<html>
<script src='matrix_vector_lib.js' ></script>
<script>
// TODO rotate selected points
// TODO control with zoom rotate or pan means that action is only applied to the camera not the selected points.
// TODO clicking and dragging on a line allows you to place a point somewhere on that line. Perhaps with the modifier key it would break up the existing line into line segments.
// TODO when lines are deleted, readd the solo points to the solo_points list
// TODO z for undo shift + z for redo.
// TODO
// TODO drop down minimalist menu in top right of canvas.
//
//
// Global variables
//
// use longer more descriptive names, especially for obscure variables, to avoid conflict in the global space,
// even if certain properties are factored into objects, if it is a large object, they work similar to globals in that exist in a large namespace accessible from many functions.
//
// All caps indicates a constant
// Some lower case variables may also be constants
// Capitalized constants indicate that we expect that variable to remain a constant
// even in future code changes, ie statically configured with an initial.
//
//
var canvas;
var origin = [0, 0, 0];
var frame_rate = 20;
var saveTimeout = 10*1000;
// to prevent camera from rotating beyond straight vertical
var vertical_camera_rotation = 0;
var zoom_scale = 2.667; // scalar zoom property.
var zoom_dist = 1;
var last_zoom_dist = 1;
var zoom_factor = 0.83;
// camera animation
var max_move_delta = 0.01;
var max_angle_delta = Math.PI;
var delta_horizontal_angle = 0;
var delta_vertical_angle = 0;
var delta_position = [0,0,0];
// Use to rotate selected points about a vector line
var selection_rotation_axis = null;
var rotation_center = origin.slice(0);
var points = []; //global
var solo_points = {};
var lines = [];
var point_projections = [];
var line_midpoint_projections = [];
var highlight_object = null;
var mouse_dragging = false;
var last_mouse_down = null;
var mouse_loc = null;
var selected_points = [];
var selected_lines = [];
var helpmsg = //"3D drawing tool\n\n" +
"Select Left Click\n" +
"Rotate Right Click\n" +
"Move wasd, qe\n" +
"Copy Space\n" +
"Delete x\n" +
"\n" +
"Click the red dot to create a point\n" +
"Drag between two points to connect them" +
"Spam a motion key to increase speed\n";
var msg = helpmsg;
var view_transform =
[[1, 0, 0],
[0, 1, 0],
[0, 0, 1]];
var key_state = {};
var key_state_augmentation_timeout = 150; // the permissible time in milliseconds since the last key event to still allow the key state to augment instead of clearing.
// constants
var MIN_DRAG_DIST = 10;
var POINT_HIGHLIGHT_DIST = 10;
var LINE_HIGHLIGHT_DIST = 15;
var MOTION_SPEED_BASE = 2.8;
var CENTER_POINT_COLOR = "rgba(250, 0, 0, 1.0)";
var AXIS_POINT_COLOR = "rgba(0, 0, 250, 1.0)";
var CENTER_POINT_RADIUS = 2.5;
var MIN_AXIS_POINT_RADIUS = 1;
var MAX_AXIS_POINT_RADIUS = 4;
var AXIS_LINE_WIDTH = 1.333;
var FORWARD_AXIS_LEN = 0.15;
var VERTICAL_AXIS_LEN = 0.075;
// The point, line, and fill colors are the same for a reason.
// Because all the colors are the same we don't have to worry about occlusion and z-order,
// because no matter which order colors are painted onto a pixel, the final result will be the same.
// Observe that this assertion holds even with a color with an alpha channel.
// This helps us use our 2d canvas happily and not have to worry about draw order or non-sensical visual effects from wrong order.
// With transparency we can still see each individual object and it almost mimics occlusion.
// This is meant to be a lightweight drawing tool, not a full featured one, so this decision is limiting but fits our goals perfectly.
var POINT_COLOR = "rgba(0, 0, 0, 0.9)";
var LINE_COLOR = "rgba(0, 0, 0, 0.9)";
var FILL_COLOR = "rgba(0, 0, 0, 0.9)";
var LINE_WIDTH = 1;
function addKeyListener(keycode, func){
if(!key_state[keycode]) key_state[keycode] = {};
var key_obj = key_state[keycode];
if(!key_obj.listeners) key_obj.listeners = [];
var listeners = key_obj.listeners;
listeners.push(func);
}
function keyDown(event, code){
var time = (new Date()).getTime();
var code = event.keyCode;
// alert("you pressed: " + code);
var key_obj = key_state[code];
if(!key_obj) key_obj = key_state[code] = {}; // create object
// update state etc.
var state = key_obj.state;
if(state) return; //key is already pressed.
state = 0;
var latest = key_obj.latest;
if(latest && time - latest < key_state_augmentation_timeout)
state = key_obj.state = key_obj.lastState + 1;
else
state = key_obj.state = 1;
key_obj.latest = time;
key_obj.lastState = state;
// call listener functions
var listeners = key_obj.listeners
if(!listeners) return; //nothing to do.
for(var i = 0; i < listeners.length; ++i)
listeners[i](event, state, state); }
function keyUp(event){
var time = (new Date()).getTime();
var code = event.keyCode;
var key_obj = key_state[code];
if(!key_obj) return; //nothing to do.
key_obj.latest = time;
key_obj.lastState = key_obj.state;
var state = key_obj.state = 0;
var lastState = key_obj.lastState;
var listeners = key_obj.listeners;
if(!listeners) return; //nothing to do.
for(var i = 0; i < listeners.length; ++i)
listeners[i](event, state, lastState); }
function setUiEvents(){
document.body.onkeydown = keyDown;
document.body.onkeyup = keyUp;
document.body.onmousedown = function(event){
var x = event.pageX;
var y = event.pageY;
x -= canvas.offsetLeft;
y -= canvas.offsetTop;
last_mouse_down = [x, y];
var button = event.button;
var keycode = button + 1000; //treat clicks like a button press but with higher keycode.
keyDown({keyCode: keycode}); } // it seems the keyCode of the original event cant be overwritten.
document.body.onmousewheel = function(event){
var delta = event.wheelDelta;
if(delta < 0)
zoom_dist /= zoom_factor;
else if(delta > 0)
zoom_dist *= zoom_factor; }
document.body.onmouseup = function(event){
var button = event.button;
var keycode = button + 1000; //treat clicks like a button press but with higher keycode.
keyUp({keyCode: keycode});
last_mouse_down = null;
mouse_dragging = false; }}
function changeVelocity(direction, positive, state, lastState){
if(state == 0){
state = lastState;
positive = !positive; } // reverse the velocity
var delta = Math.pow(MOTION_SPEED_BASE, state - 1) * max_move_delta / frame_rate;
if(!positive) delta = -delta;
var velocityChange = [0, 0, 0];
velocityChange[direction] = delta;
vector_add(delta_position, velocityChange, delta_position); }
function leftPress(e, s, lasts){
changeVelocity(0, false, s, lasts); }
function rightPress(e, s, lasts){
changeVelocity(0, true, s, lasts); }
function downPress(e, s, lasts){
changeVelocity(1, false, s, lasts); }
function upPress(e, s, lasts){
changeVelocity(1, true, s, lasts); }
function backwardPress(e, s, lasts){
changeVelocity(2, false, s, lasts); }
function forwardPress(e, s, lasts){
changeVelocity(2, true, s, lasts); }
function zoomInPress(e, s, lasts){
zoom_dist *= zoom_factor; }
function zoomOutPress(e, s, lasts){
zoom_dist *= zoom_factor; }
function copySelectedPoints(e, s, lasts){
if(s){
var new_selection = [];
var selection_map = {};
for(var i = 0; i < selected_points.length; ++i){
selection_map[selected_points[i]] = i;
var pt = points[selected_points[i]];
var newpt = addPoint(pt);
new_selection[i] = newpt; }
//if(key_state[16] && key_state[16].state){ //shift + space copies lines as well.
// copy lines as well
for(var i = 0; i < lines.length; ++i){
var line = lines[i];
if(!line) continue;
var pt1 = lines[i][0];
var pt2 = lines[i][1];
var i1 = selection_map[pt1];
var i2 = selection_map[pt2];
if(i1 !== undefined && i2 !== undefined){ // both points are selected
addLine(new_selection[i1], new_selection[i2]); }}
selected_points = new_selection; }}
addKeyListener(32, copySelectedPoints);
addKeyListener(37, leftPress); // arrow keys
addKeyListener(38, forwardPress);
addKeyListener(39, rightPress);
addKeyListener(40, backwardPress);
addKeyListener(65, leftPress); // wasd
addKeyListener(87, forwardPress);
addKeyListener(68, rightPress);
addKeyListener(83, backwardPress);
addKeyListener(69, upPress);
addKeyListener(81, downPress);
addKeyListener(88, function(e, s, lasts){ // x
if(s){
if(highlight_object !== null && highlight_object > 0){ // delete highlighted object
if(highlight_object < point_projections.length){ // point
points[highlight_object] = null; }
else if(highlight_object < point_projections.length + line_midpoint_projections.length){ // line
lines[highlight_object - point_projections.length] = null; }
else throw "highlight object index to large"; }
else if(selected_points.length){ // delete selected points
for(var i = 0; i < selected_points.length; ++i){
points[selected_points[i]] = null; }
selected_points.length = 0; }
cleanupDeletedPoints();
highlight_object = null;
selected_points.length = 0; }});
// select point
addKeyListener(1000, function(e, s, lasts){
if(s){
if(highlight_object !== null){
if(highlight_object == -1)
highlight_object = addPoint(origin); // create a new point at the origin
var alreadySelected = false; // only set for shift clicks
if(key_state[16] && key_state[16].state){ // shift key is pressed.
for(var i = 0; i < selected_points.length; ++i){
if(selected_points[i] == highlight_object){
selected_points.splice(i, 1); // deselect point
alreadySelected = true;
break; }}}
else{
selected_points.length = 0;}
if(!alreadySelected && highlight_object < points.length) selected_points.push(highlight_object); }
else if(!key_state[16] || !key_state[16].state)
selected_points.length = 0; }
else if(lasts && mouse_dragging ){ // drag actions
// connect selected points to highlight point with lines
if(selected_points.length && (!key_state[16] || !key_state[16].state)){ // TODO right now this really only works for drawing a single line,
if(highlight_object !== null && highlight_object < point_projections.length){
if(highlight_object == -1) highlight_object = addPoint(origin);
for(var i = 0; i < selected_points.length; ++i){
var pt = selected_points[i];
if(pt == highlight_object) continue;
addLine(pt, highlight_object); }
selected_points.length = 0; }}
// select points inside selection rectangle
else if(mouse_loc && last_mouse_down){
var minx = Math.min(mouse_loc[0], last_mouse_down[0]);
var maxx = Math.max(mouse_loc[0], last_mouse_down[0]);
var miny = Math.min(mouse_loc[1], last_mouse_down[1]);
var maxy = Math.max(mouse_loc[1], last_mouse_down[1]);
var selected_point_map = {};
if(!key_state[16] || !key_state[16].state){
selected_points.length = 0;
selected_lines.length = 0; }
else{
for(var i = 0; i < selected_points.length; ++i){
selected_point_map[selected_points[i]] = i; }}
for(var i = 0; i < point_projections.length; ++i){
if(selected_point_map[i]) continue; // already selected.
var pt = point_projections[i];
if(!pt) continue;
var _x = pt[0];
var _y = pt[1];
if(minx < _x && _x < maxx
&& miny < _y && _y < maxy){
selected_points.push(i); }}}
}});
// right click
addKeyListener(1002, function(e, s, lasts){
if(s == 0){
delta_horizontal_angle = 0;
delta_vertical_angle = 0; }});
function writeMsg(canvas, msg){
var lines = msg.split("\n");
var ctx = canvas.getContext("2d");
ctx.font = "9pt sans-serif"
for(var i = 0; i < lines.length; ++i){
ctx.fillText(lines[i], 5, 10 + 16 * i); }}
// camera functions
function rotateView(norm, theta, cameracentric){
// camera centric uses the camera axes to perform the rotation instead of the space axes.
if(cameracentric) norm = matrix_mult(view_transform, [norm])[0];
var rotation = vector_rotation(norm, theta);
view_transform = matrix_mult(rotation, view_transform); }
function rotatePoint(point, axis, angle, center){
}
function rotateHorizontal(theta){
rotateView([0, 1, 0], theta, false); }
function rotateVertical(theta){
if(vertical_camera_rotation + theta > Math.PI/2)
theta = Math.PI/2 - vertical_camera_rotation;
if(vertical_camera_rotation + theta < -Math.PI/2)
theta = -Math.PI/2 - vertical_camera_rotation;
vertical_camera_rotation += theta;
rotateView([1, 0, 0], theta, true); }
function moveCamera(offset, cameracentric){
if(cameracentric) offset = matrix_mult(view_transform, [offset])[0];
//alert("offset: " + offset);
vector_add(origin, offset, origin); }
// converts a point from three space to the canvas plane.
// Note: because of depth perspective, this conversion is not
// easy to define if the point lies behind the camera.
// There are two options:
// When drawing a line, another colinear point in front of the camera may be provided
// to help find an alertnate point.
// if both points lie behind the camera or the colinear_point is not provided,
// this function will return null.
function project(canvas, xyz, view_transform, origin, colinear_point){
if(!xyz) return null; // point has been deleted or does not exist
var w = canvas.width;
var h = canvas.height;
var scale = Math.min(w, h);
var v = xyz.slice(0);
if(origin) v = vector_minus(v, origin, v);
var z = vector_dot(view_transform[2], v);
if(z <= -zoom_dist){
if(!colinear_point) return null;
var v2 = colinear_point.slice(0);
if(origin) vector_minus(v2, origin, v2);
var z2 = vector_dot(view_transform[2], v2);
if(z2 < 0) return null;
// get the coefficients for a complex combination.
// t*z + (1-t)*z2 = 0.0002 -- z of new point is just barely infront of the camera.
var t = (0.0002 - z2)/(z - z2); // no division by zero, z is negative, z2 is positive
vector_add(vector_scale(v, t, v),
vector_scale(v2, 1-t, v2),
v);
z = vector_dot(view_transform[2], v); }
var scale2 = zoom_scale * scale / (zoom_dist + z);
return [ scale2 * vector_dot(view_transform[0], v) + 0.5 * w,
scale2 * vector_dot(view_transform[1], v) + 0.5 * h ]; }
// removes deleted points and lines
// works with global objects.
function cleanupDeletedPoints(){
var newpoints = [];
var newlines = [];
var pointmap = {};
var j = 0;
for(var i = 0; i < points.length; ++i){
if(points[i]){
newpoints.push(points[i]);
pointmap[i] = j;
++j; }
else{
pointmap[i] = -1; }}
for(var i = 0; i < lines.length; ++i){
if(!lines[i]) continue;
var a = lines[i][0];
var b = lines[i][1];
if(pointmap[a] != -1 && pointmap[b] != -1){
newlines.push([ pointmap[a], pointmap[b] ]); }}
points = newpoints;
lines = newlines; }
function addPoint(pt){
points.push(pt.slice(0));
var index = points.length - 1;
solo_points[index] = true;
return index; }
function addLine(pt0, pt1){
delete solo_points[pt0];
delete solo_points[pt1];
lines.push([pt0, pt1]);
return lines.length - 1; }
function draw(canvas){
var ctx = canvas.getContext('2d');
var w = canvas.width;
var h = canvas.height;
// ctx.fillStyle = "rgba(100, 100, 100, .05)";
ctx.beginPath();
for(var i = 0; i < lines.length; ++i){
var line = lines[i];
if(!line) continue;
//draw line
var pt0 = points[line[0]];
var pt1 = points[line[1]];
var _pt0 = point_projections[line[0]];
var _pt1 = point_projections[line[1]];
// finish the line even if one point is on wrong side of viewer.
if(!_pt0 && _pt1){
_pt0 = project(canvas, pt0, view_transform, origin, pt1); }
else if(_pt0 && !_pt1){
_pt1 = project(canvas, pt1, view_transform, origin, pt0); }
if(!_pt0 || !_pt1) continue;
var x0 = _pt0[0];
var y0 = _pt0[1];
var x1 = _pt1[0];
var y1 = _pt1[1];
ctx.moveTo(x0, y0);
ctx.lineTo(x1, y1); }
ctx.clearRect(0, 0, w, h);
ctx.strokeStyle = "rgba(0, 0, 0, 0.9)";
ctx.stroke();
ctx.fillStyle = "rgba(0, 0, 0, 0.9)";
for(var k in solo_points){
var pt = point_projections[k];
if(pt) ctx.fillRect(pt[0] - 2, pt[1] - 2, 4, 4); }
//
// The following drawing of axes is to help provide an perspective
// The nuances of this draw behavior are created to provide visual cues for interpreting perspective and depth.
//
// Because we use a 2d canvas library for the drawing the rest of the points/shapes after projection, these visual information nuances are important.
//
// axis lines and dots
var faxis_pt = project(canvas, vector_add(origin, [0, 0, FORWARD_AXIS_LEN]), view_transform, origin);
var vaxis_pt = project(canvas, vector_add(origin, [0, -VERTICAL_AXIS_LEN, 0]), view_transform, origin);
ctx.fillStyle = AXIS_POINT_COLOR;
var fdot = vector_dot(view_transform[2], [0, 0, 1]);
var a = MIN_AXIS_POINT_RADIUS; //random letters for intermediate computations
var b = MAX_AXIS_POINT_RADIUS;
var c = (a+b)/2;
var d = (b-a)/2;
var fr = c - d * fdot;
var vdot = vector_dot(view_transform[2], [0, -1, 0]);
var vr = c - d * vdot;
ctx.lineWidth = AXIS_LINE_WIDTH;
ctx.beginPath();
if(fdot >=0 && faxis_pt){ // occlude this axis, draw first
ctx.moveTo(w/2, h/2);
ctx.lineTo(faxis_pt[0], faxis_pt[1]);
ctx.fillRect(faxis_pt[0] - fr, faxis_pt[1] - fr, 2*fr, 2*fr); }
if(vdot >=0 && vaxis_pt){ // occlude this axis, draw first
ctx.moveTo(w/2, h/2);
ctx.lineTo(vaxis_pt[0], vaxis_pt[1]);
ctx.fillRect(vaxis_pt[0] - vr, vaxis_pt[1] - vr, 2*vr, 2*vr); }
ctx.stroke();
// draw center red square
ctx.fillStyle = CENTER_POINT_COLOR;
var cr = CENTER_POINT_RADIUS;
ctx.fillRect(w/2 - cr, h/2 - cr, 2*cr, 2*cr);
ctx.fillStyle = AXIS_POINT_COLOR;
if(fdot < 0 && faxis_pt){
ctx.beginPath();
ctx.moveTo(w/2, h/2);
ctx.lineTo(faxis_pt[0], faxis_pt[1]);
ctx.stroke();
ctx.fillRect(faxis_pt[0] - fr, faxis_pt[1] - fr, 2*fr, 2*fr); }
if(vdot < 0 && vaxis_pt){
ctx.beginPath();
ctx.moveTo(w/2, h/2);
ctx.lineTo(vaxis_pt[0], vaxis_pt[1]);
ctx.stroke();
ctx.fillRect(vaxis_pt[0] - vr, vaxis_pt[1] - vr, 2*vr, 2*vr); }
// reset line width
ctx.lineWidth = LINE_WIDTH;
for(var i = 0; i < selected_points.length; ++i){
var pt;
if(selected_points[i] == -1)
pt = [w/2, h/2];
else pt = point_projections[selected_points[i]];
ctx.fillStyle = POINT_COLOR;
if(pt) ctx.fillRect(pt[0] - 4, pt[1] - 4, 8, 8); }
if(highlight_object !== null){
if(highlight_object < point_projections.length){
var pt;
if(highlight_object == -1)
pt = [w/2, h/2];
else pt = point_projections[highlight_object];
ctx.fillStyle = "rgba(50, 50, 50, .6)";
ctx.fillRect(pt[0] - 4, pt[1] - 4, 8, 8); // TODO getting a error here that pt is null
document.body.style.cursor = "hand"; }
else if(highlight_object < point_projections.length + line_midpoint_projections.length){
// alert("drawing highlighted line");
var line = lines[highlight_object - point_projections.length];
if(line){
var pt1 = point_projections[line[0]];
var pt2 = point_projections[line[1]];
if(pt1 && pt2){
ctx.beginPath();
ctx.moveTo(pt1[0], pt1[1]);
ctx.lineTo(pt2[0], pt2[1]);
ctx.lineWidth = 3;
ctx.stroke();
ctx.lineWidth = 1; }}}
else{
throw "highlight object index to large"; }}
else{
document.body.style.cursor = "crosshair"; }
if(mouse_dragging){
if(selected_points.length && (!key_state[16] || !key_state[16].state)){ // if shift is held, we are selecting more points.
if(mouse_loc && key_state[1000] && key_state[1000].state){
ctx.beginPath();
var pt = point_projections[selected_points[0]];
if(pt){
ctx.moveTo(mouse_loc[0], mouse_loc[1]);
ctx.lineTo(pt[0], pt[1]); }
ctx.stroke(); }}
else if(mouse_loc && last_mouse_down){
if(key_state[1000] && key_state[1000].state){ // select points inside square
var minx = Math.min(mouse_loc[0], last_mouse_down[0]);
var maxx = Math.max(mouse_loc[0], last_mouse_down[0]);
var miny = Math.min(mouse_loc[1], last_mouse_down[1]);
var maxy = Math.max(mouse_loc[1], last_mouse_down[1]);
ctx.beginPath();
ctx.rect(minx, miny, maxx - minx, maxy - miny);
ctx.stroke(); }}
}
ctx.fillStyle = "rgb(0,0,0)";
writeMsg(canvas, msg); }
window.onload = function(){
// load localStorage saved state.
if(localStorage.points && localStorage.lines){
points = JSON.parse(localStorage.points);
lines = JSON.parse(localStorage.lines); }
canvas = document.createElement('canvas');
document.body.appendChild(canvas);
canvas.width = window.innerWidth - 20;
canvas.height = window.innerHeight - 20;
window.onresize = function(){
canvas.width = window.innerWidth - 20;
canvas.height = window.innerHeight - 20; }
function getRotationAngle(x, size, max, center_size){
if(!center_size) center_size = 0.05; // the proportional size of the area in which no rotation is effected by the mouse movement
if(!max) max = Math.PI/128;
// center does nothing
if(Math.abs(x) < size * center_size/2) x = 0;
else if(x < 0) x += size * center_size/2;
else x -= size * center_size/2;
return max * x / ((1 - center_size) * size/2); }
document.body.onmousemove = function(event){
//var test = function(event){
var x = event.pageX;
var y = event.pageY;
x -= canvas.offsetLeft;
y -= canvas.offsetTop;
mouse_loc = [x, y]
var w = canvas.width;
var h = canvas.height;
if(!mouse_dragging && last_mouse_down){
var _x = x - last_mouse_down[0];
var _y = y - last_mouse_down[1];
var dist2 = _x*_x + _y*_y;
if(dist2 > MIN_DRAG_DIST * MIN_DRAG_DIST){
mouse_dragging = true; }}
if(key_state[1002] && key_state[1002].state && last_mouse_down){
delta_horizontal_angle = getRotationAngle(x - last_mouse_down[0], w, max_angle_delta/frame_rate, 0);
delta_vertical_angle = -getRotationAngle(y - last_mouse_down[1], h, max_angle_delta/frame_rate, 0); }
var min_point_dist2 = LINE_HIGHLIGHT_DIST * LINE_HIGHLIGHT_DIST;
highlight_object = null;
var _x = canvas.width/2 - x;
var _y = canvas.height/2 - y;
var point_dist = _x*_x + _y*_y;
if(point_dist < POINT_HIGHLIGHT_DIST * POINT_HIGHLIGHT_DIST){
highlight_object = -1;
min_point_dist = point_dist; }
for(var i = 0; i < line_midpoint_projections.length; ++i){
var pt = line_midpoint_projections[i];
if(!pt) continue;
var _x = pt[0] - x;
var _y = pt[1] - y;
point_dist = _x*_x + _y*_y;
if(point_dist < min_point_dist2){ // alert('highlighting line');
highlight_object = i + point_projections.length;
min_point_dist = point_dist; }}
min_point_dist2 = Math.min( min_point_dist2, POINT_HIGHLIGHT_DIST * POINT_HIGHLIGHT_DIST);
for(var i = 0; i < point_projections.length; ++i){
var pt = point_projections[i];
if(!pt) continue;
var _x = pt[0] - x;
var _y = pt[1] - y;
point_dist = _x*_x + _y*_y;
if(point_dist < min_point_dist2){
highlight_object = i;
min_point_dist = point_dist; }}
}
setUiEvents();
document.body.oncontextmenu = function(){
return false; };
// draw(canvas);
// var ctx = canvas.getContext('2d');
// ctx.fillRect(0, 0, canvas.width, canvas.height);
//
function animateLoop(){
if(selected_points.length){ // move selection if exists
for(var i = 0; i < selected_points.length; ++i){
var pt = points[selected_points[i]];
vector_add(pt, delta_position, pt); }}
else{
moveCamera(delta_position, false); }
if(delta_horizontal_angle) rotateHorizontal(delta_horizontal_angle);
if(delta_vertical_angle) rotateVertical(delta_vertical_angle);
// overwrite point projections
// TODO this may not be perfect if points are deleted etc.
point_projections.length = 0;
for(var i = 0; i < points.length; ++i){
point_projections[i] = project(canvas, points[i], view_transform, origin); }
line_midpoint_projections.length = 0;
for(var i = 0; i < lines.length; ++i){
var line = lines[i];
if(!line){
line_midpoint_projections[i] = null;
continue; }
var pt1 = point_projections[line[0]];
var pt2 = point_projections[line[1]];
if(pt1 && pt2){
line_midpoint_projections[i] = [(pt1[0] + pt2[0])/2, (pt1[1] + pt2[1])/2]; }
else{
line_midpoint_projections[i] = null; }}
draw(canvas);
}
setInterval(animateLoop, 1000/frame_rate);
var saveAction = function(){
localStorage.points = JSON.stringify(points);
localStorage.lines = JSON.stringify(lines);
}
setInterval(saveAction, saveTimeout);
}
</script>
<body></body>
</html>