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.
The pixel ownership test, the scissor test, dithering, and the buffer writemasks affect the operation of glClear
. The scissor box bounds the cleared region. Blend function, stenciling, fragment shading, 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.
glGet with argument GL_DEPTH_CLEAR_VALUE
glGet with argument GL_COLOR_CLEAR_VALUE
glGet with argument GL_STENCIL_CLEAR_VALUE
open.gl - Depth and Stencil Buffers
open.gl - Geometry Shaders
opengl-tutorial.org - Tutorial 4 : A Colored Cube
glClearColor, glClearDepthf, glClearStencil, glColorMask, glDepthMask, glScissor, glStencilMask
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