glCallLists

NAME

glCallLists - execute a list of display lists

C SPECIFICATION

void glCallLists( GLsizei n, GLenum type, const GLvoid *lists )

PARAMETERS

n ? Specifies the number of display lists to be executed.

type ? Specifies the type of values in lists. Symbolic constants GL_BYTE, GL_UNSIGNED_BYTE, GL_SHORT, GL_UNSIGNED_SHORT, GL_INT, GL_UNSIGNED_INT, GL_FLOAT, GL_2_BYTES, GL_3_BYTES, and GL_4_BYTES are accepted.

lists ? Specifies the address of an array of name offsets in the display list. The pointer type is void because the offsets can be bytes, shorts, ints, or floats, depending on the value of type.

DESCRIPTION

glCallLists causes each display list in the list of names passed as lists to be executed. As a result, the commands saved in each display list are executed in order, just as if they were called without using a display list. Names of display lists that have not been defined are ignored.

glCallLists provides an efficient means for executing display lists. n allows lists with various name formats to be accepted. The formats are as follows:

GL_BYTE ? lists is treated as an array of signed bytes, each in the range -128 through 127.

GL_UNSIGNED_BYTE ?

lists is treated as an array of unsigned bytes, each in the range 0 through 255.

GL_SHORT ? lists is treated as an array of signed two-byte integers, each in the range -32768 through 32767.

GL_UNSIGNED_SHORT ?

lists is treated as an array of unsigned two-byte integers, each in the range 0 through 65535.

GL_INT ? lists is treated as an array of signed four-byte integers.

GL_UNSIGNED_INT ?

lists is treated as an array of unsigned four-byte integers.

GL_FLOAT ? lists is treated as an array of four-byte floating-point values.

GL_2_BYTES ? lists is treated as an array of unsigned bytes. Each pair of bytes specifies a single display-list name. The value of the pair is computed as 256 times the unsigned value of the first byte plus the unsigned value of the second byte.

GL_3_BYTES ? lists is treated as an array of unsigned bytes. Each triplet of bytes specifies a single display-list name. The value of the triplet is computed as 65536 times the unsigned value of the first byte, plus 256 times the unsigned value of the second byte, plus the unsigned value of the third byte.

GL_4_BYTES ? lists is treated as an array of unsigned bytes. Each quadruplet of bytes specifies a single display-list name. The value of the quadruplet is computed as 16777216 times the unsigned value of the first byte, plus 65536 times the unsigned value of the second byte, plus 256 times the unsigned value of the third byte, plus the unsigned value of the fourth byte.

The list of display list names is not null-terminated. Rather, n specifies how many names are to be taken from lists.

An additional level of indirection is made available with the glListBase command, which specifies an unsigned offset that is added to each display-list name specified in lists before that display list is executed.

glCallLists can appear inside a display list. To avoid the possibility of infinite recursion resulting from display lists calling one another, a limit is placed on the nesting level of display lists during display-list execution. This limit must be at least 64, and it depends on the implementation.

GL state is not saved and restored across a call to glCallLists. Thus, changes made to GL state during the execution of the display lists remain after execution is completed. Use glPushAttrib, glPopAttrib, glPushMatrix, and glPopMatrix to preserve GL state across glCallLists calls.

NOTES

Display lists can be executed between a call to glBegin and the corresponding call to glEnd, as long as the display list includes only commands that are allowed in this interval.

ASSOCIATED GETS

glGet with argument GL_LIST_BASE

glGet with argument GL_MAX_LIST_NESTING

glIsList

SEE ALSO

"glCallList" , "glDeleteLists" , "glGenLists" , "glListBase" , "glNewList" , "glPushAttrib" , "glPushMatrix"