end;
  WfHigh := FWfHigh; WfLow := FWfLow;
  if not FWfAGCEnabled then begin WfHigh := FWfManualHigh; WfLow := FWfManualLow; end;
  if WfHigh < WfLow + 40.0 then WfHigh := WfLow + 40.0;
  if WfHigh > 0.0   then WfHigh := 0.0;
  if WfLow  < -160  then WfLow  := -160;
  LutScale := High(FWfLut) / (WfHigh - WfLow);

  // Палитра зависит только от WfLow/WfHigh/темы — перестраиваем лишь при
  // ощутимом изменении (AGC сдвигает границы медленно).
  if (FWfLutLight <> FLightTheme) or
     (Abs(WfLow  - FWfLutLow)  > 0.05) or
     (Abs(WfHigh - FWfLutHigh) > 0.05) then
    BuildWfLut(WfLow, WfHigh);

  if (FWfBitmapW <> W) or (FWfBitmapH <> H) then
  begin
    FWfBitmapW := W; FWfBitmapH := H;
    SetLength(FWfRowBuf, W);
    Pal := NativePixel($FF000000
      or ((LongWord(FTheme.Panel) and $FF) shl 16)
      or  (LongWord(FTheme.Panel) and $FF00)
      or ((LongWord(FTheme.Panel) shr 16) and $FF));
    FillDWord(FWfRowBuf[0], W, Pal);
    FWfBitmap.SetSize(W, H);
    FWfHead := 0;
    // Заливаем всё кольцо фоном
    FWfBitmap.BeginUpdate(False);
    try
      for Row := 0 to H - 1 do
      begin
        RowPtr := PByte(FWfBitmap.ScanLine[Row]);
        if RowPtr <> nil then FillDWord(RowPtr^, W, Pal);
      end;
    finally
      FWfBitmap.EndUpdate(False);
    end;
  end;

  // Строим только новейшую строку в FWfRowBuf. В TX-режиме столбцы вне TX-полосы
  // НЕ трогаем — FWfRowBuf хранит предыдущую верхнюю строку, поэтому
  // «замороженные» участки остаются вертикально непрерывными, как и раньше.
  Step := (SrcCount - 1.0) / Max(1, W - 1);
  WatSrcF := 0.0;
  for X := 0 to W - 1 do
  begin
    if FTXMode and (FTXSpanHz > 0) and (FSpanHz > 0) then
    begin
      dB := FCenterFreq - FSpanHz * 0.5 + X * FSpanHz / Max(1, W - 1) - FTXFreq;
      if (dB < -FTXSpanHz * 0.5) or (dB > FTXSpanHz * 0.5) then
      begin
        WatSrcF := WatSrcF + Step;
        Continue;   // оставляем FWfRowBuf[X] без изменений
      end;
      frac := (dB + FTXSpanHz * 0.5) / FTXSpanHz * (SrcCount - 1);
      WatS0 := Trunc(frac);
      if WatS0 > SrcCount - 2 then WatS0 := SrcCount - 2;
      WatS1 := WatS0 + 1;
      frac := frac - WatS0;
      dB := FWaterfallBuf[WatS0] * (1.0 - frac) + FWaterfallBuf[WatS1] * frac;
    end else
    begin
      WatS0 := Trunc(WatSrcF);
      if WatS0 > SrcCount - 2 then WatS0 := SrcCount - 2;
      WatS1 := WatS0 + 1;
      frac  := WatSrcF - WatS0;
      dB    := FWaterfallBuf[WatS0] * (1.0 - frac) + FWaterfallBuf[WatS1] * frac;
    end;
    Idx := Round((dB - WfLow) * LutScale);
    if Idx < 0 then Idx := 0 else if Idx > High(FWfLut) then Idx := High(FWfLut);
    FWfRowBuf[X] := FWfLut[Idx];
    WatSrcF := WatSrcF + Step;
  end;

  // Кольцевой сдвиг: новая верхняя строка занимает слот выше предыдущей.
  // Полнокадровый Move изображения и полная перезаливка bitmap больше не нужны —
  // пишем единственную строку, а прокрутка делается в PaintWaterfall (CopyRect).
  FWfHead := (FWfHead - 1 + H) mod H;
  FWfBitmap.BeginUpdate(False);
  try
    RowPtr := PByte(FWfBitmap.ScanLine[FWfHead]);
    if RowPtr <> nil then Move(FWfRowBuf[0], RowPtr^, W * 4);
  finally
    FWfBitmap.EndUpdate(False);
  end;
end;

// ────────────────────────────────────────────────────────────────────────────
// PaintWaterfall
// ────────────────────────────────────────────────────────────────────────────

procedure TWaterfallView.PaintWaterfall(Sender: TObject);
var PB: TPaintBox; W, H, Top: Integer;
begin
  PB := TPaintBox(Sender);
  W := PB.Width; H := PB.Height;
  if (W <= 0) or (H <= 0) then Exit;
  if (FWfBitmap <> nil) and (FWfBitmap.Width = W) and (FWfBitmap.Height = H)
     and (Length(FWfRowBuf) = W) then
  begin
    // Кольцевой буфер: дисплейная строка 0 = физ. строка FWfHead.
    // Верхний сегмент — строки FWfHead..H-1, нижний — 0..FWfHead-1.
    Top := H - FWfHead;
    PB.Canvas.CopyRect(Rect(0, 0, W, Top),
                       FWfBitmap.Canvas, Rect(0, FWfHead, W, H));
    if FWfHead > 0 then
      PB.Canvas.CopyRect(Rect(0, Top, W, H),
                         FWfBitmap.Canvas, Rect(0, 0, W, FWfHead));
  end
  else begin
    PB.Canvas.Brush.Color := FTheme.Panel;
    PB.Canvas.FillRect(Rect(0, 0, W, H));
  end;
  if FMarkerActive then DrawMarkerLine(PB.Canvas, W, H);
end;

end.