glDrawRangeElements

glDrawRangeElements: man2/glDrawRangeElements.xml

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 referenced. 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.

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.