'\" te '\"! tbl|eqn | mmdoc '\"macro stdmacro .ds Vn Version 1.2 .ds Dt 24 September 1999 .ds Re Release 1.2.1 .ds Dp Jan 14 18:30 .ds Dm 01 clear.gl .ds Xs 16977 5 clear.gl .TH GLCLEAR 3G .SH NAME .B "glClear \- clear buffers to preset values .SH C SPECIFICATION void \f3glClear\fP( GLbitfield \fImask\fP ) .nf .fi .SH PARAMETERS .TP \w'\f2mask\fP\ \ 'u \f2mask\fP Bitwise OR of masks that indicate the buffers to be cleared. The four masks are \%\f3GL_COLOR_BUFFER_BIT\fP, \%\f3GL_DEPTH_BUFFER_BIT\fP, \%\f3GL_ACCUM_BUFFER_BIT\fP, and \%\f3GL_STENCIL_BUFFER_BIT\fP. .SH DESCRIPTION \%\f3glClear\fP sets the bitplane area of the window to values previously selected by \%\f3glClearColor\fP, \%\f3glClearIndex\fP, \%\f3glClearDepth\fP, \%\f3glClearStencil\fP, and \%\f3glClearAccum\fP. Multiple color buffers can be cleared simultaneously by selecting more than one buffer at a time using \%\f3glDrawBuffer\fP. .P The pixel ownership test, the scissor test, dithering, and the buffer writemasks affect the operation of \%\f3glClear\fP. The scissor box bounds the cleared region. Alpha function, blend function, logical operation, stenciling, texture mapping, and depth-buffering are ignored by \%\f3glClear\fP. .P \%\f3glClear\fP takes a single argument that is the bitwise OR of several values indicating which buffer is to be cleared. .P The values are as follows: .TP 28 \%\f3GL_COLOR_BUFFER_BIT\fP Indicates the buffers currently enabled for color writing. .TP \%\f3GL_DEPTH_BUFFER_BIT\fP Indicates the depth buffer. .TP \%\f3GL_ACCUM_BUFFER_BIT\fP Indicates the accumulation buffer. .TP \%\f3GL_STENCIL_BUFFER_BIT\fP Indicates the stencil buffer. .P The value to which each buffer is cleared depends on the setting of the clear value for that buffer. .SH NOTES If a buffer is not present, then a \%\f3glClear\fP directed at that buffer has no effect. .SH ERRORS \%\f3GL_INVALID_VALUE\fP is generated if any bit other than the four defined bits is set in \f2mask\fP. .P \%\f3GL_INVALID_OPERATION\fP is generated if \%\f3glClear\fP is executed between the execution of \%\f3glBegin\fP and the corresponding execution of \%\f3glEnd\fP. .SH ASSOCIATED GETS \%\f3glGet\fP with argument \%\f3GL_ACCUM_CLEAR_VALUE\fP .br \%\f3glGet\fP with argument \%\f3GL_DEPTH_CLEAR_VALUE\fP .br \%\f3glGet\fP with argument \%\f3GL_INDEX_CLEAR_VALUE\fP .br \%\f3glGet\fP with argument \%\f3GL_COLOR_CLEAR_VALUE\fP .br \%\f3glGet\fP with argument \%\f3GL_STENCIL_CLEAR_VALUE\fP .SH SEE ALSO \%\f3glClearAccum(3G)\fP, \%\f3glClearColor(3G)\fP, \%\f3glClearDepth(3G)\fP, \%\f3glClearIndex(3G)\fP, \%\f3glClearStencil(3G)\fP, \%\f3glColorMask(3G)\fP, \%\f3glDepthMask(3G)\fP, \%\f3glDrawBuffer(3G)\fP, \%\f3glScissor(3G)\fP, \%\f3glStencilMask(3G)\fP