1. A method, carried out by a computing device, for generating a final value for a pixel, the method comprising: in response to data representing an IF_NEIGHBOR conditional statement, comprised of an IF_THEN statement whose body includes mip mapped texture fetch instructions, generating a compiled block of shader instructions that cause a shader to: determine whether a current pixel meets a first condition of the IF_NEIGHBOR conditional statement or one of the pixels neighboring the current pixel meets the first condition of the IF_NEIGHBOR conditional statement whose body includes mip mapped texture fetch instructions wherein the neighboring pixel is one that is used to calculate a texture map; and if so, execute a compiled body of the IF_NEIGHBOR conditional statement for the current pixel including the mip map texture fetch instruction.