Develop Reference

Phaser 3: Change "Hitbox"/Interactive area of sprite without physics

The game I'm creating doesn't require any physics, however you are able to interact when hovering over/clicking on the sprite by using sprite.setInteractive({cursor: "pointer"});, sprite.on('pointermove', function(activePointer) {...}); and similar. However I noticed two issues with that:
The sprite has some area which are transparent. The interactive functions will still trigger when clicking on those transparent areas, which is unideal.
When playing a sprite animation, the interactive area doesn't seem to entirely (at all?) change, thus if the sprite ends on a frame bigger than the previous, there end up being small areas I can't interact with.
One option I thought of was to create a polygon over my sprite, which covers the area I want to be interactive. However before I do that, I simply wanted to ask if there are simpler ways to fix these issues.

Was trying to find an answer for this myself just now..
Think Make Pixel Perfect is what you're looking for.
this.add.sprite(x, y, key).setInteractive(this.input.makePixelPerfect());
https://newdocs.phaser.io/docs/3.54.0/focus/Phaser.Input.InputPlugin-makePixelPerfect

This might not be the best solution, but I would solve this problem like this. (If I don't want to use physics, and if it doesn't impact the performance too much)
I would check in the event-handler, if at the mouse-position the pixel is transparent or so, this is more exact and less work, than using bounding-boxes.
You would have to do some minor calculations, but it should work well.
btw.: if the origin is not 0, you would would have to compensate in the calculations for this. (in this example, the origin offset is implemented)
Here is a demo, for the click event:
let Scene = {
preload ()
{
this.load.spritesheet('brawler', 'https://labs.phaser.io/assets/animations/brawler48x48.png', { frameWidth: 48, frameHeight: 48 });
},
create ()
{
// Animation set
this.anims.create({
key: 'walk',
frames: this.anims.generateFrameNumbers('brawler', { frames: [ 0, 1, 2, 3 ] }),
frameRate: 8,
repeat: -1
});
// create sprite
const cody = this.add.sprite(200, 100).setOrigin(0);
cody.play('walk');
cody.setInteractive();
// just info text
this.mytext = this.add.text(10, 10, 'Click the Sprite, or close to it ...', { fontFamily: 'Arial' });
// event to watch
cody.on('pointerdown', function (pointer) {
// calculate x,y position of the sprite to check
let x = (pointer.x - cody.x) / (cody.displayWidth / cody.width)
let y = (pointer.y - cody.y) / (cody.displayHeight / cody.height);
// just checking if the properties are set
if(cody.anims && cody.anims.currentFrame){
let currentFrame = cody.anims.currentFrame;
let pixelColor = this.textures.getPixel(x, y, currentFrame.textureKey, currentFrame.textureFrame);
// alpha > 0 a visible pixel of the sprite, is clicked
if(pixelColor.a > 0) {
this.mytext.text = 'Hit';
} else {
this.mytext.text = 'No Hit';
}
// just reset the textmessage
setTimeout(_ => this.mytext.text = 'Click the Sprite, or close to it ...' , 1000);
}
}, this);
}
};
const config = {
type: Phaser.AUTO,
width: 400,
height: 200,
scene: Scene
};
const game = new Phaser.Game(config);
<script src="https://cdn.jsdelivr.net/npm/phaser#3.55.2/dist/phaser.js"></script>

How to make resizable Text on canvas using javascript

I'm pretty much new to canvas. What I'm trying to make is that I can write text in canvas using input and can be able to resize it by dragging it's corners. Also I should be able to drag text position within the canvas.
Following is the screen shot of what I want!

Canvas is raster, not vector. By simply drawing and resizing text you would expect it to get blurry or pixelated. And redrawing the whole canvas each time user moves the cursor while resizing will not result in the best performance. Consider using svg instead. In case you do need canvas and don't want to implement all the functions yourself, you can use the paperjs library.
http://paperjs.org/reference/pointtext/

As #hirasawa-yui mentioned, you can use Paper.js to greatly facilitate the implementation of what you want in a canvas.
Here is a simplified sketch showing a possible implementation of dragging/resizing interactions.
// create item
var item = new PointText({
content: 'Custom text content',
point: view.center,
justification: 'center',
fontSize: 30,
selected: true
});
// init variables so they can be shared by event handlers
var resizeVector;
var moving;
// on mouse down...
function onMouseDown(event) {
// ...do a hit test on item bounds with a small tolerance for better UX
var cornerHit = item.hitTest(event.point, {
bounds: true,
tolerance: 5
});
// if a hit is detected on one of the corners...
if (cornerHit && ['top-left', 'top-right', 'bottom-left', 'bottom-right'].indexOf(cornerHit.name) >= 0) {
// ...store current vector from item center to point
resizeVector = event.point - item.bounds.center;
// ...else if hit is detected inside item...
} else if (item.hitTest(event.point, { fill: true })) {
// ...store moving state
moving = true;
}
}
// on mouse drag...
function onMouseDrag(event) {
// ...if a corner was previously hit...
if (resizeVector) {
// ...calculate new vector from item center to point
var newVector = event.point - item.bounds.center;
// scale item so current mouse position is corner position
item.scale(newVector / resizeVector);
// store vector for next event
resizeVector = newVector;
// ...if item fill was previously hit...
} else {
// ...move item
item.position += event.delta;
}
}
// on mouse up...
function onMouseUp(event) {
// ... reset state
resizeVector = null;
moving = null;
}
// draw instructions
new PointText({
content: 'Drag rectangle to move, drag corners to resize.',
point: view.center + [0, -50],
justification: 'center'
});

Paper.js Subraster Selecting Wrong Area

I'm working in a Paper.js project where we're essentially doing image editing. There is one large Raster. I'm attempting to use the getSubRaster method to copy a section of the image (raster) that the user can then move around.
After the raster to edit is loaded, selectArea is called to register these listeners:
var selectArea = function() {
if(paper.project != null) {
var startDragPoint;
paper.project.layers[0].on('mousedown', function(event) { // TODO should be layer 0 in long run? // Capture start of drag selection
if(event.event.ctrlKey && event.event.altKey) {
startDragPoint = new paper.Point(event.point.x + imageWidth/2, (event.point.y + imageHeight/2));
//topLeftPointOfSelectionRectangleCanvasCoordinates = new paper.Point(event.point.x, event.point.y);
}
});
paper.project.layers[0].on('mouseup', function(event) { // TODO should be layer 0 in long run? // Capture end of drag selection
if(event.event.ctrlKey && event.event.altKey) {
var endDragPoint = new paper.Point(event.point.x + imageWidth/2, event.point.y + imageHeight/2);
// Don't know which corner user started dragging from, aggregate the data we have into the leftmost and topmost points for constructing a rectangle
var leftmostX;
if(startDragPoint.x < endDragPoint.x) {
leftmostX = startDragPoint.x;
} else {
leftmostX = endDragPoint.x;
}
var width = Math.abs(startDragPoint.x - endDragPoint.x);
var topmostY;
if(startDragPoint.y < endDragPoint.y) {
topmostY = startDragPoint.y;
} else {
topmostY = endDragPoint.y;
}
var height = Math.abs(startDragPoint.y - endDragPoint.y);
var boundingRectangle = new paper.Rectangle(leftmostX, topmostY, width, height);
console.log(boundingRectangle);
console.log(paper.view.center);
var selectedArea = raster.getSubRaster(boundingRectangle);
var selectedAreaAsDataUrl = selectedArea.toDataURL();
var subImage = new Image(width, height);
subImage.src = selectedAreaAsDataUrl;
subImage.onload = function(event) {
var subRaster = new paper.Raster(subImage);
// Make movable
subRaster.onMouseEnter = movableEvents.showSelected;
subRaster.onMouseDrag = movableEvents.dragItem;
subRaster.onMouseLeave = movableEvents.hideSelected;
};
}
});
}
};
The methods are triggered at the right time and the selection box seems to be the right size. It does indeed render a new raster for me that I can move around, but the contents of the raster are not what I selected. They are close to what I selected but not what I selected. Selecting different areas does not seem to yield different results. The content of the generated subraster always seems to be down and to the right of the actual selection.
Note that as I build the points for the bounding selection rectangle I do some translations. This is because of differences in coordinate systems. The coordinate system where I've drawn the rectangle selection has (0,0) in the center of the image and x increases rightward and y increases downward. But for getSubRaster, we are required to provide the pixel coordinates, per the documentation, which start at (0,0) at the top left of the image and increase going rightward and downward. Consequently, as I build the points, I translate the points to the raster/pixel coordinates by adding imageWidth/2 and imageHeight/2`.
So why does this code select the wrong area? Thanks in advance.
EDIT:
Unfortunately I can't share the image I'm working with because it is sensitive company data. But here is some metadata:
Image Width: 4250 pixels
Image Height: 5500 pixels
Canvas Width: 591 pixels
Canvas Height: 766 pixels
My canvas size varies by the size of the browser window, but those are the parameters I've been testing in. I don't think the canvas dimensions are particularly relevant because I'm doing everything in terms of image pixels. When I capture the event.point.x and event.point.y to the best of my knowledge these are image scaled coordinates, but from a different origin - the center rather than the top left. Unfortunately I can't find any documentation on this. Observe how the coordinates work in this sketch.
I've also been working on a sketch to illustrate the problem of this question. To use it, hold Ctrl + Alt and drag a box on the image. This should trigger some logging data and attempt to get a subraster, but I get an operation insecure error, which I think is because of security settings in the image request header. Using the base 64 string instead of the URL doesn't give the security error, but doesn't do anything. Using that string in the sketch produces a super long URL I can't paste here. But to get that you can download the image (or any image) and convert it here, and put that as the img.src.

The problem is that the mouse events all return points relative to 0, 0 of the canvas. And getSubRaster expects the coordinates to be relative to the 0, 0 of the raster item it is extracting from.
The adjustment needs to be eventpoint - raster.bounds.topLeft. It doesn't really have anything to do with the image width or height. You want to adjust the event points so they are relative to 0, 0 of the raster, and 0, 0 is raster.bounds.topLeft.
When you adjust the event points by 1/2 the image size that causes event points to be offset incorrectly. For the Mona Lisa example, the raster size (image size) is w: 320, h: 491; divided by two they are w: 160, h: 245.5. But bounds.topLeft of the image (when I ran my sketch) was x: 252.5, y: 155.5.
Here's a sketch that shows it working. I've added a little red square highlighting the selected area just to make it easier to compare when it's done. I also didn't include the toDataURL logic as that creates the security issues you mentioned.
Here you go: Sketch
Here's code I put into an HTML file; I noticed that the sketch I put together links to a previous version of the code that doesn't completely work.
<!doctype html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>Rasters</title>
<script src="./vendor/jquery-2.1.3.js"></script>
<script src="./vendor/paper-0.9.25.js"></script>
</head>
<body>
<main>
<h3>Raster Bug</h3>
<div>
<canvas id="canvas"></canvas>
</div>
<div id="position">
</div>
</main>
<script>
// initialization code
$(function() {
// setup paper
$("#canvas").attr({width: 600, height: 600});
var canvas = document.getElementById("canvas");
paper.setup(canvas);
// show a border to make range of canvas clear
var border = new paper.Path.Rectangle({
rectangle: {point: [0, 0], size: paper.view.size},
strokeColor: 'black',
strokeWidth: 2
});
var tool = new paper.Tool();
// setup mouse position tracking
tool.on('mousemove', function(e) {
$("#position").text("mouse: " + e.point);
});
// load the image from a dataURL to avoid CORS issues
var raster = new paper.Raster(dataURL);
raster.position = paper.view.center;
var lt = raster.bounds.topLeft;
var startDrag, endDrag;
console.log('rb', raster.bounds);
console.log('lt', lt);
// setup mouse handling
tool.on('mousedown', function(e) {
startDrag = new paper.Point(e.point);
console.log('sd', startDrag);
});
tool.on('mousedrag', function(e) {
var show = new paper.Path.Rectangle({
from: startDrag,
to: e.point,
strokeColor: 'red',
strokeWidth: 1
});
show.removeOn({
drag: true,
up: true
});
});
tool.on('mouseup', function(e) {
endDrag = new paper.Point(e.point);
console.log('ed', endDrag);
var bounds = new paper.Rectangle({
from: startDrag.subtract(lt),
to: endDrag.subtract(lt)
});
console.log('bounds', bounds);
var sub = raster.getSubRaster(bounds);
sub.bringToFront();
var subData = sub.toDataURL();
sub.remove();
var subRaster = new paper.Raster(subData);
subRaster.position = paper.view.center;
});
});
var dataURL = ; // insert data or real URL here
</script>
</body>
</html>

fabric js - Resize complete canvas according to a rectangle added in a canvas in order to achieve cropping

I am using fabric js for generating templates, I want user to set height and width of a canvas for which I am using following code
canvas.setHeight(height);
canvas.setWidth(width);
However on doing this, the full width canvas stretches itself and the object disappears from the resized canvas as it was lets say 500 px wide before and user resized it to 100px then the items disappear.
I want to achieve a functionality so that if a user wants to change the size of canvas then instead of resizing the canvas I will show a rectangle and user can move rectangle accordingly to get the visible area and once user clicks on save then I will resize the canvas according to that rectangle, so that I can process the SVG later for further conversions but by doing so I am not sure how to get the visible area in that rectangle to the resized canvas, in short I want functionality like Darkroom js but for fabric js canvas object.
The current functionality is added to this JS fiddle http://jsfiddle.net/tbqrn/102/

Finally after doing some research I am able to do that, instead of resizing the canvas I am adding a rectangle object with "cropper" type as mentioned below
var rect = new fabric.Rect({
left: 100,
top: 100,
fill: 'transparent',
width: 400,
height: 400,
strokeDashArray: [5, 5],
stroke: 'black',
type: 'cropper',
lockScalingX: true,
lockScalingY: true,
lockRotation: true
});
canvas.add(rect);
This rectangle will serve as the cropper, when a user submits the form then I am getting that cropper's dimensions as follow along with changing canvas size
var i;
var croppedLeft = 0;
var croppedTop = 0;
var canvasJson = canvas.getObjects();
// Cropping canvas according to cropper rectangle
if (canvas.getObjects().length > 0) {
var i;
for (i = 0; i < canvas.getObjects().length; i++) {
if (canvas.getObjects()[i].type == 'cropper') {
croppedLeft = canvas.getObjects()[i].left;
croppedTop = canvas.getObjects()[i].top;
canvas.setHeight(canvas.getObjects()[i].height);
canvas.setWidth(canvas.getObjects()[i].width);
canvas.getObjects()[i].remove();
}
}
}
And after that I am shifting all the other canvas objects accordingly as follow.
for (i = 0; i < canvasJson.length; i++) {
canvas.getObjects()[i].left = canvas.getObjects()[i].left - croppedLeft
canvas.getObjects()[i].top = canvas.getObjects()[i].top - croppedTop
canvas.renderAll();
}
And after doing that I am able to achieve the desired functionality, hope this helps someone.
Here is my fiddle http://jsfiddle.net/tbqrn/115/

Removing an image from html5 canvas when it's dragged to a certain location

I have an HTML5 canvas that is displaying a number of images and four description boxes. It is currently possible to drag and drop the images around the canvas, but I want to add functionality to remove an image when it is dragged to its correct description box.
I've tried writing the following function, but it does not currently seem to be doing anything... i.e. if I drag an image to its description box and drop it, it still remains on the canvas:
function initStage(images){
var stage = new Kinetic.Stage({
container: "container",
width: 1000,
height: 500
});
var descriptionLayer = new Kinetic.Layer();
//var imagesLayer = new Kinetic.Layer();
var allImages = [];
var currentScore = 0;
var descriptionBoxes = {
assetsDescriptionBox: {
x: 70,
y: 400
},
liabilitiesDescriptionBox: {
x: 300,
y: 400
},
incomeDescriptionBox: {
x: 530,
y: 400
},
expenditureDescriptionBox: {
x: 760,
y: 400
},
};
/*Code to detect whether image has been dragged to correct description box */
for (var key in sources){
/*Anonymous function to induce scope */
(function(){
var privateKey = key;
var imageSource = sources[key];
/*Check if image has been dragged to the correct box, and add it to that box's
array and remove from canvas if it has */
canvasImage.on("dragend", function(){
var descriptionBox = descriptionBoxes[privateKey];
if(!canvasImage.inRightPlace && isNearDescriptionBox(itemImage, descriptionBox)){
context.remove(canvasImage);
/*Will need to add a line in here to add the image to the box's array */
}
})
})();
}
}
The code I've written is based on the tutorial that I found at: http://www.html5canvastutorials.com/labs/html5-canvas-animals-on-the-beach-game-with-kineticjs/
Can anyone spot what I'm doing wrong, and how I can ensure that the image is removed from the canvas when it's dragged to its corresponding description box?

That example bugged me because it seemed old, so I edited it a little...
http://jsfiddle.net/LTq9C/1/
...keep in mind that I cant be positive that all my edits are the best way to do things, Im new and all ;)
And here I've edited it again for you to show the image being removed...
animal.on("dragend", function() {
var outline = outlines[privKey + "_black"];
if (!animal.inRightPlace && isNearOutline(animal, outline)) {
animal.remove();
animalLayer.draw();
}
});
http://jsfiddle.net/8S3Qq/1/