fix bug that system font is not rendered correctly on macOS Catalina (#20124)

Author: minggo

cocos/platform/mac/CCDevice-mac.mm

@@ -279,47 +279,49 @@ static bool _initWithString(const char * text, Device::TextAlign align, const ch
 
         NSSize realDimensions;
 
-        if (overflow == 2) {
+        if (overflow == 2)
             realDimensions = _calculateRealSizeForString(&stringWithAttributes, font, dimensions, enableWrap);
-        } else {
+        else
             realDimensions = _calculateStringSize(stringWithAttributes, font, &dimensions, enableWrap, overflow);
-        }
-        
 
         // Mac crashes if the width or height is 0
         CC_BREAK_IF(realDimensions.width <= 0 || realDimensions.height <= 0);
 
 
-        if(dimensions.width <= 0.f) {
+        if(dimensions.width <= 0.f)
             dimensions.width = realDimensions.width;
-        }
-        if (dimensions.height <= 0.f) {
+        if (dimensions.height <= 0.f)
             dimensions.height = realDimensions.height;
-        }
-      
-        
+
         //Alignment
         CGFloat xPadding = FontUtils::_calculateTextDrawStartWidth(align, realDimensions, dimensions);
-        
         CGFloat yPadding = _calculateTextDrawStartHeight(align, realDimensions, dimensions);
 
         NSInteger POTWide = dimensions.width;
         NSInteger POTHigh = dimensions.height;
         NSRect textRect = NSMakeRect(xPadding, POTHigh - dimensions.height + yPadding,
                                      realDimensions.width, realDimensions.height);
 
-        
-        [[NSGraphicsContext currentContext] setShouldAntialias:NO];
-        
-        NSImage *image = [[NSImage alloc] initWithSize:NSMakeSize(POTWide, POTHigh)];
-        [image lockFocus];
-        // patch for mac retina display and lableTTF
-        [[NSAffineTransform transform] set];
+        NSBitmapImageRep* offscreenRep = [[[NSBitmapImageRep alloc]
+            initWithBitmapDataPlanes:NULL
+            pixelsWide:POTWide
+            pixelsHigh:POTHigh
+            bitsPerSample:8
+            samplesPerPixel:4
+            hasAlpha:YES
+            isPlanar:NO
+            colorSpaceName:NSDeviceRGBColorSpace
+            bitmapFormat: 0
+            bytesPerRow:4 * POTWide
+            bitsPerPixel:32] autorelease];
+
+        NSGraphicsContext* g = [NSGraphicsContext graphicsContextWithBitmapImageRep:offscreenRep];
+        [NSGraphicsContext saveGraphicsState];
+        [NSGraphicsContext setCurrentContext:g];
         [stringWithAttributes drawInRect:textRect];
-        NSBitmapImageRep *bitmap = [[NSBitmapImageRep alloc] initWithFocusedViewRect:NSMakeRect (0.0f, 0.0f, POTWide, POTHigh)];
-        [image unlockFocus];
+        [NSGraphicsContext restoreGraphicsState];
 
-        auto data = (unsigned char*) [bitmap bitmapData];  //Use the same buffer to improve the performance.
+        auto data = (unsigned char*) [offscreenRep bitmapData];  //Use the same buffer to improve the performance.
 
         NSUInteger textureSize = POTWide * POTHigh * 4;
         auto dataNew = (unsigned char*)malloc(sizeof(unsigned char) * textureSize);
@@ -333,8 +335,6 @@ static bool _initWithString(const char * text, Device::TextAlign align, const ch
             info->isPremultipliedAlpha = true;
             ret = true;
         }
-        [bitmap release];
-        [image release];
     } while (0);
     return ret;
 }