glIndexPointerEXT Subroutine

OpenGL 1.1 for AIX: Reference Manual

glIndexPointerEXT Subroutine

Purpose

Defines an array of color indexes.

Library

OpenGL C bindings library: libGL.a

C Syntax

void glIndexPointerEXT(GLenum type, 
            GLsizei stride, 
            GLsizei count, 
            const GLvoid *pointer)

Parameters

type	Specifies the data type of each color index in the array. Symbolic constants GL_SHORT, GL_INT, GL_FLOAT, or GL_DOUBLE_EXT, are accepted.
stride	Specifies the byte offset between consecutive color indexes. If stride is zero the color indexes are understood to be tightly packed in the array.
count	Specifies the number of indexes, counting from the first, that are static.
pointer	Specifies a pointer to the first index in the array.

Description

The glIndexPointerEXT subroutine specifies the location and data format of an array of color indexes to use when rendering. type specifies the data type of each color index and stride gives the byte stride from one color index to the next allowing vertexes and attributes to be packed into a single array or stored in separate arrays. (Single-array storage may be more efficient on some implementations.) count indicates the number of array elements (counting from the first) that are static. Static elements may be modified by the application, but once they are modified, the application must explicitly respecify the array before using it for any rendering. When a color index array is specified, type, stride, count and pointer are saved as client-side state, and static array elements may be cached by the implementation.

The color index array is enabled and disabled using glEnable and glDisable with the argument GL_INDEX_ARRAY_EXT. If enabled, the color index array is used when glDrawArraysEXT or glArrayElementEXT is called.

Use glDrawArraysEXT to define a sequence of primitives (all of the same type) from pre-specified vertex and vertex attribute arrays. Use glArrayElementEXT to specify primitives by indexing vertexes and vertex attributes.

Notes

Non-static array elements are not accessed until glArrayElementEXT or glDrawArraysEXT is executed.

By default the color index array is disabled and it won't be accessed when glArrayElementEXT or glDrawArraysEXT is called.

Although, it is not an error to call glIndexPointerEXT between the execution of glBegin and the corresponding execution of glEnd, the results are undefined.

glIndexPointerEXT will typically be implemented on the client side with no protocol.

Since the color index array parameters are client side state, they are not saved or restored by glPushAttrib and glPopAttrib.

glIndexPointerEXT commands are not entered into display lists.

glIndexPointerEXT is part of the _extname(EXT_vertex_array) extension, not part of the core GL command set. If _extstring(EXT_vertex_array) is included in the string returned by glGetString, when called with argument GL_EXTENSIONS, extension _extname(EXT_vertex_array) is supported.

Errors

GL_INVALID_ENUM is generated if type is not an accepted value.

GL_INVALID_VALUE is generated if stride or count is negative.

Associated Gets

glIsEnabled with argument GL_INDEX_ARRAY_EXT

glGet with argument GL_INDEX_ARRAY_SIZE_EXT

glGet with argument GL_INDEX_ARRAY_TYPE_EXT

glGet with argument GL_INDEX_ARRAY_STRIDE_EXT

glGet with argument GL_INDEX_ARRAY_COUNT_EXT

glGetPointervEXT with argument GL_INDEX_ARRAY_POINTER_EXT

File

/usr/include/GL/glext.h

Contains extensions to C language constants, variable type definitions, and ANSI function prototypes for OpenGL.

Related Information

The glArrayElementEXT subroutine, glColorPointerEXT subroutine, glDrawArraysEXT subroutine, glEdgeFlagPointerEXT subroutine, glGetPointervEXT subroutine, glNormalPointerEXT subroutine, glTexCoordPointerEXT subroutine, glVertexPointerEXT subroutine.