GLCALLLISTS() MachTen Programmer’s Manual 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 exe-
cuted.

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 more
than one display list. type 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 dis-
play-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 dis-
play lists calling one another, a limit is placed on the
nesting level of display lists during display-list execu-
tion. This limit must be at least 64, and it depends on
the implementation.

GL state is not saved and restored across a call to glCal-
lLists. Thus, changes made to GL state during the execu-
tion of the display lists remain after execution is com-
pleted. 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 dis-
play list includes only commands that are allowed in this
interval.

ERRORS
GL_INVALID_VALUE is generated if n is negative.

GL_INVALID_ENUM is generated if type is not one of
GL_BYTE, GL_UNSIGNED_BYTE, GL_SHORT, GL_UNSIGNED_SHORT,
GL_INT, GL_UNSIGNED_INT, GL_FLOAT, GL_2_BYTES, GL_3_BYTES,
GL_4_BYTES.

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

MachTen 3