Open GL Super Bible:3D Modeling and Object Composition















To access the contents, click the chapter and section titles.


Open GL Super Bible


(Publisher: Macmillan Computer Publishing)

Author(s): Waite group Press

ISBN: 1571690735

Publication Date: 08/01/96

 




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Reference Section
glCallList

Purpose
Executes a display list.
Include File
<gl.h>
Syntax
void glCallList(GLuint list);
Description
Executes the display list identified by list. The OpenGL State Machine is not restored
after this function is called, so it is a good idea to call glPushMatrix
beforehand and glPopMatrix afterwards. Calls to glCallList may be
nested. The function glGet with the argument GL_MAX_LIST_NESTING returns
the maximum number of allowable nests. For Microsoft Windows, this value
is 64.


Parameters


list

GLuint: Identifies the display list to be executed.
Returns
None.


Example
The following code saves the matrix state before calling a display list. It then restores the state afterwards. This code is from the BOLTL example program from this chapterłs subdirectory on the CD.

// Save the current transform state
glPushMatrix();

// Draw the bolt including nested display lists
glCallList(BOLT_HEAD);

// Restore state
glPopMatrix();


See Also
glCallLists, glDeleteLists, glGenLists,
glNewList


glCallLists

Purpose
Executes a list of display lists.
Include File
<gl.h>
Syntax
void glCallLists(GLsizei n, GLenum type, const GLvoid *lists);
Description
This function calls the display lists listed in the *lists array sequentially. This array
can be of nearly any data type. The result is converted or clamped to
the nearest integer value to determine the actual index of the display
list. Optionally, the list values can be offset by a value specified by
the function glListBase.


Parameters


n

GLsizei: Number of elements in the array of display lists.
type

GLenum: Specifies the datatype of the array stored at *lists. This can be any one of the following values: 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.
*lists

GLvoid: An array of elements of the type specified in type. The data type is void to allow any of the above data types to be used.
Returns
None.


Example
The following code shows how to call a list of display lists with a single call:

// Storage for the display list identifiers
int lists[50];
int i;


// Create list names
for(i = 0; i < 50; i++)
lists[i] = i+1;

// Build some fifty display lists //////////
// First list
glNewList(lists[0],GL_COMPILE);


glEndList();

// Second list
glNewList(lists[1],GL_COMPILE);


glEndList();

// And so on



// Call all fifty lists with a single call
glCallLists(50, GL_INT, lists);


See Also
glCallList, glDeleteLists, glGenLists,
glListBase, glNewList


glDeleteLists

Purpose
Deletes a continuous range of display lists.
Include File
<gl.h>
Syntax
void glDeleteLists(GLuint list, GLsizei range);
Description
This function deletes a range of display lists. The range goes from an initial value and proceeds until the number of lists deleted as specified by range is
completed. Deleting unused display lists can save considerable memory.
Unused display lists in the range of those specified are ignored and do
not cause an error.


Parameters


list

GLuint: The integer name of the first display list to delete.
range

GLsizei: The number of display lists to be deleted following the initially specified list.
Returns
None.


Example
The following single line of code shows any and all display lists with identifiers between 1 and 50 being deleted:

glDeleteLists(1, 50);


See Also
glCallList, glCallLists, glGenLists, glIsList,
glNewList


glEndList

Purpose
Delimits the end of a display list.
Include File
<gl.h>
Syntax
void glEndList( void);
Description
Display lists are created by first calling glNewList. Thereafter, all OpenGL commands are compiled and placed in the display list. The glEndList function terminates the creation of this display list.
Returns
None.


Example
The following example code shows an example of a display list being delimited by glNewList and glEndList. This particular display list is composed by nesting two other display lists within it.

// Begin delimit of list
glNewList(BOLT_LIST,GL_COMPILE);

// Display list calls two previously defined display lists
glCallList(SHAFT_LIST);
glCallList(THREAD_LIST);

// End this display list
glEndList();


See Also
glCallList, glCallLists, glDeleteLists,
glGenLists, glIsList






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