glDrawElements

Name
glDrawElements — render primitives from array data
C Specification void glDrawElements(
GLenum  
mode,
 
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. count
Specifies the number of elements to be rendered. type
Specifies the type of the values in  indices . Must be one of  GL_UNSIGNED_BYTE ,  GL_UNSIGNED_SHORT , or  GL_UNSIGNED_INT .  diffrent type diffrent size of array size; indices
Specifies a pointer to the location where the indices are stored.
Description 　　glDrawElements  specifies multiple geometric primitives with very few subroutine calls. Instead of calling a GL function to pass each individual vertex, normal, texture coordinate, edge flag, or color, you can prespecify separate arrays of vertices, normals, and so on, and use them to construct a sequence of primitives with a single call to  glDrawElements .
　　When  glDrawElements  is called, it uses  count  sequential elements from an enabled array, starting at  indices  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  glDrawElements  have an unspecified value after  glDrawElements  returns. For example, if GL_COLOR_ARRAY  is enabled, the value of the current color is undefined after  glDrawElements  executes. Attributes that aren't modified maintain their previous values.
Notes 　　glDrawElements  is available only if the GL version is 1.1 or greater. 　　glDrawElements  is included in display lists. If  glDrawElements  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 　　GL_INVALID_ENUM  is generated if  mode  is not an accepted value. 　　GL_INVALID_VALUE  is generated if  count  is negative. 　　GL_INVALID_OPERATION  is generated if a non-zero buffer object name is bound to an enabled 　　array or the element array and the buffer object's data store is currently mapped. 　　GL_INVALID_OPERATION  is generated if  glDrawElements  is executed between the execution of  glBegin  and the corresponding  glEnd .