archive/saku/index.js

257 lines
7.3 KiB
JavaScript

Saku = {
Scene: function() {
this.objects = [];
this.addObject = function(obj) {
var invalid = [varType(obj) !== "Object", varType(obj)];
if(varType(obj) !== "Object") throw TypeError("Expected Object as argument; Got " + invalid[1] + ".");
this.objects.push(obj);
}
},
Object: function(vertices, name) {
if(vertices === undefined) throw TypeError("Not enough arguments; Expected Array as argument.");
var invalid = [[varType(vertices) !== "Array", varType(vertices)]];
invalid[1] = vertices.every(function(element) { return varType(element) !== "Array"; });
invalid[2] = invalid[1] || vertices.every(function(element) { return element.every(function(number) { return isNaN(number); }); });
if(invalid[0][0]) throw TypeError("Expected Array as argument; Got " + invalid[0][1]);
if(invalid[1]) throw TypeError("Expected Arrays as 1st dimensional element.");
if(invalid[2]) throw TypeError("Expected Number as 2nd dimensional element.");
this.name = name || "Unnamed Object";
this.vertices = vertices;
this.translateX = function(value) {
this.vertices.forEach(function(ele, index, arr) {
arr[index][0] = ele[0] + value;
});
}
this.translateY = function(value) {
this.vertices.forEach(function(ele, index, arr) {
arr[index][1] = ele[1] + value;
});
}
this.translateZ = function(value) {
this.vertices.forEach(function(ele, index, arr) {
arr[index][2] = ele[2] + value;
});
}
this.translate = function(value) {
this.vertices.forEach(function(ele, index, arr) {
arr[index][0] = ele[0] + value;
arr[index][1] = ele[1] + value;
arr[index][2] = ele[2] + value;
});
}
}
}
Saku["Triangle"] = function(name) {
Saku.Object.call(this, [
[500,4,500],
[250,4,800],
[250,4,600]
], (name || "Triangle"));
this.prototype = Object.create(Saku.Object.prototype);
}
Saku["Square"] = function(name) {
Saku.Object.call(this, [
[1000,4,600],
[1500,4,600],
[1500,4,1100],
[1000,4,1100]
], (name || "Square"));
this.prototype = Object.create(Saku.Object.prototype);
}
function varType(variable) {
var type = typeof variable;
if(type === "object") {
return (variable.constructor === Array) ? "Array" : "Object";
} else {
return type[0].toUpperCase() + type.slice(1);
}
}
function updateFrame() {
ctx.clearRect(0,0,canvas.width,canvas.height)
for(var i = 0; i < scene.objects.length; i++) {
var object = scene.objects[i];
object = projectObj(object);
ctx.beginPath();
ctx.moveTo(object[0][0],object[0][1]);
for(var j = 1; j < object.length; j++) {
ctx.lineTo(object[j][0],object[j][1]);
}
ctx.fill();
}
}
function projectObj(object) {
var log = [];
var newShape = [];
var cP = camera[0]; // Camera Position
var cR = camera[1]; // Camera Rotation
var cF = camera[2];
// Camera direction vector
var cV = [
Rnd(cF*Math.sin(toRad(cR[1])),3), // 0 Degrees Z points straight to Y.
Rnd(cF*Math.cos(toRad(cR[1])),3),
Rnd(cF*Math.sin(toRad(cR[0])),3) // 0 Degrees X points straight to Y.
];
if(verbose) {
log = {
"Object Name": object.name,
"Camera Position": vecToObj(cP),
"Camera Rotation": {
"X": cR[0],
"Z": cR[1]
},
"Camera Focal": cF,
"Camera Vector": vecToObj(cV),
"Object Vertice Values": {},
"Canvas Points": {}
}
}
// Perspective mapping
for(var i = 0; i < object.vertices.length; i++) { // Each point in 3D
var x = object.vertices[i][0];
var y = object.vertices[i][1];
var z = object.vertices[i][2];
var pV = [x-cP[0],y-cP[1],z-cP[2]]; // Point direction vector
// Restricting to X and Z dimensions and comparing to Y.
var distPX = mag(dim("XY",pV));
var distPZ = mag(dim("ZY",pV));
var distCX = mag(dim("XY",cV));
var distCZ = mag(dim("ZY",cV));
/* Adjacent and Opposite calculated with math simplifications
cos(arccosx) = x
sin(arccosx) = sqrt(1-x^2)
*/
var adjX = dot(dim("XY",cV),dim("XY",pV)) / distCX;
var adjZ = dot(dim("ZY",cV),dim("ZY",pV)) / distCZ;
var oppX = distPX * Math.sqrt(1-Math.pow(adjX/distPX,2));
var oppZ = distPZ * Math.sqrt(1-Math.pow(adjZ/distPZ,2));
var projOppX = distCX*oppX/adjX; // Represents X in projective plane.
var projOppZ = distCZ*oppZ/adjZ; // Represents Y in projective plane.
// If the dot product is greater than 0, b is on the right of a.
if(adjX > 0) projOppX *= -1;
if(adjZ < 0) projOppZ *= -1;
var canvasPointX = Rnd(cP[0]+projOppX,3);
var canvasPointY = Rnd(cP[2]+projOppZ,3)
if(verbose) {
var num = "Point " + (i+1).toString();
log["Object Vertice Values"][num] = {
"Point Position": vecToObj(object.vertices[i]),
"Position Vector": vecToObj(pV),
"DistancePXY": distPX,
"DistancePZY": distPZ,
"DistanceCXY": distCX,
"DistanceCZY": distCZ,
"AdjacentXY": adjX,
"AdjacentZY": adjZ,
"OppositeXY": oppX,
"OppositeZY": oppZ,
"ProjectedOppXY": projOppX,
"ProjectedOppZY": projOppZ
};
log["Canvas Points"][num] = vecToObj([canvasPointX, canvasPointY]);
}
newShape.push([canvasPointX, canvasPointY]);
}
if(verbose) console.log(log);
return newShape;
}
function toRad(deg) {
return deg/180*Math.PI;
}
function Rnd(num,fig) {
return Math.round(num*Math.pow(10,fig))/Math.pow(10,fig);
}
function dot(vecOne, vecTwo) {
if(vecOne.length !== vecTwo.length) {
throw new SizeMismatch('VectorDimMismatch', [vecOne,vecTwo]);
return;
}
var final = 0;
for(var i = 0; i < vecOne.length; i++) {
final += vecOne[i]*vecTwo[i];
}
return final;
}
function mag(vec) {
var rad = 0;
for(var i = 0; i < vec.length; i++) {
rad += Math.pow(vec[i],2);
}
return Math.sqrt(rad);
}
function dim(dimensions, vector) {
var newVec = [];
var ref = {
"x": 0,
"y": 1,
"z": 2
};
if(dimensions.constructor === Array) {
for(var i = 0; i < dimensions.length; i++) {
newVec.push(vector[dimensions[i]]);
}
} else if(dimensions.constructor === String) {
for(var i = 0; i < dimensions.length; i++) {
newVec.push(vector[ref[dimensions[i].toLowerCase()]]);
}
}
return newVec;
}
function SizeMismatch(message, obj) {
this.mesage = message;
this.name = "SizeMismatch";
this.matrix = obj;
}
function vecToObj(vec) {
var obj = {};
var ref = ["X","Y","Z"];
vec.forEach(function(part) {
obj[ref[part]] = vec[part];
});
return obj;
}
var canvas = document.getElementById("glCanvas");
canvas.width = window.innerWidth;
canvas.height = window.innerHeight;
ctx = canvas.getContext("2d");
drawObjects = [];
verbose = false;
camera = [[canvas.width/2,0,canvas.height/2],[0,0],1]; // [[Position],[Rotation(x,z)],Focal];
scene = new Saku.Scene();
var triangle = new Saku.Triangle();
var square = new Saku.Square();
scene.addObject(triangle);
scene.addObject(square);
setInterval(updateFrame, 500);