Fix macOS pixel format: use ARGB byte order in all raw ScanLine blending

On macOS Cocoa, TBitmap.pf32bit stores pixels in ARGB order
   (byte0=A, byte1=R, byte2=G, byte3=B) rather than BGRA used on
   Linux/Windows. All raw ScanLine pixel blending and channel mapping
   is now guarded with { DARWIN} to use the correct offsets.

   Also fix PortAudio library discovery on macOS: probe .dylib names
   (including Homebrew paths) before falling through to .so/.dll.

AlertOverlay.pas

@@ -42,9 +42,15 @@ begin
       Inc(Row, RR.Left * 4);
       for X := RR.Left to RR.Right - 1 do
       begin
+{$IFDEF DARWIN}
+        Row[1] := Byte((Alpha * R + InvA * Row[1]) div 255);
+        Row[2] := Byte((Alpha * G + InvA * Row[2]) div 255);
+        Row[3] := Byte((Alpha * B + InvA * Row[3]) div 255);
+{$ELSE}
         Row[0] := Byte((Alpha * B + InvA * Row[0]) div 255);
         Row[1] := Byte((Alpha * G + InvA * Row[1]) div 255);
         Row[2] := Byte((Alpha * R + InvA * Row[2]) div 255);
+{$ENDIF}
         Inc(Row, 4);
       end;
     end;

AudioInput.pas

@@ -152,14 +152,22 @@ function PaInCallback(inputBuffer, outputBuffer: Pointer;
 implementation
 
 const
-{$IFDEF UNIX}
+{$IFDEF DARWIN}
+  PA_IN_LIBS: array[0..3] of AnsiString = (
+    'libportaudio.dylib',
+    'libportaudio.2.dylib',
+    '/usr/local/lib/libportaudio.dylib',
+    '/opt/homebrew/lib/libportaudio.dylib'
+  );
+{$ELSE}
+  {$IFDEF UNIX}
   PA_IN_LIBS: array[0..3] of AnsiString = (
     'libportaudio.so.2',
     'libportaudio.so',
     'libportaudio.so.2.0.0',
     'libportaudio.so.0'
   );
-{$ELSE}
+  {$ELSE}
   PA_IN_LIBS: array[0..5] of AnsiString = (
     'portaudio_x64.dll',
     'portaudio_x86.dll',
@@ -168,6 +176,7 @@ const
     'libportaudio.dll',
     'libportaudio64.dll'
   );
+  {$ENDIF}
 {$ENDIF}
   PA_NO_ERROR  = 0;
   PA_FLOAT32   = LongWord(1);
@@ -276,7 +285,11 @@ begin
 {$IFDEF WINDOWS}
     FLastError := 'PortAudio DLL not found. Put portaudio_x64.dll, portaudio.dll, or libportaudio-2.dll next to ewsdr.exe';
 {$ELSE}
-    FLastError := 'libportaudio not found';
+  {$IFDEF DARWIN}
+    FLastError := 'libportaudio not found. Install via: brew install portaudio';
+  {$ELSE}
+    FLastError := 'libportaudio not found. sudo apt install libportaudio2';
+  {$ENDIF}
 {$ENDIF}
     Exit;
   end;

AudioOutput.pas

@@ -163,14 +163,22 @@ function PaOutCallback(inputBuffer, outputBuffer: Pointer;
 implementation
 
 const
-{$IFDEF UNIX}
+{$IFDEF DARWIN}
+  PA_LIBS: array[0..3] of AnsiString = (
+    'libportaudio.dylib',
+    'libportaudio.2.dylib',
+    '/usr/local/lib/libportaudio.dylib',
+    '/opt/homebrew/lib/libportaudio.dylib'
+  );
+{$ELSE}
+  {$IFDEF UNIX}
   PA_LIBS: array[0..3] of AnsiString = (
     'libportaudio.so.2',
     'libportaudio.so',
     'libportaudio.so.2.0.0',
     'libportaudio.so.0'
   );
-{$ELSE}
+  {$ELSE}
   PA_LIBS: array[0..5] of AnsiString = (
     'portaudio_x64.dll',
     'portaudio_x86.dll',
@@ -179,6 +187,7 @@ const
     'libportaudio.dll',
     'libportaudio64.dll'
   );
+  {$ENDIF}
 {$ENDIF}
   PA_NO_ERROR  = 0;
   PA_FLOAT32   = LongWord(1);
@@ -292,7 +301,11 @@ begin
 {$IFDEF WINDOWS}
     FLastError := 'PortAudio DLL not found. Put portaudio_x64.dll, portaudio.dll, or libportaudio-2.dll next to ewsdr.exe';
 {$ELSE}
+  {$IFDEF DARWIN}
+    FLastError := 'libportaudio not found. Install via: brew install portaudio';
+  {$ELSE}
     FLastError := 'libportaudio not found. sudo apt install libportaudio2';
+  {$ENDIF}
 {$ENDIF}
     Exit;
   end;

SampleRateOverlay.pas

@@ -98,9 +98,15 @@ begin
       Inc(Row, RR.Left * 4);
       for X := RR.Left to RR.Right - 1 do
       begin
+{$IFDEF DARWIN}
+        Row[1] := Byte((Alpha * R + InvA * Row[1]) div 255);
+        Row[2] := Byte((Alpha * G + InvA * Row[2]) div 255);
+        Row[3] := Byte((Alpha * B + InvA * Row[3]) div 255);
+{$ELSE}
         Row[0] := Byte((Alpha * B + InvA * Row[0]) div 255);
         Row[1] := Byte((Alpha * G + InvA * Row[1]) div 255);
         Row[2] := Byte((Alpha * R + InvA * Row[2]) div 255);
+{$ENDIF}
         Inc(Row, 4);
       end;
     end;

SpectrumView.pas

@@ -495,9 +495,15 @@ begin
       Inc(Row, X1 * 4);
       for X := X1 to X2 - 1 do
       begin
+{$IFDEF DARWIN}
+        Row[1] := Byte((Alpha * R + InvA * Row[1]) div 255);
+        Row[2] := Byte((Alpha * G + InvA * Row[2]) div 255);
+        Row[3] := Byte((Alpha * B + InvA * Row[3]) div 255);
+{$ELSE}
         Row[0] := Byte((Alpha * B + InvA * Row[0]) div 255);
         Row[1] := Byte((Alpha * G + InvA * Row[1]) div 255);
         Row[2] := Byte((Alpha * R + InvA * Row[2]) div 255);
+{$ENDIF}
         Inc(Row, 4);
       end;
     end;
@@ -513,6 +519,13 @@ var
 begin
   if (FSpectrumBitmap = nil) or (FGridBitmap = nil) then Exit;
   if (W <= 0) or (H <= 0) then Exit;
+{$IFDEF DARWIN}
+  // On macOS/Cocoa, Canvas writes into a CGBitmapContext; ScanLine reads the
+  // raw backing buffer which is not synced until BeginUpdate is called on the
+  // source bitmap.  Canvas.Draw goes through CoreGraphics and sees the live
+  // CGContext, so use it instead of the direct ScanLine copy.
+  FSpectrumBitmap.Canvas.Draw(0, 0, FGridBitmap);
+{$ELSE}
   FSpectrumBitmap.BeginUpdate(False);
   try
     for Y := 0 to H - 1 do
@@ -525,6 +538,7 @@ begin
   finally
     FSpectrumBitmap.EndUpdate(False);
   end;
+{$ENDIF}
 end;
 
 procedure TSpectrumView.DrawADCOverloadOverlay(C: TCanvas; W, H: Integer);
@@ -576,9 +590,15 @@ begin
       if SpPts[Col].Y <= Row then
       begin
         Off := Col * 4;
+{$IFDEF DARWIN}
+        RowPtr[Off+1] := (GradR * Alpha + RowPtr[Off+1] * (200 - Alpha)) div 200;
+        RowPtr[Off+2] := (GradG * Alpha + RowPtr[Off+2] * (200 - Alpha)) div 200;
+        RowPtr[Off+3] := (GradB * Alpha + RowPtr[Off+3] * (200 - Alpha)) div 200;
+{$ELSE}
         RowPtr[Off]   := (GradB * Alpha + RowPtr[Off]   * (200 - Alpha)) div 200;
         RowPtr[Off+1] := (GradG * Alpha + RowPtr[Off+1] * (200 - Alpha)) div 200;
         RowPtr[Off+2] := (GradR * Alpha + RowPtr[Off+2] * (200 - Alpha)) div 200;
+{$ENDIF}
       end;
   end;
   FSpectrumBitmap.EndUpdate(False);
@@ -913,7 +933,11 @@ begin
   FSpectrumBitmap.BeginUpdate(False);
   for i := 0 to H - 1 do
   begin
-    AlphaPtr := PByte(FSpectrumBitmap.ScanLine[i]) + 3;
+{$IFDEF DARWIN}
+    AlphaPtr := PByte(FSpectrumBitmap.ScanLine[i]);       // ARGB: alpha at byte 0
+{$ELSE}
+    AlphaPtr := PByte(FSpectrumBitmap.ScanLine[i]) + 3;   // BGRA: alpha at byte 3
+{$ENDIF}
     for Yp := 0 to W - 1 do
     begin
       AlphaPtr^ := $FF;

SpectrumViewOpengl.pas

@@ -185,10 +185,15 @@ begin
       Src := PByte(B.ScanLine[Y]);
       for X := 0 to T.W - 1 do
       begin
+{$IFDEF DARWIN}
+        // ARGB: byte0=A, byte1=R, byte2=G, byte3=B
+        IsKey := Keyed and (Src[1] = $FF) and (Src[2] = $00) and (Src[3] = $FF);
+        Buf[I] := Src[1]; Buf[I+1] := Src[2]; Buf[I+2] := Src[3];
+{$ELSE}
+        // BGRA: byte0=B, byte1=G, byte2=R
         IsKey := Keyed and (Src[0] = $FF) and (Src[1] = $00) and (Src[2] = $FF);
-        Buf[I] := Src[2];
+        Buf[I] := Src[2]; Buf[I+1] := Src[1]; Buf[I+2] := Src[0];
-        Buf[I + 1] := Src[1];
+{$ENDIF}
-        Buf[I + 2] := Src[0];
         if IsKey then Buf[I + 3] := 0 else Buf[I + 3] := FixedAlpha;
         Inc(Src, 4);
         Inc(I, 4);
@@ -230,7 +235,11 @@ begin
       Src := PByte(B.ScanLine[Y]);
       for X := 0 to T.W - 1 do
       begin
-        A := Max(Src[0], Max(Src[1], Src[2]));
+{$IFDEF DARWIN}
+        A := Max(Src[1], Max(Src[2], Src[3]));  // ARGB: R,G,B at bytes 1,2,3
+{$ELSE}
+        A := Max(Src[0], Max(Src[1], Src[2]));  // BGRA: B,G,R at bytes 0,1,2
+{$ENDIF}
         Buf[I] := R;
         Buf[I + 1] := G;
         Buf[I + 2] := BB;

VfoOverlay.pas

@@ -173,13 +173,23 @@ begin
       Inc(DstRow, DstX * 4);
       for X := SX0 to SX1 - 1 do
       begin
-        // KEY_COLOR is clFuchsia in pf32bit B,G,R order.
+{$IFDEF DARWIN}
+        // ARGB layout: byte0=A, byte1=R, byte2=G, byte3=B
+        if not ((SrcRow[1] = $FF) and (SrcRow[2] = $00) and (SrcRow[3] = $FF)) then
+        begin
+          DstRow[1] := Byte((Alpha * SrcRow[1] + InvA * DstRow[1]) div 255);
+          DstRow[2] := Byte((Alpha * SrcRow[2] + InvA * DstRow[2]) div 255);
+          DstRow[3] := Byte((Alpha * SrcRow[3] + InvA * DstRow[3]) div 255);
+        end;
+{$ELSE}
+        // BGRA layout: byte0=B, byte1=G, byte2=R
         if not ((SrcRow[0] = $FF) and (SrcRow[1] = $00) and (SrcRow[2] = $FF)) then
         begin
           DstRow[0] := Byte((Alpha * SrcRow[0] + InvA * DstRow[0]) div 255);
           DstRow[1] := Byte((Alpha * SrcRow[1] + InvA * DstRow[1]) div 255);
           DstRow[2] := Byte((Alpha * SrcRow[2] + InvA * DstRow[2]) div 255);
         end;
+{$ENDIF}
         Inc(SrcRow, 4);
         Inc(DstRow, 4);
       end;

WidebandView.pas

@@ -472,12 +472,17 @@ begin
       Inc(Row, RR.Left * 4);
       for X := RR.Left to RR.Right - 1 do
       begin
-        BB := Row[0];
+{$IFDEF DARWIN}
-        BG := Row[1];
+        BB := Row[3]; BG := Row[2]; BR := Row[1];
-        BR := Row[2];
+        Row[1] := Byte((SR * Alpha + BR * (255 - Alpha)) div 255);
+        Row[2] := Byte((SG * Alpha + BG * (255 - Alpha)) div 255);
+        Row[3] := Byte((SB * Alpha + BB * (255 - Alpha)) div 255);
+{$ELSE}
+        BB := Row[0]; BG := Row[1]; BR := Row[2];
         Row[0] := Byte((SB * Alpha + BB * (255 - Alpha)) div 255);
         Row[1] := Byte((SG * Alpha + BG * (255 - Alpha)) div 255);
         Row[2] := Byte((SR * Alpha + BR * (255 - Alpha)) div 255);
+{$ENDIF}
         Inc(Row, 4);
       end;
     end;
@@ -574,9 +579,15 @@ begin
         if SpPts[Col].Y <= Row then
         begin
           Off := Col * 4;
+{$IFDEF DARWIN}
+          RowPtr[Off+1] := (GradR * Alpha + RowPtr[Off+1] * (200 - Alpha)) div 200;
+          RowPtr[Off+2] := (GradG * Alpha + RowPtr[Off+2] * (200 - Alpha)) div 200;
+          RowPtr[Off+3] := (GradB * Alpha + RowPtr[Off+3] * (200 - Alpha)) div 200;
+{$ELSE}
           RowPtr[Off]   := (GradB * Alpha + RowPtr[Off]   * (200 - Alpha)) div 200;
-          RowPtr[Off + 1] := (GradG * Alpha + RowPtr[Off + 1] * (200 - Alpha)) div 200;
+          RowPtr[Off+1] := (GradG * Alpha + RowPtr[Off+1] * (200 - Alpha)) div 200;
-          RowPtr[Off + 2] := (GradR * Alpha + RowPtr[Off + 2] * (200 - Alpha)) div 200;
+          RowPtr[Off+2] := (GradR * Alpha + RowPtr[Off+2] * (200 - Alpha)) div 200;
+{$ENDIF}
         end;
     end;
   finally
@@ -984,21 +995,37 @@ begin
       Src := PByte(FLabelBitmap.ScanLine[Y]);
       for X := 0 to FLabelBitmap.Width - 1 do
       begin
-        A := Max(Src[0], Max(Src[1], Src[2]));
+{$IFDEF DARWIN}
+        // ARGB: byte0=A, byte1=R, byte2=G, byte3=B
+        A := Max(Src[1], Max(Src[2], Src[3]));
         if A < 6 then A := 0;
         if A > 0 then
         begin
-          Buf[I] := Byte(Min(255, Src[2] * 255 div A));
+          Buf[I]     := Byte(Min(255, Src[1] * 255 div A));  // R
-          Buf[I + 1] := Byte(Min(255, Src[1] * 255 div A));
+          Buf[I + 1] := Byte(Min(255, Src[2] * 255 div A));  // G
-          Buf[I + 2] := Byte(Min(255, Src[0] * 255 div A));
+          Buf[I + 2] := Byte(Min(255, Src[3] * 255 div A));  // B
           A := Byte(Min(255, A + (255 - A) div 3));
         end
         else
         begin
-          Buf[I] := 0;
+          Buf[I] := 0; Buf[I + 1] := 0; Buf[I + 2] := 0;
-          Buf[I + 1] := 0;
-          Buf[I + 2] := 0;
         end;
+{$ELSE}
+        // BGRA: byte0=B, byte1=G, byte2=R
+        A := Max(Src[0], Max(Src[1], Src[2]));
+        if A < 6 then A := 0;
+        if A > 0 then
+        begin
+          Buf[I]     := Byte(Min(255, Src[2] * 255 div A));  // R
+          Buf[I + 1] := Byte(Min(255, Src[1] * 255 div A));  // G
+          Buf[I + 2] := Byte(Min(255, Src[0] * 255 div A));  // B
+          A := Byte(Min(255, A + (255 - A) div 3));
+        end
+        else
+        begin
+          Buf[I] := 0; Buf[I + 1] := 0; Buf[I + 2] := 0;
+        end;
+{$ENDIF}
         Buf[I + 3] := A;
         Inc(Src, 4);
         Inc(I, 4);