Package org.lwjgl.opengl

Class ARBMultiDrawIndirect

java.lang.Object

org.lwjgl.opengl.ARBMultiDrawIndirect

public class ARBMultiDrawIndirect
extends java.lang.Object

Native bindings to the ARB_multi_draw_indirect extension.

The ARB_draw_indirect extension (included in OpenGL 4.0) introduced mechanisms whereby the parameters for a draw function may be provided in a structure contained in a buffer object rather than as parameters to the drawing procedure. This is known as an indirect draw and is exposed as two new functions, DrawArraysIndirect and DrawElementsIndirect. Each of these functions generates a single batch of primitives.

This extension builds on this functionality by providing procedures to invoke multiple draws from a single procedure call. This allows large batches of drawing commands to be assembled in server memory (via a buffer object) which may then be dispatched through a single function call.

Requires OpenGL 4.0 or ARB_draw_indirect. Promoted to core in OpenGL 4.3.

Method Summary

Modifier and Type	Method and Description
static void	glMultiDrawArraysIndirect(int mode, java.nio.ByteBuffer indirect, int primcount, int stride) Renders multiple sets of primitives from array data, taking parameters from memory.
static void	glMultiDrawArraysIndirect(int mode, int[] indirect, int primcount, int stride) Array version of: MultiDrawArraysIndirect
static void	glMultiDrawArraysIndirect(int mode, java.nio.IntBuffer indirect, int primcount, int stride) Renders multiple sets of primitives from array data, taking parameters from memory.
static void	glMultiDrawArraysIndirect(int mode, long indirect, int primcount, int stride) Renders multiple sets of primitives from array data, taking parameters from memory.
static void	glMultiDrawElementsIndirect(int mode, int type, java.nio.ByteBuffer indirect, int primcount, int stride) Renders multiple indexed primitives from array data, taking parameters from memory.
static void	glMultiDrawElementsIndirect(int mode, int type, int[] indirect, int primcount, int stride) Array version of: MultiDrawElementsIndirect
static void	glMultiDrawElementsIndirect(int mode, int type, java.nio.IntBuffer indirect, int primcount, int stride) Renders multiple indexed primitives from array data, taking parameters from memory.
static void	glMultiDrawElementsIndirect(int mode, int type, long indirect, int primcount, int stride) Renders multiple indexed primitives from array data, taking parameters from memory.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

glMultiDrawArraysIndirect

public static void glMultiDrawArraysIndirect(int mode,
                                             java.nio.ByteBuffer indirect,
                                             int primcount,
                                             int stride)

public static void glMultiDrawArraysIndirect(int mode,
                                             long indirect,
                                             int primcount,
                                             int stride)

public static void glMultiDrawArraysIndirect(int mode,
                                             java.nio.IntBuffer indirect,
                                             int primcount,
                                             int stride)

Renders multiple sets of primitives from array data, taking parameters from memory.

The parameters addressed by indirect are packed into an array of structures, each element of which takes the form (in C):

typedef struct {
    uint count;
    uint primCount;
    uint first;
    uint baseInstance;
} DrawArraysIndirectCommand;

A single call to glMultiDrawArraysIndirect is equivalent, assuming no errors are generated to:

const ubyte *ptr = (const ubyte *)indirect;
for ( i = 0; i < primcount; i++ ) {
    DrawArraysIndirect(mode, (DrawArraysIndirectCommand*)ptr);
    if ( stride == 0 )
        ptr += sizeof(DrawArraysIndirectCommand);
    else
        ptr += stride;
}

Parameters:

mode - what kind of primitives to render. One of:

POINTS	LINE_STRIP	LINE_LOOP	LINES	POLYGON	TRIANGLE_STRIP	TRIANGLE_FAN
TRIANGLES	QUAD_STRIP	QUADS	LINES_ADJACENCY	LINE_STRIP_ADJACENCY	TRIANGLES_ADJACENCY	TRIANGLE_STRIP_ADJACENCY
PATCHES

indirect - an array of structures containing the draw parameters

primcount - the number of elements in the array of draw parameter structures

stride - the distance in basic machine units between elements of the draw parameter array

glMultiDrawElementsIndirect

public static void glMultiDrawElementsIndirect(int mode,
                                               int type,
                                               java.nio.ByteBuffer indirect,
                                               int primcount,
                                               int stride)

public static void glMultiDrawElementsIndirect(int mode,
                                               int type,
                                               long indirect,
                                               int primcount,
                                               int stride)

public static void glMultiDrawElementsIndirect(int mode,
                                               int type,
                                               java.nio.IntBuffer indirect,
                                               int primcount,
                                               int stride)

Renders multiple indexed primitives from array data, taking parameters from memory.

The parameters addressed by indirect are packed into a structure that takes the form (in C):

typedef struct {
    uint count;
    uint primCount;
    uint firstIndex;
    uint baseVertex;
    uint baseInstance;
} DrawElementsIndirectCommand;

A single call to glMultiDrawElementsIndirect is equivalent, assuming no errors are generated to:

const ubyte *ptr = (const ubyte *)indirect;
for ( i = 0; i < primcount; i++ ) {
    DrawElementsIndirect(mode, type, (DrawElementsIndirectCommand *)ptr);
    if ( stride == 0 )
        ptr += sizeof(DrawElementsIndirectCommand);
    else
        ptr += stride;
}

Parameters:

mode - what kind of primitives to render. One of:

POINTS	LINE_STRIP	LINE_LOOP	LINES	POLYGON	TRIANGLE_STRIP	TRIANGLE_FAN
TRIANGLES	QUAD_STRIP	QUADS	LINES_ADJACENCY	LINE_STRIP_ADJACENCY	TRIANGLES_ADJACENCY	TRIANGLE_STRIP_ADJACENCY
PATCHES

type - the type of data in the buffer bound to the GL_ELEMENT_ARRAY_BUFFER binding. One of:

UNSIGNED_BYTE

UNSIGNED_SHORT

UNSIGNED_INT

indirect - a structure containing an array of draw parameters

primcount - the number of elements in the array addressed by indirect

stride - the distance in basic machine units between elements of the draw parameter array

glMultiDrawArraysIndirect

public static void glMultiDrawArraysIndirect(int mode,
                                             int[] indirect,
                                             int primcount,
                                             int stride)

Array version of: MultiDrawArraysIndirect

glMultiDrawElementsIndirect

public static void glMultiDrawElementsIndirect(int mode,
                                               int type,
                                               int[] indirect,
                                               int primcount,
                                               int stride)

Array version of: MultiDrawElementsIndirect