## P

page flipping
  See flip.
palette
  The set of colors used by an object or application. In DirectX, a DirectDrawPalette object.
palette index
  An integer index into the palette table array that is used to select a particular color.
pan value
  The relative volume, measured in hundredths of decibels, between the left and right audio channels.
parallel point
  A light source that illuminates objects with parallel light, but the orientation of the light is taken from the position of the parallel point light source. For example, two meshes on either side of a parallel point light source are lit on the side that faces the position of the source.
penumbra
  The outer, dimly lit section of a spotlight's cone of light. The penumbra surrounds the umbra and merges with the surrounding deep shadow. See also umbra, and spotlight.
perspective correction
  The technique of applying a texture map to a polygon that is angled away from the camera, interpolating so that the texture is stretched onto the polygon appropriately for the apparent depth of the polygon. Direct3D supplies perspective correction automatically.
pick
  To search for visuals in a scene given a 2-D coordinate in a viewport.
pitch
  The distance, in bytes, between an address that represents the beginning of a bitmap line and the beginning of the next line. Do not confuse memory pitch and memory width, since not all display memory is laid out as one linear block. For example, with rectangular memory, the pitch of the display memory could include the width of the bitmap plus part of a cache. See also width, stride.
player
  A single participant in a DirectPlay session. Each player is associated with a player ID that enables messages to be exchanged among players.
player ID
  A unique number that is assigned to each participant in a DirectPlay session when the participant is created. The application can exchange messages among players by using player IDs. The host is always assigned the DPID_SYSMSG player ID.
point
  A light source that radiates equally in all directions from its origin.
power
  In the specular property of a material, the value that determines the sharpness of specular highlights. A value of 5 gives a metallic appearance, and higher values give a more plastic appearance.
primary sound buffer
  The buffer the user hears when a game is playing. The primary buffer is generally used to mix sound from secondary buffers, but it can be accessed directly for custom mixing or other specialized activities.
primary surface
  The area in memory containing the image being displayed on the monitor. In DirectX, the primary surface is represented by the primary DirectDrawSurface object.