Class ARBInstancedArrays
- java.lang.Object
-
- org.lwjgl.opengl.ARBInstancedArrays
-
public class ARBInstancedArrays extends java.lang.Object
Native bindings to the ARB_instanced_arrays extension.A common use case in GL for some applications is to be able to draw the same object, or groups of similar objects that share vertex data, primitive count and type, multiple times. This extension provides a means of accelerating such use cases while restricting the number of API calls, and keeping the amount of duplicate data to a minimum.
In particular, this extension specifies an alternative to the read-only shader variable introduced by ARB_draw_instanced. It uses the same draw calls introduced by that extension, but redefines them so that a vertex shader can instead use vertex array attributes as a source of instance data.
This extension introduces an array "divisor" for generic vertex array attributes, which when non-zero specifies that the attribute is "instanced". An instanced attribute does not advance per-vertex as usual, but rather after every
divisor
conceptual draw calls.(Attributes which aren't instanced are repeated in their entirety for every conceptual draw call.)
By specifying transform data in an instanced attribute or series of instanced attributes, vertex shaders can, in concert with the instancing draw calls, draw multiple instances of an object with one draw call.
Promoted to core in
OpenGL 3.3
.
-
-
Field Summary
Fields Modifier and Type Field and Description static int
GL_VERTEX_ATTRIB_ARRAY_DIVISOR_ARB
Accepted by thepname
parameters of GetVertexAttribdv, GetVertexAttribfv, and GetVertexAttribiv.
-
Method Summary
All Methods Static Methods Concrete Methods Modifier and Type Method and Description static void
glVertexArrayVertexAttribDivisorEXT(int vaobj, int index, int divisor)
EXT_direct_state_access version ofVertexAttribDivisorARB
.static void
glVertexAttribDivisorARB(int index, int divisor)
Modifies the rate at which generic vertex attributes advance when rendering multiple instances of primitives in a single draw call.
-
-
-
Field Detail
-
GL_VERTEX_ATTRIB_ARRAY_DIVISOR_ARB
public static final int GL_VERTEX_ATTRIB_ARRAY_DIVISOR_ARB
Accepted by thepname
parameters of GetVertexAttribdv, GetVertexAttribfv, and GetVertexAttribiv.- See Also:
- Constant Field Values
-
-
Method Detail
-
glVertexAttribDivisorARB
public static void glVertexAttribDivisorARB(int index, int divisor)
Modifies the rate at which generic vertex attributes advance when rendering multiple instances of primitives in a single draw call. Ifdivisor
is zero, the attribute at slotindex
advances once per vertex. Ifdivisor
is non-zero, the attribute advances once perdivisor
instances of the set(s) of vertices being rendered. An attribute is referred to asinstanced
if itsdivisor
value is non-zero.- Parameters:
index
- the attribute indexdivisor
- the divisor value
-
glVertexArrayVertexAttribDivisorEXT
public static void glVertexArrayVertexAttribDivisorEXT(int vaobj, int index, int divisor)
EXT_direct_state_access version ofVertexAttribDivisorARB
.This function was added to the extension specification in July 2013. Implemenations are allowed to expose ARB_instanced_arrays without providing this function. The correct way to test its availability is:
GLCapabilities caps = GL.getCapabilities(); if ( caps.GL_ARB_instanced_arrays && ARBInstancedArrays.getInstance().VertexArrayVertexAttribDivisorEXT != NULL ) glVertexArrayVertexAttribDivisorEXT(...); // the DSA function can now be used
- Parameters:
vaobj
- the vertex array objectindex
- the attribute indexdivisor
- the divisor value
-
-