GLCLEAR

Index

NAME

glClear - clear buffers to preset values

C SPECIFICATION

void f3glClearfP( GLbitfield fImaskfP )

PARAMETERS

f2maskfP: Bitwise OR of masks that indicate the buffers to be cleared. The four masks are %f3GL_COLOR_BUFFER_BITfP, %f3GL_DEPTH_BUFFER_BITfP, %f3GL_ACCUM_BUFFER_BITfP, and %f3GL_STENCIL_BUFFER_BITfP.

DESCRIPTION

%f3glClearfP sets the bitplane area of the window to values previously selected by %f3glClearColorfP, %f3glClearIndexfP, %f3glClearDepthfP, %f3glClearStencilfP, and %f3glClearAccumfP. Multiple color buffers can be cleared simultaneously by selecting more than one buffer at a time using %f3glDrawBufferfP. The pixel ownership test, the scissor test, dithering, and the buffer writemasks affect the operation of %f3glClearfP. The scissor box bounds the cleared region. Alpha function, blend function, logical operation, stenciling, texture mapping, and depth-buffering are ignored by %f3glClearfP. %f3glClearfP takes a single argument that is the bitwise OR of several values indicating which buffer is to be cleared. The values are as follows:

%f3GL_COLOR_BUFFER_BITfP: Indicates the buffers currently enabled for color writing.
%f3GL_DEPTH_BUFFER_BITfP: Indicates the depth buffer.
%f3GL_ACCUM_BUFFER_BITfP: Indicates the accumulation buffer.
%f3GL_STENCIL_BUFFER_BITfP: 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 %f3glClearfP directed at that buffer has no effect.

ERRORS

%f3GL_INVALID_VALUEfP is generated if any bit other than the four defined bits is set in f2maskfP. %f3GL_INVALID_OPERATIONfP is generated if %f3glClearfP is executed between the execution of %f3glBeginfP and the corresponding execution of %f3glEndfP.

ASSOCIATED GETS

%f3glGetfP with argument %f3GL_ACCUM_CLEAR_VALUEfP
%f3glGetfP with argument %f3GL_DEPTH_CLEAR_VALUEfP
%f3glGetfP with argument %f3GL_INDEX_CLEAR_VALUEfP
%f3glGetfP with argument %f3GL_COLOR_CLEAR_VALUEfP
%f3glGetfP with argument %f3GL_STENCIL_CLEAR_VALUEfP

GLCLEAR

NAME

C SPECIFICATION

PARAMETERS

DESCRIPTION

NOTES

ERRORS

ASSOCIATED GETS

SEE ALSO

Index