glClear(3G)glClear(3G)NAMEglClear - clear buffers to preset values
SYNOPSIS
void glClear(
GLbitfield mask );
PARAMETERS
Bitwise OR of masks that indicate the buffers to be cleared. The four
masks are GL_COLOR_BUFFER_BIT, GL_DEPTH_BUFFER_BIT, GL_ACCUM_BUF‐
FER_BIT, and GL_STENCIL_BUFFER_BIT.
DESCRIPTIONglClear() sets the bitplane area of the window to values previously
selected by glClearColor(), glClearIndex(), glClearDepth(), glClearS‐
tencil(), and glClearAccum(). Multiple color buffers can be cleared
simultaneously by selecting more than one buffer at a time using
glDrawBuffer().
The pixel ownership test, the scissor test, dithering, and the buffer
writemasks affect the operation of glClear(). The scissor box bounds
the cleared region. Alpha function, blend function, logical operation,
stenciling, texture mapping, and depth-buffering are ignored by
glClear().
glClear() takes a single argument that is the bitwise OR of several
values indicating which buffer is to be cleared.
The values are as follows: Indicates the buffers currently enabled for
color writing. Indicates the depth buffer. Indicates the accumulation
buffer. Indicates the stencil buffer.
The value to which each buffer is cleared depends on the setting of the
clear value for that buffer.
NOTES
If a buffer is not present, then a glClear() directed at that buffer
has no effect.
ERRORS
GL_INVALID_VALUE is generated if any bit other than the four defined
bits is set in mask.
GL_INVALID_OPERATION is generated if glClear() is executed between the
execution of glBegin() and the corresponding execution of glEnd().
ASSOCIATED GETSglGet() with argument GL_ACCUM_CLEAR_VALUE
glGet() with argument GL_DEPTH_CLEAR_VALUE
glGet() with argument GL_INDEX_CLEAR_VALUE
glGet() with argument GL_COLOR_CLEAR_VALUE
glGet() with argument GL_STENCIL_CLEAR_VALUE
SEE ALSOglClearAccum(3), glClearColor(3), glClearDepth(3), glClearIndex(3),
glClearStencil(3), glColorMask(3), glDepthMask(3), glDrawBuffer(3),
glScissor(3), glStencilMask(3)glClear(3G)
