html5-canvas

问题 I want to be able to scale text-based objects (for example with classes and subclasses of IText, Textbox) without stretching the text inside of the object. The interaction of scaling and moving is on user-side (UI), not programmatically (I am working on a drawing editor). The behaviour I am looking for is similar to the one in the sticky notes apps: You can scale the paper but this action does not scale your text too. I have already checked this, but this is only for horizontal prevention:

问题 can the JavaScript check the color mode of a image? I did a lot of search about this but the only thing I saw was color mode convert (but the convert wants you to set the original color mode) I add this: --allow-file-access-from-files to have a full control of img in canvas beacause I am using GoogleChrome Html <canvas id="canvas" width=6000 height=7919></canvas> Js var canvas = document.getElementById("canvas"); var ctx = canvas.getContext("2d"); var img = new Image(); img.crossOrigin =

问题 The following is an example from Konvajs library to load an image: var imageObj = new Image(); imageObj.onload = function() { var yoda = new Konva.Image({ x: 50, y: 50, image: imageObj, width: 106, height: 118 }); And here is my code var annotation = new Konva.Line({ points: this.contour, stroke: color, closed: true, strokeWidth: 1 }); var nativeImageObject = new Image(); nativeImageObject.onload = function() { var konvaImage = new Konva.Image({ image: nativeImageObject }); annotation

问题 The following is an example from Konvajs library to load an image: var imageObj = new Image(); imageObj.onload = function() { var yoda = new Konva.Image({ x: 50, y: 50, image: imageObj, width: 106, height: 118 }); And here is my code var annotation = new Konva.Line({ points: this.contour, stroke: color, closed: true, strokeWidth: 1 }); var nativeImageObject = new Image(); nativeImageObject.onload = function() { var konvaImage = new Konva.Image({ image: nativeImageObject }); annotation

问题 In Chrome I get the following error on jsfiddle when trying to test canvas drawing images from a remote url. Error: Failed to execute 'toDataURL' on 'HTMLCanvasElement': Tainted canvases may not be exported. On S3 bucket I have the following CORS policy, which allows for cross resource sharing: <?xml version="1.0" encoding="UTF-8"?> <CORSConfiguration xmlns="http://s3.amazonaws.com/doc/2006-03-01/"> <CORSRule> <AllowedOrigin>*</AllowedOrigin> <AllowedMethod>GET</AllowedMethod> </CORSRule> <

问题 I'm trying to develop a way to select objects that are layered below and (totally) covered by other objects. One idea is to select the top object and then via doubleclick walk downwards through the layers. This is what I got at the moment: var canvas = new fabric.Canvas("c"); fabric.util.addListener(canvas.upperCanvasEl, "dblclick", function (e) { var _canvas = canvas; var _mouse = _canvas.getPointer(e); var _active = _canvas.getActiveObject(); if (e.target) { var _targets = _canvas

问题 I'm trying to develop a way to select objects that are layered below and (totally) covered by other objects. One idea is to select the top object and then via doubleclick walk downwards through the layers. This is what I got at the moment: var canvas = new fabric.Canvas("c"); fabric.util.addListener(canvas.upperCanvasEl, "dblclick", function (e) { var _canvas = canvas; var _mouse = _canvas.getPointer(e); var _active = _canvas.getActiveObject(); if (e.target) { var _targets = _canvas

问题 This question already has answers here : MediaStream Capture Canvas and Audio Simultaneously (2 answers) Closed 2 years ago . I am making a small interactive animation/game (on canvas with PixiJS) and wish to give users an option to save the rendered animation. After doing my research, MediaRecorder appears to be the API that I should use to record and render the video. However the MediaRecorder constructor only allows one stream to be used as source. How can I merge additional streams (audio

问题 I'm making a simple engine for isometric games to use in the future. The thing is i'm having trouble drawing on the canvas. Take for instance this code: function pre_load() { var imgs = ['1', '1000','1010','1011','1012','1013']; var preload_image_object = new Image(); $.each(imgs,function(i,c){ preload_image_object.src='img/sprites/'+c.logo+'.png'; }) } function GameWorld() { //[...] this.render = function() { this.draw(1000, this.center); this.draw(1013, this.center); this.draw(1010, this

问题 I'm making a simple engine for isometric games to use in the future. The thing is i'm having trouble drawing on the canvas. Take for instance this code: function pre_load() { var imgs = ['1', '1000','1010','1011','1012','1013']; var preload_image_object = new Image(); $.each(imgs,function(i,c){ preload_image_object.src='img/sprites/'+c.logo+'.png'; }) } function GameWorld() { //[...] this.render = function() { this.draw(1000, this.center); this.draw(1013, this.center); this.draw(1010, this