graphics

问题 I have my UIView . I draw something in my UIView . I added a CALayer to my UIView . Now I would like my controller to only redraw my added CALayer. How do I do that ? In my actual Code it will redraw the main view. How can I redraw my subview (myshapelayer) ? override func drawRect(rect: CGRect) { var myshapelayer:CAShapeLayer=CAShapeLayer(); var testbezier:UIBezierPath=UIBezierPath(); testbezier.moveToPoint(CGPoint(x: 60, y: 80)); ... ... myshapelayer.strokeColor=UIColor.blueColor().CGColor;

问题 I am writing a viewer for a proprietary mesh & animation format in OpenGL. During rendering a transformation matrix is created for each bone (node) and is applied to the vertices that bone is attached to. It is possible for a bone to be marked as "Billboarded" which as most everyone knows, means it should always face the camera. So the idea is to generate a matrix for that bone which when used to transform the vertices it's attached to, causes the vertices to be billboarded. On my test model

问题 I am trying to follow the ocaml manual to draw something. But here is a strange response from Ocaml's toplevel. Anyone sees why? Thanks. # #load "graphics.cma";; # Graphics.open_graph "foo:0";; _X11TransSocketINETConnect() can't get address for foo:6000: nodename nor servname provided, or not known Exception: Graphics.Graphic_failure "Cannot open display foo:0". 回答1: I use Graphics.open_graph " 600x400" , and it works. Note the space before the resolution specification. As to why foo:0 would

问题 I am printing a ° or a µ on my view using the CGContextShowTextAtPoint call. the line of code is as shown. int number = 100; NSString *theText2 = [NSString stringWithFormat:@"%d°", number]; CGContextShowTextAtPoint(context, 10, 5, [theText2 cStringUsingEncoding:NSUTF8StringEncoding], [theText2 length]); The output of this comes out as "100¬" If I increase the length of the string printed it shows the following "100¬°" The expected output should be: "100°" This surely has to do something with

问题 I'm trying to generate polygons from a preprocessed world map, What i have done so far is: 1: Generated a contour map for each of the countries, it looks like this: From here i filled each of these countries with an random color like this: So far ive tried to just select a random pixel in the countour image and followed the line around until i hit the start point. This did give me a relatively good result, without about 90% accuracy on the polygons, However some countries dissapeared totally.

问题 I'm working on a multithreaded app that simultaneously renders geometry to multiple FBOs. I'm experiencing a leak (as described on this question). I've been able to narrow it down a little — if I make one change, it stops leaking — but I can't figure out why. On each of 4 threads (each with its own shared context), I'm doing the following each render cycle: // Upload positionBuffer = getUnusedArrayBufferFromPool(); glBindBuffer(GL_ARRAY_BUFFER, positionBuffer); glBufferData(GL_ARRAY_BUFFER,

问题 I am making a custom Field representing an image and a label near it. I am drawing the image by graphics.drawBitmap(...) Nw for the text, I am using graphics.drawText(String, x, y); but if the text it bigger than the display, it doesn't return to the line. I tried to add \n but that didn't solve the problem. How can I draw a text that can expand on several lines? Thanks, 回答1: I found a solution to the problem. You can find it below for those who are interested in this question: public void

问题 So I'm making a graphical card game. Each card is a JPanel with a button and two images associated with it. I have a flip method, which is the first thing I call in my action listener when a card is clicked on. public void flip() { if(b1.getIcon() == card2) b1.setIcon(card1); else b1.setIcon(card2); revalidate(); repaint(); } However, for some reason the card doesnt flip (meaning the icons don't change) until some point after I call this method. For example, when I put a Thread.sleep after I

问题 I need to create a bufferedimage (circular type) but I am able to create only rectangular type. Then I want to create a oval inside the bufferedimage with some configurations and finally i want to draw a rectangular icon inside the circular shape which should be inserted on the circular shape and not on the rectangular bufferedimage. Now i am able to do the following BufferedImage img = "SomeImage.png"; BufferedImage bfImage = new BufferedImage(200,200,BufferedImage.TYPE_INT_ARGB); Graphics2D

问题 We are moving a large codebase from GDI to QPainter. One thing we used to get on Windows easily was the EMF clipboard format, which enabled customers to manipulate their pasted output in other programs (like Office) in a vector format. It's easy for us to produce bitmaps from Qt into EMF, but that really doesn't give us back the editability of the old format. We can also make mime data from Postscript, which in some programs will retain vector format, but won't allow editability in Office,