indexbuffer.md

IndexBuffer

Manage ELEMENT_ARRAY_BUFFER type IndexBuffers.

##exemples

IndexBuffer creation

// create empty IndexBuffer
// initialized as UNSIGNED_SHORT / DYNAMIC_DRAW
var buffer = new IndexBuffer( gl );

// you can also provide initial datatype, data and optional usage hint
var data = new Uint8Array([
  0, 1, 2,
  1, 3, 2
]);
var buffer = new IndexBuffer( gl, gl.UNSIGNED_BYTE, data, gl.DYNAMIC_DRAW );

Populate Buffer

var buffer = new IndexBuffer( gl, gl.UNSIGNED_INT );

// allocate buffer with TypedArray
var data = new Uint32Array([
  0, 1, 2,
  1, 3, 2
]);
buffer.data( data );

// update the second triangle
var part = new Uint8Array([ 1, 2, 3 ] );
buffer.subData( part, 12 );

Drawing commands

IndexBuffer provide gl.drawElements shortcuts, with optional count/offset.

• drawPoints(count, offset)
• drawLineStrip(count, offset)
• drawLineLoop(count, offset)
• drawLines(count, offset)
• drawTriangleStrip(count, offset)
• drawTriangleFan(count, offset)
• drawTriangles(count, offset)

count in elements and offset in bytes If count/ offset is missing, the full buffer is drawn.