HP Workstation zx2000 OpenGL 1.1 Reference for HP-UX 11.x - Page 331

P glPixelStore equivalent to incrementing the pointer by jk components or indices, where k is the number of components or indices per row, as just computed in the GL_UNPACK_ROW_LENGTH section. GL_UNPACK_ALIGNMENT Specifies the alignment requirements for the start of each pixel row in memory. The allowable values are 1 (byte-alignment), 2 (rows aligned to even-numbered bytes), 4 (word-alignment), and 8 (rows start on double-word boundaries). The following table gives the type, initial value, and range of valid values for each storage parameter that can be set with glPixelStore. pname Type GL_PACK_SWAP_BYTES GL_PACK_LSB_FIRST GL_PACK_ROW_LENGTH GL_PACK_SKIP_ROWS GL_PACK_SKIP_PIXELS GL_PACK_ALIGNMENT GL_UNPACK_SWAP_BYTES GL_UNPACK_LSB_FIRST GL_UNPACK_ROW_LENGTH GL_UNPACK_SKIP_ROWS GL_UNPACK_SKIP_PIXELS GL_UNPACK_ALIGNMENT boolean boolean integer integer integer integer boolean boolean integer integer integer integer Initial Value false false 0 0 0 4 false false 0 0 0 4 Valid Range true or false true or false [0, ∞] [0, ∞] [0, ∞] 1, 2, 4 or 8 true or false true or false [0, ∞] [0, ∞] [0, ∞] 1, 2, 4 or 8 glPixelStoref can be used to set any pixel store parameter. If the parameter type is boolean, then if param is 0, the parameter is false; otherwise it is set to true. If pname is a integer type parameter, param is rounded to the nearest integer. Likewise, glPixelStorei can also be used to set any of the pixel store parameters. Boolean parameters are set to false if param is 0 and true otherwise. Notes The pixel storage modes in effect when glDrawPixels, glReadPixels, glTexImage1D, glTexImage2D, glTexSubImage1D, glTexSubImage2D, glBitmap, or glPolygonStipple is placed in a display list control the interpretation of memory data. The pixel storage modes in effect when a display list is executed are not significant. Pixel storage modes are client state and must be pushed and restored using glPushClientAttrib and glPopClientAttrib. Chapter 14 331