I'm using the Pixi.js v4 graphics library to make a game with JavaScript. I know that I can draw a black + rounded rectangle like so:
const rectangle = new pixi.Graphics();
rectangle.beginFill(0); // Color it black
rectangle.drawRoundedRect(
0,
0,
100, // Make it 100x100
100,
5, // Make the rounded corners have a radius of 5
);
rectangle.endFill();
stage.addChild(rectangle);
How do I draw a rounded rectangle with a gradient from white to black?
How do I draw a rounded rectangle that has gradual opacity such that it fades in from left to right?
It looks like it's not possible to implement what you need with pixi.js without additional code, but we can do some magic to make it happen. Here's the result of what I've got: https://jsfiddle.net/exkf3zfo/21/
The bottom color is a pure red with 0.2 alpha.
I would split the whole process to the next steps:
Drawing the gradient
Masking the gradient with the rounded mask
Here is the code itself:
var app = new PIXI.Application(800, 600, {
antialias: true
});
document.body.appendChild(app.view);
// Functions
// param color is a number (e.g. 255)
// return value is a string (e.g. ff)
var prepareRGBChannelColor = function(channelColor) {
var colorText = channelColor.toString(16);
if (colorText.length < 2) {
while (colorText.length < 2) {
colorText = "0" + colorText;
}
}
return colorText;
}
// Getting RGB channels from a number color
// param color is a number
// return an RGB channels object {red: number, green: number, blue: number}
var getRGBChannels = function(color) {
var colorText = color.toString(16);
if (colorText.length < 6) {
while (colorText.length < 6) {
colorText = "0" + colorText;
}
}
var result = {
red: parseInt(colorText.slice(0, 2), 16),
green: parseInt(colorText.slice(2, 4), 16),
blue: parseInt(colorText.slice(4, 6), 16)
};
return result;
}
// Preparaiton of a color data object
// param color is a number [0-255]
// param alpha is a number [0-1]
// return the color data object {color: number, alpha: number, channels: {red: number, green: number, blue: number}}
var prepareColorData = function(color, alpha) {
return {
color: color,
alpha: alpha,
channels: getRGBChannels(color)
}
}
// Getting the color of a gradient for a very specific gradient coef
// param from is a color data object
// param to is a color data object
// return value is of the same type
var getColorOfGradient = function(from, to, coef) {
if (!from.alpha && from.alpha !== 0) {
from.alpha = 1;
}
if (!from.alpha && from.alpha !== 0) {
to.alpha = 1;
}
var colorRed = Math.floor(from.channels.red + coef * (to.channels.red - from.channels.red));
colorRed = Math.min(colorRed, 255);
var colorGreen = Math.floor(from.channels.green + coef * (to.channels.green - from.channels.green));
colorGreen = Math.min(colorGreen, 255);
var colorBlue = Math.floor(from.channels.blue + coef * (to.channels.blue - from.channels.blue));
colorBlue = Math.min(colorBlue, 255);
var rgb = prepareRGBChannelColor(colorRed) + prepareRGBChannelColor(colorGreen) + prepareRGBChannelColor(colorBlue);
return {
color: parseInt(rgb, 16),
alpha: from.alpha + coef * (to.alpha - from.alpha)
};
}
var startTime = Date.now();
console.log("start: " + startTime);
// Drawing the gradient
//
var gradient = new PIXI.Graphics();
app.stage.addChild(gradient);
//
var rect = {
width: 200,
height: 200
};
var round = 20;
//
var colorFromData = prepareColorData(0xFF00FF, 1);
var colorToData = prepareColorData(0xFF0000, 0.2);
//
var stepCoef;
var stepColor;
var stepAlpha;
var stepsCount = 100;
var stepHeight = rect.height / stepsCount;
for (var stepIndex = 0; stepIndex < stepsCount; stepIndex++) {
stepCoef = stepIndex / stepsCount;
stepColor = getColorOfGradient(colorFromData, colorToData, stepCoef);
gradient.beginFill(stepColor.color, stepColor.alpha);
gradient.drawRect(
0,
rect.height * stepCoef,
rect.width,
stepHeight
);
}
// Applying a mask with round corners to the gradient
var roundMask = new PIXI.Graphics();
roundMask.beginFill(0x000000);
roundMask.drawRoundedRect(0, 0, rect.width, rect.height, round);
app.stage.addChild(roundMask);
gradient.mask = roundMask;
var endTime = Date.now();
console.log("end: " + endTime);
console.log("total: " + (endTime - startTime));
The interesting thing is that it takes only about 2-5 ms for the whole process!
If you wan't to change colors of the gradient to white>black (as described in the question), just change the next params:
var colorFromData = prepareColorData(0xFF00FF, 1);
var colorToData = prepareColorData(0xFF0000, 0.2);
To:
var colorFromData = prepareColorData(0xFFFFFF, 1);
var colorToData = prepareColorData(0x000000, 0.2);
Not full answer but some extra information
As far I know, you can't use gradient for PIXI.Graphics even for sprites you need extra canvas
Just draw the gradient you want to a canvas:
https://developer.mozilla.org/en-US/docs/Web/API/CanvasRenderingContext2D/createLinearGradient
Then use that canvas as a texture: Texture.fromCanvas(canvas);
Look at this article.
For gradual opacity, Alpha Mask can help
http://pixijs.io/examples/#/demos/alpha-mask.js
P.S Maybe phaser.js can do more
Did you ever figure this out? I couldn't find a solution online either, so I implemented it myself using a filter. Have a look: https://codepen.io/Lancer611/pen/KodabK.
Some of the pixi code:
function newGradientPoly(poly, fill, fillSize){
var container = new PIXI.Sprite();
app.stage.addChild(container);
var shape = new PIXI.Graphics();
shape.beginFill(0xffffff)
.lineStyle(1, 0x333333)
.drawPolygon(poly);
var mask = new PIXI.Graphics();
mask.beginFill(0xffffff, 1)
.drawPolygon(poly);
container.mask = mask;
container.addChild(shape);
var fshaderCode = document.getElementById("fragShader").innerHTML;
fogShader = new PIXI.Filter(null, fshaderCode);
fogShader.uniforms.resolution = [width, height];
fogShader.uniforms.segments = poly.slice();
fogShader.uniforms.count = poly.length/2;
fogShader.uniforms.gSize = fillSize;
fogShader.uniforms.fill = fill;
shape.filters=[fogShader];
}
I've created a pixi plugin for displaying vector drawings in Pixi. The main limitation is that you need to draw your rectangle in the vector art program Omber first, so you need to know the size of your rectangle beforehand (since everything is vector-based, you could theoretically scale things later, but then the rounded corners would end up being a little uneven). The workflow is similar to using sprites: 1. draw your rectangles in Omber 2. export them to gltf 3. load the gltf files in your Pixi program 4. position the rectangles where you want them.
Another possibility is that you could create the gradient as a separate object, and then you can mask it out with a polygon. Here's an example. In that example, I'm using a vector drawing for the gradient, but since gradients don't become blurry when resized, you could probably use a sprite for that as well. I'm not sure if masks have good performance, but if you just need a few of them, then it's probably fine.
Related
I am a back-end programmer who is using leaflet for the first time. I don’t know much about js animation steps. I want to use L.canvas to draw a dynamic circle, just like the picture below.
Specify the range of the circle or the latitude and longitude of the center of the circle, and the radius will continue to fluctuate and spread outward, similar to water waves (this effect in the picture is made by me using a highly encapsulated animation library)
I hope someone can provide me with an example, or give me a suggestion so that I can smoothly draw a dynamic circle on the map. thanks a lot
You can create mutliple circles and update the radius each millisecond:
var canvasRenderer = L.canvas();
function createWavingCircle(latlng, color, fromRadius, toRadius){
var circle = L.circle(latlng, {radius: fromRadius, color, renderer: canvasRenderer}).addTo(map);
var nextCircle;
var interval = setInterval(()=>{
var radius = circle.getRadius()+1;
if(radius <= toRadius){
circle.setRadius(radius);
if(Math.round((radius / toRadius) * 100) >= 30 && !nextCircle){
nextCircle = createWavingCircle(latlng, color, fromRadius, toRadius);
}
} else {
if(nextCircle && nextCircle.getRadius() >= toRadius){
circle.remove();
clearInterval(interval);
}
}
},1)
return circle;
}
// replace this values with your custom ones
createWavingCircle(map.getCenter(), 'red', 10, 400);
https://plnkr.co/edit/IT5VcxokeCWpkpEx
Create a new L.canvas object and specify the desired options, and use the addTo() method to add the circle to your map.
This will create a circle that is initially drawn with a radius of 10, and will have its radius redrawn with a new random value every second. The circle will continue to fluctuate in size until the setInterval() loop is stopped.
import { L } from 'leaflet';
const circle = L.canvas({
center: [51.505, -0.09],
radius: 10,
color: 'red',
});
circle.addTo(map);
setInterval(() => {
const newRadius = Math.random() * 50;
circle.setRadius(newRadius);
}, 1000);
Hope it works!
// build CircleMarker
createFloatCircle(latLng, color, fromRadius, toRadius){
var _this = this;
var circle = L.circleMarker(latLng,
{radius: fromRadius,
color: color,
renderer: L.canvas({ padding: 0.5 }),
fillColor: color,
fillOpacity: 0.5,
stroke: false,
});
circle.addTo(_this.offMap);
setInterval(() => {
var newRadius = circle.getRadius() + 1;
if(newRadius <= toRadius){
circle.setRadius(newRadius);
} else {
circle.setRadius(fromRadius);
}
circle.setStyle({fillColor: _this.getColor(newRadius, fromRadius, toRadius)});
}, 20);
},
getColor(radius, fromRadius, toRadius){
var _this = this;
var color = 'red';
var percent = (radius - fromRadius) / (toRadius - fromRadius);
var red = Math.round(255 * percent);
var green = Math.round(255 * (1 - percent));
color = 'rgb(' + red + ',' + green + ',0)';
return color;
},
This is my implementation, as the circle expands, the color of the layer gradually deepens
I want to draw a diamond using paper.js. The shape and colors of the diamond should change randomly everytime I re-run the function. How do i go about this task
Here is a sketch demonstrating a possible implementation.
// Diamond random size settings
const MIN_RADIUS = 10;
const MAX_RADIUS = 50;
// Draw first diamond.
let diamond = drawDiamond(view.center);
// Display instructions.
new PointText({
content: 'Click to draw a new diamond',
point: view.center + [0, -80],
justification: 'center'
});
// Draws a random diamond around the given point and returns it.
function drawDiamond(point) {
// Get random radiuses.
const verticalRadius = getRandomRadius();
const horizontalRadius = getRandomRadius();
// Calculate diamond points.
const top = point + [0, -verticalRadius];
const bottom = point + [0, verticalRadius];
const left = point + [-horizontalRadius, 0];
const right = point + [horizontalRadius, 0];
// Build path.
return new Path({
segments: [top, right, bottom, left],
fillColor: Color.random()
});
}
function getRandomRadius() {
return MIN_RADIUS + Math.random() * (MAX_RADIUS - MIN_RADIUS);
}
// On mouse down...
function onMouseDown() {
// ...delete existing diamond...
diamond.remove();
// ...and draw a new one.
diamond = drawDiamond(view.center);
}
var diamond = new Path.RegularPolygon(new Point(x,y), 4, 50);
diamond.fillColor = '#e9e9ff';
diamond.selected = true;
diamond.rotate(45);
x,y -> your coordinates
to generate random color have a look at this Random color generator
as of your final code should look something like this
function diamonds(){
var diamond = new Path.RegularPolygon(new Point(x,y), 4, 50);
diamond.fillColor = getRandomColor();
diamond.selected = true;
diamond.rotate(45);
}
function getRandomColor() {
var letters = '0123456789ABCDEF';
var color = '#';
for (var i = 0; i < 6; i++) {
color += letters[Math.floor(Math.random() * 16)];
}
return color;
}
I'm looking for a way to zoom from place to place on a globe in D3 v4 (v4 is important). What I'm looking for is basically exactly this: https://www.jasondavies.com/maps/zoom/ My problem is that Jason Davies obfuscated his code, so I can't read it, and I can't find a bl.ock containing that project or anything similar to it. I'll provide a link to what I've got here: http://plnkr.co/edit/0mjyR3ovTfkDXB8FTG0j?p=preview
The relevant is probably inside the .tween():
.tween("rotate", function () {
var p = d3.geoCentroid(points[i]),
r = d3.geoInterpolate(projection.rotate(), [-p[0], -p[1]]);
return function (t) {
projection.rotate(r(t));
convertedLongLats = [projection(points[0].coordinates), projection(points[1].coordinates)]
c.clearRect(0, 0, width, height);
c.fillStyle = colorGlobe, c.beginPath(), path(sphere), c.fill();
c.fillStyle = colorLand, c.beginPath(), path(land), c.fill();
for (var j = 0; j < points.length; j++) {
var textCoords = projection(points[j].coordinates);
c.fillStyle = textColors, c.textAlign = "center", c.font = "18px FontAwesome", c.fillText(points[j].icon, textCoords[0], textCoords[1]);
textCoords[0] += 15;
c.textAlign = "left", c.font = " 12px Roboto", c.fillText(points[j].location, textCoords[0], textCoords[1]);
}
c.strokeStyle = textColors, c.lineWidth = 4, c.setLineDash([10, 10]), c.beginPath(), c.moveTo(convertedLongLats[0][0], convertedLongLats[0][1]), c.lineTo(convertedLongLats[1][0], convertedLongLats[1][1]), c.stroke();
};
})
Basically, I want what I've got now but I want it to zoom in, pretty much exactly like it is in the Animated World Zoom example I provided above. I'm not really looking for code, I'd rather someone point me in the right direction with an example or something (it's worth noting that I'm fairly new to d3 and that this project is heavily based on World Tour by mbostock, so it uses canvas). Thank you all in advance!
Based on your plunker and comment, a challenge in zooming out between two points in a transition is that the interpolator will only interpolate between two values. The solution in your plunker relies on two interpolators, one for zooming in and zooming out. This method has added un-needed complexity and somewhere along the line, as you note, it jumps to an incorrect scale. You could simplify this:
Take an interpolator that interpolates between -1 and 1, and weight each scale according to the absolute value of the interpolator. At zero, the zoom should be out all the way, while at -1,1, you should be zoomed in:
var s = d3.interpolate(-1,1);
// get the appropriate scale:
scale = Math.abs(0-s(t))*startEndScale + (1-Mat.abs(0-s(t)))*middleScale
This is a little clunky as it goes from zooming out to zooming in rather abruptly, so you could ease it with a sine type easing:
var s = d3.interpolate(0.0000001,Math.PI);
// get the appropriate scale:
scale = (1-Math.abs(Math.sin(s(t))))*startEndScale + Math.abs(Math.sin(s(t)))*middleScale
I've applied this to your plunker here.
For a simple and minimal example using the example that I suggested and your two points and path (and using your plunkr as a base), stripping out the animated line and icons, I would probably put together something like (plunker, snippet below best viewed on full screen):
var width = 600,
height = 600;
var points = [{
type: "Point",
coordinates: [-74.2582011, 40.7058316],
location: "Your Location",
icon: "\uF015"
}, {
type: "Point",
coordinates: [34.8887969, 32.4406351],
location: "Caribe Royale Orlando",
icon: "\uF236"
}];
var canvas = d3.select("body").append("canvas")
.attr("width", width)
.attr("height", height);
var c = canvas.node().getContext("2d");
var point = points[0].coordinates;
var projection = d3.geoOrthographic()
.translate([width / 2, height / 2])
.scale(width / 2)
.clipAngle(90)
.precision(0.6)
.rotate([-point[0], -point[1]]);
var path = d3.geoPath()
.projection(projection)
.context(c);
var colorLand = "#4d4f51",
colorGlobe = "#2e3133",
textColors = "#fff";
d3.json("https://unpkg.com/world-atlas#1/world/110m.json", function (error, world) {
if (error) throw error;
var sphere = { type: "Sphere" };
var land = topojson.feature(world, world.objects.land);
var i = 0;
var scaleMiddle = width/2;
var scaleStartEnd = width * 2;
loop();
function loop() {
d3.transition()
.tween("rotate",function() {
var flightPath = {
type: 'Feature',
geometry: {
type: "LineString",
coordinates: [points[i++%2].coordinates, points[i%2].coordinates]
}
};
// next point:
var p = points[i%2].coordinates;
// current rotation:
var currentRotation = projection.rotate();
// next rotation:
var nextRotation = projection.rotate([-p[0],-p[1]]).rotate();
// Interpolaters:
var r = d3.geoInterpolate(currentRotation,nextRotation);
var s = d3.interpolate(0.0000001,Math.PI);
return function(t) {
// apply interpolated values
projection.rotate(r(t))
.scale( (1-Math.abs(Math.sin(s(t))))*scaleStartEnd + Math.abs(Math.sin(s(t)))*scaleMiddle ) ;
c.clearRect(0, 0, width, height);
c.fillStyle = colorGlobe, c.beginPath(), path(sphere), c.fill();
c.fillStyle = colorLand, c.beginPath(), path(land), c.fill();
c.beginPath(), path(flightPath), c.globalAlpha = 0.5, c.shadowColor = "#fff", c.shadowBlur = 5, c.lineWidth = 0.5, c.strokeStyle = "#fff", c.stroke(), c.shadowBlur = 0, c.globalAlpha = 1;
}
})
.duration(3000)
.on("end", function() { loop(); })
}
});
<script src="http://d3js.org/d3.v4.min.js"></script>
<script src="http://d3js.org/topojson.v1.min.js"></script>
I have five rectangles placed at different points along a circle like this - http://imgur.com/uVYkwl7.
Upon clicking any rectangle i want the circle to move to the left of the screen, gradually scaling down it's radius until the circle's center reaches x=0. I'd like the five rectangles to move along with the circle while its being scaled down and also adjust their own positions and scale on the circle so that they are within the view's bounds, like this - http://imgur.com/acDG0Aw
I'd appreciate any help on how to go about doing this. Heres my code for getting to the 1st image and animating the circle:
var radius = 300;
var center = view.center;
var circle = new Path.Circle({
center: view.center,
radius: radius,
strokeColor: 'black',
name: 'circle'
});
var path = new Path.Rectangle({
size: [230, 100],
fillColor: '#1565C0'
});
var rectText = ['Text 1',
'Text 2',
'Text 3',
'Text 4',
'Text 5'
];
var symbol = new Symbol(path);
var corners = [
new Point(center.x, center.y - radius),
new Point(center.x - radius, center.y - radius / 2),
new Point(center.x + radius, center.y - radius / 2),
new Point(center.x - radius, center.y + radius / 2),
new Point(center.x + radius, center.y + radius / 2)
];
var rectClicked = false;
var clickedRect = null;
var rectClick = function(event) {
rectClicked = true;
clickedRect = this;
};
function onFrame(event) {
// Your animation code goes in here
if (rectClicked) {
for (var i = 0; i < 1; i++) {
var item = project.activeLayer.children[i];
if (item.name == 'circle') {
if (item.position.x < 0) {
rectClicked = false;
} else {
item.position.x -= 10;
item.scale(1/1.01);
}
}
}
}
}
// Place the instances of the symbol:
for (var i = 0; i < corners.length; i++) {
var placedSymbol = symbol.place(corners[i]);
placedSymbol.onMouseDown = rectClick;
var rText = new PointText({
point: placedSymbol.bounds.topLeft + 20,
content: rectText[i],
fontSize: '20',
fillColor: 'white'
});
}
Paper.js provides rotations around a pivot out of the box.
var pivotPoint = new Point(10, 5);
circle.rotate(30,pivotPoint);
Here is the docs reference for this behaviour and here is a very basic Sketch example to illustrate this
The above snippet will rotate a circle(you can change this to rectangle in your case) by 30 degrees around a pivot point at coordinates 10,5 on the x/y axis.
Thus what you describe is certainly doable as long as the path that your elements will follow is always circular.
Bear in mind that in order for the pivot rotation to work the way you want them to you need to update the pivotPoint and reinitiate the rotation again.
Note: In case you want to move along an arbitrary shape instead of circular path, you should search for Paper.js animation-along-a-path which is something that I've seen been done before without much difficulty - e.g this simple Sketch by the creator of Paper.js himself.
The sketch I provided above is a basic example of rotation around a pivot point.
I'm dumping the Sketch code here in case the link goes dead:
//Create a center point
var centerCircle = new Path.Circle(paper.view.center, 100);
centerCircle.strokeColor = 'black';
centerCircle.dashArray = [10, 12];
//Create the circles
var circle1Radius = 30;
var circle1 = new Path.Circle((centerCircle.position-centerCircle.bounds.width/2)+circle1Radius, circle1Radius);
circle1.fillColor = '#2196F3';
var circle2Radius = 40;
var circle2 = new Path.Circle((centerCircle.position-centerCircle.bounds.width/2)+circle2Radius, circle2Radius);
circle2.fillColor = '#E91E63';
var circle3Radius = 40;
var circle3 = new Path.Circle((centerCircle.position-centerCircle.bounds.width/2)+circle2Radius, circle2Radius);
circle3.fillColor = '#009688';
var i=0;
var animationGap = 125; //how long to move before animating the next circle
var rotationSpeed = 2;
function onFrame(event) {
circle1.rotate(rotationSpeed,centerCircle.position);
if(i>animationGap)
circle2.rotate(rotationSpeed,centerCircle.position);
if(i>animationGap*2)
circle3.rotate(rotationSpeed,centerCircle.position);
i++;
}
I am trying to draw an isometric square with some custom code to build the pixel data up and then put it on a canvas with putImageData.
But I'm not getting the expected results, after a quick look through the raw pixel data of the canvas it seems all the pixel data I built up is getting messed with.
What I want from the below code is a red diamond on a black background. Where am i going wrong?
var Drawing = {};
Drawing.DrawIsoMetricSquare = function(cRenderContext, x, y, iWidth, cColor) {
var iHeight = iWidth / 2;
var iYPos = Math.floor(iHeight / 2) + 1;
var iXPos = 0;
var iRenderGirth = 1;
cPixelData = cRenderContext.createImageData(iWidth, iHeight);
var bExpand = true;
while (iXPos != iWidth) {
var iCurrentRenderGirth = 0;
while (iCurrentRenderGirth != iRenderGirth) {
var iY = iYPos + iCurrentRenderGirth;
//Draw first pixel then second
Drawing.ColorPixelAtPos(cPixelData.data, iXPos, iY, iWidth, cColor);
Drawing.ColorPixelAtPos(cPixelData.data, iXPos + 1, iY, iWidth, cColor);
iCurrentRenderGirth++;
}
//Move to next Render Start
iYPos = bExpand ? (iYPos - 1) : (iYPos + 1);
iXPos += 2;
iRenderGirth = bExpand ? (iRenderGirth + 2) : (iRenderGirth - 2);
bExpand &= iRenderGirth < iHeight;
}
cRenderContext.putImageData(cPixelData, x, y);
};
Drawing.XYPosToPixelPos = function(x, y, iWidth) {
return (x + y * iWidth) * 4;
};
Drawing.ColorPixelAtPos = function(cPixelData, x, y, iWidth, cColor) {
var iPixPos = Drawing.XYPosToPixelPos(x, y, iWidth);
cPixelData[iPixPos++] = cColor.r;
cPixelData[iPixPos++] = cColor.g;
cPixelData[iPixPos++] = cColor.b;
cPixelData[iPixPos] = 1; //Fixed alpha for now
};
var eCanvas = $("<canvas></canvas>");
eCanvas[0].width = 50;
eCanvas[0].height = 50;
$("#render").append(eCanvas);
var cRenderContext = eCanvas[0].getContext('2d');
cRenderContext.fillStyle = "rgba(1, 1, 1, 1)";
cRenderContext.fillRect(0, 0, 50, 50);
Drawing.DrawIsoMetricSquare(cRenderContext, 0, 0, 42, {
r: 255,
g: 0,
b: 0
});
JSFiddle example here
The problems were
a math error which you already fixed.
RGBA specifiers go from 0..255 not 0..1
You need to fill your pixel data with black opaque pixels (they are white by default).
I added a few lines of code and made a new fiddle for you.
http://jsfiddle.net/bsssq/1/
Now you should see the red diamond on the black square.