1. A graphics pipeline for rendering graphics using forward texture mapping, the pipeline comprising: an input for receiving texture data and vertex data, the texture data defining texture maps in a texture space, each texture map comprising texels associated with texture space grid coordinates (u g ,v g ), the vertex data comprising texture space input coordinates (u r ,v r ) of input rectangles and screen space input coordinates (x h r ,y h r ,w h r ) of output quadrilaterals, the input rectangles being axis-aligned in the texture space, each one of the input rectangles being associated with a corresponding one of the output quadrilaterals; a rasterizer for receiving the texture space input coordinates of the input rectangles and for providing the texture space grid coordinates of the texels inside the input rectangles; and a mapper for mapping the texels inside the input rectangles onto the output quadrilaterals, the mapping being performed by calculating screen space output coordinates (x c ,y c ) from the texture space grid coordinates of the texels and the screen space input coordinates of the output quadrilaterals using a mapping function comprising at least one linear combination of the texture space grid coordinates of the texels inside the input rectangles, and at least one product of real powers (u g n v g m n,mÎµR) of the texture space grid coordinates of the texels inside the input rectangles; wherein the graphics pipeline renders graphics using forward texture mapping.