NAMEglPointSize- specify the diameter of rasterized pointsCSPECIFICATIONvoidglPointSize( GLfloatsize)PARAMETERSsizeSpecifies the diameter of rasterized points. The initial value is 1.DESCRIPTIONglPointSizespecifies the rasterized diameter of both aliased and antialiased points. Using a point size other than 1 has different effects, depending on whether point antialiasing is enabled. To enable and disable point antialiasing, callglEnableandglDisablewith argumentGL_POINT_SMOOTH. Point antialiasing is initially disabled. If point antialiasing is disabled, the actual size is determined by rounding the supplied size to the nearest integer. (If the rounding results in the value 0, it is as if the point size were 1.) If the rounded size is odd, then the center point (x, y) of the pixel fragment that represents the point is computed as ( | x | + .5, | y | + .5) w w where w subscripts indicate window coordinates. All pixels that lie within the square grid of the rounded size centered at (x, y) make up the fragment. If the size is even, the center point is ( | x + .5 |, | y + .5 |) w w and the rasterized fragment's centers are the half-integer window coordinates within the square of the rounded size centered at (x, y). All pixel fragments produced in rasterizing a nonantialiased point are assigned the same associated data, that of the vertex corresponding to the point. If antialiasing is enabled, then point rasterization produces a fragment for each pixel square that intersects the region lying within the circle having diameter equal to the current point size and centered at the point's (x , y ). The coverage value for each fragment is the window w w coordinate area of the intersection of the circular region with the corresponding pixel square. This value is saved and used in the final rasterization step. The data associated with each fragment is the data associated with the point being rasterized. Not all sizes are supported when point antialiasing is enabled. If an unsupported size is requested, the nearest supported size is used. Only size 1 is guaranteed to be supported; others depend on the implementation. To query the range of supported sizes and the size difference between supported sizes within the range, callglGetwith argumentsGL_POINT_SIZE_RANGEandGL_POINT_SIZE_GRANULARITY.NOTESThe point size specified byglPointSizeis always returned whenGL_POINT_SIZEis queried. Clamping and rounding for aliased and antialiased points have no effect on the specified value. A non-antialiased point size may be clamped to an implementation-dependent maximum. Although this maximum cannot be queried, it must be no less than the maximum value for antialiased points, rounded to the nearest integer value.ERRORSGL_INVALID_VALUEis generated ifsizeis less than or equal to 0.GL_INVALID_OPERATIONis generated ifglPointSizeis executed between the execution ofglBeginand the corresponding execution ofglEnd.ASSOCIATEDGETSglGetwith argumentGL_POINT_SIZEglGetwith argumentGL_POINT_SIZE_RANGEglGetwith argumentGL_POINT_SIZE_GRANULARITYglIsEnabledwith argumentGL_POINT_SMOOTHSEEALSOglEnable