How to write a correct URL?

In its earliest incarnation, Direct3D was known to be rather clumsy to use — to perform a state change, for instance, it required a number of complex operations. For example, to enable alpha blending, one had to create an execute buffer, lock it, fill it with the correct opcodes (along with a structure header telling how many opcodes the buffer contained and a special "exit" opcode), unlock it, and finally send it to the driver for execution. In contrast, OpenGL only requires a single "glEnable(GL_BLEND);" call. The Direct3D model frustrated many programmers. The most famous complaint was probably made by high-profile game developer John Carmack in the .plan file in which he urged Microsoft to abandon Direct3D in favor of OpenGL.