- Method glClear
glClear sets the bitplane area of the window to values previously selected by glClearColor, glClearIndex, glClearDepth, glClearStencil, and glClearAccum. Multiple color buffers can be cleared simultaneously by selecting more than one buffer at a time using glDrawBuffer.
The pixel ownership test, the scissor test, dithering, and the buffer writemasks affect the operation of glClear. The scissor box bounds the cleared region. Alpha function, blend function, logical operation, stenciling, texture mapping, 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_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.
GL_INVALID_VALUE is generated if any bit other than the four defined bits is set in mask.