canvas

问题 I want to get the fill color or any other property of a item drawn in a canvas in tkinter. def createWidgets(self): self.canvas_1= tk.Canvas(self, bg='#FAFAFA',selectforeground='#BBDEFB'); i=self.canvas_1.create_rectangle((self.canvas_1.winfo_reqwidth()/2)+100, (self.canvas_1.winfo_reqheight()/2)+50, (self.canvas_1.winfo_reqwidth()/2)+150, (self.canvas_1.winfo_reqheight()/2)+100, fill='#FF4081',width=0) self.canvas_1.grid(); color= #want to access the fill color of item i using some getter

问题 How can I pinch/pucker some area of an image in canvas? I've made a solar system animation some time ago, and I started rewriting it. Now, I want to add gravity effect to masses. To make the effect visible, I turned the background into a grid and I'll be modifying it. Desired effect is something like this (made in PS) context.background("rgb(120,130,145)"); context.grid(25, "rgba(255,255,255,.1)"); var sun = { fill : "rgb(220,210,120)", radius : 30, boundingBox : 30*2 + 3*2, position : { x :

问题 How I clean text from canvas shape ? this my code: <div id="ways" style="width:1000px;margin:0 auto;height:100%;"> <canvas id="canvas" width="1000" height="1000"></canvas> and fiddle 回答1: Just refactor the code a bit - Extract the lines which draws the circle into a single function which takes one of those circle objects as an argument: function drawCircle(circle) { context.beginPath(); context.arc(circle.x, circle.y, circle.radius, 0, 2 * Math.PI, false); context.fillStyle = 'green'; context

问题 I'm working on a image editor/uploader based around Pixastic where I grab image data out of an <input> tag, put it into a canvas, and after manipulating it, encode the data in base 64 and post it to my app with javascript, where it will be saved as a new image file. If it were a standard file upload, I would give the file a new (safe) name, test to make sure it was really an image file and copy it to strip any potentially malicious/personal EXIF data before making it available to users. My

问题 I have been working on a drawing app like paint. I am in the part of the floodfill and I am using and algorithm that I found on internet, however, it left some white pixels near the line of the figure without color, detecting what happens, I found that those pixels are not white, but its a color very close. I tried putting the alpha value of those pixels on 1, in case that those were like a transparent color, but it doesn't works. There is an example of the problem: There is my code, it's a

问题 Is it normal that Tkinter's Canvas' create_text 's font size doesn't change when I change the Canvas' scale with canvas.scale ? I thought that, as it is a high level GUI management system, I wouldn't have to resize manually the text done with create_text after a zooming. Isn't this strange, or am I wrong ? 回答1: It's normal, even if not entirely what you want. The scale method just changes the coordinate lists, but text items only have one of those so they just get (optionally) translated.

问题 I have simple drawing canvas like this: public class DrawingCanvas extends JPanel private BufferedImage image; @Override public void paintComponent(Graphics g) { super.paintComponent(g); image = new BufferedImage(this.getWidth(), this.getHeight(), BufferedImage.TYPE_INT_ARGB); Graphics2D g2 = (Graphics2D) image.getGraphics(); // draw some items.... g2.dispose(); g.drawImage(image, 0, 0, null); } } I want to ask you, if I can set some render quality? For example Antialiasing.. I want use BEST

问题 I'm trying to use a smaller canvas as a viewport for another much bigger canvas. I really like the approach used in this the solution on a similar question. He basically uses CanvasRenderingContext2D.drawImage() to "crop" the buffer/offset canvas and then displays that portion of the image on the smaller canvas (viewport). I'm trying to implement a simpler version of the given solution in this fiddle: https://jsfiddle.net/avvac0x8/2/. But as you can see the viewport is not entirely in sync

问题 I have followed the answer in this post; fill image with texture pattern, and it is working perfectly. Is there a way to do the same with KonvaJS? 回答1: AFAIK, KonvaJS does not yet support the compositing required to create your texture overlay. But a Konva.Image can take a native html5 canvas element as its image source, so just do your overlay on an html5 canvas element and then feed it to Konva: var textureImage = new Konva.Image({ image:myCanvasElement }) Example annotated code and a Demo:

问题 I have followed the answer in this post; fill image with texture pattern, and it is working perfectly. Is there a way to do the same with KonvaJS? 回答1: AFAIK, KonvaJS does not yet support the compositing required to create your texture overlay. But a Konva.Image can take a native html5 canvas element as its image source, so just do your overlay on an html5 canvas element and then feed it to Konva: var textureImage = new Konva.Image({ image:myCanvasElement }) Example annotated code and a Demo: