GL_SUN_multi_draw_arrays

Name

    EXT_multi_draw_arrays
    SUN_multi_draw_arrays

Name Strings

    GL_EXT_multi_draw_arrays
    GL_SUN_multi_draw_arrays

    (Note: this extension has been promoted from SUN to EXT status.
    Implementations should advertise both name strings, and both EXT
    and SUN versions of the new GL functions should be provided).

Contact

    Ron Bielaski, Sun (Ron.Bielaski 'at' eng.sun.com)
    Jack Middleton, Sun (Jack.Middleton 'at' eng.sun.com)

Status

    Shipping

Version

    $Date: 1999/12/28 01:40:37 $ $Revision: 1.6 $
    SUN Date: 99/06/25 15:07:37  Revision: 1.2

Number

    148

Dependencies

    OpenGL 1.1 is required. The language is written against the OpenGL 1.2
    specification.

Overview

    These functions behave identically to the standard OpenGL 1.1 functions
    glDrawArrays() and glDrawElements() except they handle multiple lists of
    vertices in one call. Their main purpose is to allow one function call
    to render more than one primitive such as triangle strip, triangle fan,
    etc.

New Procedures and Functions

    void glMultiDrawArraysEXT( GLenum mode,
			       GLint *first,
			       GLsizei *count,
			       GLsizei primcount)
    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.

	first		Points to an array of starting indices in
			the enabled arrays.

	count		Points to an array of the number of indices
			to be rendered.

	primcount	Specifies the size of first and count


    void glMultiDrawElementsEXT( GLenum mode,
				 GLsizei *count,
				 GLenum type,
				 const GLvoid **indices,
				 GLsizei primcount)

    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		Points to and array of the element counts

	type		Specifies the type of the values in indices.
			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.

	primcount	Specifies the size of the count array

New Tokens

    None

Additions to Chapter 2 of the 1.2 Specification (OpenGL Operation)

    Section 2.8 Vertex Arrays:

    The command

	void glMultiDrawArraysEXT( GLenum mode,
				   GLint* first,
				   GLsizei *count,
				   GLsizei primcount)

    Behaves identically to DrawArrays except that a list of arrays is
    specified instead. The number of lists is specified in the primcount
    parameter. It has the same effect as:

	for(i=0; i<primcount; i++) {
	   if (*(count+i)>0) DrawArrays(mode, *(first+i), *(count+i));
	}

    The command

	void glMultiDrawElementsEXT( GLenum mode,
				     GLsizei *count,
				     GLenum type,
				     const GLvoid **indices,
				     GLsizei primcount)

    Behaves identically to DrawElements except that a list of arrays is
    specified instead. The number of lists is specified in the primcount
    parameter. It has the same effect as:

	for(i=0; i<primcount; i++) {
	    if (*(count+i)>0) DrawElements(mode, *(count+i), type,
					   *(indices+i));
	}

Additions to Chapter 3 of the 1.2 Specification (Rasterization)

    None

Additions to Chapter 4 of the 1.2 Specification (Per-Fragment Operations and

    None

Additions to Chapter 5 of the 1.2 Specification (Special Functions)

    None

Additions to Chapter 6 of the 1.2 Specification (State and State Requests)

    None

Additions to the GLX / WGL / AGL Specifications

    None

GLX Protocol

    None

Errors

    GL_INVALID_ENUM is generated if <mode> is not an accepted value.

    GL_VALUE is generated if <primcount> is negative.

    GL_INVALID_OPERATION is generated if glMultiDrawArraysEXT or
    glMultiDrawElementsEXT is executed between the execution of glBegin
    and the corresponding glEnd.

New State

    None

Revision History

    6/24/99 - Added fields from the new extension template.

Implementation Support

   List of OpenGL implementations supporting the GL_SUN_multi_draw_arrays extension

Original File

   Original text file for the GL_SUN_multi_draw_arrays extension