glClearAccum - specify clear values for the accumulation buffer
void glClearAccum( GLfloat red,
GLfloat green,
GLfloat blue,
GLfloat alpha )
- red, green, blue, alpha
- Specify the red, green, blue, and alpha values used when the accumulation
buffer is cleared. The initial values are all 0.
glClearAccum specifies the red, green, blue, and alpha values used by
glClear to clear the accumulation buffer.
Values specified by glClearAccum are clamped to the range
[-1,1].
GL_INVALID_OPERATION is generated if glClearAccum is executed
between the execution of glBegin and the corresponding execution of
glEnd.
glGet with argument GL_ACCUM_CLEAR_VALUE