GPU - The GE Some notes about the PSP's GPU: The GE (Graphics Engine) At a first glance, the PSP GPU, known as the GE (graphics engine), looks like a conventional small fixed-function GPU not unlike something like the original Geforce 256 (but without multitexturing sup...Read more » The GE vertex transform pipeline The GE implements something pretty similar to a standard T&L fixed function pipeline from early PC GPUs, but with some differences and additions.Read more » GE lighting The GE lights each vertex with up to four lights: directional, point or spot. Each light has ambient, diffuse and specular colors, and its "computation" is diffuse only, diffuse plus specular, or powe...Read more » The GE raster pipeline This page picks up where the vertex pipeline leaves off. There, vertices end up with screen X and Y in 12.4 fixed point (4 subpixel bits), a 16-bit Z, an 8-bit fog value, colors and texture coordinate...Read more » GE curves: Bezier and spline patches The GE can tessellate surfaces itself. A BEZIER command draws one or more bicubic Bezier patches from a grid of control points (4x4 per patch, sharing edges), and a SPLINE command draws a uniform cubi...Read more » The texture cache and self-texturing The GE reads textures through a small texture cache, 8 KB in size. For nearly all rendering, the cache is invisible: textures don't change while they're drawn with. It does become visible when a game ...Read more » GE arithmetic The GE doesn't compute with IEEE floats, or with any single format. Each stage of the pipeline has its own small set of operations, and each of them rounds in its own way, nearly always by truncating ...Read more » Image formats and tricks The PSP supports a relatively wide range of image formats, and can freely "cast" between them. That means that it can render to a buffer in R5G6B5 format for example, and then texture from it as if it...Read more » Block transfers The GE can copy a rectangle of pixels from one buffer to another on its own, with a block transfer (TRXKICK, 0xEA): source and destination address and buffer width, source and destination position, si...Read more » Display list control A display list is a sequence of 32-bit commands in RAM: a command number in the top 8 bits and a 24-bit parameter. Most commands set a register or draw. This page is about the others, which decide whe...Read more »