Develop Reference

Adding duplicate tiles from different arrays PIXI.js

I'm trying to create a slot game;
I have some images that I put into an array
var createSlots = function(){
//setup images as tilingSprites
var slot1 = new PIXI.extras.TilingSprite(t1, 200, 200);
var slot2 = new PIXI.extras.TilingSprite(t2, 200, 200);
var slot3 = new PIXI.extras.TilingSprite(t3, 200, 200);
var slot4 = new PIXI.extras.TilingSprite(t4, 200, 200);
var slot5 = new PIXI.extras.TilingSprite(t5, 200, 200);
var slot6 = new PIXI.extras.TilingSprite(t6, 200, 200);
var slot7 = new PIXI.extras.TilingSprite(t7, 200, 200);
var slot8 = new PIXI.extras.TilingSprite(t8, 200, 200);
var slot9 = new PIXI.extras.TilingSprite(t9, 200, 200);
var slot10 = new PIXI.extras.TilingSprite(t10, 200, 200);
//push slots into array; images, sprites etc.
mainSlotArr.push(slot1, slot2, slot3, slot4, slot5, slot6, slot7, slot8, slot9, slot10);
};
for the moment I have 2 functions (will combine them once I get this working)
createReels1 and createReels2
what they do is copy the mainSlotArray use a shuffle function
Then populate to 2 columns (reels) each (at the moment createReels2 only does one reel)
it then removes the array element from the array it's using
The trouble I'm having is that whatever image tiles are used in createReels2, disappear if they are being used in createReels1 function, e.g if image1.png used in createReels2 and createReels1, then it is not visible in the first 2 reels
createReels functions below (alot of hard coding!)
var createReels1 = function(){
slotArr1 = mainSlotArr.slice();
shuffle(slotArr1);
var counter = 0;
var num = 0
for(var i = 0; i <2; i++){
var slotContainer = new PIXI.Container();
slotContainer.width = 100;
slotContainer.height = 400;
slotContainer.y = 100;
slotContainer.x = i*130;
stage.addChild(slotContainer);
slotContainerArr.push(slotContainer);
for(var j = 0; j < 3; j++){
var slot = slotArr1[j];
var toDel = slotArr1.indexOf(slot);
slot.scale.y = slot.scale.x = .5;
console.log(slot);
var nextY = j*(slot.height/2);
slot.y = nextY;
slotContainerArr[i].addChild(slot);
slotArr1.splice(toDel, 1);//remove from array
}
}
}
var createReels2 = function(){
slotArr2 = mainSlotArr.slice();
shuffle(slotArr2);
var counter = 0;
var num = 0
for(var i = 0; i <1; i++){
var slotContainer = new PIXI.Container();
slotContainer.width = 100;
slotContainer.height = 400;
slotContainer.y = 100;
slotContainer.x = 260;
stage.addChild(slotContainer);
slotContainerArr.push(slotContainer);
for(var j = 0; j < 3; j++){
var slot = slotArr2[j];
var toDel = slotArr2.indexOf(slot);
slot.scale.y = slot.scale.x = .5;
var nextY = j*(slot.height/2);
slot.y = nextY;
slotContainerArr[2].addChild(slot);
slotArr2.splice(toDel, 1);//remove from array
}
}
}

If I understood the code correctly, with quick check:
Sprites can have only one parent. If you check the Sprite object, it actually has a parent property. So slotArr1 and slotArr2 have identical Sprites and that fact doesn't change id you slice them. Then when you are assigning them to different containers, they get moved from one container to the other. You can reuse textures sure, but one Sprite can only have on parent.

Make other nodes follow when dragging a node in Cytoscape.js

I'm new to cytoscape.js, I just want to make other nodes follow when dragging one node.
Appreciate your help

Write a listener, and update the other node positions appropriately in your callback:
eles.on()
node.position()

Here is how I did it. Note you have to save off the original positions at the grab event, and then update during the drag event.
function add_drag_listeners()
{
var all = cy.elements("node");
for (j = 0; j < all.length; j++)
{
cynode = all[j];
cynode.on("grab",handle_grab);
cynode.on("drag",handle_drag);
}
}
var grab_x = 0;
var grab_y = 0;
var drag_subgraph = [];
function handle_grab(evt)
{
grab_x = this.position().x ;
grab_y = this.position().y ;
var succ = this.successors();
drag_subgraph = [];
var succstr = "";
for (i = 0; i < succ.length; i++)
{
if (succ[i].isNode())
{
var old_x = succ[i].position().x;
var old_y = succ[i].position().y;
succstr += " " + succ[i].data("id");
drag_subgraph.push({old_x:old_x, old_y:old_y, obj:succ[i]});
}
}
}
function handle_drag(evt)
{
var new_x = this.position().x;
var new_y = this.position().y;
var delta_x = new_x - grab_x;
var delta_y = new_y - grab_y;
for (i = 0; i < drag_subgraph.length; i++)
{
var obj = drag_subgraph[i].obj;
var old_x = drag_subgraph[i].old_x;
var old_y = drag_subgraph[i].old_y;
var new_x = old_x + delta_x;
var new_y = old_y + delta_y;
obj.position({x:new_x, y:new_y});
}
}

Display unique image from array using javascript

I have a following code that displays random images from array.
It generates random images, but however it fails to load unique image.
For more info i would like to add that this code is for Solitaire game so i need to generate unique image.
var imgArray = ['c1.png', 'c2.png', 'd3.png', 'd4.png', 'h5.png', 'h6.png', 'd7.png', 'h8.png'];
var basePath="card/";
function imgRandom() {
for (var i = 2; i < 8; i++) {
var rand = imgArray[Math.floor(Math.random() * imgArray.length)];
var image = new Image();
image.src = basePath+rand;
image.id = 'imageid';
image.width = '100';
image.height = '130';
image.style.position = 'absolute';
document.getElementById('myimg'+i).appendChild(image);
}
}

var imgArray = ['c1.png', 'c2.png', 'd3.png', 'd4.png', 'h5.png', 'h6.png', 'd7.png', 'h8.png'];
var basePath="card/";
function imgRandom() {
var imgArrayCopy = imgArray.slice(0); //make a copy of the array.
for (var i = 2; i < 8; i++) {
var rNumber = Math.floor(Math.random() * imgArrayCopy.length);
var rand = imgArrayCopy.splice(rNumber, 1); //deletes the img from the array and returns it;
var image = new Image();
image.src = basePath+rand;
image.id = 'imageid';
image.width = '100';
image.height = '130';
image.style.position = 'absolute';
document.getElementById('myimg'+i).appendChild(image);
}
}
This should do that.

Faulty Logic in this image color equalization algorithm

Somewhere in my code, I seem to be doing something wrong and I cannot tell which part is going awry. I've printed to console the values I'm getting from the various arrays and it seems to match up. Then when I run the equalization function (a la Wikipedia-Histogram Equalization) my output image is close to total black. I was trying to interpret this guy's php into javascript just to test some stuff out and figured I did a decent job. But I'm not an expert.
The pertinent parts:
function imageLoaded(ev) {
element = document.getElementById("canvas1");
c = element.getContext("2d");
im = ev.target; // the image
// read the width and height of the canvas
width = element.width;
height = element.height;
// stamp the image on the left of the canvas:
c.drawImage(im, 0, 0);
// get all canvas pixel data
imageData = c.getImageData(0, 0, width, height);
w2 = width / 2;
var reds = new Array();
var greens = new Array();
var blues = new Array();
var freqR = new Array();
var freqG = new Array();
var freqB = new Array();
if (imageData){
buildHistograms(reds, greens,blues);
buildFrequencies(reds, greens, blues, freqR, freqG, freqB);
}
var alpha = 255/(w2*height);
// run through the image
for (y = 0; y < height; y++) {
inpos = y * width * 4; // *4 for 4 ints per pixel
outpos = inpos + w2 * 4;
for (x = 0; x < w2; x++) {
//reads pixel data(of img c)to each channel of rgb
r = imageData.data[inpos++];
g = imageData.data[inpos++];
b = imageData.data[inpos++];
a = imageData.data[inpos++];
//using histogram eqalization formula:
adjR = freqR[r]*alpha;
adjG = freqG[g]*alpha;
adjB = freqB[b]*alpha;
//assigns pixel data of output image
imageData.data[outpos++] = adjR;
imageData.data[outpos++] = adjG;
imageData.data[outpos++] = adjB;
imageData.data[outpos++] = a;
}
}
// put pixel data on canvas
c.putImageData(imageData, 0,0);
}
im = new Image();
im.onload = imageLoaded;
im.src = "Lenna.png";
function buildHistograms(reds,greens,blues){
//run through image building histogram
for (y=0; y < height; y++){
inpos = y * width *4;
for (x=0; x < w2; x++){
rd = imageData.data[inpos++];
g = imageData.data[inpos++];
b = imageData.data[inpos++];
a = imageData.data[inpos++];
// Add counts to our histogram arrays for each color.
reds.push(rd);
greens.push(g);
blues.push(b);
}
}
// Sort them by keys into order
reds.sort(function(a,b){return a-b});
greens.sort(function(a,b){return a-b});
blues.sort(function(a,b){return a-b});
}
function buildFrequencies(reds, greens, blues, freqR, freqG, freqB){
// Build frequency charts for all colors: takes REDS GREENS BLUES from buildHistograms and places them on top of each other accordingly
for(i=0; i<=255; i++){
sumR=0;
sumG=0;
sumB=0;
for(j=0; j<= i; j++){
if (reds[j]){sumR+=reds[j];}
if (greens[j]){sumG+=greens[j];}
if (blues[j]){sumB+=blues[j];}
}
freqR[i] = sumR;
freqG[i] = sumG;
freqB[i] = sumB;
}
}
Any help is appreciated, Thanks.

Looks like my build frequencies section was all wrong. I modified it in this way:
var len = reds.length;
for (j=0; j < len; j++) {
var rCurrVal = reds[j];
var gCurrVal = greens[j];
var bCurrVal = blues[j];
if (freqR.hasOwnProperty(rCurrVal)) {
freqR[rCurrVal] += 1;
} else {
freqR[rCurrVal] = 1;
}
if (freqG.hasOwnProperty(gCurrVal)) {
freqG[gCurrVal] += 1;
} else {
freqG[gCurrVal] = 1;
}
if (freqB.hasOwnProperty(bCurrVal)) {
freqB[bCurrVal] += 1;
} else {
freqB[bCurrVal] = 1;
}
}
for (i=0; i<255; i++){
if ($.inArray(i,reds)===-1){freqR[i]=0;}
if ($.inArray(i,greens)=== -1){freqG[i]=0;}
if ($.inArray(i,blues)=== -1){freqB[i]=0;}
if (i>0){
freqR[i]+=freqR[i-1];
freqG[i]+=freqG[i-1];
freqB[i]+=freqB[i-1];
}
}

Drawing multiple random canvas images in a loop

I'm trying to draw a grid with random images assigned to each square. I'm having trouble with the draw sequence and potentially closure issues with the Javascript variables. Any help is appreciated.
var tileSize = 30;
var drawCanvasImage = function(ctx,tile,x,y) {
return function() {
ctx.drawImage(tile,x,y);
console.log("x = " + x + "/ y = " + y);
}
}
function textures(ctx) {
var grass = new Image();
var sea = new Image();
var woods = new Image();
for (var i=0; i<=10; i++) {
for (var j=0; j<=20; j++) {
rand = Math.floor(Math.random()*3 + 1);
x = i * tileSize;
y = j * tileSize;
if (rand == 1) {
grass.onload = drawCanvasImage(ctx,grass,x,y);
} else if (rand == 2) {
sea.onload = drawCanvasImage(ctx,sea,x,y);
} else {
woods.onload = drawCanvasImage(ctx,woods,x,y);
}
}
}
grass.src = "textures/grass.png";
sea.src = "textures/sea.png";
woods.src = "textures/woods.png";
}
//function called by the onload event in the html body tag
function draw() {
var ctx = document.getElementById("grid").getContext('2d');
grid(ctx); //a function to draw the background grid - works fine
textures(ctx);
}
The current result is three drawn tiles, all at the position of x = 300 (equivalent to the i loop of 10 * the tileSize of 30) and a random y position.
After following a lead and accounting for (maybe?) closure issues by creating the variable drawCanvasImage, I at least got those three tiles to draw.
----Edit----
Working Code - Revision 2:
function randomArray() {
for (var i=0; i<=(xValue/tileSize); i++) {
terrainArray[i] = [];
for (var j=0; j<=(yValue/tileSize); j++) {
rand = Math.floor(Math.random()*4 + 1);
if (rand == 1) {
terrainArray[i][j] = 3;
} else if (rand == 2) {
terrainArray[i][j] = 2;
} else if (rand == 3) {
terrainArray[i][j] = 1;
} else {
terrainArray[i][j] = 0;
}
}
}
}
var drawTerrain = function(ctx,tile,landUseValue) {
return function() {
for (var i=0; i<=(xValue/tileSize); i++) {
for (var j=0; j<=(yValue/tileSize); j++) {
if (terrainArray[i][j] == landUseValue) {
ctx.drawImage(tile,i*tileSize,j*tileSize);
}
}
}
}
}
function textures(ctx) {
var grass = new Image();
var sea = new Image();
var woods = new Image();
var desert = new Image();
grass.onload = drawTerrain(ctx,grass,3);
sea.onload = drawTerrain(ctx,sea,0);
woods.onload = drawTerrain(ctx,woods,2);
desert.onload = drawTerrain(ctx,desert,1);
grass.src = "textures/grass.png";
sea.src = "textures/sea.png";
woods.src = "textures/woods.png";
desert.src = "textures/desert.png";
}

You're rewriting the onloads of the three images in every iteratiom. So, it will only execute the last-added onload f or every image.
Suggestion: run your drawing method only after the thred are loaded(and them just call drawCanvasImage every iteration without an .onload=)
Even better:store the randoms in an array, have each image independantly walk through the array on load and add copies of only itself wherever applicable .
Improvement to rev 2
function randomArray() {
for (var i=0; i<=(xValue/tileSize); i++) {
terrainArray[i] = [];
for (var j=0; j<=(yValue/tileSize); j++) {
rand = Math.floor(Math.random()*4 + 1);
terrainArray[i][j] = 4-rand;
//OR: replace above two lines with terrainArray[i][j]=Math.floor(Math.random()*4 + 1);. There's no need to have them in exactly reverse order.
}
}
}
var drawTerrain = function(ctx,tile,landUseValue) {
return function() {
for (var i=0; i<=(xValue/tileSize); i++) {
for (var j=0; j<=(yValue/tileSize); j++) {
if (terrainArray[i][j] == landUseValue) {
ctx.drawImage(tile,i*tileSize,j*tileSize);
}
}
}
}
}
function textures(ctx) {
var grass = new Image();
var sea = new Image();
var woods = new Image();
var desert = new Image();
grass.onload = drawTerrain(ctx,grass,3);
sea.onload = drawTerrain(ctx,sea,0);
woods.onload = drawTerrain(ctx,woods,2);
desert.onload = drawTerrain(ctx,desert,1);
grass.src = "textures/grass.png";
sea.src = "textures/sea.png";
woods.src = "textures/woods.png";
desert.src = "textures/desert.png";
}
To make it even more flexible, you could use an array to store the images, and then use length. This way, if you want to add another image, all you have to do is modify the array.
var srcArray=["textures/grass.png","textures/sea.png","textures/woods.png","textures/desert.png"];
var imgArray=[];
var terrainArray=[];
function textures(ctx){
randomArray();
for(var i=0;i<srcArray.length;i++){
imgArray[i]=new Image();
imgArray[i].src=srcArray[i];
imgArray[i].onload=drawTerrain(ctx,i);
}
}
function randomArray() {
for (var i=0; i<=(xValue/tileSize); i++) {
terrainArray[i] = [];
for (var j=0; j<=(yValue/tileSize); j++) {
terrainArray[i][j]=Math.floor(Math.random()*srcArray.length);
}
}
}
var drawTerrain = function(ctx,index) {
return function() {
for (var i=0; i<=(xValue/tileSize); i++) {
for (var j=0; j<=(yValue/tileSize); j++) {
if (terrainArray[i][j] == index) {
ctx.drawImage(imgArray[index],i*tileSize,j*tileSize);
}
}
}
}
}
So now, all you have to do is call terrain(ctx) when you want to load all the images. And, whenever you want to add an image to the list of images, just add it to the array up top. You won't have to dig deeper and modify the random values and whatnot.

It's because every time you do a loop, you assign a new function to [image].onload, overwriting the previous one. That's how you end up with only three images.
This should work:
if (rand == 1) {
grass.addEventlistener('load', drawCanvasImage(ctx,grass,x,y), false);
} else if (rand == 2) {
sea.addEventlistener('load', drawCanvasImage(ctx,sea,x,y), false);
} else {
woods.addEventlistener('load', drawCanvasImage(ctx,woods,x,y), false);
}
Here you just add a new listener for every loop.