"use strict"; // 參考 https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Strict_mode
////////////////////////////////////////////////////////////////////////////////
// 後照攝影機作業
////////////////////////////////////////////////////////////////////////////////

var camera, rearCam, scene, renderer;
var cameraControls;

var clock = new THREE.Clock();

var canvasWidth;
var canvasHeight;
var rearTarget;

function fillScene() {
	scene = new THREE.Scene();
	scene.fog = new THREE.Fog( 0xDDDDDD, 3000, 4000 );

// 光源
	scene.add( new THREE.AmbientLight( 0x222222 ) );

var light = new THREE.DirectionalLight( 0xFFFFFF, 0.7 );
	light.position.set( 200, 500, 500 );

scene.add( light );

light = new THREE.DirectionalLight( 0xFFFFFF, 0.9 );
	light.position.set( -200, -100, -400 );

scene.add( light );

// 一些物件
	var x,z;

for ( x = -4500; x <= 4500; x += 1000 ) {
		for ( z = -4500; z <= 4500; z += 1000 ) {
			var coneMaterial = new THREE.MeshLambertMaterial();
			// 色輪
			var coneDistance = Math.sqrt( x*x + z*z );
			// 將值從角度轉換到 2*PI 範圍
			var colorHue = Math.acos( x / coneDistance );
			if ( z > 0 )
			{
				colorHue = Math.PI*2 - colorHue;
			}
			var colorSat = 1 - (coneDistance / 6364);
			coneMaterial.color.setHSL((colorHue+1)/(Math.PI*2), colorSat, 0.6 );
			coneMaterial.ambient.copy( coneMaterial.color );
			var cone = new THREE.Mesh(
				new THREE.CylinderGeometry( 100 - colorSat*100, colorSat*100, 300 ), coneMaterial );
			cone.position.set( x, 150, z );
			scene.add( cone );
		}
	}

// 材質
	var headMaterial = new THREE.MeshLambertMaterial( );
	headMaterial.color.r = 104/255;
	headMaterial.color.g = 1/255;
	headMaterial.color.b = 5/255;

var hatMaterial = new THREE.MeshPhongMaterial( { shininess: 100 } );
	hatMaterial.color.r = 24/255;
	hatMaterial.color.g = 38/255;
	hatMaterial.color.b = 77/255;
	hatMaterial.specular.setRGB( 0.5, 0.5, 0.5 );

var bodyMaterial = new THREE.MeshPhongMaterial( { shininess: 100 } );
	bodyMaterial.color.setRGB( 31/255, 86/255, 169/255 );
	bodyMaterial.specular.setRGB( 0.5, 0.5, 0.5 );

var glassMaterial = new THREE.MeshPhongMaterial( { color: 0x0, specular: 0xFFFFFF, shininess: 100, opacity: 0.3, transparent: true } );

var legMaterial = new THREE.MeshPhongMaterial( { shininess: 4 } );
	legMaterial.color.setHex( 0xAdA79b );
	legMaterial.specular.setRGB( 0.5, 0.5, 0.5 );

var footMaterial = new THREE.MeshPhongMaterial( { color: 0x960f0b, shininess: 30 } );
	footMaterial.specular.setRGB( 0.5, 0.5, 0.5 );

var sphere, cylinder, cube;

var bevelRadius = 1.9;	// TODO: 2.0 會造成幾何問題

// 建模
	// 基底
	cube = new THREE.Mesh(
		new THREE.BeveledBlockGeometry( 20+64+110, 4, 2*77+12, bevelRadius ), footMaterial );
	cube.position.x = -45;	// (20+32) - 寬度的一半 (20+64+110)/2
	cube.position.y = 4/2;	// 高的的一半
	cube.position.z = 0;	// 中心在原點
	scene.add( cube );

// 腳掌
	cube = new THREE.Mesh(
		new THREE.BeveledBlockGeometry( 20+64+110, 52, 6, bevelRadius ), footMaterial );
	cube.position.x = -45;	// (20+32) - 寬度的一半 (20+64+110)/2
	cube.position.y = 52/2;	// 高的的一半
	cube.position.z = 77 + 6/2;	// 偏移 77 + 深度的一半 6/2
	scene.add( cube );

cube = new THREE.Mesh(
		new THREE.BeveledBlockGeometry( 20+64+110, 52, 6, bevelRadius ), footMaterial );
	cube.position.x = -45;	// (20+32) - 寬度的一半 (20+64+110)/2
	cube.position.y = 52/2;	// 高的的一半
	cube.position.z = -(77 + 6/2);	// 負的偏移 77 + 深度的一半 6/2
	scene.add( cube );

cube = new THREE.Mesh(
		new THREE.BeveledBlockGeometry( 64, 104, 6, bevelRadius ), footMaterial );
	cube.position.x = 0;	// X 方向在原點
	cube.position.y = 104/2;
	cube.position.z = 77 + 6/2;	// 負的偏移 77 + 深度的一半 6/2
	scene.add( cube );

cube = new THREE.Mesh(
		new THREE.BeveledBlockGeometry( 64, 104, 6, bevelRadius ), footMaterial );
	cube.position.x = 0;	// X 方向在原點
	cube.position.y = 104/2;
	cube.position.z = -(77 + 6/2);	// 負的偏移 77 + 深度的一半 6/2
	scene.add( cube );

// 腳
	cube = new THREE.Mesh(
		new THREE.BeveledBlockGeometry( 60, 282+4, 4, bevelRadius ), legMaterial );
	cube.position.x = 0;	// X 方向在原點
	cube.position.y = 104 + 282/2 - 2;
	cube.position.z = 77 + 6/2;	// 負的偏移 77 + 深度的一半 6/2
	scene.add( cube );

cube = new THREE.Mesh(
		new THREE.BeveledBlockGeometry( 60, 282+4, 4, bevelRadius ), legMaterial );
	cube.position.x = 0;	// X 方向在原點
	cube.position.y = 104 + 282/2 - 2;
	cube.position.z = -(77 + 6/2);	// 負的偏移 77 + 深度的一半 6/2
	scene.add( cube );

// 身體
	sphere = new THREE.Mesh(
		new THREE.SphereGeometry( 104/2, 32, 16, 0, Math.PI * 2, Math.PI/2, Math.PI ), bodyMaterial );
	sphere.position.x = 0;
	sphere.position.y = 160;
	sphere.position.z = 0;
	scene.add( sphere );

// 半球的上蓋
	cylinder = new THREE.Mesh(
		new THREE.CylinderGeometry( 104/2, 104/2, 0, 32 ), bodyMaterial );
	cylinder.position.x = 0;
	cylinder.position.y = 160;
	cylinder.position.z = 0;
	scene.add( cylinder );

cylinder = new THREE.Mesh(
		new THREE.CylinderGeometry( 12/2, 12/2, 390 - 100, 32 ), bodyMaterial );
	cylinder.position.x = 0;
	cylinder.position.y = 160 + 390/2 - 100;
	cylinder.position.z = 0;
	scene.add( cylinder );

// 玻璃
	sphere = new THREE.Mesh(
		new THREE.SphereGeometry( 116/2, 32, 16 ), glassMaterial );
	sphere.position.x = 0;
	sphere.position.y = 160;
	sphere.position.z = 0;
	scene.add( sphere );

cylinder = new THREE.Mesh(
		new THREE.CylinderGeometry( 24/2, 24/2, 390, 32 ), glassMaterial );
	cylinder.position.x = 0;
	cylinder.position.y = 160 + 390/2;
	cylinder.position.z = 0;
	scene.add( cylinder );

// 頭
	sphere = new THREE.Mesh(
		new THREE.SphereGeometry( 104/2, 32, 16 ), headMaterial );
	sphere.position.x = 0;
	sphere.position.y = 160 + 390;
	sphere.position.z = 0;
	scene.add( sphere );

// 帽子
	cylinder = new THREE.Mesh(
		new THREE.CylinderGeometry( 142/2, 142/2, 10, 32 ), hatMaterial );
	cylinder.position.x = 0;
	cylinder.position.y = 160 + 390 + 40 + 10/2;
	cylinder.position.z = 0;
	scene.add( cylinder );

cylinder = new THREE.Mesh(
		new THREE.CylinderGeometry( 80/2, 80/2, 70, 32 ), hatMaterial );
	cylinder.position.x = 0;
	cylinder.position.y = 160 + 390 + 40 + 10 + 70/2;
	cylinder.position.z = 0;
	scene.add( cylinder );

var crossbarMaterial = new THREE.MeshPhongMaterial( { color: 0x808080, specular: 0xFFFFFF, shininess: 400 } );
	var eyeMaterial = new THREE.MeshPhongMaterial( { color: 0x000000, specular: 0x303030, shininess: 4 } );

// 橫桿
	cylinder = new THREE.Mesh(
		new THREE.CylinderGeometry( 5, 5, 200, 32 ), crossbarMaterial );
	cylinder.position.set( 0, 360, 0 );
	cylinder.rotation.x = 90 * Math.PI / 180.0;
	scene.add( cylinder );

// 鼻子
	cylinder = new THREE.Mesh(
		new THREE.CylinderGeometry( 6, 14, 70, 32 ), headMaterial );
	cylinder.position.set( -70, 530, 0 );
	cylinder.rotation.z = 90 * Math.PI / 180.0;
	scene.add( cylinder );

// 眼睛
	var sphGeom = new THREE.SphereGeometry( 10, 32, 16 );

// 左眼
	sphere = new THREE.Mesh( sphGeom, eyeMaterial );
	sphere.position.set( -48, 560, 0 );
	var eye = new THREE.Object3D();
	eye.add( sphere );
	eye.rotation.y = 20 * Math.PI / 180.0;
	scene.add( eye );

// 右眼
	sphere = new THREE.Mesh( sphGeom, eyeMaterial );
	sphere.position.set( -48, 560, 0 );
	eye = new THREE.Object3D();
	eye.add( sphere );
	eye.rotation.y = -20 * Math.PI / 180.0;
	scene.add( eye );
}

function init() {
	canvasWidth = window.innerWidth;
	canvasHeight = window.innerHeight;

// 配置一次，而非每影格配置
	rearTarget = new THREE.Vector3();

// RENDERER
	renderer = new THREE.WebGLRenderer( { antialias: true } );
	renderer.gammaInput = true;
	renderer.gammaOutput = true;
	renderer.setSize(canvasWidth, canvasHeight);
	renderer.setClearColorHex( 0xDDDDDD, 1.0 );
	// 第二視埠繪製時不要清除螢幕
	renderer.autoClear = false;

// 攝影機
	camera = new THREE.PerspectiveCamera( 45, canvasWidth / canvasHeight, 1, 7000 );
	camera.position.set( -810, 310, -1230 );
	rearCam = new THREE.PerspectiveCamera( 45, canvasWidth / canvasHeight, 1, 7000 );
	rearCam.position.set( -810, 310, -1230 );
	rearCam.lookAt( new THREE.Vector3( 0, 0, 0 ) );

// 控制
	cameraControls = new THREE.OrbitAndPanControls(camera, renderer.domElement);
	cameraControls.target.set(0,130,0);
}

function drawHelpers() {
	Coordinates.drawGround({size:10000});
	Coordinates.drawGrid({size:10000,scale:0.01});
}

function addToDOM() {
	var container = document.getElementById('container');
	var canvas = container.getElementsByTagName('canvas');
	if (canvas.length>0) {
		container.removeChild(canvas[0]);
	}
	container.appendChild( renderer.domElement );
}

function animate() {
	window.requestAnimationFrame(animate);
	render();
}

function render() {
	var delta = clock.getDelta();
	cameraControls.update(delta);

renderer.enableScissorTest( false );
	renderer.setViewport( 0, 0, canvasWidth, canvasHeight );
	renderer.clear();
	renderer.render( scene, camera );

// 學生作業：設定 rearCam 使它看向相反方向

// 後照 render
	renderer.enableScissorTest( true );
	// setScissor 在這裡可以改成只設定一次
	// 因為範圍不會改變
	renderer.setScissor( 0.75 * canvasWidth, 0.75 * canvasHeight,
		0.25 * canvasWidth, 0.25 * canvasHeight );
	renderer.setViewport( 0.75 * canvasWidth, 0.75 * canvasHeight,
		0.25 * canvasWidth, 0.25 * canvasHeight );
	renderer.clear();
	renderer.render( scene, rearCam );
}