摘要： Glyph（字形）A glyph is an element of writing: an individual mark on a written medium that contributes to the meaning of what is written.glyph是一个独立的标记，用来表达一个它之所以被写出的意思。也就是写了表示一个意思，不写表示另外一个意思。For example, in most languages written in any variety of the Latin alphabet the dot on a lower-case "i" 阅读全文

摘要： Graphics ContextsGraphics contexts are a fundamental part of the drawing infrastructure in Cocoa applications. As the name suggests, a graphics context provides the context for subsequent drawing operations. It identifies the current drawing destination (screen, printer, file, and so on), the coordi 阅读全文