Страницы справочника OS X

Эта страница руководства является частью версии 5.0 Инструментов XCode

Читать страницы руководства

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 constants 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 vertices in the range [start, end] be refer-enced. referenced.
       enced.  However, the implementation may partially process unused vertices, reducing performance  from
       what could be achieved with an optimal index set.

       When glDrawRangeElements is called, it uses count sequential elements from an enabled array, starting
       at start to construct a sequence of geometric primitives. mode specifies what kind of primitives  are
       constructed,  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)