在iOS中,我将使用UIKit将它们绘制到一个上下文中,但OSX似乎不可能(不支持UIKit).

堆叠两张图片最简单的方法是什么？谢谢

NSImage *background = [NSImage imageNamed:@"background"];NSImage *overlay = [NSImage imageNamed:@"overlay"];NSImage *newImage = [[NSImage alloc] initWithSize:[background size]];[newImage lockFocus];CGRect newImageRect = CGRectZero;newImageRect.size = [newImage size];[background drawInRect:newImageRect];[overlay drawInRect:newImageRect];[newImage unlockFocus];CGImageRef newImageRef = [newImage CGImageForProposedRect:NULL context:nil hints:nil];

如果你不喜欢,那么您期望的大多数CGContext API都可以跨平台,用于绘制更多的控制.同样,您可以查看NSGraphicsContext.

如果Firefox是用Objective C编写的,您可以非常轻松地添加执行此操作所需的one line of Objective C code.但事实并非如此.有没有办法从C调用这个Cocoa函数,以便它可以添加到Firefox中,以便所有Mac用户受益？

文档和代码示例here.

- (void)scaleIcons:(Nsstring *)outputPath{
NSImage *anImage;
NSSize imageSize;
Nsstring *finalPath;

anImage = [self image];

imageSize = [anImage size];
imageSize.width = 512;
imageSize.height = 512;
[anImage setSize:imageSize];

finalPath = [outputPath stringByAppendingString:@"/icon_512x512.png"];

NSData *imageData = [anImage TIFFRepresentation];
NSBitmapImageRep *rep = [NSBitmapImageRep imageRepWithData:imageData];
NSData *dataToWrite = [rep representationUsingType:NSPNGFileType properties:nil];
[dataToWrite writetoFile:finalPath atomically:NO];
}

一切正常,除了我的图像没有缩放的事实.有人可以帮忙吗？

- (NSImage *)scaleImage:(NSImage *)image toSize:(NSSize)targetSize
{
  if ([image isValid])
  {
    NSSize imageSize = [image size];
    float width  = imageSize.width;
    float height = imageSize.height;
    float targetWidth  = targetSize.width;
    float targetHeight = targetSize.height;
    float scaleFactor  = 0.0;
    float scaledWidth  = targetWidth;
    float scaledHeight = targetHeight;

    NSPoint thumbnailPoint = NSZeroPoint;

    if (!NSEqualSizes(imageSize,targetSize))
    {
      float widthFactor  = targetWidth / width;
      float heightFactor = targetHeight / height;

      if (widthFactor < heightFactor)
      {
        scaleFactor = widthFactor;
      }
      else
      {
        scaleFactor = heightFactor;
      }

      scaledWidth  = width  * scaleFactor;
      scaledHeight = height * scaleFactor;

      if (widthFactor < heightFactor)
      {
        thumbnailPoint.y = (targetHeight - scaledHeight) * 0.5;
      }

      else if (widthFactor > heightFactor)
      {
        thumbnailPoint.x = (targetWidth - scaledWidth) * 0.5;
      }

    NSImage *newImage = [[NSImage alloc] initWithSize:targetSize];

    [newImage lockFocus];

     NSRect thumbnailRect;
     thumbnailRect.origin = thumbnailPoint;
     thumbnailRect.size.width = scaledWidth;
     thumbnailRect.size.height = scaledHeight;

     [image drawInRect:thumbnailRect
              fromrect:NSZeroRect
             operation:NSCompositeSourceOver
              fraction:1.0];

    [newImage unlockFocus];
  }

  return newImage;
}

如果将其集成到现有方法中：

- (void)scaleIcons:(Nsstring *)outputPath{

    NSSize outputSize = NSMakeSize(512.0f,512.0f);
    NSImage *anImage  = [self scaleImage:[self image] toSize:outputSize];

    Nsstring *finalPath = [outputPath stringByAppendingString:@"/icon_512x512.png"];
    NSData *imageData = [anImage TIFFRepresentation];
    NSBitmapImageRep *rep = [NSBitmapImageRep imageRepWithData:imageData];
    NSData *dataToWrite = [rep representationUsingType:NSPNGFileType properties:nil];
   [dataToWrite writetoFile:finalPath atomically:NO];
}

虽然它不直接编译到Objective-C,但它声称生成与Objective-C相同的二进制代码

Eero compiles down to the same binary code as Objective-C

Eero offers excellent,nearly seamless interoperability with
Objective-C,C,and C++.

我发现这种方法非常有趣,我想知道是否有类似的编程语言和项目提供与Objective-C和iOS的大腿集成.
我正在为Objective-C寻找类似Coffeescript的东西.

它确实需要记录在一个更明显的地方……