glClear — clear buffers to preset values
void glClear(
|
GLbitfield mask) ; |
mask
Bitwise OR of masks that indicate the buffers to be cleared.
The three masks are
GL_COLOR_BUFFER_BIT
,
GL_DEPTH_BUFFER_BIT
, and
GL_STENCIL_BUFFER_BIT
.
glClear
sets the bitplane area of the window to values previously selected
by glClearColor
, glClearDepthf
, and
glClearStencil
.
Multiple color buffers can be cleared simultaneously by selecting
more than one buffer at a time using glDrawBuffers.
The pixel ownership test,
the scissor test,
sRGB conversion,
dithering, and the buffer writemasks affect the operation of glClear
.
The scissor box bounds the cleared region.
Alpha function,
blend function,
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:
GL_COLOR_BUFFER_BIT
Indicates the buffers currently enabled for color writing.
GL_DEPTH_BUFFER_BIT
Indicates the depth buffer.
GL_STENCIL_BUFFER_BIT
Indicates the stencil buffer.
The value to which each buffer is cleared depends on the setting of the clear value for that buffer.
If a buffer is not present,
then a glClear
directed at that buffer has no effect.
GL_INVALID_VALUE
is generated if any bit other than the three defined
bits is set in mask
.
glGet with argument GL_DEPTH_CLEAR_VALUE
glGet with argument GL_COLOR_CLEAR_VALUE
glGet with argument GL_STENCIL_CLEAR_VALUE
OpenGL ES API Version | ||||
---|---|---|---|---|
Function Name | 2.0 | 3.0 | 3.1 | 3.2 |
glClear | ✔ | ✔ | ✔ | ✔ |
glClearBuffer, glClearColor, glClearDepthf, glClearStencil, glColorMask, glDepthMask, glDrawBuffers, glScissor, glStencilMask
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