let gl;
let program;
let positions1,
	positions2,
	colors1,
	colors2,
	indices1,
	indices2;
let posVBO1,
	posVBO2,
	colorVBO1,
	colorVBO2,
	indexVBO1,
	indexVBO2;
let posLoc,
	colorLoc;
let objects = [];
let lastTimestamp;
const {mat4, mat3, vec3} = glMatrix;

function main() {

	// Get canvas and setup WebGL context
    const canvas = document.getElementById("gl-canvas");
	gl = canvas.getContext('webgl2');

	// Configure viewport
	gl.viewport(0,0,canvas.width,canvas.height);
	gl.clearColor(1.0,1.0,1.0,1.0);

	gl.enable(gl.DEPTH_TEST);

	// Init shader program via additional function and bind it
	program = initShaders(gl, "vertex-shader", "fragment-shader");
	gl.useProgram(program);

	// Get locations of shader variables
	posLoc = gl.getAttribLocation(program, "vPosition");
	colorLoc = gl.getAttribLocation(program, "vColor");
	
	const moveLoc = gl.getUniformLocation(program, "moveDown");
	
	transformMatrix = [
		1, 0, 0, 0,
		0, 1, 0, -0.2,
		0, 0, 1, 0,
		0, 0, 0, 1,
	];	
	
	gl.uniformMatrix4fv(moveLoc, false, transformMatrix)

	const viewLoc = gl.getUniformLocation(program, "viewMatrix");

	/*
	viewMatrix = [
		0.1767766922712326, -0.0589255653321743, -0.013334667310118675, 0, 
		0, 0.2357022613286972, -0.006667333655059338, 0, 
		-0.1767766922712326, -0.0589255653321743, -0.013334667310118675, 0, 
		0, 0, -0.8801880478858948, 1
	];
	*/

	viewMatrix = mat4.create();
	projectionMatrix = mat4.create();
	modelViewProjection = mat4.create();
	mat4.perspective(projectionMatrix, 90.0, 1.0, 0.0001, 1000.0);

	gl.uniformMatrix4fv(viewLoc, false, viewMatrix);


	// Only clear once
	gl.clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT);

	objects.push(new Insel());
	objects.push(new River());

	//initListener();

	window.requestAnimationFrame(render);
};


function initListener()
{
	document.body.addEventListener('mousemove', printMouseMovement);
	document.body.addEventListener('keydown', printKeyPress);
}

function printMouseMovement(e)
{
	console.log('mousemoved');
}

function printKeyPress(e)
{
	console.log(e.which);
}


function render(timestamp)
{
	if(lastTimestamp == undefined) 
	{
		lastTimestamp = timestamp;
	}
		
	const elapsed = timestamp - lastTimestamp;

	let p = [3 * Math.sin(0.001 * timestamp), 1, 3 * Math.cos(0.001 * timestamp)];
	mat4.lookAt(viewMatrix, p, [0, 0, 0], [0, 1, 0]);

	mat4.multiply(modelViewProjection, projectionMatrix, viewMatrix);
	viewLoc = gl.getUniformLocation(program, "viewMatrix");
	gl.uniformMatrix4fv(viewLoc, false, modelViewProjection);

	for (var i = 0; i < objects.length; i++)
	{
		objects[i].render();
	} 

	window.requestAnimationFrame(render);
}

function init1() {

	// Specify geometry
	positions1 = [
			-0.344503,-0.106899,-2.313329,
			0.254658,0.065420,-2.430170,
			0.506020,-0.293147,-2.207084,
			1.415955,0.064912,-1.957500,
			1.489208,-0.318759,-1.320762,
			1.685851,0.084184,-1.268915,
			2.014675,-0.126122,-0.782958,
			0.957233,-1.089151,-0.905606,
			0.454708,-1.256676,-0.897711,
			0.810208,-0.709404,-1.141590,
			0.739686,-1.249709,-0.541415,
			0.231851,-1.904112,-0.621845,
			0.052641,-1.633897,-0.758536,
			-0.020753,-0.743329,-1.377161,
			1.364762,-0.324582,0.647285,
			2.074500,0.090083,0.068582,
			1.608835,0.037777,0.559365,
			1.955554,-0.191974,0.132568,
			1.393132,0.037777,1.383312,
			1.210661,-0.322174,1.134609,
			0.514977,-0.286422,1.576757,
			0.507135,-1.581211,0.348922,
			0.342563,-2.052501,-0.027325,
			0.620568,-1.491335,-0.146730,
			0.745909,-0.723539,0.485115,
			0.089439,-1.345612,0.360167,
			1.089500,-0.770651,-0.314462,
			-0.123718,-0.298339,1.611730,
			-0.930959,0.037777,1.550149,
			-0.866234,-0.291222,1.300128,
			-0.414258,0.037777,1.808618,
			-1.444312,-0.282136,0.794076,
			-1.591571,0.097928,0.827036,
			-1.839477,-0.177971,0.145553,
			-0.936850,-0.751093,-0.176985,
			-0.611777,-1.317411,-0.262516,
			-0.326162,-1.310280,0.225784,
			0.289486,-0.743127,0.679448,
			0.020776,-1.770522,0.330532,
			-1.675519,-0.336500,-0.606829,
			-1.607249,0.010755,-1.680275,
			-0.625318,-0.725192,-1.039731,
			-2.011082,0.043485,-0.744422,
			-1.247727,0.059337,-1.332687,
			-0.934732,-0.314137,-1.943344,
			-0.184171,-0.491687,-2.096484,
			-0.707720,0.065178,-2.205832,
			-0.350659,-1.373304,-0.758204,
			-0.299529,-2.155551,-0.308846,
			-0.086080,-2.478361,-0.004677,
			0.091215,-2.267556,0.130842,
			-0.260030,-2.240649,0.060849,
			-0.470828,-1.954876,0.024811,
			-0.278168,0.037777,-0.209083,
			-0.914878,0.210568,-1.267986,
			-0.862298,0.231412,-0.781910,
			-0.302799,0.520691,-1.301783,
			-1.068480,0.101026,-0.360536,
			-1.736910,0.103204,0.106553,
			0.236277,0.037777,0.701510,
			0.656348,0.037777,-0.098120,
			0.501631,0.037777,1.688231,
			1.034499,0.275328,-1.269756,
			0.471459,0.267036,-1.698558,
			0.637660,0.376390,-1.207861,
			0.812177,0.491673,-0.567514,
			1.244986,0.398908,-0.324291,
			1.002755,0.639249,-0.717163,
			1.381545,0.288786,-0.765328,
			1.348978,0.284964,-1.076072,
			-0.505260,0.213488,-1.704558,
			-0.221831,0.306144,-1.838428,
			-0.274246,0.065420,-2.359878,
			2.054775,0.091828,-0.677912,
			-0.148262,0.773865,-0.947432,
			0.101020,0.922236,-0.839739,
			0.312442,0.779166,-1.109731,
			-0.262315,0.721321,-1.533752,
			-0.404757,0.197895,-0.782219,
			0.568488,0.537125,-0.913448,
			0.115069,0.760356,-1.450921,
			-0.061115,0.654189,-0.643377,
			0.205810,0.801703,-0.757537,
			0.344937,0.262088,-0.492076,
			0.077232,0.934717,-1.202342,
			-0.102879,0.422805,-0.489015,
			-0.269697,0.566033,-0.874217,
			-0.186512,0.743264,-1.152426
		];

	indices1 = [
			0,1,2,
			3,4,2,
			5,6,4,
			7,8,9,
			8,10,11,
			9,12,13,
			14,15,16,
			14,6,17,
			6,15,17,
			14,18,19,
			18,20,19,
			21,22,23,
			24,25,21,
			24,23,26,
			27,28,29,
			20,30,27,
			28,31,29,
			32,33,31,
			34,35,36,
			36,25,37,
			36,38,25,
			39,40,41,
			40,42,43,
			33,42,39,
			40,44,41,
			44,0,45,
			40,46,44,
			46,0,44,
			41,12,47,
			47,12,48,
			41,35,34,
			48,35,47,
			48,11,49,
			11,50,49,
			50,51,49,
			50,52,51,
			51,48,49,
			53,32,28,
			54,55,56,
			57,58,32,
			59,16,60,
			28,59,53,
			59,61,18,
			62,63,64,
			65,66,67,
			68,5,69,
			70,43,54,
			63,1,71,
			71,72,46,
			13,45,2,
			9,4,7,
			4,26,7,
			26,14,24,
			26,6,14,
			19,37,24,
			37,29,36,
			29,34,36,
			44,13,41,
			2,1,3,
			2,45,0,
			0,72,1,
			9,2,4,
			3,5,4,
			5,73,6,
			7,10,8,
			7,26,10,
			9,8,12,
			8,11,12,
			14,17,15,
			6,73,15,
			14,16,18,
			18,61,20,
			24,21,23,
			21,38,22,
			24,37,25,
			21,25,38,
			26,23,10,
			23,22,10,
			27,30,28,
			20,61,30,
			28,32,31,
			32,58,33,
			36,35,52,
			74,75,76,
			36,52,38,
			40,39,42,
			33,58,42,
			40,43,46,
			46,72,0,
			41,13,12,
			41,47,35,
			48,52,35,
			48,12,11,
			11,22,50,
			11,10,22,
			50,38,52,
			22,38,50,
			48,51,52,
			53,57,32,
			43,42,57,
			57,42,58,
			59,18,16,
			28,30,59,
			59,30,61,
			5,62,69,
			60,16,15,
			66,73,68,
			71,70,77,
			63,3,1,
			71,1,72,
			13,2,9,
			4,6,26,
			14,19,24,
			19,20,37,
			37,27,29,
			37,20,27,
			29,31,34,
			31,33,34,
			34,39,41,
			34,33,39,
			44,45,13,
			55,78,56,
			59,60,53,
			79,60,65,
			77,56,80,
			81,82,75,
			82,76,75,
			60,76,83,
			76,80,84,
			53,83,85,
			86,74,87,
			64,76,79,
			74,84,87,
			53,60,83,
			78,85,86,
			67,64,79,
			67,79,65,
			67,66,68,
			67,69,62,
			67,68,69,
			60,66,65,
			67,62,64,
			62,3,63,
			68,73,5,
			5,3,62,
			66,15,73,
			79,76,60,
			64,63,76,
			60,15,66,
			76,82,83,
			85,82,81,
			85,83,82,
			74,85,81,
			56,78,86,
			56,87,84,
			56,86,87,
			56,84,80,
			71,80,63,
			53,55,57,
			56,77,70,
			56,70,54,
			43,55,54,
			70,46,43,
			71,46,70,
			76,63,80,
			86,85,74,
			74,76,84,
			78,53,85,
			71,77,80,
			53,78,55,
			43,57,55,
			74,81,75
		];

	colors1 = [];
	for(var i = 0; i < positions1.length; i += 3) {
		colors1.push(0.5, 0.5, 0.5, 1);
	}

	initBuffers1();
}

function initBuffers1() {

	// Create VBO for positions and activate it
	posVBO1 = gl.createBuffer();
	gl.bindBuffer(gl.ARRAY_BUFFER, posVBO1);

    // Fill VBO with positions
	gl.bufferData(gl.ARRAY_BUFFER, new Float32Array(positions1), gl.STATIC_DRAW);

	// Create VBO for colors and activate it
	colorVBO1 = gl.createBuffer();
	gl.bindBuffer(gl.ARRAY_BUFFER, colorVBO1);

    // Fill VBO with colors
	gl.bufferData(gl.ARRAY_BUFFER, new Float32Array(colors1), gl.STATIC_DRAW);

	// Create VBO for indices and activate it
	indexVBO1 = gl.createBuffer();
	gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, indexVBO1);

	// Fill VBO with indices
	gl.bufferData(gl.ELEMENT_ARRAY_BUFFER, new Uint16Array(indices1), gl.STATIC_DRAW);
}

function render1() {

	// Link data in VBO to shader variables
	gl.bindBuffer(gl.ARRAY_BUFFER, posVBO1);
	gl.enableVertexAttribArray(posLoc);
	gl.vertexAttribPointer(posLoc, 3, gl.FLOAT, false, 0, 0);

    // Link data in VBO to shader variables
    gl.bindBuffer(gl.ARRAY_BUFFER, colorVBO1);
	gl.enableVertexAttribArray(colorLoc);
	gl.vertexAttribPointer(colorLoc, 4, gl.FLOAT, false, 0, 0);

	// Render
	gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, indexVBO1);
	gl.drawElements(gl.TRIANGLES, indices1.length, gl.UNSIGNED_SHORT, 0);
}

function init2() {

	// Specify geometry
	positions2 = [
			 0.0,  0.0, 14.0, 	 // index 0
			 0.75, 0.0, 12.5, 	 // index 1
			 1.25, 0.0, 12.5, 	 // index 2
			 1.0,  0.0, 11.0, 	 // index 3
			 2.0,  0.0, 11.0, 	 // index 4
			 0.75, 0.0,  9.5, 	 // index 5
			 2.25, 0.0,  9.5, 	 // index 6
			 0.0,  0.0,  8.0, 	 // index 7
			 2.0,  0.0,  8.0, 	 // index 8
			-2.25, 0.0,  6.1875, // index 9
			 0.25, 0.0,  6.1875, // index 10
			-3.0,  0.0,  4.0, 	 // index 11
			 0.0,  0.0,  4.0, 	 // index 12
			-2.25, 0.0,  1.8125, // index 13
			 1.25, 0.0,  1.8125, // index 14
			 0.0,  0.0,  0.0, 	 // index 15
			 4.0,  0.0,  0.0, 	 // index 16
			 0.0, -7.0,  0.0, 	 // index 17 -> additional for waterfall
			 4.0, -6.0,  0.0  	 // index 18 -> additional for waterfall
		];

	indices2 = [
			0, 1, 2,
			1, 2, 3,
			2, 3, 4,
			3, 4, 5,
			4, 5, 6,
			5, 6, 7,
			6, 7, 8,
			7, 8, 9,
			8, 9, 10,
			9, 10, 11,
			10, 11, 12,
			11, 12, 13,
			12, 13, 14,
			13, 14, 15,
			14, 15, 16,
			15, 16, 17, // additional for waterfall
			16, 17, 18  // additional for waterfall
		];

	colors2 = [];
	for(var i = 0; i < positions2.length; i += 3) {
		colors2.push(0.2, 0.2, 0.8, 1);
	}

	initBuffers2();
}

function initBuffers2() {
	// Create VBO for positions and activate it
	posVBO2 = gl.createBuffer();
	gl.bindBuffer(gl.ARRAY_BUFFER, posVBO2);

	// Fill VBO with positions
	gl.bufferData(gl.ARRAY_BUFFER, new Float32Array(positions2), gl.STATIC_DRAW);
	
	// Create VBO for colors and activate it
	colorVBO2 = gl.createBuffer();
	gl.bindBuffer(gl.ARRAY_BUFFER, colorVBO2);
	
	// Fill VBO with colors
	gl.bufferData(gl.ARRAY_BUFFER, new Float32Array(colors2), gl.STATIC_DRAW);
	
	// Create VBO for indices and activate it
	indexVBO2 = gl.createBuffer();
	gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, indexVBO2);
	
	// Fill VBO with indices
	gl.bufferData(gl.ELEMENT_ARRAY_BUFFER, new Uint16Array(indices2), gl.STATIC_DRAW);
}

function render2() {
	// Link data in VBO to shader variables
	gl.bindBuffer(gl.ARRAY_BUFFER, posVBO2);
	gl.enableVertexAttribArray(posLoc);
	gl.vertexAttribPointer(posLoc, 3, gl.FLOAT, false, 0, 0);

    // Link data in VBO to shader variables
    gl.bindBuffer(gl.ARRAY_BUFFER, colorVBO2);
	gl.enableVertexAttribArray(colorLoc);
	gl.vertexAttribPointer(colorLoc, 4, gl.FLOAT, false, 0, 0);

	// Render
	gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, indexVBO2);
	gl.drawElements(gl.TRIANGLES, indices2.length, gl.UNSIGNED_SHORT, 0);
}

main();