glDrawRangeElements

GLDRAWRANGEELEMENTS(3G)				      GLDRAWRANGEELEMENTS(3G)



NAME
       glDrawRangeElements - render primitives from array data


C SPECIFICATION
       void glDrawRangeElements( GLenum mode,
				 GLuint start,
				 GLuint end,
				 GLsizei count,
				 GLenum type,
				 const GLvoid *indices )


PARAMETERS
       mode	Specifies  what	 kind of primitives to render.	Symbolic con-
		stants	GL_POINTS,  GL_LINE_STRIP,  GL_LINE_LOOP,   GL_LINES,
		GL_TRIANGLE_STRIP,	 GL_TRIANGLE_FAN,	GL_TRIANGLES,
		GL_QUAD_STRIP, GL_QUADS, and GL_POLYGON are accepted.

       start	Specifies the minimum array index contained in indices.

       end	Specifies the maximum array index contained in indices.

       count	Specifies the number of elements to be rendered.

       type	Specifies the type of the values in count.  Must  be  one  of
		GL_UNSIGNED_BYTE, GL_UNSIGNED_SHORT, or GL_UNSIGNED_INT.

       indices	Specifies  a  pointer  to  the location where the indices are
		stored.

DESCRIPTION
       glDrawRangeElements is a	 restricted  form  of  glDrawElements.	mode,
       start,	end,   and   count   match  the	 corresponding	arguments  to
       glDrawElements, with the additional constraint that all values in  the
       arrays count must lie between start and end, inclusive.

       Implementations denote recommended maximum amounts of vertex and
       index  data,  which  may	 be  queried  by  calling glGet with argument
       GL_MAX_ELEMENTS_VERTICES and GL_MAX_ELEMENTS_INDICES.  If  end−start+1
       is  greater than the value of GL_MAX_ELEMENTS_VERTICES, or if count is
       greater than the value of GL_MAX_ELEMENTS_INDICES, then the  call  may
       operate at reduced performance.	There is no requirement that all ver-
       tices in the range [start, end] be referenced.  However, the implemen-
       tation  may  partially  process	unused vertices, reducing performance
       from what could be achieved with an optimal index set.

       When glDrawRangeElements is called, it uses start sequential  elements
       from  an	 enabled  array, starting at count to construct a sequence of
       geometric primitives. mode specifies what kind of primitives are	 con-
       structed,  and  how  the array elements construct these primitives. If
       more than one array is enabled, each is used.  If  GL_VERTEX_ARRAY  is
       not enabled, no geometric primitives are constructed.

       Vertex  attributes  that	 are  modified by glDrawRangeElements have an
       unspecified value after glDrawRangeElements returns. For	 example,  if
       GL_COLOR_ARRAY is enabled, the value of the current color is undefined
       after glDrawRangeElements executes. Attributes  that  aren’t  modified
       maintain their previous values.

NOTES
       glDrawRangeElements  is	available  only	 if  the GL version is 1.2 or
       greater.

       glDrawRangeElements    is    included	in    display	 lists.	   If
       glDrawRangeElements  is	entered	 into  a  display list, the necessary
       array data (determined by the array  pointers  and  enables)  is	 also
       entered	into the display list. Because the array pointers and enables
       are client-side state, their values  affect  display  lists  when  the
       lists are created, not when the lists are executed.

ERRORS
       It  is an error for indices to lie outside the range [start, end], but
       implementations may not check for this situation. Such  indices	cause
       implementation-dependent behavior.

       GL_INVALID_ENUM is generated if mode is not an accepted value.

       GL_INVALID_VALUE is generated if count is negative.

       GL_INVALID_VALUE is generated if end < start.

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

ASSOCIATED GETS
       glGet with argument GL_MAX_ELEMENTS_VERTICES

       glGet with argument GL_MAX_ELEMENTS_INDICES

SEE ALSO
       glArrayElement(3G),	 glColorPointer(3G),	    glDrawArrays(3G),
       glDrawElements(3G),	glEdgeFlagPointer(3G),	   glGetPointerv(3G),
       glIndexPointer(3G),   glInterleavedArrays(3G),	 glNormalPointer(3G),
       glTexCoordPointer(3G), glVertexPointer(3G)



						      GLDRAWRANGEELEMENTS(3G)