glClearIndex function

Article
12/11/2020

The glClearIndex function specifies the clear value for the color-index buffers.

Syntax

void WINAPI glClearIndex(
   GLfloat c
);

Parameters

c: The index used when the color-index buffers are cleared. The default value is zero.

Return value

This function does not return a value.

Error codes

The following error codes can be retrieved by the glGetError function.

Name	Meaning
GL_INVALID_OPERATION	The function was called between a call to glBegin and the corresponding call to glEnd.

Remarks

The glClearIndex function specifies the index used by glClear to clear the color-index buffers. The c parameter is not clamped. Rather, c is converted to a fixed-point value with unspecified precision to the right of the binary point. The integer part of this value is then masked with 2^m - 1, where m is the number of bits in a color index stored in the framebuffer.

The following functions retrieve information related to glClearIndex:

glGet with argument GL_INDEX_CLEAR_VALUE

glGet with argument GL_INDEX_BITS

Requirements

Requirement	Value
Minimum supported client	Windows 2000 Professional [desktop apps only]
Minimum supported server	Windows 2000 Server [desktop apps only]
Header	Gl.h
Library	Opengl32.lib
DLL	Opengl32.dll