📄 clear.html
字号:
<HTML><BODY><PRE> <STRONG>NAME</STRONG> <STRONG>glClear</STRONG> - clear buffers to preset values <STRONG>C</STRONG> <STRONG>SPECIFICATION</STRONG> void <STRONG>glClear</STRONG>( GLbitfield <EM>mask</EM> ) <STRONG>PARAMETERS</STRONG> <EM>mask</EM> Bitwise OR of masks that indicate the buffers to be cleared. The four masks are <STRONG>GL_COLOR_BUFFER_BIT</STRONG>, <STRONG>GL_DEPTH_BUFFER_BIT</STRONG>, <STRONG>GL_ACCUM_BUFFER_BIT</STRONG>, and <STRONG>GL_STENCIL_BUFFER_BIT</STRONG>. <STRONG>DESCRIPTION</STRONG> <STRONG>glClear</STRONG> sets the bitplane area of the window to values previously selected by <STRONG>glClearColor</STRONG>, <STRONG>glClearIndex</STRONG>, <STRONG>glClearDepth</STRONG>, <STRONG>glClearStencil</STRONG>, and <STRONG>glClearAccum</STRONG>. Multiple color buffers can be cleared simultaneously by selecting more than one buffer at a time using <STRONG>glDrawBuffer</STRONG>. The pixel ownership test, the scissor test, dithering, and the buffer writemasks affect the operation of <STRONG>glClear</STRONG>. The scissor box bounds the cleared region. Alpha function, blend function, logical operation, stenciling, texture mapping, and depth-buffering are ignored by <STRONG>glClear</STRONG>. <STRONG>glClear</STRONG> takes a single argument that is the bitwise OR of several values indicating which buffer is to be cleared. The values are as follows: <STRONG>GL_COLOR_BUFFER_BIT</STRONG> Indicates the buffers currently enabled for color writing. <STRONG>GL_DEPTH_BUFFER_BIT</STRONG> Indicates the depth buffer. <STRONG>GL_ACCUM_BUFFER_BIT</STRONG> Indicates the accumulation buffer. <STRONG>GL_STENCIL_BUFFER_BIT</STRONG> Indicates the stencil buffer. The value to which each buffer is cleared depends on the setting of the clear value for that buffer. <STRONG>NOTES</STRONG> If a buffer is not present, then a <STRONG>glClear</STRONG> directed at that buffer has no effect. <STRONG>ERRORS</STRONG> <STRONG>GL_INVALID_VALUE</STRONG> is generated if any bit other than the four defined bits is set in <EM>mask</EM>. <STRONG>GL_INVALID_OPERATION</STRONG> is generated if <STRONG>glClear</STRONG> is executed between the execution of <STRONG>glBegin</STRONG> and the corresponding execution of <STRONG>glEnd</STRONG>. <STRONG>ASSOCIATED</STRONG> <STRONG>GETS</STRONG> <STRONG>glGet</STRONG> with argument <STRONG>GL_ACCUM_CLEAR_VALUE</STRONG> <STRONG>glGet</STRONG> with argument <STRONG>GL_DEPTH_CLEAR_VALUE</STRONG> <STRONG>glGet</STRONG> with argument <STRONG>GL_INDEX_CLEAR_VALUE</STRONG> <STRONG>glGet</STRONG> with argument <STRONG>GL_COLOR_CLEAR_VALUE</STRONG> <STRONG>glGet</STRONG> with argument <STRONG>GL_STENCIL_CLEAR_VALUE</STRONG> <STRONG>SEE</STRONG> <STRONG>ALSO</STRONG> <STRONG>glClearAccum</STRONG>, <STRONG>glClearColor</STRONG>, <STRONG>glClearDepth</STRONG>, <STRONG>glClearIndex</STRONG>, <STRONG>glClearStencil</STRONG>, <STRONG>glDrawBuffer</STRONG>, <STRONG>glScissor</STRONG></PRE></BODY></HTML>⌨️ 快捷键说明
复制代码
Ctrl + C
搜索代码
Ctrl + F
全屏模式
F11
切换主题
Ctrl + Shift + D
显示快捷键
?
增大字号
Ctrl + =
减小字号
Ctrl + -