glVertexPointerEXT Subroutine

OpenGL 1.1 for AIX: Reference Manual

glVertexPointerEXT Subroutine

Purpose

Defines an array of vertex data.

Library

OpenGL C bindings library: libGL.a

C Syntax

void glVertexPointerEXT(GLint size, 
             GLenum type, 
             GLsizei stride, 
             GLsizei count, 
             const GLvoid *pointer)

Parameters

size	Specifies the number of coordinates per vertex, must be 2,3, or 4.
type	Specifies the data type of each coordinate in the array. Symbolic constants GL_SHORT, GL_INT, GL_FLOAT, or GL_DOUBLE_EXT are accepted.
stride	Specifies the byte offset between consecutive vertexes. If stride is 0 the vertexes are understood to be tightly packed in the array.
count	Specifies the number of vertexes, counting from the first, that are static.
pointer	Specifies a pointer to the first coordinate of the first vertex in the array.

Description

The glVertexPointerEXT subroutine specifies the location and data format of an array of vertex coordinates to use when rendering. size specifies the number of coordinates per vertex and type the data type of the coordinates. stride gives the byte stride from one vertex 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 vertex array is specified, size, type, stride, count, and pointer are saved as client-side state, and static array elements may be cached by the implementation.

The vertex array is enabled and disabled using glEnable and glDisable with the argument GL_VERTEX_ARRAY_EXT. If enabled, the vertex 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 vertex array is disabled and it won't be accessed when glArrayElementEXT or glDrawArraysEXT is called.

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

The glVertexPointerEXT subroutine will typically be implemented on the client side with no protocol.

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

The glVertexPointerEXT commands are not entered into display lists.

The glVertexPointerEXT subroutine 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_VALUE is generated if size is not 2, 3, or 4.

GL_INVALID_ENUM is generated if type is is not an accepted value.

GL_INVALID_VALUE is generated if stride or count is negative.

Associated Gets

glIsEnabled with argument GL_VERTEX_ARRAY_EXT

glGet with argument GL_VERTEX_ARRAY_SIZE_EXT

glGet with argument GL_VERTEX_ARRAY_TYPE_EXT

glGet with argument GL_VERTEX_ARRAY_STRIDE_EXT

glGet with argument GL_VERTEX_ARRAY_COUNT_EXT

glGetPointervEXT with argument GL_VERTEX_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, glIndexPointerEXTsubroutine, glNormalPointerEXT subroutine, glTexCoordPointerEXT subroutine.