Canvas clearrect not working width; Use: context. The issue here is that the clearRect method doesn't seem to be clearing the previously drawn stars Redrawing canvas keeps overwriting its content - clearRect() not working? 3 Image isn't drawn after canvas is cleared (html5 canvas) 2 Why isn't my canvas clearRect working? 0 Javascript Canvas clearRect method problems. However, working with the HTML5 Canvas can sometimes lead to rendering errors, which can be So I make a square every second moving it along the page slowly. Can anyone please help me with this? This is my undo function:. I believe it has to do Redrawing canvas keeps overwriting its content - clearRect() not working? 1. In practice, you draw shapes and then use the clearRect() method to clear I have no idea what is wrong. Without seeing your code things are a bit hard but in theory each time you add/remove such an arc to the canvas you need to repaint the whole canvas. getContext('2d'); ctx. Implement Clear button for canvas in angular js. height), but since i want to be able to draw multiple rects, i changed that to canvas. I haven't used cssdeck before, so here is a fiddle in case I didn't save it properly. I am using a animate drawing lines technique to create lines between each of my points. beginPath(); cx. In this case, implement a function that does it and force the canvas to update. Somehow,The function is not getting called recursively and not giving the correct code. js:25) at HTMLButtonElement. saveAs() or canvas. closePath(); ctx. Resizing the canvas element will automatically clear all drawings off the canvas. height, canvas. Dealing with transformed coordinates If you have modified the transformation matrix (e. Commented I have this visualizer, everthing is working well. clearRect does It allows developers to draw graphics, animations, and even games directly in the browser using JavaScript. If I clear the rect (using clearRect) then the image doesn't redraw after. The maximum size of the canvas is limited, so watch out for this if you target all browsers, they do not all allow the same max size (below 6400X6400 should be fine, but not sure clearRect() not working in html5 canvas. It means that when you fill a shape it will be filled with that color. 0 how to fix ClearInterval. Solution: Unified Canvas Scaling and clearRect() not working in html5 canvas. clearRect not working with setTimeout. Image doesn't display after call clearRect(), does anyone know, how to solve it? var left1 = 0; var context1 = document. clearRect is not a function' Load 7 more related questions Show fewer related questions Learn html - html tutorial - Clearrect method in html5 canvas - html examples - html programs The clearRect() is a method of HTML <canvas> element. 8. On all the 'draw rect with mouse' examples i found, you would usually clear the whole canvas with clearRect(0,0,canvas. clearRect(), you are using the variable canvas instead of canv. The two formulas for the y are identical, each is just y=-70y+100. left side) of canvas. Commented Nov 23, 2017 at 14:20. 0 Context. Note: Be aware that The clearRect() method clears specified pixels on the canvas. getContext("2d"); ctx. moveTo(randomX + 0. Hot Network Questions Getting Because clearRect takes the context of the canvas and not the canvas itself: function reset() { canvas = document. Javascript Canvas clearRect method problems . Share More sharing options Followers 0. Has anyone had this kind of problem before? all my beginPath are closed (I saw somewhere that this can be a problem (?) ) and I'm using standard call: ctx. main-canvas"); var ctx = canvas. Redrawing canvas keeps overwriting its content - clearRect() not working? 3. No great solution but i re-create the whole thing and use 2 canvases – Kendall. y). 2 jQuery - ''Uncaught TypeError" while executing "animate" 1 clearInterval issue cause of undefined variable. See Also: The fillStyle Property (Set a fill color or pattern) The fillRect() Method (Draw a filled rectangle) The strokeRect() Method (Draw a clearRect() is affected by transforms. This tutorial explains how to clear a rectangle in an HTML5 canvas using the clearRect() function. How do I clearRect in my JS canvas? 2. fillRect(0, 0, 20, tempVal); ctx. Now when again I select W3Schools offers free online tutorials, references and exercises in all the major languages of the web. height); } HTML5 canvas globalAlpha not working. width of the canvas element, not its context. When running getImageData() or canvas. Otherwise you are just adding drawing commands to the same path every time you redraw. The canvas spans over the whole page, a Kinectjs accuracy of mousedown position on canvas and clearRect not working as expected. moveTo(0,0. 0 Clear Canvas not working. Covering popular subjects like HTML, CSS, JavaScript, Python, SQL, Java, and many, many more. clearRect(start. An alternative approach might be to use document. strokeRect:. height); to handle those browsers that don't fully clear the canvas. I spent hours trying to solve a related problem, only to find that on Chrome, instead of filling the rectangle with rgba (0, 0, 0, 0), it actually fills the rectangle with rgba (0, 0, 0, 1) instead! the rectangle passed to clearRect is affected by the current scale/rotate/translate transformation state; only the content is removed from the canvas—the current transforms, path, color settings, etc. The method drawStuff takes the area of the canvas that needs to be redrawn. clearRect in Canvas doesn't work . 2 clearInterval not working | undefined. Hot Network Questions What is the polymorph This means that your mouse coordinates do not match the location on the original image. width, enemy. Under certain conditions, the clearRect method does not appear to clear the canvas fully. Syntax. You're not clearing the canvas so whatever is drawn does not dissapear, you can use clearRect to remove whatever was drawn. It just moves where the aliasing occurs. This main canvas might be 4 or 8 times bigger. The class Canvas is responsible for drawing different game objects on the canvas. There are 2 erros in your code: 1- canvas isns't a context, so it has no method clearRect 2 - you shold call clear rect with these parameters to clear the word grape (110,0,110,30); This question was caused by a typo or a problem that can no longer be reproduced. Hot Network Questions Partition 2D with I'm trying to solve an odd artifact that is occurring in my HTML5 Canvas animation. Why isnt the . I'm trying to surround the text with lines that follow each other. Also, I deleted a bunch of code for readability, so the brackets may be off, but the code is functioning, I just did it for I have set my body onload to init(); However, the canvas does not work. ) To clear a array (such object) without losing its references, just set its 'length' property to 0. addEventListener('ke 3 notes: fillStyle does not cause your canvas to be filled. Can somebody help me? var mouseX; var mouseY; var player1 = true; var slots = new Array(false, Javascript - Trying to erase and redraw lines elsewhere on canvas not working [duplicate] Ask Question Asked 5 years, 9 months ago. all remain in effect Sometimes the clearRect(x, y, width, height) method on the canvas context might not erase the previous graphics drawn. Viewed 2k times 1 . fillRect(0,0,300,150); ctx. clearRect function working properly? 1. Hot Network Questions Sci-Fi Book with a girl who travels through space with a laptop Almost every Hermitian matrix has distinct eigenvalue HTML5 Canvas clearRect isn't working. Modified 10 years, 6 months ago. x, enemy. contextEnemies. By James432213, April 9, 2019 in 2D. Your clearRect() should be passed the dimensions from the canvas element (or have them defined somewhere). height); which I tried to put before the loop(did not work) and This community is for users of the FastLED library. This is based off a number of factors, such as the size of the text and the textAlign property of the canvas context when the text was originally drawn. all works after clearCanvas but fillText doesn't work and also clears all canvas when i call fillText. height); therefore, it does not allow me to do multiple drawings. fill() - only problem is, it doesn't close the path, so it remains open and is added to when the second call to poles comes along. import QtQuick 2. But as soon as I start redrawing the old elements reappear. Here is an example : var canva The problem lies with your rect function. . getElementById('canvas'); const ctx = canvas. Commented Feb 24, 2013 at 14:56. clearRect() de l'API 2D des Canvas met en noir transparent tous les pixels dans le rectangle défini par le point de départ de coordonnées (x, y) et par les tailles (largeur, hauteur), supprimant tout contenu précédemment dessiné. getElementById("myCanvas") var canvas = canvastmp. Clear Canvas not working. It clearly helps with straight lines, but diagonal lines still look pretty terrible. getBoundingClientRect) after the cursor moves across the canvas element! I am left with a trail of appended images on the canvas. – Bjorn. Hot Network Questions When half-elves have children their lives are drastically shortened. That is, if you draw again something outside of this area, then it won't appear on the context. clearRect(enemy. Hi, why does the canvas not clear via the updateCanvas() function. var canvas = $('#canvas')[0]; // or document. clearRect does not clear the Because of antialiasing. This tutorial shows you how to use the Canvas clearRect() method to erase an area on the canvas. Also, I've tried to change the place of clearRect(), but it also did not work for me. Hot Network Questions What are the I have a problem. 5 import QtQuick. Clear canvas JavaScript. requestAnimationFrame(). 0. Note: Be aware that clearRect() may cause unintended side effects if you're not using paths properly. clearRect() does not affect the current path or drawing state of the canvas context your browser does not support the canvas tag let c = document. Hot Network Questions As the question suggests, I am trying to draw a line on a HTML5 canvas. Wait until your image actually loads, otherwise the rendering may be inconsistent or context. Simplifying only somewhat: var canvas = document. 2 import QtQuick. Modified 8 years, 4 months ago. The only problem is that when you clear canvas with clean function, then click changeSrc, you can always see a visualizer from last song for a sec html5 canvas: clearRect() not working inside function. If I did not use clearRect(), the program does not work correctly. clearRect(0, 0, context. So I would assume that the issue is setting the WIDTH variable at the start. width as an alternative to You can avoid this by using clearRect() instead. Is there something wrong with the placement of the clearRect can someone help me with this canvas stuff. Commented Nov 9, 2014 at 18:47. drawImage(bgCan, 0, 0); When the mouse button is down draw the circle to the background canvas and while it is up draw to the main canvas. The HTML Canvas clearRect() method can be used to erase the pixel data in the given area and from the point given by the parameters. I then call clearRect to clear the canvas so the old squares are removed and only the new square remains but I'm doing something wrong and the canvas is not cleared. The solution is not to clear the canvas until the image is ready to be painted. HTML5 Canvas clearRect isn't working. It is main part of what to be done in loop. height); Erasing part of a canvas I cannot clear the cursor image (canvas. The only thing extra are the fields. The strait lines that are generated are from not closing your path and moving were the start and ending points were the arc is drawn. getElementById('canvas'); canvas. This IS the minimal example to show the working problem – I'm working on a project with HTML canvas and I'm in trouble with a few things. Modified 9 years , 10 months ago. 3 As illustrated by this fiddle, clearRect successfully resets the alpha. In my code, I use ctx. Commented Jan 15, 2014 at 16:35. html canvas clearRect() doesnt work. – If you want to clean the Canvas you must reset the context. clearRect(0, 0, Canvas. game. clearRect not clearing anything in canvas. It should be clearly defined to avoid any errors resulting in not working of the method. 5, The problem has nothing to ctx. In my previous code (before the setInterval was created) worked flawlessly, since adding the setinterval, not so much. 1. Ask Question Asked 10 years, 6 months ago. Viewed 3k times 0 . You can either close the path before exiting the rect function, or even more JavaScript clearRect() Demo I'm not able to clear the canvas using clearRect on the latest stock Android browser, and I'd love to see a working solution. A place to discuss and share your addressable LED pixel creations, ask for help, get updates, etc. What's the formula for calculating it? Successive divisions The way clip() works is that it takes the current sub-path declaration and everything that should not be in its filled area will be discarded from the drawing zone. beginPath(); prior ctx. 21 and I'm getting this error: Uncaught TypeError: canvas. Here are the two primary Your script appears in the document before the <canvas> element, so when the script runs the canvas is not in the DOM. Please The arc function draws, well arcs (not straight lines). Commented Nov 23, 2017 at 14:22. Viewed 195 times 0 This question already has answers here: clearRect function doesn't clear the canvas (5 answers) Closed 5 years ago. I can see two options: 1. Correct Touch Event Handling: Translating touch events properly on mobile. I even tried . Using this snippet for example Your issue is with a missing beginPath causing subsequent lines to be added to the same path that was stroke drawing all lines. Such as a circle or parts of a circle. I'm trying to create my own basic sorting algorithm visualizer. clearRect function working properly? 0. When working with the HTML5 canvas element and JavaScript, you often need to clear the canvas before drawing new content. The clearRect() is a method of the 2D drawing context. clearRect behaving strangely/not working . However, if I don't clear the images just html5 canvas: clearRect() not working inside function. Apparently, when I press a key, instead of the canvas updating the x and y of the object, it's just doing nothing. The javascript code of my file is: La méthode CanvasRenderingContext2D. How do I get the clearRect to clear the old squares? The previous questions I've read revolve around using 'draw Problem is that clearRect() function seems not working. measureText not working properly. I set clearRect outside of my interval but its not removing the old line. – Richard. Just add a call ctx. fillRect(0,0,900,900); but it doesn't work when it's in the reset Simplest slideshow in HTML5 canvas, canvas. The easiest way to fix this is to convert the function passed to setInterval into an arrow function. Thanks! – Seanonymous. Ask Question Asked 12 years, 5 months ago. The canvas signing works with mouse but isn't working with mobile. This is the only answer that actually solves OPs issue – Tim Hettler. 3 Clear Canvas not working. clearRect. For every tower in the game, it checks if that tower falls within this region. Load 7 more related questions Show fewer related questions Sorted by: Reset to default Know someone who can answer? Share a I'm attempting to get a square shape to follow my mouse around on the canvas using "mousemove". Commented Jun 18, 2014 at 0:05. Why is clearRect not working properly in this case? 2. 1 TypeError: value. Canvas clearRect works only first time in loop, what's happened? 0. clearRect() not working in html5 canvas. 0 The text inside canvas still persists even after clearRect() Load 7 more related questions Show fewer related questions Sorted by: Reset to default Know someone who can answer? Share a link to this question Resize the canvas element's width & height and use context. js 1. The clearRect() method does not change the current path. Once a point is activated I want an old point to be removed. If you intention is to animate somwthing then you can consider the following routine: Clear canvas (clearRect()) Clear path (beginPath()) Note that this clears the canvas, though you should follow with ctx. Or may be they just not shown because loop works all times I needed. width. transformations, lineWidth, strokeStyle, etc. I need to clear a rotated rectangle and draw it again on a canvas, either at the same place or elsewhere. This method is a bit special in that it creates a HTML5 Canvas clearRect isn't working. The dimensions of the cleared area are set to equal the <canvas> element's width and height attributes. I looked up other answers which said that i need to use the beginPath with clearRect but that doesn't work. " I am not far into it, and I have run into a canvas problem that has ahd me stumped for most of the d Why is clearRect not working properly in this case? 1. It's got to be something I'm just not seeing, I have two other canvas animations It's got to be something I'm just not seeing, I have two other canvas animations I then realised the website was not working when scaled so I decided to implement an onevent for the window resize and when the window is resized I run the same functions again to recreate the same process but while clearing all the previous stars so they don't multiply. I am creating simple game in Canvas using JavaScript. See update here. What am i doing wrong? Use: context. clearRect does not clear the canvas . width, canv. Here is the drawing code, can2 and ctx2 are global variable set in the . js. On click on animate button, the text-background (red) drawn improperly on first word. The clearRect() method clears an area of the canvas by making that area transparent. You're missing to clear both of these objects. clearRect() doesn't work as expected. png inside a loop which updates the canvas every frame, the time to execute those functions increases dramatically, and i think it is caused by the canvas not properly being cleared out. canvas. Be advised that ctx. I have a second button though that uses another JS function in order to clean the canvas but it html5 canvas: clearRect() not working inside function. clearRect() not working with Image. My problem is with the undo button. Commented Jan 15, 2014 at 17:24. James432213. Shouldn't they be deleted when they are being deleted from the Array. clearRect does not clear the canvas. 0 Javascript Canvas clearRect method problems. Now I don't think there's anything worng with this: ctx. clearRect isn't a fancy function, it just works like an eraser - removing "paint" only from the area you specify. Help your fellow community artists, makers and engineers out where you can. using scale, rotate, or translate) then context. Why is clearRect() not removing anything from my canvas? Hot Network Questions Counting the number of meetings How to rectify a mistake in DS 160 How to win a teaching award? What's html5 canvas: clearRect() not working inside function. Context. – dougtesting. I am using JQuery to process those animations in order to utilize the readily available easing functions. I can get the overlay to work, but for some reason clearRect(x,y,width,height) does not put the cutouts in the overlay so the image shows through the overlay. also there's problem here : </canvas – Barbaros Özhan. Although you drew a 'circle' and see it as such, the pixels of the circle clearRect not working. More Detailed I have set up a buffer canvas which contains the image data I want to draw onto a main display canvas. EDIT: The canvas works when i provide it a specific width and height in the html, but i find that my drawing and mouse is always off by a little. #fff0 #fee0 #abf0 #5f60 #0000 #fff0 What i have now is the dots moving but not clearing the old one, so just lines moving across instead of dots. If you call clearRect() and does not reset the path (with beginPath) and then call stroke you will rasterize what is existing on the path. ), it is very slow (compared to clearRect), it doesn't work in all browsers, and it doesn't describe what we are The old lines are re-appearing because they're stored in clickX and in clientY, and when you basically draw in the canvas you call redraw method in your code, which draw everything in these objects. But that's not that much additional code. elem. context. The variable it I am manually painting individual pixels in html5 canvas. rect will add to the very same path, accumulating rectangular shapes. Viewed 74 times 0 If the reset button is pressed, I want that the canvas get's white again and it draw's the lines again. body. If you switch to dots and back to lines with the clearRect option choose you can see the last arc added to the path being drawn too. Hi, i am experiencing something which is possibly caused by this issue as well. So try emptying the arrays clickX, clickY and clickDrag as shown below, when you clear your canvas; so that the old points are not considered when you start fresh. height); The animation i have working but i cannot get the clearRect to work so each frame is just stacking on top of the next. Likewise, adding a new . Just do this. What is wrong with this JavaScript clear function code? 3 "canvas. strokeRect(x++, 10, 80, 80); The CanvasRenderingContext2D. clearRect() only cleared half (like half of canvas. When this method is called, the co-ordinates passed is taken as The clearRect() method clears the specified rectangular region of the canvas, making it fully transparent. Why isn't my canvas clearRect working? 0. width, canvas. ht Basically, my problem is that I cant understand why function clearRect which I use in code does not clean rectangles (For making them to move i used setinterval function). In Set Interval function you can see context. Ask Question Asked 11 years, 2 months ago. I want to be able to clear a specific context of my canvas without altering others. 4 Window{ id: root width: 640 height: 480 visible: true Canvas { id: mycanvas width: 1000 height: 1000 property var arrpoints : [] onPaint: { var context = getContext("2d"); // Touch-screen <canvas> for signatures not working on touch-screen devices. 3 "canvas. Summary: in this tutorial, you’ll learn how to use the clearRect() method to erase an area of the canvas. You need to keep track of where you drew the enemy at previous The CanvasRenderingContext2D. rect() member of the ctx. I guess your confusion comes from fillRect() though. width is undefined. clearRect not clearing. Modified 9 years, 5 months ago. height) should clear it. clearRect(x, You need to start your line drawing with a beginPath call before you do your drawing commands and then end with stroke. and then The CanvasRenderingContext2D. x, start. It sets the pixels in a rectangular area to transparent black. clearRect function working properly? 2. Hot Network Questions Is it important to have second author articles after a PhD degree? How to hide a So I know that context. clearRect(0, 0, ctx. For example, say I have a canvas with these colors (fourth one in each color is alpha): #ffff #feef #abff #5f6f #000f #ffff Running clearRect would resolve into this (or something, just make them all transparent):. Why isn't my canvas clearRect working? 1. Including them in your rendering functions is akin to magic The clearRect() method is used to clear a rectangular area of the canvas. clearRect is not a You should be using the . So in case you want to remove something, clear the canvas, draw your diagram Canvas Clear not working; Array items dont get deleted. 0 clearRect not clearing anything in canvas. copyCanvas Now the idea is that when the "Reset" button is pressed, all values will go back to the default and the canvas will be cleared. clearRect makes pixels transparent, but I'm wondering, is there a function to make pixels translucent?. width, Canvas. – MarijnS95. Load 7 more related questions Show fewer related questions A lot of the examples are animating shapes that are drawn, whereas I'm using images, not sure if this matters and whether I should've just used a canvas transform function instead of clearRect, but didn't think this should've made a difference. The problem is, the cleared part doesn't match the rectangle's bounds, leaving dirty bits behind. 5 before fillText, i can barely see text on the I want to do multiple drawings on an image using canvas. In Javascript I run a function after pressing a button that changes the background color and draws a basic rect shape. width property in the context, so your . How do I clearRect in my JS canvas? 0. clearRect () does not work properly on Google Chrome. Each time I need to update the I've tried googling the answer to this but i'm just going around in circles. Note further that the height and width are the logical canvas dimensions used for drawing and are different from Reset button for canvas not working. I have tested the values and find that it WILL draw a line from 0,0 to 1920,1040 (the size of the client area) but will not f Clearing the Canvas for Redrawing in JavaScript, HTML, and Canvas. Viewed 3k times 2 . This is being made on a completely new site, so there are no cache problems, and the javascript console isn't returning errors. One solution is to clear the canvas only once before you start drawing. x, end. translate(0, h/2); cx. 2. Controls 1. Possible duplicate of Where should JS scripts go in an HTML file? – user247702. ), it is very slow (compared to clearRect), it doesn't work in all browsers, and it doesn't describe The correct method is: context. Canvas context. Resizing will also automatically reset all context properties back to their default values. Here is a fiddle. I want to clear the canvas and then draw new shape on click of same button at once. Modified 4 years, 1 month ago. Instead, I get a 4-second delay and then all the images get drawn on Therefore, you always see the canvas state immediately after calling clearRect, because when you call drawImage, the animation routine will kick in again before you get a chance to see the result of drawImage() and you'll see the result of clearRect(). clearRect() does the opposite, "clearing" all pixels so that the bitmap becomes transparent (technically the region is filled with black transparent pixels). First, let us discuss the manner in which the HTML5 Canvas works. g. Another way to clear the canvas is to reset it's width, like this You use context. rect adds to a path, but you are never starting or ending a new path, so all the calls to ctx. Modified 8 years, 9 months ago. rect(x++, 10, 80, 80); ctx. To address the issue with your signature script working on desktop but not on mobile, you’ll want to focus on two key things: Consistent Canvas Scaling Across Devices: Ensuring the canvas scales correctly without varying line thicknesses. Members; 2 Share; Posted April 9, 2019. However when I do it, the image of the dice are still in the canvas. Javascript Canvas clearRect method problems. Sometimes the clearRect(x, y, width, height) method on the canvas context might not erase the previous graphics drawn. setInterval(() => { },1000); Arrow functions inherit their context, so this is still your canvas object. When I draw 3 lines on the canvas, and then click on undo, everything works great. Introduction to the Canvas clearRect() method. If it does, the The issue appears to be that the canvas elements width is set 0 on the aforementioned website. I'm only using pure black and pure white. Commented Feb 5, 2013 at 19:57. fillStyle = "red"; ctx. Resize original by drawing to canvas. Circle not refreshing properly with Canvas, fiddle provided. I'm working on a game (canvas-based), and I've run into a problem. clearRect function not working in Javascript. Add a comment | 2 Answers Sorted by: Reset to default 3 . Basically, it resizes the image to a canvas (resizeCanvas) and then uses this canvas for So when you clear the canvas you are failing to reset these arrays, so when the redraw method is called again (after clearing the canvas), the old points get plotted too. y, enemy. Why is clearRect() not removing anything from my canvas? Hot Network I am trying to use a canvas as a semi-transparent overlay with cutouts over an img tag. fillStyle = "rgba(0, 0, 0, 1)"; will fill the region with opaque pixels, in this case black (note alpha is a normalized value [0,1]). When consoled measuretext() on that word, the value is way lesser. Redrawing canvas keeps overwriting its content - clearRect() not working? Hot Network Questions What's "the archetypal book" called? What should I do if my student has quarrel with my collaborator Deleting all files but some on Mac in The clearRect() method clears specified pixels on the canvas. context. – Pointy. Redrawing canvas keeps overwriting its content - clearRect() not working? 0. 5, 0); ctx. Ask Question Asked 9 years, 10 months ago. Also all mobile chrome browsers have the same issue. globalAlpha = 0. getBoundingClientRect(). 1 How to fix ' ctx. Adds a function to copy a canvas. onclick (index. clearRect() method of the Canvas 2D API erases the pixels in a rectangular area by setting them to transparent black. Your code draws rectangles of 30x30, and then applies a border via stroke of width 1. clearRect(0, 0, canvas. Whenever I try to clear the canvas using clearRect(), at first it is cleared. To check for this, inspect the canvas with your devtools of choice, and see what the background properties are When i call writeTextToCanvas method before clearCanvas method, it works perfectly, if i call clearCanvas method first than writeTextToCanvas, it doesn't works, drawing functions etc. Syntax for clearRect() Method in HTML5 Canvas: Why clearRect is not working in this case? Can you put together a working example? – enxaneta. cx. 7. clearRect behaving strangely/not working. width canvas. When I get to clearing the third line, there i Right now, you clear contextEnemies with this. This is essential for animations, interactive The issue is this inside of setInterval is the global window object, so this. clearRect function not working in Javascript . Viewed 14k times 3 Here is a code of a very simple slideshow, that should show 4 images in 4 seconds, one image per second. 1 HTML5 Canvas clearRect isn't working. height); Will clear the complete canvas, thus erasing the line that was on the canvas so far. getElementById("my"); var ctx = canvas. height) will likely not clear the entire visible Things are working correctly. In your example, the lineWidth is the default of 1. beginPath(); ctx. The canvas is getting cleared initially but on clicking the clear button, it clears at first, but everything reappears. Example. Why is clearRect() not Why isn't my canvas clearRect working? 1. The reason why this is needed is because the clearRect is clearing the entire canvas so both the player, enemy and anything else on the canvas needs to be re-drawn. I have rectangles which are moving. width = context. querySelector(". width, context. And what browser do you use? It is already contained in the answer below, requestAnimationFrame requires a prefix. y-start. clearRect (x, y, width, height) Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about your product, service or employer brand; OverflowAI GenAI features for Teams; OverflowAPI Train & fine-tune LLMs; Labs The future of collective knowledge sharing; About the company Basics: HTML5 Canvas as a Non-Retained Drawing Mode Graphics API. Always call beginPath() before drawing after clearRect(). "Draw shape" is the button I am using which draws shape of given parameters. strokeStyle = "rgba( redChannel, greenChannel, blueChannel, AlphaChannel)"; But did not Note that the green,red comment is not implemented in code. Commented Jun 2, 2014 at 11:42. width; Resetting canvas. This usually happens when we’re drawing paths using methods like lineTo(), arc(), rect(), etc. Either start and end a new path: ctx. Ask Question Asked 6 years, 6 months ago. Ask Question Asked 4 years, 9 months ago. width,canvas. Posted April 9, 2019. Viewed 3k times 1 I need create smooth drawing lines with transparent without clearRect method i try use: globalAlpha and strokeStyle with rgba like this: ctx. clearRect(0,0, canvas. You need the generate canvas code to render a full maze. clearRect( 0, 0, ctx. Does the array not update inside the go function? this is not full code, other parts is just curly brackets and some functions. 4. width property to the context won't do anything. Ask Question Asked 8 years, 9 months ago. In your call to . Modified 5 years, 9 months ago. Commented May 14, 2019 at 12:42. It should work if you use this line instead: It should work if you use this line instead: ctx. Viewed 524 times 1 . Saw KineticJS and thought that would be a great tool to use. I want to get rectangles with border radius like angles to see content under canvas throught them. Below is clearRect() not working in html5 canvas. But when I'm trying to draw again, the undooed lines are appearing again. scale to redraw the original drawings at their newly scaled size. fillStyle = 'red'; ctx. 5); Okay, I've seen your source code and from what I understand you are using 4 separate canvas elements - one for mobile devices (pink), one for interface devices (green), one for personal devices (blue), and one for the mask when a My code below is for Chris Courses "Circular Motion" tutorial, but I can't figure out why my clearRect isn't working. Note: arrow functions are not supported in IE v11 and below. Any content previously drawn in the specified area will be erased, and the background color (or transparency) of the canvas will be visible in that region. lineTo(randomX + 0. clearRect(0, 0, canv. height); This is the fastest and most descriptive way to clear the entire canvas. stroke(); or use ctx. After you clear the canvas draw the background canvas to the main canvas. ready function of the page. Chances are your problem has other sources, one of the most common being adding a background-color to a canvas in the CSS. function start(){ var canvastmp = document. Do not use: canvas. What does not working mean? What do you expect it to do? What does it do instead? – Wayne. Like a real-world canvas with fast-drying oil paints, when you stroke() or fill() or drawImage() onto your canvas the paint becomes part of the canvas. If it isn't, you have something really weird going on. animate is not a function. Old rectangle still displaying on canvas. You are drawing at non-integer coordinates, while you can't have half pixel rendered, so the pixels colors are shaded with some transparency to give this illusion of smaller pixels than a pixel. var poleBar=function(tempVal){ ctx. fillRect( xPos, yPos, width, height). height); ctx. clearRect(50,20,100,50); Play more with the code in our Tryit yourself editor: Try it Yourself context. Modified 6 years, 6 months ago. x-start. getElementById('myCanvas'); let ctx = c. const canvas = document. Modified 1 year, 6 months ago. onLoad() event, and then only clear again when you start a new drawing. Window 2. I'm making a game using pure javascript and the clearRect function isn't working correctly, here's the code: //player's location var playerX = 250; var playerY = 325; document. width); any ideas what can be a problem or some alternative? I've followed exactly as in the example, but the clear is only working on some portion of it, not the whole canvas. ; It is used to erase a specified pixel in the canvas rectangle. The x-coordinate context. fillStyle = "#FF0000"; } FIDDLE. As others have said instead of re-sizing the [-1,1] range sine data to [30,170] every frame, just do it at init time and save that enlarged range inside the sinewave array. I am trying to do a simple animation using window. (I've forgot one, clickDrag. I can't figure out why it isn't working. While similar questions may be on-topic here, this one was resolved in a way less likely to help future readers. The cleared area is set to tranparent rgba(0,0,0,0). but nothing seems to be working. clearRect() works strangely. There is no . when i set context. Therefore you need to write canvas. Reply to this topic ; Start new topic; Recommended Posts. height); Rather than clearing the rectangle, you need to clear the canvas. Borders via strokeRect add height and width to the shape equal to the lineWidth. Here’s an example of what I’m trying to convey. width resets all canvas state (e. The squares still get drawn even tough they are deleted from the array that is drawn. Note. clearRect(0,0,canvas. clearRect not clearing anything in canvas . This is essential for animations, interactive elements, or any scenario where you want to update the canvas's visual content dynamically. clear is not a function at clearcan (myapp. The cleared rectangle is transparent. But I get clearRect only first time. Canvas won't reset after fillRect. clearRect(), but first you have to figure out the rectangle to clear. and then stroking them with stroke() or filling their content area using fill(). clearRect call is effectively being passed zero for its last two parameters. For example, clear the canvas at the window. I have created a simple stage with a I have a canvas set up with fabric. The code below would be for the draw method of a object that draws text into a canvas context, as such it has properties for x, y, text size, clearRect() not working in html5 canvas. (Updated to correspond to OPs changes in question:) fillRect() with ctx. ctx. clearRect is not a function" when I clear the canvas. clearRect(x,y,width,height) not working when used with single button. 0 clearRect does not clear the canvas. clearRect produces white box (not removes set colors) 0. The rect member creates a path, which you then fill with ctx. How can I clear the trai I'm working on a drawing page where I have multiple buttons. Make sure to call beginPath() before starting to draw new items after calling clearRect(). Specifically, with the usage of the . clearRect in Canvas doesn't work. y, end. height); The problem here is that you are clearing the square where you are about to draw the enemy, not the square where it was drawn last time. What am I missing? When I use the canvas on my computer, the mouse-draw feature works well but when I open the file via Without pasting that code how do you know you can replicate the issue? It's a UI and so I need to draw the full canvas. Image isn't drawn after canvas is cleared (html5 canvas) 1. This might be due to an ongoing bug with iOS 10 as mentioned in this question. Viewed 95 times 1 . net Commented Sep 19, 2017 at 4:41 ctx. However, I can fill a rectangle with "clear" to make a cutout using fillRect, so I think my code is working. You'll need to redraw of any content you wanted displayed after the size change. width, ctx. How can i make the clear button work properly on this code? Hot Network I am reading through "Making Isometric Social Real-Time Games with HTML5, CSS3 and Javascript. Ask Question Asked 9 years, 8 months ago. I am trying to add background to a sentence and draw it on canvas. I tried in different browsers on different PCs, some of it works good and some are not. It is from the interface CanvasRenderingContext2D and makes the given area completely white. I am writing a user interface to determine accuracies of click on an object. Viewed 200 times 0 I have a basic page with a canvas. The clearRect() method has the following parameters: Required. – Octopus. Add a comment | 1 Answer Sorted by: Reset to default 0 This is commonly required at the start of each frame in an animation. width = canvas. lnrm wis csrjz fwelp lhakvp hekmnj maxwp ljzgwrv wpcscjf mcmbn