Function init

MathBox/mathbox-bundle.js:25029–25279

()

	var tempTexture, occlusionTexture;

	var init = function () {

		var vertices = new Float32Array( [
			-1, -1,  0, 0,
			 1, -1,  1, 0,
			 1,  1,  1, 1,
			-1,  1,  0, 1
		] );

		var faces = new Uint16Array( [
			0, 1, 2,
			0, 2, 3
		] );

		// buffers

		vertexBuffer     = gl.createBuffer();
		elementBuffer    = gl.createBuffer();

		gl.bindBuffer( gl.ARRAY_BUFFER, vertexBuffer );
		gl.bufferData( gl.ARRAY_BUFFER, vertices, gl.STATIC_DRAW );

		gl.bindBuffer( gl.ELEMENT_ARRAY_BUFFER, elementBuffer );
		gl.bufferData( gl.ELEMENT_ARRAY_BUFFER, faces, gl.STATIC_DRAW );

		// textures

		tempTexture      = gl.createTexture();
		occlusionTexture = gl.createTexture();

		gl.bindTexture( gl.TEXTURE_2D, tempTexture );
		gl.texImage2D( gl.TEXTURE_2D, 0, gl.RGB, 16, 16, 0, gl.RGB, gl.UNSIGNED_BYTE, null );
		gl.texParameteri( gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE );
		gl.texParameteri( gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE );
		gl.texParameteri( gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.NEAREST );
		gl.texParameteri( gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.NEAREST );

		gl.bindTexture( gl.TEXTURE_2D, occlusionTexture );
		gl.texImage2D( gl.TEXTURE_2D, 0, gl.RGBA, 16, 16, 0, gl.RGBA, gl.UNSIGNED_BYTE, null );
		gl.texParameteri( gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE );
		gl.texParameteri( gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE );
		gl.texParameteri( gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.NEAREST );
		gl.texParameteri( gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.NEAREST );

		hasVertexTexture = gl.getParameter( gl.MAX_VERTEX_TEXTURE_IMAGE_UNITS ) > 0;

		var shader;

		if ( hasVertexTexture ) {

			shader = {

				vertexShader: [

					"uniform lowp int renderType;",

					"uniform vec3 screenPosition;",
					"uniform vec2 scale;",