WOFF fonts may contain 'hints' for the alignment of graphical elements of the glyphs with the target display pixel grid, and depending on the font technology utilized in the creation of a font these hints may represent active code interpreted and executed by the font rasterizer. Even though they operate within the confines of the glyph outline conversion system and have no access outside the font rendering machinery, hint instructions can be, however, quite complex, and a maliciously designed complex font could cause undue resource consumption (. memory or CPU cycles) on a machine interpreting it. Indeed, fonts are sufficiently complex that most if not all interpreters cannot be completely protected from malicious fonts without undue performance penalties.
wglCreateContext() creates an OpenGL rendering context for drawing on the device in the selected pixel format of the device context. (To create an OpenGL rendering context for overlay or underlay windows, use wglCreateLayerContext() instead.) To make a rendering context current, use wglMakeCurrent() ; wglGetCurrentContext() returns the current context. You can also obtain the current device context with wglGetCurrentDC() . You can copy some OpenGL state variables from one context to another with wglCopyContext() or make two contexts share the same display lists and texture objects with wglShareLists() . When you're finished with a particular context, destroy it with wglDestroyContext() .