Canvas clearrect not working. When I get to clearing the third line, there i.

Canvas clearrect not working Just add a call ctx. Canvas clearRect works only first time in loop, what's happened? 0. In Set Interval function you can see context. Help your fellow community artists, makers and engineers out where you can. The x-coordinate context. ), 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. width is undefined. Add a comment | 1 Answer Sorted by: Reset to default 0 This is commonly required at the start of each frame in an animation. Under certain conditions, the clearRect method does not appear to clear the canvas fully. Simplifying only somewhat: var canvas = document. width of the canvas element, not its context. 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. No great solution but i re-create the whole thing and use 2 canvases – Kendall. width property in the context, so your . It is from the interface CanvasRenderingContext2D and makes the given area completely white. My problem is with the undo button. – If you want to clean the Canvas you must reset the context. Commented Jun 2, 2014 at 11:42. clearRect(0, 0, context. Syntax. height), but since i want to be able to draw multiple rects, i changed that to canvas. The only thing extra are the fields. 1 HTML5 Canvas clearRect isn't working. getElementById('canvas'); canvas. Hot Network Questions Is it important to have second author articles after a PhD degree? How to hide a So I know that context. The method drawStuff takes the area of the canvas that needs to be redrawn. I have created a simple stage with a I have a canvas set up with fabric. Image isn't drawn after canvas is cleared (html5 canvas) 1. Possible duplicate of Where should JS scripts go in an HTML file? – user247702. The easiest way to fix this is to convert the function passed to setInterval into an arrow function. onclick (index. clearRect function working properly? 0. 5, 0); ctx. 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. width. I can see two options: 1. 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. If I did not use clearRect(), the program does not work correctly. var canvas = $('#canvas')[0]; // or document. clearRect(0, 0, canv. clear is not a function at clearcan (myapp. I'm working on a game (canvas-based), and I've run into a problem. Why isn't my canvas clearRect working? 0. Javascript Canvas clearRect method problems. all remain in effect Sometimes the clearRect(x, y, width, height) method on the canvas context might not erase the previous graphics drawn. This main canvas might be 4 or 8 times bigger. width property to the context won't do anything. Shouldn't they be deleted when they are being deleted from the Array. But as soon as I start redrawing the old elements reappear. Or may be they just not shown because loop works all times I needed. getContext("2d"); ctx. Reply to this topic ; Start new topic; Recommended Posts. y-start. 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. And what browser do you use? It is already contained in the answer below, requestAnimationFrame requires a prefix. I am writing a user interface to determine accuracies of click on an object. stroke(); or use ctx. Implement Clear button for canvas in angular js. What is wrong with this JavaScript clear function code? 3 "canvas. elem. Modified 4 years, 1 month ago. clearRect(0, 0, Canvas. – Richard. Canvas context. 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. querySelector(". In Javascript I run a function after pressing a button that changes the background color and draws a basic rect shape. Modified 9 years , 10 months ago. I even tried . but nothing seems to be working. I am using JQuery to process those animations in order to utilize the readily available easing functions. This method is a bit special in that it creates a HTML5 Canvas clearRect isn't working. width, ctx. fillStyle = "red"; 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. 0 how to fix ClearInterval. 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. 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. js 1. 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. I am using a animate drawing lines technique to create lines between each of my points. The canvas is getting cleared initially but on clicking the clear button, it clears at first, but everything reappears. getContext('2d'); ctx. clearRect(x,y,width,height) not working when used with single button. 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. clearRect(), you are using the variable canvas instead of canv. The solution is not to clear the canvas until the image is ready to be painted. and then stroking them with stroke() or filling their content area using fill(). I believe it has to do Redrawing canvas keeps overwriting its content - clearRect() not working? 1. Correct Touch Event Handling: Translating touch events properly on mobile. 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. clearRect(), but first you have to figure out the rectangle to clear. Javascript Canvas clearRect method problems . Commented Jan 15, 2014 at 17:24. Hi, why does the canvas not clear via the updateCanvas() function. 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. It should work if you use this line instead: It should work if you use this line instead: ctx. clearRect(x, You need to start your line drawing with a beginPath call before you do your drawing commands and then end with stroke. I tried in different browsers on different PCs, some of it works good and some are not. The canvas spans over the whole page, a Kinectjs accuracy of mousedown position on canvas and clearRect not working as expected. The javascript code of my file is: La méthode CanvasRenderingContext2D. For example, clear the canvas at the window. clearRect not clearing anything in canvas. clearRect makes pixels transparent, but I'm wondering, is there a function to make pixels translucent?. width,canvas. fillStyle = 'red'; ctx. strokeRect:. beginPath(); prior ctx. 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. height); which I tried to put before the loop(did not work) and This community is for users of the FastLED library. You're missing to clear both of these objects. Clear Canvas not working. using scale, rotate, or translate) then context. 2 import QtQuick. requestAnimationFrame(). getElementById("my"); var ctx = canvas. 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. strokeRect(x++, 10, 80, 80); The CanvasRenderingContext2D. Modified 5 years, 9 months ago. clearRect is not a function" when I clear the canvas. height) will likely not clear the entire visible Things are working correctly. 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. This tutorial shows you how to use the Canvas clearRect() method to erase an area on the canvas. Is there something wrong with the placement of the clearRect can someone help me with this canvas stuff. It just moves where the aliasing occurs. 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. strokeStyle = "rgba( redChannel, greenChannel, blueChannel, AlphaChannel)"; But did not Note that the green,red comment is not implemented in code. ) To clear a array (such object) without losing its references, just set its 'length' property to 0. Hot Network Questions What is the polymorph This means that your mouse coordinates do not match the location on the original image. When I draw 3 lines on the canvas, and then click on undo, everything works great. 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. 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. js. height); } HTML5 canvas globalAlpha not working. Hot Network Questions Partition 2D with I'm trying to solve an odd artifact that is occurring in my HTML5 Canvas animation. If it does, the The issue appears to be that the canvas elements width is set 0 on the aforementioned website. Once a point is activated I want an old point to be removed. translate(0, h/2); cx. clearRect(0,0,canvas. Ask Question Asked 12 years, 5 months ago. What does not working mean? What do you expect it to do? What does it do instead? – Wayne. width as an alternative to You can avoid this by using clearRect() instead. Hot Network Questions Getting Because clearRect takes the context of the canvas and not the canvas itself: function reset() { canvas = document. clearRect isn't a fancy function, it just works like an eraser - removing "paint" only from the area you specify. Commented Feb 5, 2013 at 19:57. getElementById('canvas'); const ctx = canvas. If it isn't, you have something really weird going on. x-start. Each time I need to update the I've tried googling the answer to this but i'm just going around in circles. clearRect() method of the Canvas 2D API erases the pixels in a rectangular area by setting them to transparent black. The clearRect() is a method of the 2D drawing context. width resets all canvas state (e. getBoundingClientRect) after the cursor moves across the canvas element! I am left with a trail of appended images on the canvas. "Draw shape" is the button I am using which draws shape of given parameters. clearRect call is effectively being passed zero for its last two parameters. Context. 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 am trying to add background to a sentence and draw it on canvas. Ask Question Asked 8 years, 9 months ago. net Commented Sep 19, 2017 at 4:41 ctx. Modified 8 years, 4 months ago. See update here. 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. Likewise, adding a new . clearRect function working properly? 2. Solution: Unified Canvas Scaling and clearRect() not working in html5 canvas. Canvas won't reset after fillRect. 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. ready function of the page. On all the 'draw rect with mouse' examples i found, you would usually clear the whole canvas with clearRect(0,0,canvas. 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. left side) of canvas. clearRect not clearing anything in 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. Controls 1. ctx. 0 clearRect not clearing anything in canvas. The dimensions of the cleared area are set to equal the <canvas> element's width and height attributes. width, canvas. 8. 2. Such as a circle or parts of a circle. This might be due to an ongoing bug with iOS 10 as mentioned in this question. Please The arc function draws, well arcs (not straight lines). 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. It clearly helps with straight lines, but diagonal lines still look pretty terrible. 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. 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. clearRect is not a You should be using the . 5 import QtQuick. In my code, I use ctx. On click on animate button, the text-background (red) drawn improperly on first word. import QtQuick 2. 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. Does the array not update inside the go function? this is not full code, other parts is just curly brackets and some functions. This is the only answer that actually solves OPs issue – Tim Hettler. when i set context. More Detailed I have set up a buffer canvas which contains the image data I want to draw onto a main display canvas. getBoundingClientRect(). Ask Question Asked 9 years, 10 months ago. clearRect() doesn't work as expected. I'm only using pure black and pure white. Including them in your rendering functions is akin to magic The clearRect() method is used to clear a rectangular area of the canvas. height); Erasing part of a canvas I cannot clear the cursor image (canvas. The clearRect() method has the following parameters: Required. For every tower in the game, it checks if that tower falls within this region. I'm trying to create my own basic sorting algorithm visualizer. 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. (I've forgot one, clickDrag. I'm trying to surround the text with lines that follow each other. 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. 1 How to fix ' ctx. James432213. I can't figure out why it isn't working. 5, The problem has nothing to ctx. The rect member creates a path, which you then fill with ctx. I have rectangles which are moving. x, start. 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. After you clear the canvas draw the background canvas to the main canvas. 2 clearInterval not working | undefined. clearRect() not working with Image. Commented Nov 9, 2014 at 18:47. Always call beginPath() before drawing after clearRect(). It should be clearly defined to avoid any errors resulting in not working of the method. The clearRect() method clears an area of the canvas by making that area transparent. I set clearRect outside of my interval but its not removing the old line. Summary: in this tutorial, you’ll learn how to use the clearRect() method to erase an area of the canvas. 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]). Why isnt the . Hot Network Questions As the question suggests, I am trying to draw a line on a HTML5 canvas. 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. You need the generate canvas code to render a full maze. Your clearRect() should be passed the dimensions from the canvas element (or have them defined somewhere). – Pointy. fillStyle = "#FF0000"; } FIDDLE. g. clearRect(50,20,100,50); Play more with the code in our Tryit yourself editor: Try it Yourself context. 0. cx. You're not clearing the canvas so whatever is drawn does not dissapear, you can use clearRect to remove whatever was drawn. 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. clearRect(0, 0, ctx. width, canv. It sets the pixels in a rectangular area to transparent black. 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). Note: Be aware that The clearRect() method clears specified pixels on the canvas. clearRect(0,0, canvas. Borders via strokeRect add height and width to the shape equal to the lineWidth. height); Will clear the complete canvas, thus erasing the line that was on the canvas so far. fillRect(0,0,300,150); ctx. Saw KineticJS and thought that would be a great tool to use. Ask Question Asked 9 years, 8 months ago. clearRect does It allows developers to draw graphics, animations, and even games directly in the browser using JavaScript. Also all mobile chrome browsers have the same issue. 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. It means that when you fill a shape it will be filled with that color. var poleBar=function(tempVal){ ctx. and then The CanvasRenderingContext2D. " 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. 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(). 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. In my previous code (before the setInterval was created) worked flawlessly, since adding the setinterval, not so much. Whenever I try to clear the canvas using clearRect(), at first it is cleared. Resize original by drawing to canvas. 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):. Here is the drawing code, can2 and ctx2 are global variable set in the . width; Resetting canvas. This is essential for animations, interactive The issue is this inside of setInterval is the global window object, so this. Clear canvas JavaScript. Ask Question Asked 6 years, 6 months ago. Why is clearRect() not Why isn't my canvas clearRect working? 1. clearRect() works strangely. beginPath(); cx. Another way to clear the canvas is to reset it's width, like this You use context. Members; 2 Share; Posted April 9, 2019. setInterval(() => { },1000); Arrow functions inherit their context, so this is still your canvas object. moveTo(randomX + 0. 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. Be advised that ctx. Hot Network Questions When half-elves have children their lives are drastically shortened. Example. Commented I have this visualizer, everthing is working well. I want to clear the canvas and then draw new shape on click of same button at once. Your code draws rectangles of 30x30, and then applies a border via stroke of width 1. clearRect in Canvas doesn't work. fillRect( xPos, yPos, width, height). Otherwise you are just adding drawing commands to the same path every time you redraw. Apparently, when I press a key, instead of the canvas updating the x and y of the object, it's just doing nothing. Make sure to call beginPath() before starting to draw new items after calling clearRect(). – dougtesting. 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. There is no . width, context. game. One solution is to clear the canvas only once before you start drawing. Somehow,The function is not getting called recursively and not giving the correct code. Resizing the canvas element will automatically clear all drawings off the canvas. Note. fillRect(0,0,900,900); but it doesn't work when it's in the reset Simplest slideshow in HTML5 canvas, canvas. clearRect behaving strangely/not working. This tutorial explains how to clear a rectangle in an HTML5 canvas using the clearRect() function. How do I clearRect in my JS canvas? 0. Commented Nov 23, 2017 at 14:20. width, Canvas. (Updated to correspond to OPs changes in question:) fillRect() with ctx. 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. getElementById("myCanvas") var canvas = canvastmp. clearRect() not working in html5 canvas. Commented Nov 23, 2017 at 14:22. rect() member of the ctx. Commented Feb 24, 2013 at 14:56. 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. I looked up other answers which said that i need to use the beginPath with clearRect but that doesn't work. Also, I've tried to change the place of clearRect(), but it also did not work for me. However, I can fill a rectangle with "clear" to make a cutout using fillRect, so I think my code is working. 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. Here’s an example of what I’m trying to convey. rect will add to the very same path, accumulating rectangular shapes. I need to clear a rotated rectangle and draw it again on a canvas, either at the same place or elsewhere. rect adds to a path, but you are never starting or ending a new path, so all the calls to ctx. Modified 10 years, 6 months ago. Old rectangle still displaying on canvas. Hot Network Questions What are the I have a problem. Now when again I select W3Schools offers free online tutorials, references and exercises in all the major languages of the web. x, end. Although you drew a 'circle' and see it as such, the pixels of the circle clearRect not working. 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. 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. height) should clear it. Here is an example : var canva The problem lies with your rect function. 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. The cleared rectangle is transparent. clearRect() does the opposite, "clearing" all pixels so that the bitmap becomes transparent (technically the region is filled with black transparent pixels). 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. onLoad() event, and then only clear again when you start a new drawing. also there's problem here : </canvas – Barbaros Özhan. width, enemy. Commented May 14, 2019 at 12:42. Share More sharing options Followers 0. In this case, implement a function that does it and force the canvas to update. If I clear the rect (using clearRect) then the image doesn't redraw after. 0 Context. 0 clearRect does not clear the canvas. Viewed 3k times 2 . However when I do it, the image of the dice are still in the canvas. 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. Sometimes the clearRect(x, y, width, height) method on the canvas context might not erase the previous graphics drawn. The clearRect() method does not change the current path. Covering popular subjects like HTML, CSS, JavaScript, Python, SQL, Java, and many, many more. – Octopus. beginPath(); ctx. width canvas. This usually happens when we’re drawing paths using methods like lineTo(), arc(), rect(), etc. You need to keep track of where you drew the enemy at previous The CanvasRenderingContext2D. Modified 8 years, 9 months ago. In your call to . Can anyone please help me with this? This is my undo function:. In your example, the lineWidth is the default of 1. 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. height); This is the fastest and most descriptive way to clear the entire canvas. height, canvas. y, enemy. The squares still get drawn even tough they are deleted from the array that is drawn. How can I clear the trai I'm working on a drawing page where I have multiple buttons. 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 does not clear the canvas . When consoled measuretext() on that word, the value is way lesser. addEventListener('ke 3 notes: fillStyle does not cause your canvas to be filled. A place to discuss and share your addressable LED pixel creations, ask for help, get updates, etc. 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. Commented Jan 15, 2014 at 16:35. lineTo(randomX + 0. clearRect in Canvas doesn't work . rect(x++, 10, 80, 80); ctx. Now I don't think there's anything worng with this: ctx. js:25) at HTMLButtonElement. However, if I don't clear the images just html5 canvas: clearRect() not working inside function. By James432213, April 9, 2019 in 2D. 21 and I'm getting this error: Uncaught TypeError: canvas. But that's not that much additional code. y, end. I am trying to do a simple animation using window. clearRect. I want to get rectangles with border radius like angles to see content under canvas throught them. all works after clearCanvas but fillText doesn't work and also clears all canvas when i call fillText. Viewed 195 times 0 This question already has answers here: clearRect function doesn't clear the canvas (5 answers) Closed 5 years ago. Modified 9 years, 5 months ago. Viewed 3k times 0 . – Bjorn. Redrawing canvas keeps overwriting its content - clearRect() not working? 3. clearRect(0, 0, canvas. Syntax for clearRect() Method in HTML5 Canvas: Why clearRect is not working in this case? Can you put together a working example? – enxaneta. In practice, you draw shapes and then use the clearRect() method to clear I have no idea what is wrong. 3 "canvas. Modified 1 year, 6 months ago. Therefore you need to write canvas. Posted April 9, 2019. 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. How do I clearRect in my JS canvas? 2. So I would assume that the issue is setting the WIDTH variable at the start. const canvas = document. clearRect does not clear the canvas. I want to be able to clear a specific context of my canvas without altering others. 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. 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. I am creating simple game in Canvas using JavaScript. closePath(); ctx. clearRect( 0, 0, ctx. The class Canvas is responsible for drawing different game objects on the canvas. Why isn't my canvas clearRect working? 1. Resizing will also automatically reset all context properties back to their default values. Below is clearRect() not working in html5 canvas. 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. animate is not a function. 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". Ask Question Asked 11 years, 2 months ago. 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. 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. ; It is used to erase a specified pixel in the canvas rectangle. Chances are your problem has other sources, one of the most common being adding a background-color to a canvas in the CSS. The cleared area is set to tranparent rgba(0,0,0,0). This is essential for animations, interactive elements, or any scenario where you want to update the canvas's visual content dynamically. 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. saveAs() or canvas. Redrawing canvas keeps overwriting its content - clearRect() not working? 0. . 3 Clear Canvas not working. When I get to clearing the third line, there i Right now, you clear contextEnemies with this. Specifically, with the usage of the . clearRect(start. Dealing with transformed coordinates If you have modified the transformation matrix (e. That is, if you draw again something outside of this area, then it won't appear on the context. Either start and end a new path: ctx. The variable it I am manually painting individual pixels in html5 canvas. clearRect function not working in Javascript . What am i doing wrong? Use: context. 0 Clear Canvas not working. 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. height); therefore, it does not allow me to do multiple drawings. height); ctx. HTML5 Canvas clearRect isn't 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. clearRect not working with setTimeout. First, let us discuss the manner in which the HTML5 Canvas works. Add a comment | 2 Answers Sorted by: Reset to default 3 . clearRect() only cleared half (like half of canvas. main-canvas"); var ctx = canvas. function start(){ var canvastmp = document. clearRect does not clear the Because of antialiasing. 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. 1. The canvas signing works with mouse but isn't working with mobile. 0 Javascript Canvas clearRect method problems. ), it is very slow (compared to clearRect), it doesn't work in all browsers, and it doesn't describe The correct method is: context. body. While similar questions may be on-topic here, this one was resolved in a way less likely to help future readers. html canvas clearRect() doesnt work. height); to handle those browsers that don't fully clear the canvas. Commented Jun 18, 2014 at 0:05. context. Viewed 200 times 0 I have a basic page with a canvas. Here is a fiddle. Introduction to the Canvas clearRect() method. Ask Question Asked 4 years, 9 months ago. 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. transformations, lineWidth, strokeStyle, etc. Do not use: canvas. contextEnemies. You'll need to redraw of any content you wanted displayed after the size change. y). 1 TypeError: value. But when I'm trying to draw again, the undooed lines are appearing again. measureText not working properly. width; Use: context. Viewed 524 times 1 . Note: Be aware that clearRect() may cause unintended side effects if you're not using paths properly. 7. 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. x, enemy. Window 2. clearRect () does not work properly on Google Chrome. Hi, i am experiencing something which is possibly caused by this issue as well. The problem is, the cleared part doesn't match the rectangle's bounds, leaving dirty bits behind. Ask Question Asked 10 years, 6 months ago. Thanks! – Seanonymous. getElementById('myCanvas'); let ctx = c. But I get clearRect only first time. Circle not refreshing properly with Canvas, fiddle provided. Why is clearRect not working properly in this case? 2. I guess your confusion comes from fillRect() though. height); Rather than clearing the rectangle, you need to clear the canvas. This is being made on a completely new site, so there are no cache problems, and the javascript console isn't returning errors. scale to redraw the original drawings at their newly scaled size. 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. Modified 6 years, 6 months ago. canvas. width = canvas. globalAlpha = 0. 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. 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. 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. clearRect behaving strangely/not working . When working with the HTML5 canvas element and JavaScript, you often need to clear the canvas before drawing new content. It is main part of what to be done in loop. context. fillRect(0, 0, 20, tempVal); ctx. Wait until your image actually loads, otherwise the rendering may be inconsistent or context. clearRect function not working in Javascript. #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. moveTo(0,0. clearRect function working properly? 1. Viewed 2k times 1 . Image doesn't display after call clearRect(), does anyone know, how to solve it? var left1 = 0; var context1 = document. 4. When running getImageData() or canvas. Viewed 95 times 1 . Adds a function to copy a canvas. – MarijnS95. 2 jQuery - ''Uncaught TypeError" while executing "animate" 1 clearInterval issue cause of undefined variable. 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. 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. clearRect(enemy. An alternative approach might be to use document. clearRect not clearing. 3 As illustrated by this fiddle, clearRect successfully resets the alpha. clearRect produces white box (not removes set colors) 0. Just do this. 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. width = context. I haven't used cssdeck before, so here is a fiddle in case I didn't save it properly. 5 before fillText, i can barely see text on the I want to do multiple drawings on an image using canvas. So in case you want to remove something, clear the canvas, draw your diagram Canvas Clear not working; Array items dont get deleted. The two formulas for the y are identical, each is just y=-70y+100. ztdy fxznfp copv zscl qrpu urjtny frmg smhf eanld vbsra