| Extracted from Pike v7.8 release 866 at 2018-07-18.

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GL

# Method GL.glClear()

Method glClear

  `void glClear(int mask)`

Description

  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.

Parameter `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 .

Throws

  GL_INVALID_VALUE is generated if any bit other than the four defined bits is set in mask.

  GL_INVALID_OPERATION is generated if glClear is executed between the execution of glBegin and the corresponding execution of glEnd .