From e5159ea7a2dd2f16eb4782170f43cfb0dd5ae133 Mon Sep 17 00:00:00 2001
From: rich2014 <rich2014.git@outlook.com>
Date: Tue, 17 Sep 2024 21:02:26 +0800
Subject: [PATCH] cocoa: fix some legacy transparent icon format issues #41131

there are two transparent formats:
1. the one with alpha channel like modern graphic formats (supported previously)
2. the other historical legacy with extra 1bit/pixel MaskBitmap (fixed this time), scaled mask supported also.
---
 lcl/interfaces/cocoa/cocoagdiobjects.pas | 56 +++++++++++++++++-------
 1 file changed, 40 insertions(+), 16 deletions(-)

diff --git a/lcl/interfaces/cocoa/cocoagdiobjects.pas b/lcl/interfaces/cocoa/cocoagdiobjects.pas
index a36c7a52fa..d9b13a62b3 100644
--- a/lcl/interfaces/cocoa/cocoagdiobjects.pas
+++ b/lcl/interfaces/cocoa/cocoagdiobjects.pas
@@ -281,6 +281,7 @@ type
     procedure ReCreateHandle_IfModified();
     procedure SetModified();
     function CreateSubImage(const ARect: TRect): CGImageRef;
+    function CreateMaskImage(const ARect: TRect): CGImageRef;
     procedure PreMultiplyAlpha();
     function GetNonPreMultipliedData(): PByte;
   public
@@ -1080,6 +1081,22 @@ begin
 end;
 
 
+function TCocoaBitmap.CreateMaskImage(const ARect: TRect): CGImageRef;
+var
+  CGDataProvider: CGDataProviderRef;
+  Mask: CGImageRef;
+begin
+  CGDataProvider := CGDataProviderCreateWithData(nil, FData, FDataSize, nil);
+  try
+    Mask := CGImageMaskCreate(FWidth, FHeight, FBitsPerPixel,
+      FBitsPerPixel, FBytesPerRow, CGDataProvider, nil, 0);
+    Result := CGImageCreateWithImageInRect(Mask, RectToCGRect(ARect));
+  finally
+    CGDataProviderRelease(CGDataProvider);
+    CGImageRelease(Mask);
+  end;
+end;
+
 function TCocoaBitmap.GetColorSpace: NSString;
 begin
   if FType in [cbtMono, cbtGray] then
@@ -2148,36 +2165,43 @@ function TCocoaContext.StretchDraw(X, Y, Width, Height: Integer;
   SrcDC: TCocoaBitmapContext; XSrc, YSrc, SrcWidth, SrcHeight: Integer;
   Msk: TCocoaBitmap; XMsk, YMsk: Integer; Rop: DWORD): Boolean;
 var
-  Bmp: TCocoaBitmap;
-  ImgRect: CGRect;
-
-  dcWidth: Integer;
-  dcHeight: Integer;
+  dcBitmap: TCocoaBitmap;
+  maskImage: CGImageRef = nil;
+  cgImage: CGImageRef;
+  imageRep: NSBitmapImageRep;
 begin
-  Bmp := SrcDC.Bitmap;
-  if not Assigned(Bmp) then
+  dcBitmap := SrcDC.Bitmap;
+  if not Assigned(dcBitmap) then
     Exit(False);
 
-  dcWidth:= Max(Width,FSize.Width);
-  dcHeight:= Max(Height,FSize.Height);
-
   // Make sure that bitmap is the most up-to-date
-  Bmp.ReCreateHandle_IfModified(); // Fix for bug 28102
+  dcBitmap.ReCreateHandle_IfModified(); // Fix for bug 28102
 
   // see https://bugs.freepascal.org/view.php?id=34197
   // Bitmap context windowsofs should be used when rendering a bitmap
   inc(XSrc, -SrcDC.WindowOfs.X);
   inc(YSrc, -SrcDC.WindowOfs.Y);
 
-  CGContextSaveGState(CGContext);
-
   if NOT SrcDC.ctx.isFlipped then begin
-    YSrc := Bmp.Height - (SrcHeight + YSrc);
+    YSrc := dcBitmap.Height - (SrcHeight + YSrc);
   end;
 
-  Result := DrawImageRep(GetNSRect(X, Y, Width, Height),GetNSRect(XSrc, YSrc, SrcWidth, SrcHeight), bmp.ImageRep);
+  imageRep:= dcBitmap.ImageRep;
+  if (Msk <> nil) and (Msk.Image <> nil) then begin
+    maskImage := Msk.CreateMaskImage(Bounds(XMsk, YMsk, SrcWidth, SrcHeight));
+    cgImage:= CGImageCreateWithMask(imageRep.CGImage, maskImage);
+    imageRep:= NSBitmapImageRep.alloc.initWithCGImage(cgImage);
+  end;
 
-  CGContextRestoreGState(CGContext);
+  Result := DrawImageRep( GetNSRect(X, Y, Width, Height),
+                          GetNSRect(XSrc, YSrc, SrcWidth, SrcHeight),
+                          imageRep );
+
+  if Assigned(maskImage) then begin
+    imageRep.release;
+    CGImageRelease(cgImage);
+    CGImageRelease(maskImage);
+  end;
 
   AttachedBitmap_SetModified();
 end;