position | 易学教程

webgl 坐标系转换

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绘制多个点 1、通过变量来传递顶点坐标，获取顶点坐标变量的位置 var a_Position = gl.getAttribLocation(program, ‘a_Position’) 2、传入变量坐标 gl.vertexAttrib3f(a_Position, x, y, z) 3、canvas坐标系转为webgl坐标系，webgl的坐标是x[-1, 1]，y[-1, 1] var VERTEX_SOURCE = `attribute vec4 a_Position;\n void main() {\n gl_Position = a_Position;\n gl_PointSize = 10.0;\n }\n` ; var FRAGMENT_SOURCE = `void main() {\n gl_FragColor = vec4(0.0, 1.0, 0.0, 1.0);\n }\n` ; function main ( ) { var canvas = document . querySeletor ( '#webgl' ) ; var gl = canvas . getContext ( 'webgl' ) || canvas . getContext ( 'experimental-webgl' ) ; var vertexShader = gl .

Place annotation above span

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问题 JSFIDDLE What I need to do is place some annotation on some spans of text. Here is my code HTML <!DOCTYPE html> <html> <head> <link rel="stylesheet" href="css/demo.css" /> <script type="text/javascript" src="js/jquery-1.9.1.min.js"></script> <script type="text/javascript" src="js/demo.js"></script> </head> <body> <div class="dialog-container"> <div class="annotation-head"></div> <div class="annotation-segment"> <span class="marker" data-anno-id="0">This is a</span> <span class="marker" data

Footer at the bottom

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问题 here's my problem, my footer dont stay at the bottom of the page. I try anything: clear:boths;bottom:0; margin... nothing is working.. My question is: How can i put it in the bottom of the page. HERE IS MY CODE <div id = "wrapper"> ..... .... <div id = "content2"> <div id = "fastMenu"> <a href="conseil-d-administration"> <img src="<?php echo 'http://dev201.viglob.gtvr.com/client_file/themes /default/interface/FR/menuAdmin.png'; ?>" border="0" /> </a> <a href="congres-2012"> <img src="<?php

How can I get my mesh has gone off screen?

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问题 I cannot figure out how to detect it going off screen, can anybody help? I am using WebGL and Three.js. 回答1: You can use Frustum testing, a little like this: // Create a new Frustum object (for efficiency, do this only once) var frustum = new THREE.Frustum(); // Helper matrix (for efficiency, do this only once) var projScreenMatrix = new THREE.Matrix4(); // Set the matrix from camera matrices (which are updated on each renderer.render() call) projScreenMatrix.multiply( camera.projectionMatrix

绝对定位和浮动会脱离文档流

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1.脱离文档流 position : absolute ; // 绝对定位 float : left ; // 浮动 2.不会脱离文档流 position : relative ; // 相对定位来源： CSDN 作者：冰夕_lyn 链接： https://blog.csdn.net/lyn1772671980/article/details/79296307

CSS之定位与脱离文档流与过渡

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CSS介绍实现移动的三种方法可以用 margin 可以用浮动布局可以用定位脱离文档流 <!DOCTYPE html> < html lang = "en" > < head > < meta charset = "utf-8" > < title > 脱离文档流 </ title > < link rel = "stylesheet" href = "脱离文档流.css" /> </ head > < body > < div class = "redDiv" > </ div > < div class = "blueDiv" > < div class = "item" > </ div > </ div > </ body > </ html > body{ margin:0px; } .redDiv{ width: 200px; height: 200px background-color: red; } .blueDiv{ width: 400px; height: 100px; background-color: yellow; float:right; } .item{ width: 20px; height: 100px; background-color: yellow; float:right; } 定位定位浮动行标签 inline 不能设置宽-高

Adding physics body to Sprite in SpriteKit alters its position fractionally

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问题 I have a Swift / SpriteKit game in which a whole bunch of sprites have physics bodies to detect collision with the player - but otherwise they are not supposed to move. My issue is that as soon as I add a physics body, the sprite appears to move fractionally. More specifically its position changes by a small fraction (like 0.0003). Initially such a small change does not matter, but it keeps changing like this until the sprite actually moves onscreen and messes up the game. To narrow it down I

Android: EditText listener for cursor position change [duplicate]

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问题 This question already has answers here : Android EditText listener for cursor position change (8 answers) Closed 4 years ago . I'm looking for a way to detect a cursor position changed in an EditText. I couldn't find anything in the documentation so far. Has anyone solved this already? 回答1: You can override onSelectionChanged (int selStart, int selEnd) to get notified about selection changes. If the cursor is moved, this is called as well (in this case selStart == selEnd) 来源： https:/

Get current cursor lower left position so that tooltip could be displayed properly

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问题 I'm trying to display the tooltip by calling "ToolTip.Show(String, IWin32Window, Point)", but I wanted to do it like what Windows explorer does - displays the tooltip at the lower left corner of the cursor. I could get the mouse position by "MousePosition", but how could I get its lower left corner position? Thanks, 回答1: If nobody comes up with a better answer you can try this: toolTip1.Show("Am I where you want me to be?", this, this.PointToClient(MousePosition).X, this.PointToClient

Accessing words around a positional match in Lucene

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问题 Given a term match in a document, what’s the best way to access words around that match? I have read this article http://searchhub.org//2009/05/26/accessing-words-around-a-positional-match-in-lucene/, but the problem is that the Lucene API completely changed since this post(2009), could someone point to me how to do this in newer version of Lucene, such as Lucene 4.6.1? EDIT : I figure this out now ( The postings APIs (TermEnum, TermDocsEnum, TermPositionsEnum) have been removed in favor of