GLINDEXPOINTER

Section: Misc. Reference Manual Pages (3G)
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NAME

glIndexPointer - define an array of color indexes

C SPECIFICATION

void glIndexPointer( GLenum type,


                       GLsizei stride,
                       const GLvoid *ptr )

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PARAMETERS

type: Specifies the data type of each color index in the array. Symbolic constants GL_UNSIGNED_BYTE, GL_SHORT, GL_INT, GL_FLOAT, and GL_DOUBLE are accepted. The initial value is GL_FLOAT.
stride: Specifies the byte offset between consecutive color indexes. If stride is 0 (the initial value), the color indexes are understood to be tightly packed in the array. The initial value is 0.
ptr: Specifies a pointer to the first index in the array. The initial value is 0.

DESCRIPTION

glIndexPointer specifies the location and data 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 vertices and attributes to be packed into a single array or stored in separate arrays. (Single-array storage may be more efficient on some implementations; see glInterleavedArrays.) type, stride, and ptr are saved as client-side state. The color index array is initially disabled. To enable and disable the array, call glEnableClientState and glDisableClientState with the argument GL_INDEX_ARRAY. If enabled, the color index array is used when glDrawArrays, glDrawElements or glArrayElement is called. Use glDrawArrays to construct a sequence of primitives (all of the same type) from prespecified vertex and vertex attribute arrays. Use glArrayElement to specify primitives by indexing vertices and vertex attributes and glDrawElements to construct a sequence of primitives by indexing vertices and vertex attributes.

NOTES

glIndexPointer is available only if the GL version is 1.1 or greater. The color index array is initially disabled, and it isn't accessed when glArrayElement, glDrawElements, or glDrawArrays is called. Execution of glIndexPointer is not allowed between glBegin and the corresponding glEnd, but an error may or may not be generated. If an error is not generated, the operation is undefined. glIndexPointer is typically implemented on the client side. Since the color index array parameters are client-side state, they are not saved or restored by glPushAttrib and glPopAttrib. Use glPushClientAttrib and glPopClientAttrib instead.

ERRORS

GL_INVALID_ENUM is generated if type is not an accepted value. GL_INVALID_VALUE is generated if stride is negative.

ASSOCIATED GETS

glIsEnabled with argument GL_INDEX_ARRAY
glGet with argument GL_INDEX_ARRAY_TYPE
glGet with argument GL_INDEX_ARRAY_STRIDE
glGetPointerv with argument GL_INDEX_ARRAY_POINTER