how do I make the scale rotate separately? Instead of rotating the whole canvas? Canvas novice asks the boss to answer 
how do I make the scale rotate separately? Instead of rotating the whole canvas? Canvas novice asks the boss to answer
before drawing the scale
ctx.save ();
ctx.rotate (the angle you want to turn)
ctx.drawImage ctx.fill the process of drawing the scale
ctx.restore ()
then loop
write a line chart with native JS, right-angled ones can be written, but now you need to change into a smooth curve, similar to: the inflection point is still at a right angle, is there any god who can provide the next solution ...
to complete the following effect diagram, the move: method cannot achieve the desired automatic movement at the speed shift 2, . ...
the only thing I can think of now is to save the current canvas to an array every time I finish drawing, and then take it out of the array when I undo it ...
canvas draws multiple ball collisions on the canvas. How can I add a click event to the ball? as far as I know, adding an event to the canvas actually gets an area on the canvas to fix an event? Is it true that the ball can not be added if it keeps ch...
and then realize the painting function on the canvas of the background map, such as drawing a circle and so on. I want to make a rubber Sassafras function, which can remove part of the circle without affecting the background image. How can this be realiz...
1. The designer designed the following graph, which is very similar to the force map, so that it can be implemented on the page, and each circle in the graph can click on the trigger event. 2, my current two ideas: (1) simple and rude html+css. In...
DWcanvas there is an attempt to adjust the location of canvas and z-index to make him on the picture, but in this way, the hot area of the picture cannot be clicked. want to create a canvas node after clicking in the hot area, but it seems that oth...
the style changes after using the html2canvas screenshot. Excuse me, have you ever met a boss? How did you solve it? ...
now you need to pass a image object to the drawImage (img,dx,dy) method of canvas for drawing. but the picture it draws by default has a transparent area around it and is filled with white by default. is the image source as follows: : in t...
vue created periodically receives the values transmitted by eventbus, using respectively. setTimeout (function () { _this.generatePoster(); }, 2000); this.$nextTick (() = > { DOM _this.generatePoster(); }); use dom, after rendering to take scre...
here is my code to convert a web page to pdf through html2canvas.js and jspdf.js pdf () { let that = this this.loading = false html2Canvas(this.$refs.pictureData).then(canvas => { var contentWidth = canvas.width; var contentHeight = canvas...
Today, I wrote an H5 that generates a poster on WeChat, in which a poster needs to get the user s avatar and draw it on canvas. The avatar was obtained, and the attribute crossOrigin = anonymous was added to the picture when loading. There was a pr...
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Mobile canvas image editing, hand drawing, writing, similar to the picture editing operation after qq screenshot, are there any ideas or js plug-ins ...
I want to make a model with 3dmax and load using ThreeJS . Given the mapping rules, the map image resource is later loaded image or canvas, can replace the map and re-render with one click. because the model is not a simple square or other regular g...
Why is there only one context.beginPath (); in the sceneFunc method of Konva custom graphics? sceneFunc(context) { context.beginPath(); context.moveTo(200, 50); context.lineTo(420, 80); context.quadraticCurveTo(300, 100, 260, 170); ...
Why doesn t re-setting the points property and then calling the draw method not empty the previous painting? when clicked, it becomes two lines $(function() { const stage = new Konva.Stage({ container: -sharpcontainer , ...
get the target image from the background canvas through the getImageData () method, which is square. Now you want to make the square into a jigsaw puzzle . s r ctx_ceng.beginPath(); ctx_ceng.moveTo(0, cY...
1. Use html2canvas plug-in to take screenshots. When using custom canvas, the desired intercept area is located in the center of the view, but each time the result starts from the upper left corner of the screen . 2. The code is as follows: var create...
I do mobile photo clipping and upload pictures, and there will be a problem of automatic rotation of pictures under ios. Now I want to use canvas to deal with the cropped pictures, but canvas drawing pictures have not been displayed. Have you ever encou...