I am trying to centre my whole canvas in the middle so I can scale it, as the edges are not complete and I can't fill up the space using values lower or bigger than the canvas as it bring up errors. Here is a picture without scaling and with scaling.
var rows = 10;
var cols = 10;
var points = [];
var sat = 70;
var bright = 80;
var timesDrawed = 0;
function setup() {
createCanvas(600, 600);
colorMode(HSB, 100, 100, 100);
noStroke();
rectMode(CENTER);
}
function draw() {
translate(width/2,height/2);
if (timesDrawed >= 3) {
noLoop();
} else {
timesDrawed++;
}
scale(1.2);
for (var r = 0; r < rows; r++) {
for (var c = 0; c < cols; c++) {
var tempX = random((width / (cols)) * c - (width / cols * 0.5), (width / (cols)) * c + (width / cols * 0.5));
var tempY = random((height / (rows)) * r - (height / rows * 0.5), (height / (rows)) * r + (height / rows * 0.5));
points.push([tempX, tempY]);
}
}
print(points);
for (var r = 0; r < rows - 1; r++) {
for (var c = 0; c < cols -1; c++) {
fill(random(0, 100), sat, bright);
var point1 = c + (r * rows);
var point2 = c + (r * rows) + 1;
var point3 = c + (r * rows) + rows;
triangle(points[point1][0], points[point1][1], points[point2][0], points[point2][1], points[point3][0], points[point3][1]);
fill(random(0, 100), sat, bright);
var point1 = c + (r * rows) + rows;
var point2 = c + (r * rows) + 1;
var point3 = c + (r * rows) + rows + 1;
triangle(points[point1][0], points[point1][1], points[point2][0], points[point2][1], points[point3][0], points[point3][1]);
}
}
}
If the canvas is tiled in columns (cols) and rows rows, then the start of each column is c * width/cols and the end of each column is (c+1) * width/cols, the start of each row is (r * height/rowsand the end of each row is(r+1) * height/rows, wherecis the column andr` is the row.
Since the center of the canvas is (0, 0), the half with and the half height have to be subtracted from the coordinate:
var tempX = random(c * width/cols - width/2, (c+1) * width/cols - width/2);
var tempY = random(r * height/rows - height/2, (r+1) * height/rows - height/2);
or
var tempX = random(c, c+1) * width/cols - width/2;
var tempY = random(r, r+1) * height/rows - height/2;
See the preview, where I applied the suggested changes to your original code and I removed the scale scale(1.2):
var rows = 10;
var cols = 10;
var points = [];
var sat = 70;
var bright = 80;
var timesDrawed = 0;
function setup() {
createCanvas(400, 400);
colorMode(HSB, 100, 100, 100);
noStroke();
rectMode(CENTER);
}
function draw() {
background(64);
translate(width/2,height/2);
if (timesDrawed >= 3) {
noLoop();
} else {
timesDrawed++;
}
//scale(1.2);
for (var r = 0; r < rows; r++) {
for (var c = 0; c < cols; c++) {
var tempX = random(c, c+1) * width/cols - width/2;
var tempY = random(r, r+1) * height/rows - height/2;
points.push([tempX, tempY]);
}
}
print(points);
for (var r = 0; r < rows - 1; r++) {
for (var c = 0; c < cols -1; c++) {
fill(random(0, 100), sat, bright);
var point1 = c + (r * rows);
var point2 = c + (r * rows) + 1;
var point3 = c + (r * rows) + rows;
triangle(points[point1][0], points[point1][1], points[point2][0], points[point2][1], points[point3][0], points[point3][1]);
fill(random(0, 100), sat, bright);
var point1 = c + (r * rows) + rows;
var point2 = c + (r * rows) + 1;
var point3 = c + (r * rows) + rows + 1;
triangle(points[point1][0], points[point1][1], points[point2][0], points[point2][1], points[point3][0], points[point3][1]);
}
}
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/p5.js/0.6.1/p5.js"></script>
Related
Im noob with p5j and i need help from someone please! :-(
On the website i must upload it , they not allow the external links.
and i need to change the "let url" to a png/jpg local link ( not external link ).
i dont know what the solution is ( maybe something similar with: "loadImage" or something.... please help me :-) )
Thank you so much and have a blessed week!
Here is the code:
//let url = "https://coolors.co/3a2e39-1e555c-f4d8cd-edb183-f15152";
let url = "https://blog.logrocket.com/wp-content/uploads/2022/03/Creating-animations-p5-js.png";
let palette;
let font;
function preload() {
font = loadFont("https://openprocessing.org/sketch/1359269/files/Happy Monsters.ttf");
}
function setup() {
createCanvas(1112, 834);
colorMode(HSB, 360, 100, 100, 100);
angleMode(DEGREES);
palette = createPalette(url);
background(10);
}
function draw() {
//background(0, 0, 90);
let offset = 100//width / 100;
let margin = 0; //offset / 5;
let cells = 1//int(random(2, 8));
let d = (width - offset * 2 - margin * (cells - 1)) / cells;
for (let j = 0; j < cells; j++) {
for (let i = 0; i < cells; i++) {
let x = offset + i * (d + margin) + d / 2;
let y = offset + j * (d + margin) + d / 2;
drawFancyShape(x, y, d, palette.concat());
}
}
frameRate(0.5);
noLoop();
}
function drawFancyShape(x, y, d, colors, char = String.fromCodePoint(65 + int(random(26)))) {
let g = createGraphics(d, d);
let g2 = createGraphics(d, d);
colors = shuffle(colors);
let c0 = colors[0];
colors.splice(0, 1);
let ratio = 0.2;
let xStep, yStep;
for (let y = 0; y < g.height; y += yStep) {
yStep = random(ratio, 1 - ratio) * g.height / 2;
if (y + yStep > g.height) yStep = g.height - y;
if (g.height - y - yStep < g.height / 100) yStep = g.height - y;
for (let x = 0; x < g.width; x += xStep) {
xStep = random(ratio, 1 - ratio) * g.width / 2;
if (x + xStep > g.width) xStep = g.width - x;
if (g.width - x - xStep < g.width / 100) xStep = g.width - x;
let r = [];
for (let i = 0; i < 4; i++) {
r.push(int(random(5)) * max(xStep, yStep) / 4);
}
g.rectMode(CENTER);
g.fill(random(colors));
g.noStroke();
g.rect(x + xStep / 2, y + yStep / 2, xStep - 2, yStep - 2, r[0], r[1], r[2], r[3]);
}
}
g2.textSize(g.width * 0.6);
g2.textAlign(CENTER, CENTER);
g2.textFont(font)
g2.textStyle(BOLD);
g2.fill(c0);
// g2.stroke(0);
g2.text(char, g.width / 2, g.height / 2 - g.height / 8);
let g_tmp = g.get();
let g2_tmp = g2.get();
g_tmp.mask(g2_tmp);
// g_tmp.mask(g2_tmp);
drawingContext.shadowColor = color(0, 0, 0, 33);
drawingContext.shadowBlur = d / 10;
push();
translate(x, y);
imageMode(CENTER);
// image(g, 0, 0);
let scl = 1.1;
image(g2, 0, 0, g2.width * scl, g2.height * scl);
image(g_tmp, 0, 0, g_tmp.width * scl, g_tmp.height * scl);
pop();
}
function createPalette(_url) {
let slash_index = _url.lastIndexOf('/');
let pallate_str = _url.slice(slash_index + 1);
let arr = pallate_str.split('-');
for (let i = 0; i < arr.length; i++) {
arr[i] = color('#' + arr[i]);
}
return arr;
}
// save jpg
let lapse = 0; // mouse timer
function mousePressed(){
// prevents mouse press from registering twice
if (millis() - lapse > 400){
save("img_" + month() + '-' + day() + '_' + hour() + '-' + minute() + '-' + second() + ".jpg");
lapse = millis();
}
}
When rotating a custom shape using translate(width/2,height/2); rotate(angle)),
it moves the shape in the bottom left corner. I tried making translate values negative, it fixed it but then the origin was at 0,0. I have used pop(); push() and beginShape(); endShape with no success.
var points = [];
var r;
var lines = 30;
function setup() {
createCanvas(window.innerWidth, window.windowHeight);
angleMode(DEGREES);
// get the points of the corners of the hexagon
r = Math.min(width, height) * 0.4;
var angle = 60;
for (var i = 1; i < 7; i++) {
var tempX = r * sin((angle * i + 30) % 360) + width / 2;
var tempY = r * cos((angle * i + 30) % 360) + height / 2;
points.push([tempX, tempY]);
}
background(0);
stroke(0, 0, 255);
rectMode(CENTER);
}
function draw() {
background(0);
// draw the lines of ...
push();
translate(width/2, height/2);
rotate(frameCount * 0.75);
beginShape();
for (var i = 0; i < points.length; i++) {
// ... the hexagon perimeter
line(points[i][0], points[i][1], points[(i + 1) % 6][0], points[(i + 1) % 6][1]);
var tempAngle = 240 + i * 60;
var tempX = r * 1.1545 * sin(tempAngle) + points[i][0];
var tempY = r * 1.1545 * cos(tempAngle) + points[i][1];
for (var j = 0; j < lines + 1; j++) {
// ... the lines inside the hexagon
var tempAngle2 = tempAngle = (30 / lines * j) + 210 + i * 60;
var distance = r / cos(30 / lines * j);
var tempX2 = distance * sin(tempAngle2) + points[i][0];
var tempY2 = distance * cos(tempAngle2) + points[i][1];;
line(points[i][0], points[i][1], tempX2, tempY2);
}
endShape();
}
pop();
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/p5.js/0.6.1/p5.js"></script>
I think the problem is that you are defining your points for your shape with an x/y offset. By removing the width / 2 & height / 2 from your point definitions it centers your shape.
var points = [];
var r;
var lines = 30;
function setup() {
createCanvas(window.innerWidth, window.windowHeight);
angleMode(DEGREES);
// get the points of the corners of the hexagon
r = Math.min(width, height) * 0.4;
var angle = 60;
for (var i = 1; i < 7; i++) {
var tempX = r * sin((angle * i + 30) % 360)
var tempY = r * cos((angle * i + 30) % 360)
points.push([tempX, tempY]);
}
background(0);
stroke(0, 0, 255);
//rectMode(CENTER);
}
function draw() {
background(0);
// draw the lines of ...
push();
translate(width/2, height/2);
rotate(frameCount * 0.75);
beginShape();
for (var i = 0; i < points.length; i++) {
// ... the hexagon perimeter
line(points[i][0], points[i][1], points[(i + 1) % 6][0], points[(i + 1) % 6][1]);
var tempAngle = 240 + i * 60;
var tempX = r * 1.1545 * sin(tempAngle) + points[i][0];
var tempY = r * 1.1545 * cos(tempAngle) + points[i][1];
for (var j = 0; j < lines + 1; j++) {
// ... the lines inside the hexagon
var tempAngle2 = tempAngle = (30 / lines * j) + 210 + i * 60;
var distance = r / cos(30 / lines * j);
var tempX2 = distance * sin(tempAngle2) + points[i][0];
var tempY2 = distance * cos(tempAngle2) + points[i][1];;
line(points[i][0], points[i][1], tempX2, tempY2);
}
endShape();
}
pop();
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/p5.js/0.6.1/p5.js"></script>
How to achieve a similar effect on an image instead of raw canvas?
/**
* Water ripple effect.
* Original code (Java) by Neil Wallis
* #link http://www.neilwallis.com/java/water.html
*
* #author Sergey Chikuyonok (serge.che#gmail.com)
* #link http://chikuyonok.ru
*/
(function(){
var canvas = document.getElementById('c'),
/** #type {CanvasRenderingContext2D} */
ctx = canvas.getContext('2d'),
width = 400,
height = 400,
half_width = width >> 1,
half_height = height >> 1,
size = width * (height + 2) * 2,
delay = 30,
oldind = width,
newind = width * (height + 3),
riprad = 3,
mapind,
ripplemap = [],
last_map = [],
ripple,
texture,
line_width = 20,
step = line_width * 2,
count = height / line_width;
canvas.width = width;
canvas.height = height;
/*
* Water ripple demo can work with any bitmap image
* (see example here: http://media.chikuyonok.ru/ripple/)
* But I need to draw simple artwork to bypass 1k limitation
*/
with (ctx) {
fillStyle = '#a2ddf8';
fillRect(0, 0, width, height);
fillStyle = '#07b';
save();
rotate(-0.785);
for (var i = 0; i < count; i++) {
fillRect(-width, i * step, width * 3, line_width);
}
restore();
}
texture = ctx.getImageData(0, 0, width, height);
ripple = ctx.getImageData(0, 0, width, height);
for (var i = 0; i < size; i++) {
last_map[i] = ripplemap[i] = 0;
}
/**
* Main loop
*/
function run() {
newframe();
ctx.putImageData(ripple, 0, 0);
}
/**
* Disturb water at specified point
*/
function disturb(dx, dy) {
dx <<= 0;
dy <<= 0;
for (var j = dy - riprad; j < dy + riprad; j++) {
for (var k = dx - riprad; k < dx + riprad; k++) {
ripplemap[oldind + (j * width) + k] += 512;
}
}
}
/**
* Generates new ripples
*/
function newframe() {
var i, a, b, data, cur_pixel, new_pixel, old_data;
i = oldind;
oldind = newind;
newind = i;
i = 0;
mapind = oldind;
// create local copies of variables to decrease
// scope lookup time in Firefox
var _width = width,
_height = height,
_ripplemap = ripplemap,
_mapind = mapind,
_newind = newind,
_last_map = last_map,
_rd = ripple.data,
_td = texture.data,
_half_width = half_width,
_half_height = half_height;
for (var y = 0; y < _height; y++) {
for (var x = 0; x < _width; x++) {
data = (
_ripplemap[_mapind - _width] +
_ripplemap[_mapind + _width] +
_ripplemap[_mapind - 1] +
_ripplemap[_mapind + 1]) >> 1;
data -= _ripplemap[_newind + i];
data -= data >> 5;
_ripplemap[_newind + i] = data;
//where data=0 then still, where data>0 then wave
data = 1024 - data;
old_data = _last_map[i];
_last_map[i] = data;
if (old_data != data) {
//offsets
a = (((x - _half_width) * data / 1024) << 0) + _half_width;
b = (((y - _half_height) * data / 1024) << 0) + _half_height;
//bounds check
if (a >= _width) a = _width - 1;
if (a < 0) a = 0;
if (b >= _height) b = _height - 1;
if (b < 0) b = 0;
new_pixel = (a + (b * _width)) * 4;
cur_pixel = i * 4;
_rd[cur_pixel] = _td[new_pixel];
_rd[cur_pixel + 1] = _td[new_pixel + 1];
_rd[cur_pixel + 2] = _td[new_pixel + 2];
}
++_mapind;
++i;
}
}
mapind = _mapind;
}
canvas.onmousemove = function(/* Event */ evt) {
disturb(evt.offsetX || evt.layerX, evt.offsetY || evt.layerY);
};
setInterval(run, delay);
// generate random ripples
var rnd = Math.random;
setInterval(function() {
disturb(rnd() * width, rnd() * height);
}, 700);
})();
<canvas id="c"></canvas>
Just look at this majestic unicorn: codepen. Data URI used to avoid CORS problems, it'll work with any number of images (all images by default).
JS:
window.addEventListener('load',()=>{
document.querySelectorAll('img').forEach((img)=>{
var cont = document.createElement('div');
cont.style.position = 'relative'
cont.style.display = 'inline-block'
img.parentNode.insertBefore(cont,img);
img.style.verticalAlign = 'top';
cont.appendChild(img)
console.dir(img)
var c = document.createElement('canvas');
c.width = img.clientWidth
c.height = img.clientHeight
c.style.position = 'absolute'
c.style.top = '0px'
c.style.left = '0px'
cont.appendChild(c)
console.log(c)
makeRipple(c,img)
})
})
function makeRipple(el,img){
var canvas = el,
/** #type {CanvasRenderingContext2D} */
ctx = canvas.getContext('2d'),
width = img.clientWidth,
height = img.clientHeight,
half_width = width >> 1,
half_height = height >> 1,
size = width * (height + 2) * 2,
delay = 30,
oldind = width,
newind = width * (height + 3),
riprad = 3,
mapind,
ripplemap = [],
last_map = [],
ripple,
texture,
line_width = 20,
step = line_width * 2,
count = height / line_width;
canvas.width = width;
canvas.height = height;
/*
* Water ripple demo can work with any bitmap image
* (see example here: http://media.chikuyonok.ru/ripple/)
* But I need to draw simple artwork to bypass 1k limitation
*/
ctx.drawImage(img,0,0,img.clientWidth,img.clientHeight)
texture = ctx.getImageData(0, 0, width, height);
ripple = ctx.getImageData(0, 0, width, height);
for (var i = 0; i < size; i++) {
last_map[i] = ripplemap[i] = 0;
}
/**
* Main loop
*/
function run() {
console.log('bbb')
newframe();
ctx.putImageData(ripple, 0, 0);
}
/**
* Disturb water at specified point
*/
function disturb(dx, dy) {
dx <<= 0;
dy <<= 0;
for (var j = dy - riprad; j < dy + riprad; j++) {
for (var k = dx - riprad; k < dx + riprad; k++) {
ripplemap[oldind + (j * width) + k] += 512;
}
}
}
/**
* Generates new ripples
*/
function newframe() {
var i, a, b, data, cur_pixel, new_pixel, old_data;
i = oldind;
oldind = newind;
newind = i;
i = 0;
mapind = oldind;
// create local copies of variables to decrease
// scope lookup time in Firefox
var _width = width,
_height = height,
_ripplemap = ripplemap,
_mapind = mapind,
_newind = newind,
_last_map = last_map,
_rd = ripple.data,
_td = texture.data,
_half_width = half_width,
_half_height = half_height;
for (var y = 0; y < _height; y++) {
for (var x = 0; x < _width; x++) {
data = (
_ripplemap[_mapind - _width] +
_ripplemap[_mapind + _width] +
_ripplemap[_mapind - 1] +
_ripplemap[_mapind + 1]) >> 1;
data -= _ripplemap[_newind + i];
data -= data >> 5;
_ripplemap[_newind + i] = data;
//where data=0 then still, where data>0 then wave
data = 1024 - data;
old_data = _last_map[i];
_last_map[i] = data;
if (old_data != data) {
//offsets
a = (((x - _half_width) * data / 1024) << 0) + _half_width;
b = (((y - _half_height) * data / 1024) << 0) + _half_height;
//bounds check
if (a >= _width) a = _width - 1;
if (a < 0) a = 0;
if (b >= _height) b = _height - 1;
if (b < 0) b = 0;
new_pixel = (a + (b * _width)) * 4;
cur_pixel = i * 4;
_rd[cur_pixel] = _td[new_pixel];
_rd[cur_pixel + 1] = _td[new_pixel + 1];
_rd[cur_pixel + 2] = _td[new_pixel + 2];
}
++_mapind;
++i;
}
}
mapind = _mapind;
}
canvas.onmousemove = function(/* Event */ evt) {
console.log('XXXX',evt.offsetX)
disturb(evt.offsetX || evt.layerX, evt.offsetY || evt.layerY);
};
setInterval(run, delay);
// generate random ripples
var rnd = Math.random;
setInterval(function() {
console.log('aaa')
disturb(rnd() * width, rnd() * height);
}, 700);
};
I made a compress or resize the image on the client side with canvas, but I am wondering how to fill the image into canvas with a FileUpload control from c #.
then each took a picture of how that canvas cleaned first and then filled with the new picture?
this is my source:
$(document).ready(function() {
var canvas = document.getElementById("cc");
var ctx = canvas.getContext("2d");
var img = new Image();
img.crossOrigin = "Anonymous";
img.onload = function() {
var W = img.width;
var H = img.height;
canvas.width = W;
canvas.height = H;
ctx.drawImage(img, 0, 0);
resample_hermite(canvas, W, H, 439, 222);
}
img.src = 'http://i.imgur.com/8VsK7gS.png';
});
function resample_hermite(canvas, W, H, W2, H2) {
var time1 = Date.now();
W2 = Math.round(W2);
H2 = Math.round(H2);
var img = canvas.getContext("2d").getImageData(0, 0, W, H);
var img2 = canvas.getContext("2d").getImageData(0, 0, W2, H2);
var data = img.data;
var data2 = img2.data;
var ratio_w = W / W2;
var ratio_h = H / H2;
var ratio_w_half = Math.ceil(ratio_w / 2);
var ratio_h_half = Math.ceil(ratio_h / 2);
for (var j = 0; j < H2; j++) {
for (var i = 0; i < W2; i++) {
var x2 = (i + j * W2) * 4;
var weight = 0;
var weights = 0;
var weights_alpha = 0;
var gx_r = gx_g = gx_b = gx_a = 0;
var center_y = (j + 0.5) * ratio_h;
for (var yy = Math.floor(j * ratio_h); yy < (j + 1) * ratio_h; yy++) {
var dy = Math.abs(center_y - (yy + 0.5)) / ratio_h_half;
var center_x = (i + 0.5) * ratio_w;
var w0 = dy * dy //pre-calc part of w
for (var xx = Math.floor(i * ratio_w); xx < (i + 1) * ratio_w; xx++) {
var dx = Math.abs(center_x - (xx + 0.5)) / ratio_w_half;
var w = Math.sqrt(w0 + dx * dx);
if (w >= -1 && w <= 1) {
//hermite filter
weight = 2 * w * w * w - 3 * w * w + 1;
if (weight > 0) {
dx = 4 * (xx + yy * W);
//alpha
gx_a += weight * data[dx + 3];
weights_alpha += weight;
//colors
if (data[dx + 3] < 255)
weight = weight * data[dx + 3] / 250;
gx_r += weight * data[dx];
gx_g += weight * data[dx + 1];
gx_b += weight * data[dx + 2];
weights += weight;
}
}
}
}
data2[x2] = gx_r / weights;
data2[x2 + 1] = gx_g / weights;
data2[x2 + 2] = gx_b / weights;
data2[x2 + 3] = gx_a / weights_alpha;
}
}
console.log("hermite = " + (Math.round(Date.now() - time1) / 1000) + " s");
canvas.getContext("2d").clearRect(0, 0, Math.max(W, W2), Math.max(H, H2));
canvas.width = W2;
canvas.height = H2;
canvas.getContext("2d").putImageData(img2, 0, 0);
}
thanks for all your help
I am working with a javascript animation that shows ripples in water in html canvas.
This is the javascript code and the jfiddle link
(function(){
var canvas = document.getElementById('c'),
/** #type {CanvasRenderingContext2D} */
ctx = canvas.getContext('2d'),
width = 400,
height = 400,
half_width = width >> 1,
half_height = height >> 1,
size = width * (height + 2) * 2,
delay = 30,
oldind = width,
newind = width * (height + 3),
riprad = 3,
ripplemap = [],
last_map = [],
ripple,
texture,
line_width = 20,
step = line_width * 2,
count = height / line_width;
canvas.width = width;
canvas.height = height;
with (ctx) {
fillStyle = '#a2ddf8';
fillRect(0, 0, width, height);
fillStyle = '#07b';
save();
rotate(-0.785);
for (var i = 0; i < count; i++) {
fillRect(-width, i * step, width * 3, line_width);
}
restore();
}
texture = ctx.getImageData(0, 0, width, height);
ripple = ctx.getImageData(0, 0, width, height);
for (var i = 0; i < size; i++) {
last_map[i] = ripplemap[i] = 0;
}
/**
* Main loop
*/
function run() {
newframe();
ctx.putImageData(ripple, 0, 0);
}
/**
* Disturb water at specified point
*/
function disturb(dx, dy) {
dx <<= 0;
dy <<= 0;
for (var j = dy - riprad; j < dy + riprad; j++) {
for (var k = dx - riprad; k < dx + riprad; k++) {
ripplemap[oldind + (j * width) + k] += 128;
}
}
}
/**
* Generates new ripples
*/
function newframe() {
var a, b, data, cur_pixel, new_pixel, old_data;
var t = oldind; oldind = newind; newind = t;
var i = 0;
// create local copies of variables to decrease
// scope lookup time in Firefox
var _width = width,
_height = height,
_ripplemap = ripplemap,
_last_map = last_map,
_rd = ripple.data,
_td = texture.data,
_half_width = half_width,
_half_height = half_height;
for (var y = 0; y < _height; y++) {
for (var x = 0; x < _width; x++) {
var _newind = newind + i, _mapind = oldind + i;
data = (
_ripplemap[_mapind - _width] +
_ripplemap[_mapind + _width] +
_ripplemap[_mapind - 1] +
_ripplemap[_mapind + 1]) >> 1;
data -= _ripplemap[_newind];
data -= data >> 5;
_ripplemap[_newind] = data;
//where data=0 then still, where data>0 then wave
data = 1024 - data;
old_data = _last_map[i];
_last_map[i] = data;
if (old_data != data) {
//offsets
a = (((x - _half_width) * data / 1024) << 0) + _half_width;
b = (((y - _half_height) * data / 1024) << 0) + _half_height;
//bounds check
if (a >= _width) a = _width - 1;
if (a < 0) a = 0;
if (b >= _height) b = _height - 1;
if (b < 0) b = 0;
new_pixel = (a + (b * _width)) * 4;
cur_pixel = i * 4;
_rd[cur_pixel] = _td[new_pixel];
_rd[cur_pixel + 1] = _td[new_pixel + 1];
_rd[cur_pixel + 2] = _td[new_pixel + 2];
}
++i;
}
}
}
canvas.onmousemove = function(/* Event */ evt) {
disturb(evt.offsetX || evt.layerX, evt.offsetY || evt.layerY);
};
setInterval(run, delay);
// generate random ripples
var rnd = Math.random;
setInterval(function() {
disturb(rnd() * width, rnd() * height);
}, 700);
})();
The issue is the ripple spills over from one side of the canvas and animates on the opposite side, I want to keep them from moving into the opposite sides.
Thanks!
Stopping waves at edges
To stop the propagation of the waves across the edges you need to limit the function that adds the disturbance so that it does not write past the edges.
So change...
function disturb(dx, dy) {
dx <<= 0;
dy <<= 0;
for (var y = dy - riprad; y < dy + riprad; y++) {
for (var x = dx - riprad; x < dx + riprad; x++) {
ripplemap[oldind + (y * width) + x] += 128;
}
}
}
to...
function disturb(dx, dy) {
dx <<= 0;
dy <<= 0;
for (var y = dy - riprad; y < dy + riprad; y++) {
for (var x = dx - riprad; x < dx + riprad; x++) {
// don't go past the edges.
if(y >= 0 && y < height && x >= 0 && x < width){
ripplemap[oldind + (y * width) + x] += 128;
}
}
}
}
And you also need to change the wave propagation that is in the function newFrame. The propagation is controlled by the value in data. A value of zero means no wave and no propagation. So test if the pixel is on the edge. If the pixel is an edge pixel then just stop the wave by setting data to zero. To save CPU cycles I have added to vars h, w that are height - 1 and width - 1 so you don't have to perform the subtraction twice for every pixel.
Change the code in the function newFrame from...
for (var y = 0; y < _height; y++) {
for (var x = 0; x < _width; x++) {
var _newind = newind + i, _mapind = oldind + i;
data = (
_ripplemap[_mapind - _width] +
_ripplemap[_mapind + _width] +
_ripplemap[_mapind - 1] +
_ripplemap[_mapind + 1]) >> 1;
}
To...
var w = _width - 1; // to save having to subtract 1 for each pixel
var h = _height - 1; // dito
for (var y = 0; y < _height; y++) {
for (var x = 0; x < _width; x++) {
var _newind = newind + i, _mapind = oldind + i;
// is the pixel on the edge
if(y === 0 || x === 0 || y === h || x === w){
data = 0; // yes edge pixel so stop propagation.
}else{
// not on the edge so just do as befor.
data = (
_ripplemap[_mapind - _width] +
_ripplemap[_mapind + _width] +
_ripplemap[_mapind - 1] +
_ripplemap[_mapind + 1]) >> 1;
}
This is not perfect as it will dampen the waves bouncing from the sides but you don't have much CPU time so it is a good solution.
Some notes.
Use requestAnimationFrame rather than setInterval(run, delay) to time the animation as you will cause some devices to crash the page with the code you currently have, if the device can not handle the CPU load. requestAnimationFrame will stop this happening.
Change the run function to
function run() {
newframe();
ctx.putImageData(ripple, 0, 0);
requestAnimationFrame(run);
}
At bottom of code remove setInterval(run,delay); and add
requestAnimationFrame(run);
And change the second setInterval to
var drops = function() {
disturb(rnd() * width, rnd() * height);
setTimeout(drops,700)
};
drops();
NEVER use setInterval, especially for this type of CPU intensive code. You will cause many machines to crash the page. Us setTimeout or requestAnimationFrame instead.
Also remove the with statement where you create the texture.