The VertexBuffer3D class represents a set of vertex data uploaded to a rendering context.
Use a VertexBuffer3D object to define the data associated with each point in a set of vertexes. You can upload the vertex data either from a Vector array or a ByteArray. (Once uploaded, the data in the original array is no longer referenced; changing or discarding the source array does not change the vertex data.)
The data associated with each vertex is in an application-defined format and is used
as the input for the vertex shader program. Identify which values belong to which
vertex program input using the Context3D setVertexBufferAt() function. A vertex
program can use up to eight inputs (also known as vertex attribute registers). Each
input can require between one and four 32-bit values. For example, the [x,y,z]
position coordinates of a vertex can be passed to a vertex program as a vector
containing three 32 bit values. The Context3DVertexBufferFormat class defines
constants for the supported formats for shader inputs. You can supply up to
sixty-four 32-bit values (256 bytes) of data for each point (but a single vertex
shader cannot use all of the data in this case).
The setVertexBufferAt() function also identifies which vertex buffer to use for
rendering any subsequent drawTriangles() calls. To render data from a different
vertex buffer, call setVertexBufferAt() again with the appropriate arguments. (You
can store data for the same point in multiple vertex buffers, say position data in
one buffer and texture coordinates in another, but typically rendering is more
efficient if all the data for a point comes from a single buffer.)
The Index3DBuffer object passed to the Context3D drawTriangles() method organizes
the vertex data into triangles. Each value in the index buffer is the index to a
vertex in the vertex buffer. A set of three indexes, in sequence, defines a triangle.
You cannot create a VertexBuffer3D object directly. Use the Context3D
createVertexBuffer() method instead.
To free the render context resources associated with a vertex buffer, call the object's
dispose() method.
Methods
dispose():Void
Frees all resources associated with this object. After disposing a vertex
buffer, calling upload() and rendering using this object will fail.
uploadFromByteArray(data:ByteArray, byteArrayOffset:Int, startVertex:Int, numVertices:Int):Void
Uploads the data for a set of points to the rendering context from a byte array.
Parameters:
data | a byte array containing the vertex data. Each data value is four
bytes long. The number of values in a vertex is specified at buffer creation
using the data32PerVertex parameter to the Context3D |
|---|---|
byteArrayOffset | number of bytes to skip from the beginning of data |
startVertex | The index of the first vertex to be loaded. A value for startVertex not equal to zero may be used to load a sub-region of the vertex data. |
numVertices | The number of vertices to be loaded from data. |
Throws:
TypeError | Null Pointer Error: when data is |
|---|---|
RangeError | Bad Input Size: if |
Error | 3768: The Stage3D API may not be used during background execution. |
uploadFromTypedArray(data:ArrayBufferView, byteLength:Int = -1):Void
Uploads the data for a set of points to the rendering context from a typed array.
Parameters:
data | a typed array of 32-bit values. A single vertex is comprised of a
number of values stored sequentially in the vector. The number of values in a
vertex is specified at buffer creation using the |
|---|---|
byteLength | The number of bytes to read. |
uploadFromVector(data:Vector<Float>, startVertex:Int, numVertices:Int):Void
Uploads the data for a set of points to the rendering context from a vector array.
Parameters:
data | a vector of 32-bit values. A single vertex is comprised of a
number of values stored sequentially in the vector. The number of values in a
vertex is specified at buffer creation using the data32PerVertex parameter to the
Context3D |
|---|---|
startVertex | The index of the first vertex to be loaded. A value for
|
numVertices | The number of vertices represented by data. |
Throws:
TypeError | Null Pointer Error: when |
|---|---|
RangeError | Bad Input Size: when number of elements in data is less than
|