Package org.lwjgl.opengl

Class ARBIndirectParameters

java.lang.Object

org.lwjgl.opengl.ARBIndirectParameters

public class ARBIndirectParameters
extends java.lang.Object

Native bindings to the ARB_indirect_parameters extension.

OpenGL 4.3 (with the introduction of the ARB_multi_draw_indirect extension) enhanced the ability of OpenGL to allow a large sets of parameters for indirect draws (introduced with OpenGL 4.0) into a buffer object and dispatch the entire list with one API call. This allows, for example, a shader (such as a compute shader via shader storage buffers, or a geometry shader via transform feedback) to produce lists of draw commands that can then be consumed by OpenGL without a server-client round trip. However, when a variable and potentially unknown number of draws are produced by such a shader, it becomes difficult to know how many draws are in the output array(s). Applications must resort to techniques such as transform feedback primitive queries, or mapping buffers containing the content of atomic counters, which can cause stalls or bubbles in the OpenGL pipeline.

This extension introduces the concept of the "parameter buffer", which is a target allowing buffers to store parameters for certain drawing commands. Also in this extension, new variants of MultiDrawArraysIndirect and MultiDrawElementsIndirect are introduced that source some of their parameters from this buffer. Further commands could potentially be introduced that source other parameters from a buffer.

Requires OpenGL 4.2.

Field Summary

Fields

Modifier and Type	Field and Description
static int	GL_PARAMETER_BUFFER_ARB Accepted by the target parameters of BindBuffer, BufferData, BufferSubData, MapBuffer, UnmapBuffer, GetBufferSubData, GetBufferPointerv, MapBufferRange, FlushMappedBufferRange, GetBufferParameteriv, and CopyBufferSubData.
static int	GL_PARAMETER_BUFFER_BINDING_ARB Accepted by the value parameter of GetIntegerv, GetBooleanv, GetFloatv, and GetDoublev.

Method Summary

Modifier and Type	Method and Description
static void	glMultiDrawArraysIndirectCountARB(int mode, java.nio.ByteBuffer indirect, long drawcount, int maxdrawcount, int stride) Behaves similarly to MultiDrawArraysIndirect, except that drawcount defines an offset (in bytes) into the buffer object bound to the PARAMETER_BUFFER_ARB binding point at which a single sizei typed value is stored, which contains the draw count.
static void	glMultiDrawArraysIndirectCountARB(int mode, int[] indirect, long drawcount, int maxdrawcount, int stride) Array version of: MultiDrawArraysIndirectCountARB
static void	glMultiDrawArraysIndirectCountARB(int mode, java.nio.IntBuffer indirect, long drawcount, int maxdrawcount, int stride) Behaves similarly to MultiDrawArraysIndirect, except that drawcount defines an offset (in bytes) into the buffer object bound to the PARAMETER_BUFFER_ARB binding point at which a single sizei typed value is stored, which contains the draw count.
static void	glMultiDrawArraysIndirectCountARB(int mode, long indirect, long drawcount, int maxdrawcount, int stride) Behaves similarly to MultiDrawArraysIndirect, except that drawcount defines an offset (in bytes) into the buffer object bound to the PARAMETER_BUFFER_ARB binding point at which a single sizei typed value is stored, which contains the draw count.
static void	glMultiDrawElementsIndirectCountARB(int mode, int type, java.nio.ByteBuffer indirect, long drawcount, int maxdrawcount, int stride) Behaves similarly to MultiDrawElementsIndirect, except that drawcount defines an offset (in bytes) into the buffer object bound to the PARAMETER_BUFFER_ARB binding point at which a single sizei typed value is stored, which contains the draw count.
static void	glMultiDrawElementsIndirectCountARB(int mode, int type, int[] indirect, long drawcount, int maxdrawcount, int stride) Array version of: MultiDrawElementsIndirectCountARB
static void	glMultiDrawElementsIndirectCountARB(int mode, int type, java.nio.IntBuffer indirect, long drawcount, int maxdrawcount, int stride) Behaves similarly to MultiDrawElementsIndirect, except that drawcount defines an offset (in bytes) into the buffer object bound to the PARAMETER_BUFFER_ARB binding point at which a single sizei typed value is stored, which contains the draw count.
static void	glMultiDrawElementsIndirectCountARB(int mode, int type, long indirect, long drawcount, int maxdrawcount, int stride) Behaves similarly to MultiDrawElementsIndirect, except that drawcount defines an offset (in bytes) into the buffer object bound to the PARAMETER_BUFFER_ARB binding point at which a single sizei typed value is stored, which contains the draw count.

Methods inherited from class java.lang.Object

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

Field Detail

GL_PARAMETER_BUFFER_ARB

Accepted by the target parameters of BindBuffer, BufferData, BufferSubData, MapBuffer, UnmapBuffer, GetBufferSubData, GetBufferPointerv, MapBufferRange, FlushMappedBufferRange, GetBufferParameteriv, and CopyBufferSubData.

GL_PARAMETER_BUFFER_BINDING_ARB

Accepted by the value parameter of GetIntegerv, GetBooleanv, GetFloatv, and GetDoublev.

Method Detail

glMultiDrawArraysIndirectCountARB

public static void glMultiDrawArraysIndirectCountARB(int mode,
                                                     java.nio.ByteBuffer indirect,
                                                     long drawcount,
                                                     int maxdrawcount,
                                                     int stride)

public static void glMultiDrawArraysIndirectCountARB(int mode,
                                                     long indirect,
                                                     long drawcount,
                                                     int maxdrawcount,
                                                     int stride)

public static void glMultiDrawArraysIndirectCountARB(int mode,
                                                     java.nio.IntBuffer indirect,
                                                     long drawcount,
                                                     int maxdrawcount,
                                                     int stride)

Behaves similarly to MultiDrawArraysIndirect, except that drawcount defines an offset (in bytes) into the buffer object bound to the PARAMETER_BUFFER_ARB binding point at which a single sizei typed value is stored, which contains the draw count. maxdrawcount specifies the maximum number of draws that are expected to be stored in the buffer. If the value stored at drawcount into the buffer is greater than maxdrawcount, an implementation stop processing draws after maxdrawcount parameter sets. drawcount must be a multiple of four.

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

drawcount - the offset into the parameter buffer object

maxdrawcount - the maximum number of draws

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

glMultiDrawElementsIndirectCountARB

public static void glMultiDrawElementsIndirectCountARB(int mode,
                                                       int type,
                                                       java.nio.ByteBuffer indirect,
                                                       long drawcount,
                                                       int maxdrawcount,
                                                       int stride)

public static void glMultiDrawElementsIndirectCountARB(int mode,
                                                       int type,
                                                       long indirect,
                                                       long drawcount,
                                                       int maxdrawcount,
                                                       int stride)

public static void glMultiDrawElementsIndirectCountARB(int mode,
                                                       int type,
                                                       java.nio.IntBuffer indirect,
                                                       long drawcount,
                                                       int maxdrawcount,
                                                       int stride)

Behaves similarly to MultiDrawElementsIndirect, except that drawcount defines an offset (in bytes) into the buffer object bound to the PARAMETER_BUFFER_ARB binding point at which a single sizei typed value is stored, which contains the draw count. maxdrawcount specifies the maximum number of draws that are expected to be stored in the buffer. If the value stored at drawcount into the buffer is greater than maxdrawcount, an implementation stop processing draws after maxdrawcount parameter sets. drawcount must be a multiple of four.

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

drawcount - the offset into the parameter buffer object

maxdrawcount - the maximum number of draws

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

glMultiDrawArraysIndirectCountARB

public static void glMultiDrawArraysIndirectCountARB(int mode,
                                                     int[] indirect,
                                                     long drawcount,
                                                     int maxdrawcount,
                                                     int stride)

Array version of: MultiDrawArraysIndirectCountARB

glMultiDrawElementsIndirectCountARB

public static void glMultiDrawElementsIndirectCountARB(int mode,
                                                       int type,
                                                       int[] indirect,
                                                       long drawcount,
                                                       int maxdrawcount,
                                                       int stride)

Array version of: MultiDrawElementsIndirectCountARB