fglClear(3G) OpenGL Reference fglClear(3G)NAMEfglClear - clear buffers to preset values
FORTRAN SPECIFICATION
SUBROUTINE fglClear( INTEGER*4 mask )
PARAMETERS
mask 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_BUFFER_BIT, and GL_STENCIL_BUFFER_BIT.
DESCRIPTIONfglClear sets the bitplane area of the window to values previously
selected by fglClearColor, fglClearIndex, fglClearDepth, fglClearStencil,
and fglClearAccum. Multiple color buffers can be cleared simultaneously
by selecting more than one buffer at a time using fglDrawBuffer.
The pixel ownership test, the scissor test, dithering, and the buffer
writemasks affect the operation of fglClear. The scissor box bounds the
cleared region. Alpha function, blend function, logical operation,
stenciling, texture mapping, and depth-buffering are ignored by fglClear.
fglClear 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_ACCUM_BUFFER_BIT Indicates the accumulation 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.
NOTES
If a buffer is not present, then a fglClear 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 fglClear is executed between the
execution of fglBegin and the corresponding execution of fglEnd.
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fglClear(3G) OpenGL Reference fglClear(3G)ASSOCIATED GETS
fglGet with argument GL_ACCUM_CLEAR_VALUE
fglGet with argument GL_DEPTH_CLEAR_VALUE
fglGet with argument GL_INDEX_CLEAR_VALUE
fglGet with argument GL_COLOR_CLEAR_VALUE
fglGet with argument GL_STENCIL_CLEAR_VALUE
SEE ALSO
fglClearAccum, fglClearColor, fglClearDepth, fglClearIndex,
fglClearStencil, fglColorMask, fglDepthMask, fglDrawBuffer, fglScissor,
fglStencilMask
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