Move wideband OpenGL background to primitives

WidebandView.pas

@@ -24,6 +24,7 @@ type
   TWidebandView = class
   private
     FBitmap: TBitmap;
+    FLabelBitmap: TBitmap;
     FRulerBitmap: TBitmap;
     FTheme: TAppTheme;
     FData: array of Single;
@@ -57,6 +58,8 @@ type
     procedure PaintCPU(C: TCanvas);
     procedure PaintGL(C: TOpenGLControl);
     procedure ColorToGL(AColor: TColor; out R, G, B: GLFloat);
+    procedure DrawBackgroundGL(W, H, PlotW: Integer);
+    procedure DrawGridGL(W, H, PlotW: Integer);
     procedure DrawSpectrumGL(PlotW, H: Integer);
     procedure DrawHamBandGL(PlotW, H: Integer; F1, F2: Double; AColor: TColor);
     procedure DrawHamBandsGL(PlotW, H: Integer);
@@ -71,7 +74,9 @@ type
       const Name: string; AColor: TColor);
     procedure DrawFrequencyMarker(C: TCanvas; PlotW, H: Integer);
     procedure DrawSpectrumGradient(const SpPts: array of TPoint; PlotW, H: Integer);
-    procedure UploadBitmapToGL;
+    procedure DrawGLLabels(W, H, PlotW: Integer);
+    procedure UploadLabelTextureToGL;
+    procedure DrawLabelTextureGL(W, H: Integer);
   public
     constructor Create;
     destructor Destroy; override;
@@ -107,6 +112,8 @@ begin
   inherited Create;
   FBitmap := TBitmap.Create;
   FBitmap.PixelFormat := pf32bit;
+  FLabelBitmap := TBitmap.Create;
+  FLabelBitmap.PixelFormat := pf32bit;
   FRulerBitmap := TBitmap.Create;
   FRulerBitmap.PixelFormat := pf32bit;
   FTheme := DarkTheme;
@@ -137,6 +144,7 @@ begin
   if FGLTex <> 0 then
     glDeleteTextures(1, @FGLTex);
   FRulerBitmap.Free;
+  FLabelBitmap.Free;
   FBitmap.Free;
   inherited Destroy;
 end;
@@ -230,6 +238,11 @@ begin
     FBitmap.SetSize(W, H);
     FGLBackgroundDirty := True;
   end;
+  if (FLabelBitmap.Width <> W) or (FLabelBitmap.Height <> H) then
+  begin
+    FLabelBitmap.SetSize(W, H);
+    FGLBackgroundDirty := True;
+  end;
 end;
 
 procedure TWidebandView.SetBitmapSize(W, H: Integer);
@@ -666,8 +679,6 @@ begin
 
   DrawHamBands(C, PlotW, H);
 
-  C.Font.Color := FTheme.Text;
-  C.TextOut(6, 4, 'Wideband');
   if IncludeSpectrum then
     FDirty := False
   else
@@ -742,6 +753,67 @@ begin
   B := ((AColor shr 16) and $FF) / 255.0;
 end;
 
+procedure TWidebandView.DrawBackgroundGL(W, H, PlotW: Integer);
+var
+  R1, G1, B1, R2, G2, B2: GLFloat;
+begin
+  ColorToGL(FTheme.SpecGradTop, R1, G1, B1);
+  ColorToGL(FTheme.SpecGradBot, R2, G2, B2);
+  glBegin(GL_QUADS);
+    glColor3f(R1, G1, B1); glVertex2f(0, H);
+    glColor3f(R1, G1, B1); glVertex2f(W, H);
+    glColor3f(R2, G2, B2); glVertex2f(W, 0);
+    glColor3f(R2, G2, B2); glVertex2f(0, 0);
+  glEnd;
+
+  ColorToGL(FTheme.SpecLabelBand, R1, G1, B1);
+  glColor3f(R1, G1, B1);
+  glBegin(GL_QUADS);
+    glVertex2f(PlotW, 0);
+    glVertex2f(W, 0);
+    glVertex2f(W, H);
+    glVertex2f(PlotW, H);
+  glEnd;
+end;
+
+procedure TWidebandView.DrawGridGL(W, H, PlotW: Integer);
+var
+  X, Y, TopH: Integer;
+  DB, DBMin, InvRange, StepHz, FreqHz: Double;
+  R, G, B: GLFloat;
+begin
+  DBMin := FRefLevel - FRange;
+  InvRange := 1.0 / Max(1.0, FRange);
+  TopH := Max(1, H - 1);
+  ColorToGL(FTheme.SpecGrid, R, G, B);
+  glColor4f(R, G, B, 0.78);
+  glBegin(GL_LINES);
+    FLabelBitmap.Canvas.Font.Name := 'Courier New';
+    FLabelBitmap.Canvas.Font.Size := 7;
+    StepHz := RulerGridStepHz(FLabelBitmap.Canvas, PlotW);
+    FreqHz := Ceil(FViewStartHz / StepHz) * StepHz;
+    while FreqHz <= FViewEndHz + 0.5 do
+    begin
+      X := FreqToX(FreqHz, PlotW);
+      glVertex2f(X, 0);
+      glVertex2f(X, H);
+      FreqHz := FreqHz + StepHz;
+    end;
+
+    DB := FRefLevel - 20.0;
+    while DB >= DBMin do
+    begin
+      Y := Round((FRefLevel - DB) * InvRange * TopH);
+      glVertex2f(0, H - Y);
+      glVertex2f(W, H - Y);
+      DB := DB - 20.0;
+    end;
+
+    glVertex2f(PlotW, 0);
+    glVertex2f(PlotW, H);
+  glEnd;
+end;
+
 procedure TWidebandView.DrawSpectrumGL(PlotW, H: Integer);
 var
   I: Integer;
@@ -826,66 +898,158 @@ begin
   DrawHamBandGL(PlotW, H, 50000000, 51990000, TColor($003C729A));
 end;
 
-procedure TWidebandView.UploadBitmapToGL;
+procedure TWidebandView.DrawGLLabels(W, H, PlotW: Integer);
+var
+  C: TCanvas;
+  X1, X2, LabelX, LabelY, TW, TH, Y, TopH, ScaleX: Integer;
+  DB, DBMin, InvRange: Double;
+
+  procedure BandLabel(F1, F2: Double; const Name: string);
+  begin
+    X1 := FreqToX(F1, PlotW);
+    X2 := FreqToX(F2, PlotW);
+    if (X2 <= 0) or (X1 >= PlotW) then Exit;
+    X1 := EnsureRange(X1, 0, PlotW - 1);
+    X2 := EnsureRange(X2, 0, PlotW - 1);
+    if X2 <= X1 then Exit;
+    TW := C.TextWidth(Name);
+    TH := C.TextHeight(Name);
+    LabelX := EnsureRange(((X1 + X2) div 2) - TW div 2, 2, Max(2, PlotW - TW - 5));
+    LabelY := Max(1, Min(H - TH - 1, 2));
+    C.TextOut(LabelX, LabelY, Name);
+  end;
+
+begin
+  if (W <= 0) or (H <= 0) then Exit;
+  if (FLabelBitmap.Width <> W) or (FLabelBitmap.Height <> H) then
+    FLabelBitmap.SetSize(W, H);
+
+  C := FLabelBitmap.Canvas;
+  C.Brush.Style := bsSolid;
+  C.Brush.Color := clBlack;
+  C.FillRect(Rect(0, 0, W, H));
+  C.Brush.Style := bsClear;
+
+  DBMin := FRefLevel - FRange;
+  InvRange := 1.0 / Max(1.0, FRange);
+  TopH := Max(1, H - 1);
+  ScaleX := PlotW;
+
+  C.Font.Name := 'Courier New';
+  C.Font.Quality := fqDefault;
+  C.Font.Size := 7;
+  C.Font.Color := FTheme.SpecLabelText;
+  DB := FRefLevel - 20.0;
+  while DB >= DBMin do
+  begin
+    Y := Round((FRefLevel - DB) * InvRange * TopH);
+    C.TextOut(ScaleX + 2, Y - 9, Format('%4.0f', [DB]));
+    DB := DB - 20.0;
+  end;
+
+  C.Font.Name := 'Sans';
+  C.Font.Quality := fqDefault;
+  C.Font.Size := 7;
+  C.Font.Color := TColor($00EAF7D7);
+  BandLabel(1810000, 2000000, '160m');
+  BandLabel(3500000, 3800000, '80m');
+  BandLabel(5258500, 5403500, '60m');
+  BandLabel(7000000, 7300000, '40m');
+  BandLabel(10100000, 10150000, '30m');
+  BandLabel(14000000, 14350000, '20m');
+  BandLabel(18068000, 18168000, '17m');
+  BandLabel(21000000, 21450000, '15m');
+  BandLabel(24890000, 24990000, '12m');
+  BandLabel(28000000, 29700000, '10m');
+  BandLabel(50000000, 51990000, '6m');
+
+end;
+
+procedure TWidebandView.UploadLabelTextureToGL;
 var
   X, Y, I: Integer;
   Src: PByte;
   Buf: array of Byte;
+  A: Byte;
 begin
-  if (FBitmap.Width <= 0) or (FBitmap.Height <= 0) then Exit;
+  if (FLabelBitmap.Width <= 0) or (FLabelBitmap.Height <= 0) then Exit;
   if FGLTex = 0 then
     glGenTextures(1, @FGLTex);
-  SetLength(Buf, FBitmap.Width * FBitmap.Height * 4);
+  SetLength(Buf, FLabelBitmap.Width * FLabelBitmap.Height * 4);
-  FBitmap.BeginUpdate(False);
+  FLabelBitmap.BeginUpdate(False);
   try
     I := 0;
-    for Y := 0 to FBitmap.Height - 1 do
+    for Y := 0 to FLabelBitmap.Height - 1 do
     begin
-      Src := PByte(FBitmap.ScanLine[Y]);
+      Src := PByte(FLabelBitmap.ScanLine[Y]);
-      for X := 0 to FBitmap.Width - 1 do
+      for X := 0 to FLabelBitmap.Width - 1 do
       begin
-        Buf[I] := Src[2];
+        A := Max(Src[0], Max(Src[1], Src[2]));
-        Buf[I + 1] := Src[1];
+        if A < 6 then A := 0;
-        Buf[I + 2] := Src[0];
+        if A > 0 then
-        Buf[I + 3] := $FF;
+        begin
+          Buf[I] := Byte(Min(255, Src[2] * 255 div A));
+          Buf[I + 1] := Byte(Min(255, Src[1] * 255 div A));
+          Buf[I + 2] := Byte(Min(255, Src[0] * 255 div A));
+          A := Byte(Min(255, A + (255 - A) div 3));
+        end
+        else
+        begin
+          Buf[I] := 0;
+          Buf[I + 1] := 0;
+          Buf[I + 2] := 0;
+        end;
+        Buf[I + 3] := A;
         Inc(Src, 4);
         Inc(I, 4);
       end;
     end;
   finally
-    FBitmap.EndUpdate(False);
+    FLabelBitmap.EndUpdate(False);
   end;
   glBindTexture(GL_TEXTURE_2D, FGLTex);
-  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
-  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
-  glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, FBitmap.Width, FBitmap.Height, 0,
+  glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, FLabelBitmap.Width, FLabelBitmap.Height, 0,
     GL_RGBA, GL_UNSIGNED_BYTE, @Buf[0]);
 end;
 
+procedure TWidebandView.DrawLabelTextureGL(W, H: Integer);
+begin
+  if FGLTex = 0 then Exit;
+  glEnable(GL_BLEND);
+  glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+  glEnable(GL_TEXTURE_2D);
+  glBindTexture(GL_TEXTURE_2D, FGLTex);
+  glColor4f(1, 1, 1, 1);
+  glBegin(GL_QUADS);
+    glTexCoord2f(0, 1); glVertex2f(0, 0);
+    glTexCoord2f(1, 1); glVertex2f(W, 0);
+    glTexCoord2f(1, 0); glVertex2f(W, H);
+    glTexCoord2f(0, 0); glVertex2f(0, H);
+  glEnd;
+  glBindTexture(GL_TEXTURE_2D, 0);
+  glDisable(GL_TEXTURE_2D);
+  glDisable(GL_BLEND);
+end;
+
 procedure TWidebandView.PaintGL(C: TOpenGLControl);
 var
   W, H, PlotW, X: Integer;
-  NeedUpload: Boolean;
 begin
   if C = nil then Exit;
   W := Max(1, C.Width);
   H := Max(1, C.Height);
   if not C.MakeCurrent then Exit;
-  NeedUpload := False;
   if (FBitmap.Width <> W) or (FBitmap.Height <> H) then
-  begin
     SetBitmapSize(W, H);
-    NeedUpload := True;
-  end;
   if FGLBackgroundDirty then
   begin
-    DrawCPU(W, H, False);
+    PlotW := Max(1, W - WB_DB_SCALE_W);
-    NeedUpload := True;
+    DrawGLLabels(W, H, PlotW);
+    UploadLabelTextureToGL;
+    FGLBackgroundDirty := False;
   end;
-  if FGLTex = 0 then
-    NeedUpload := True;
-  if NeedUpload then
-    UploadBitmapToGL;
   glViewport(0, 0, W, H);
   glMatrixMode(GL_PROJECTION);
   glLoadIdentity;
@@ -895,21 +1059,13 @@ begin
   glDisable(GL_DEPTH_TEST);
   glClearColor(0, 0, 0, 1.0);
   glClear(GL_COLOR_BUFFER_BIT);
-  glEnable(GL_TEXTURE_2D);
-  glBindTexture(GL_TEXTURE_2D, FGLTex);
-  glColor3f(1, 1, 1);
-  glBegin(GL_QUADS);
-    glTexCoord2f(0, 1); glVertex2f(0, 0);
-    glTexCoord2f(1, 1); glVertex2f(W, 0);
-    glTexCoord2f(1, 0); glVertex2f(W, H);
-    glTexCoord2f(0, 0); glVertex2f(0, H);
-  glEnd;
-  glBindTexture(GL_TEXTURE_2D, 0);
-  glDisable(GL_TEXTURE_2D);
 
   PlotW := Max(1, W - WB_DB_SCALE_W);
+  DrawBackgroundGL(W, H, PlotW);
+  DrawGridGL(W, H, PlotW);
   DrawSpectrumGL(PlotW, H);
   DrawHamBandsGL(PlotW, H);
+  DrawLabelTextureGL(W, H);
   FDirty := False;
 
   if (FMarkerHz >= FViewStartHz) and (FMarkerHz <= FViewEndHz) then