{"id":115,"date":"2017-11-02T22:10:14","date_gmt":"2017-11-02T14:10:14","guid":{"rendered":"https:\/\/blog.indeex.club\/?p=115"},"modified":"2020-06-20T23:01:07","modified_gmt":"2020-06-20T15:01:07","slug":"%e7%9f%a9%e9%98%b5","status":"publish","type":"post","link":"https:\/\/blog.indeex.club\/index.php\/2017\/11\/02\/%e7%9f%a9%e9%98%b5\/","title":{"rendered":"\u77e9\u9635"},"content":{"rendered":"<hr \/>\n<h4>1. \u77e9\u9635\u7684\u6765\u6e90<\/h4>\n<p>\u82f1\u6587matrix\u5c31\u662f\u77e9\u9635\u7684\u610f\u601d\uff0c\u7b80\u5355\u7684\u8bf4\uff0c<strong>\u77e9\u9635\u7528\u6765\u6539\u53d8\u9876\u70b9\u4f4d\u7f6e\u4fe1\u606f<\/strong>\u7684\uff0c\u5148\u7262\u8bb0\u8fd9\u53e5\u8bdd\uff0c\u7136\u540e\u6211\u4eec\u5148\u4ececanvas2D\u5165\u624b\uff0c\u6211\u4eec\u6709\u4e00\u4e2a100*100\u7684canvas\u753b\u5e03\uff0c\u7136\u540e\u753b\u4e00\u4e2a\u77e9\u5f62\uff1a<\/p>\n<pre><code class=\"language-javascript line-numbers\">&lt;canvas width=\"100\" height=\"100\"&gt;&lt;\/canvas&gt;\nctx.rect(40, 40, 20, 20);\nctx.fill();\n<\/code><\/pre>\n<p>\u8fd9\u6837\u6211\u4eec\u5728\u753b\u5e03\u4e2d\u95f4\u753b\u4e86\u4e00\u4e2a\u77e9\u5f62<\/p>\n<p>\u73b0\u5728\u6211\u4eec\u5e0c\u671b\u5c06\u77e9\u5f62\u5411\u5de6\u79fb\u52a810px\uff1a<\/p>\n<pre><code class=\"language-javascript line-numbers\">ctx.rect(30, 40, 20, 20);\nctx.fill();\n<\/code><\/pre>\n<p><center><br \/>\n<img src=\"http:\/\/hungking.cc\/assets\/imgs\/indeex.cc\/canvas1.png\" alt=\"\u77e9\u9635\" \/><br \/>\n<\/center><\/p>\n<p>\u53ea\u8981\u6539\u53d8rect\u65b9\u6cd5\u7b2c\u4e00\u4e2a\u53c2\u6570\u5c31\u53ef\u4ee5\u5b9e\u73b0\u5de6\u53f3\u79fb\u52a8\uff0c\u56e0\u4e3arect()\u5bf9\u5e94\u7684\u5c31\u662f\u4e00\u4e2a\u77e9\u5f62\uff0c\u662f\u4e00\u4e2a\u5bf9\u8c61\uff0ccanvas2D\u662f\u5bf9\u8c61\u7ea7\u522b\u7684\u753b\u5e03\u64cd\u4f5c\uff0c\u4f46\u57283D\u7684\u4e16\u754c\u91cc\uff0c\u6211\u4eec\u64cd\u4f5c\u7684\u662f\u9876\u70b9\uff1a<\/p>\n<pre data-language=HTML><code class=\"language-markup line-numbers\">&lt;canvas id=\"c\" width=\"200\" height=\"200\"&gt;&lt;\/canvas&gt;\n<\/code><\/pre>\n<pre><code class=\"language-javascript line-numbers\">var canvas = document.getElementById('c');\n        var webgl = canvas.getContext('webgl');\n\n        var vsScript = document.getElementById('shader-vs').innerText;\n        var fsScript = document.getElementById('shader-fs').innerText;\n\n        var vs = webgl.createShader(webgl.VERTEX_SHADER);\n        var fs = webgl.createShader(webgl.FRAGMENT_SHADER);\n\n        webgl.shaderSource(vs, vsScript);\n        webgl.shaderSource(fs, fsScript);\n\n        webgl.compileShader(vs);\n        webgl.compileShader(fs);\n\n        if(!webgl.getShaderParameter(vs, webgl.COMPILE_STATUS)) {\n            alert('error');\n        }\n\n        if(!webgl.getShaderParameter(fs, webgl.COMPILE_STATUS)) {\n            alert('error');\n        }\n\n        var program = webgl.createProgram();\n\n        webgl.attachShader(program, vs);\n        webgl.attachShader(program, fs);\n\n        webgl.linkProgram(program);\n        webgl.useProgram(program);\n\n        var aPosition = webgl.getAttribLocation(program, 'aPosition');\n\n        webgl.enableVertexAttribArray(aPosition);\n\n        var aPo = [\n            -0.2, -0.2, 0,\n            0.2, -0.2, 0,\n            0.2, 0.2, 0,\n            -0.2, 0.2, 0\n        ];\n\n        var aIndex = [0, 1, 2, 0, 2, 3];\n\n        webgl.bindBuffer(webgl.ARRAY_BUFFER, webgl.createBuffer());\n        webgl.bufferData(webgl.ARRAY_BUFFER, new Float32Array(aPo), webgl.STATIC_DRAW);\n        webgl.vertexAttribPointer(aPosition, 3, webgl.FLOAT, false, 0, 0);\n\n        webgl.bindBuffer(webgl.ELEMENT_ARRAY_BUFFER, webgl.createBuffer());\n        webgl.bufferData(webgl.ELEMENT_ARRAY_BUFFER, new Uint16Array(aIndex), webgl.STATIC_DRAW);\n\n\n        webgl.drawElements(webgl.TRIANGLES, 6, webgl.UNSIGNED_SHORT, 0);\n\n\n        btn.onclick = function() {\n            var aPo = [\n                -0.3, -0.2, 0,\n                0.1, -0.2, 0,\n                0.1, 0.2, 0,\n                -0.3, 0.2, 0\n            ];\n\n            webgl.bindBuffer(webgl.ARRAY_BUFFER, webgl.createBuffer());\n            webgl.bufferData(webgl.ARRAY_BUFFER, new Float32Array(aPo), webgl.STATIC_DRAW);\n            webgl.vertexAttribPointer(aPosition, 3, webgl.FLOAT, false, 0, 0);\n\n            webgl.drawElements(webgl.TRIANGLES, 6, webgl.UNSIGNED_SHORT, 0);\n\n            btn.onclick = function() {};\n        };\n<\/code><\/pre>\n<p>\u540c\u6837\u4e5f\u53ef\u4ee5\u5f97\u5230\u4e00\u4e2a\u77e9\u5f62\u3002<\/p>\n<p>\u8fd9\u91cc\u6211\u4eec\u53ef\u4ee5\u770b\u5230position\u8fd9\u4e2a\u6570\u7ec4\uff0c\u8fd9\u91cc\u9762\u5b58\u7684\u5c31\u662f\u77e9\u5f624\u4e2a\u70b9\u7684\u9876\u70b9\u4fe1\u606f\uff0c\u6211\u4eec\u53ef\u4ee5\u901a\u8fc7\u64cd\u4f5c\u6539\u53d8\u5176\u4e2d\u70b9\u7684\u503c\u6765\u6539\u53d8\u4f4d\u7f6e\uff0c\u4f46\u662f\u8fd9\u6837\u4e0d\u7d2f\u5417\uff1f\u6709\u6ca1\u6709\u53ef\u4ee5\u4e00\u6b21\u6027\u6539\u53d8\u67d0\u4e2a\u7269\u4f53\u6240\u6709\u9876\u70b9\u7684\u65b9\u5f0f\u5462\uff1f<\/p>\n<p>\u7b54\u6848\u662f\u80af\u5b9a\u7684\uff0c\u90a3\u5c31\u662f\u77e9\u9635matrix\u3002<\/p>\n<p><center><br \/>\n1  0  0  0<br \/>\n0  1  0  0<br \/>\n0  0  1  0<br \/>\n0  0  0  1<br \/>\n<\/center><\/p>\n<p>\u4ee5\u5355\u4f4d\u77e9\u9635\u6765\u8bf4\uff0c\u6211\u4eec\u7528\u8fd9\u4e2a\u5355\u4f4d\u77e9\u9635\u4e58\u4e00\u4e2a\u9876\u70b9(2,1,0)\uff1a<\/p>\n<p><center><br \/>\n<img src=\"http:\/\/hungking.cc\/assets\/imgs\/indeex.cc\/matrix2.png\" alt=\"\u77e9\u9635\" \/><br \/>\n<\/center><\/p>\n<p>\u8fd9\u662f\u6211\u4eec\u770b\u4e0d\u5230\u4ec0\u4e48\u53d8\u5316\uff0c\u90a3\u6211\u4eec\u6362\u4e00\u4e2a\u77e9\u9635\u6765\u770b\uff1a<\/p>\n<p><center><br \/>\n1  0  0  1<br \/>\n0  1  0  0<br \/>\n0  0  1  0<br \/>\n0  0  0  1<br \/>\n<\/center><\/p>\n<p>\u518d\u4e58\u4e4b\u524d\u90a3\u4e2a\u9876\u70b9:<\/p>\n<p><center><br \/>\n<img src=\"http:\/\/hungking.cc\/assets\/imgs\/indeex.cc\/matrix3.png\" alt=\"\u77e9\u9635\" \/><br \/>\n<\/center><\/p>\n<p>\u518d\u591a\u7528\u51e0\u4e2a\u9876\u70b9\u8bd5\u4e00\u4e0b\u5c31\u4f1a\u53d1\u73b0\uff0c\u65e0\u8bba\u6211\u4eec\u7528\u54ea\u4e2a\u9876\u70b9\uff0c\u90fd\u4f1a\u5f97\u5230\u8fd9\u6837\u7684\u4e00\u4e2ax\u5750\u6807+1\u8fd9\u6837\u4e00\u4e2a\u7ed3\u679c\uff0c\u8fd9\u6b63\u597d\u80fd\u89e3\u51b3\u6211\u4eec\u524d\u9762\u63d0\u5230\u7684\u4e00\u6b21\u6027\u6539\u53d8\u9876\u70b9\u4f4d\u7f6e\u95ee\u9898\u3002<\/p>\n<h4>2. \u77e9\u9635\u89c4\u5f8b<\/h4>\n<p>\u6211\u4eec\u6539\u53d8\u4e86\u77e9\u963516\u4e2a\u503c\u4e2d\u7684\u4e00\u4e2a\uff0c\u5c31\u4f7f\u5f97\u77e9\u9635\u6709\u6539\u53d8\u9876\u70b9\u7684\u80fd\u529b\uff0c\u6211\u4eec\u603b\u7ed3\u4e00\u4e0b\u77e9\u9635\u5404\u4e2a\u503c\u7684\u89c4\u5f8b,\u5982\u4e0b\u56fe:<\/p>\n<p><center><br \/>\n1  0  0  <span style='color:red'>X<\/span><br \/>\n0  1  0  <span style='color:red'>Y<\/span><br \/>\n0  0  1  <span style='color:red'>Z<\/span><br \/>\n0  0  0  1<br \/>\n<\/center><\/p>\n<p>\u8fd9\u91cc\u7ea2\u8272\u7684x\uff0cy\uff0cz\u5206\u522b\u5bf9\u5e94\u4e09\u4e2a\u65b9\u5411\u4e0a\u7684\u504f\u79fb:<\/p>\n<p><center><br \/>\n<span style='color:red'>X<\/span>  0  0  0<br \/>\n0  <span style='color:red'>Y<\/span>  0  0<br \/>\n0  0  <span style='color:red'>Z<\/span>  0<br \/>\n0  0  0  1<br \/>\n<\/center><\/p>\n<p>\u8fd9\u91cc\u84dd\u8272\u7684x\uff0cy\uff0cz\u5206\u522b\u5bf9\u5e94\u4e09\u4e2a\u65b9\u5411\u4e0a\u7684\u7f29\u653e<\/p>\n<p>\u7136\u540e\u5c31\u662f\u56f4\u7ed5\u5404\u4e2a\u8f74\u7684\u65cb\u8f6c\u77e9\u9635\u4e86\uff1a<\/p>\n<p><center><br \/>\n<img src=\"http:\/\/hungking.cc\/assets\/imgs\/indeex.cc\/matrix4.png\" alt=\"\u77e9\u9635\" \/><br \/>\n<\/center><\/p>\n<p>\u8fd8\u6709\u526a\u5207(skew)\u6548\u679c\u7684\u53d8\u6362\u77e9\u9635\uff0c\u8fd9\u91cc\u7528\u4e2ax\u8f74\u7684\u4f8b\u5b50\u6765\u4f53\u73b0\uff1a<\/p>\n<p><center><br \/>\n<img src=\"http:\/\/hungking.cc\/assets\/imgs\/indeex.cc\/matrix5.png\" alt=\"\u77e9\u9635\" \/><br \/>\n<\/center><\/p>\n<p>\u8fd9\u91cc\u90fd\u662f\u67d0\u4e00\u79cd\u5355\u4e00\u6548\u679c\u7684\u53d8\u5316\u77e9\u9635\uff0c\u53ef\u4ee5\u76f8\u4e58\u914d\u5408\u4f7f\u7528\uff0c\u9996\u5148\uff0c\u4f3c\u4e4e\u6240\u6709\u7684\u64cd\u4f5c\u90fd\u662f\u56f4\u7ed5\u7740\u7ea2\u6846\u8fd9\u4e00\u5757\u6765\u7684\uff1a<\/p>\n<p><center><br \/>\n<img src=\"http:\/\/hungking.cc\/assets\/imgs\/indeex.cc\/matrix6.png\" alt=\"\u77e9\u9635\" \/><br \/>\n<\/center><\/p>\n<p>\u8fd9\u91cc\u4e5f\u6bd4\u8f83\u597d\u7406\u89e3\uff0c\u56e0\u4e3a\u77e9\u9635\u6bcf\u4e00\u884c\u5bf9\u5e94\u4e86\u4e2a\u5750\u6807\uff1a<\/p>\n<p><center><br \/>\n<img src=\"http:\/\/hungking.cc\/assets\/imgs\/indeex.cc\/matrix7.png\" alt=\"\u77e9\u9635\" \/><br \/>\n<\/center><\/p>\n<p>\u90a3\u4e48\u95ee\u9898\u662f\uff0c\u6700\u4e0b\u9762\u90a3\u884c\u5e72\u5565\u7528\u7684\uff1f<\/p>\n<p>\u4e00\u4e2a\u9876\u70b9\uff0c\u5750\u6807(x,y,z)\uff0c\u8fd9\u4e2a\u662f\u5728\u7b1b\u5361\u5c14\u5750\u6807\u7cfb\u4e2d\u7684\u8868\u793a\uff0c\u57283D\u4e16\u754c\u4e2d\u6211\u4eec\u4f1a\u5c06\u5176\u8f6c\u6362\u4e3a<a class=\"wp-editor-md-post-content-link\" href=\"https:\/\/zh.wikipedia.org\/zh-cn\/%E9%BD%90%E6%AC%A1%E5%9D%90%E6%A0%87\">\u9f50\u6b21\u5750\u6807\u7cfb<\/a>\uff0c\u4e5f\u5c31\u662f\u53d8\u6210\u4e86(x,y,z,w)\u3002<\/p>\n<p>\u90a3\u4e48\u9f50\u6b21\u5750\u6807\u6709\u4ec0\u4e48\u7528\u5462\uff1f\u5f88\u591a\u4e66\u4e0a\u90fd\u8bf4\u9f50\u6b21\u5750\u6807\u53ef\u4ee5\u533a\u5206\u4e00\u4e2a\u5750\u6807\u662f\u70b9\u8fd8\u662f\u5411\u91cf\uff0c\u70b9\u7684\u8bdd\u9f50\u6b21\u9879\u662f1\uff0c\u5411\u91cf\u7684\u8bdd\u9f50\u6b21\u9879\u662f0(\u6240\u4ee5\u4e4b\u524d\u56fe\u4e2dw=1)\u3002<\/p>\n<p>\u4e5f\u5c31\u662f\u8bf4\u5bf9\u4e8e3D\u4e16\u754c\u4e2d\u7684Matrix\uff0c<strong>\u9f50\u6b21\u9879\u53ef\u4ee5\u8ba9\u7269\u4f53\u6709\u900f\u89c6\u7684\u6548\u679c<\/strong><\/p>\n<p>\u6211\u4eec\u4ee5\u900f\u89c6\u77e9\u9635\u4e3a\u4f8b\uff1a<\/p>\n<p><center><br \/>\n<img src=\"http:\/\/hungking.cc\/assets\/imgs\/indeex.cc\/matrix1.png\" alt=\"\u77e9\u9635\" \/><br \/>\n<\/center><\/p>\n<p>\u5728\u7b2c\u56db\u884c\u7684\u7b2c\u4e09\u5217\u6709\u503c\uff0c\u800c\u4e0d\u50cf\u4e4b\u524d\u7684\u662f0\uff1b\u8fd8\u6709\u7b2c\u56db\u884c\u7684\u7b2c\u56db\u5217\u662f0\uff0c\u800c\u4e0d\u662f\u4e4b\u524d\u76841\u3002\u8fd9\u91cc\u6d89\u53ca\u5230\u6b63\u89c6\u548c\u900f\u89c6\u6295\u5f71\u77e9\u9635\uff0c\u8fd9\u91cc\u4e0d\u505a\u6df1\u7a76\uff0c\u6211\u4eec\u5148\u53ea\u8003\u8651\u7ea2\u6846\u90e8\u5206\u7684\u77e9\u9635\u6240\u5e26\u6765\u7684\u53d8\u5316\u3002<\/p>\n<h4>3. 3D\u5750\u6807\u7cfb<\/h4>\n<p>\u4e00\u822c\u5730\uff0c\u6211\u4eec\u5e38\u7528\u7684\u77e9\u9635\u6709\uff1a<\/p>\n<ol>\n<li>MMatrix \uff0d\uff0d\uff0d>  \u6a21\u578b\u77e9\u9635\uff08\u7528\u4e8e\u7269\u4f53\u5728\u4e16\u754c\u4e2d\u53d8\u5316\uff09<\/li>\n<li>VMatrix \uff0d\uff0d\uff0d>  \u89c6\u56fe\u77e9\u9635\uff08\u7528\u4e8e\u4e16\u754c\u4e2d\u6444\u50cf\u673a\u7684\u53d8\u5316\uff09<\/li>\n<li>PMatrix \uff0d\uff0d\uff0d>  \u900f\u89c6\u77e9\u9635<\/li>\n<\/ol>\n<p>\u6a21\u578b\u77e9\u9635\u548c\u89c6\u56fe\u77e9\u9635\u4e00\u822c\u662f\u4eff\u5c04\u53d8\u6362\uff0c\u4e5f\u5c31\u662f\u5e73\u79fb\u3001\u65cb\u8f6c\u4e4b\u7c7b\u7684\u53d8\u5316\uff0c\u4e00\u4e2a\u662f\u5148\u65cb\u8f6c\uff0c\u540e\u5e73\u79fb(MMatrix)\uff0c\u53e6\u4e00\u4e2a\u662f\u5148\u5e73\u79fb\uff0c\u540e\u65cb\u8f6c(VMatrix)\uff0c\u7ed9\u4eba\u7684\u611f\u89c9\uff0c\u4e00\u4e2a\u662f\u7269\u4f53\u672c\u8eab\u5728\u53d8\u5316\uff0c\u4e00\u4e2a\u662f\u6444\u50cf\u673a\u5728\u53d8\u5316\u3002<\/p>\n<p>\u90a3\u4e48\u5bf9\u4e8ePMatrix\uff0c\u6211\u4eec\u5148\u601d\u80032D\u548c3D\u7684\u533a\u522b\u3002\u5b83\u4eec\u5728DOM\u4e2d\u7684\u5bbd\u9ad8\u90fd\u662f\u901a\u8fc7\u8bbe\u7f6ecanvas\u6807\u7b7e\u4e0awidth\u548cheight\u5c5e\u6027\u6765\u8bbe\u7f6e\u7684\uff0c\u8fd9\u5f88\u4e00\u81f4\u3002\u4f46\u57283D\u4e2d\u6211\u4eec\u7684\u5750\u6807\u7a7a\u95f4\u662f-1 ~ 1\uff1a<\/p>\n<p><center><br \/>\n<img src=\"http:\/\/hungking.cc\/assets\/imgs\/indeex.cc\/matrix8.png\" alt=\"\u77e9\u9635\" \/><br \/>\n(width=800,height=600\u4e2dcanvas2D\u4e2d\uff0c\u77e9\u5f62\u5de6\u9876\u70b9\u5c45\u4e2d\u65f6\uff0crect\u65b9\u6cd5\u7684\u524d\u4e24\u4e2a\u53c2\u6570)<br \/>\n<\/center><\/p>\n<p><center><br \/>\n<img src=\"http:\/\/hungking.cc\/assets\/imgs\/indeex.cc\/matrix9.png\" alt=\"\u77e9\u9635\" \/><br \/>\n(width=800,height=600\u4e2d3D\u4e2d\uff0c\u77e9\u5f62\u5de6\u9876\u70b9\u5c45\u4e2d\u65f6\uff0c\u5de6\u9876\u70b9\u7684\u5750\u6807)<br \/>\n<\/center><\/p>\n<p>\u6211\u4eec\u4f1a\u53d1\u73b0x\u5750\u6807\u5c0f\u4e8e-1\u6216\u8005\u5927\u4e8e1\u7684\u7684\u8bdd\u5c31\u4e0d\u4f1a\u5c55\u793a\u4e86(y\u540c\u7406)\uff0cx\u548cy\u5f88\u597d\u7406\u89e3\uff0c\u56e0\u4e3a\u5c4f\u5e55\u662f2D\u7684\uff0c\u753b\u5e03\u662f2D\u7684\uff0c2D\u5c31\u53ea\u6709x\uff0cy\uff0c\u4e5f\u5c31\u662f\u6211\u4eec\u76f4\u89c2\u4e0a\u6240\u770b\u5230\u7684\u4e1c\u897f,\u90a3z\u5750\u6807\u9760\u4ec0\u4e48\u6765\u770b\u5230\u5462\uff1f<\/p>\n<h5>\u5bf9\u6bd4<\/h5>\n<p>\u9996\u5148\u81f3\u5c11\u6709\u4e24\u4e2a\u7269\u4f53\uff0c\u5b83\u4eec\u7684z\u5750\u6807\u4e0d\u540c\uff0c\u8fd9\u4e2az\u5750\u6807\u4f1a\u51b3\u5b9a\u5b83\u4eec\u5728\u5c4f\u5e55\u4e0a\u663e\u793a\u7684\u4f4d\u7f6e\uff08\u6216\u8005\u8bf4\u8986\u76d6\uff09\u7684\u60c5\u666f:<\/p>\n<pre><code class=\"language-javascript line-numbers\">var aPo = [\n    -0.2, -0.2, -0.5,\n    0.2, -0.2, -0.5,\n    0.2, 0.2, -0.5,\n    -0.2, 0.2, -0.5\n];\n\nvar aIndex = [0, 1, 2, 0, 2, 3];\n\nwebgl.bindBuffer(webgl.ARRAY_BUFFER, webgl.createBuffer());\nwebgl.bufferData(webgl.ARRAY_BUFFER, new Float32Array(aPo), webgl.STATIC_DRAW);\nwebgl.vertexAttribPointer(aPosition, 3, webgl.FLOAT, false, 0, 0);\n\nwebgl.vertexAttrib3f(aColor, 1, 0, 0);\n\nwebgl.bindBuffer(webgl.ELEMENT_ARRAY_BUFFER, webgl.createBuffer());\nwebgl.bufferData(webgl.ELEMENT_ARRAY_BUFFER, new Uint16Array(aIndex), webgl.STATIC_DRAW);\n\n\/\/ \u5148\u753b\u4e00\u4e2az\u8f74\u662f-0.5\u7684\u77e9\u5f62\uff0c\u989c\u8272\u662f\u7ea2\u8272\nwebgl.drawElements(webgl.TRIANGLES, 6, webgl.UNSIGNED_SHORT, 0);\n\naPo = [\n    0, -0.4, -0.8,\n    0.4, -0.4, -0.8,\n    0.4, 0, -0.8,\n    0, 0, -0.8\n];\n\nwebgl.bindBuffer(webgl.ARRAY_BUFFER, webgl.createBuffer());\nwebgl.bufferData(webgl.ARRAY_BUFFER, new Float32Array(aPo), webgl.STATIC_DRAW);\nwebgl.vertexAttribPointer(aPosition, 3, webgl.FLOAT, false, 0, 0);\n\nwebgl.vertexAttrib3f(aColor, 0, 1, 0);\n\n\/\/ \u518d\u753b\u4e00\u4e2az\u8f74\u662f-0.8\u7684\u77e9\u5f62\uff0c\u989c\u8272\u662f\u7eff\u8272\nwebgl.drawElements(webgl.TRIANGLES, 6, webgl.UNSIGNED_SHORT, 0);\n<\/code><\/pre>\n<p>\u6ce8\u610f\u5f00\u542f\u6df1\u5ea6\u6d4b\u8bd5\uff08\u4e0d\u5f00\u542f\u6df1\u5ea6\u6d4b\u8bd5\uff0c\u8ba1\u7b97\u673a\u4f1a\u65e0\u89c6\u9876\u70b9\u7684z\u5750\u6807\u4fe1\u606f\uff0c\u53ea\u5173\u6ce8drawElements(drawArrays)\u65b9\u6cd5\u7684\u8c03\u7528\u987a\u5e8f\uff0c\u6700\u540e\u753b\u7684\u4e00\u5b9a\u662f\u6700\u4e0a\u4e00\u5c42\uff09<br \/>\n\u4ee3\u7801\u4e2dA\u77e9\u5f62(\u7ea2\u8272)\u7684z\u503c\u4e3a-0.5,B\u77e9\u5f62(\u7eff\u8272)\u7684z\u503c\u4e3a-0.8\uff0c\u6700\u7ec8\u753b\u5e03\u4e0a\u8c01\u4f1a\u8986\u76d6\u8c01\u5462\uff1f<\/p>\n<p>\u5982\u679cx\uff1d0.5\u548cx\uff1d0.8\u4e4b\u95f4\uff0c\u8c01\u5728\u5de6\uff0c\u8c01\u5728\u53f3\uff0c\u8fd9\u4e2a\u5f88\u597d\u786e\u5b9a\uff0c\u56e0\u4e3a\u5c4f\u5e55\u5c31\u662f2D\u7684\uff0c\u753b\u5e03\u5750\u6807x\u8f74\u5c31\u662f\u53f3\u5927\u5de6\u5c0f\u3002<\/p>\n<p>\u201c\u5de6\u624b\u5750\u6807\u7cfb\u201d\u548c\u201c\u53f3\u624b\u5750\u6807\u7cfb\u201d\u4e2dx\uff0cy\u8f74\u662f\u4e00\u6837\u7684\uff0c\u5982\u56fe\u6240\u793a\uff1a<\/p>\n<p><center><br \/>\n<img src=\"http:\/\/hungking.cc\/assets\/imgs\/indeex.cc\/matrix10.png\" alt=\"\u77e9\u9635\" \/><br \/>\n<\/center><\/p>\n<p>\u800c\u5de6\u624b\u5750\u6807\u7cfb\u548c\u53f3\u624b\u5750\u6807\u7cfb\u4e2d\u7684z\u8f74\u6b63\u65b9\u5411\u4e0d\u540c\uff0c\u4e00\u4e2a\u662f\u5c4f\u5e55\u5411\u5185\uff0c\u4e00\u4e2a\u662f\u5c4f\u5e55\u5411\u5916\uff0c\u6240\u4ee5\u53ef\u4ee5\u8ba4\u4e3a\uff1a\u5982\u679c\u5de6\u624b\u5750\u6807\u7cfb\u4e0b\uff0cB\u77e9\u5f62(z=-0.8)\u5c0f\u4e8eA\u77e9\u5f62(z=-0.5)\uff0c\u90a3\u4e48\u7406\u5e94\u8986\u76d6\u4e86A\u77e9\u5f62\uff0c\u53f3\u624b\u5750\u6807\u7cfb\u6070\u6070\u76f8\u53cd\uff1a<\/p>\n<pre><code class=\"language-javascript line-numbers\">var oC = document.getElementById('c');\n        var webgl = oC.getContext('webgl');\n\n        var vsScript = document.getElementById('shader-vs').innerText;\n        var fsScript = document.getElementById('shader-fs').innerText;\n\n        var vs = webgl.createShader(webgl.VERTEX_SHADER);\n        var fs = webgl.createShader(webgl.FRAGMENT_SHADER);\n\n        webgl.shaderSource(vs, vsScript);\n        webgl.shaderSource(fs, fsScript);\n\n        webgl.compileShader(vs);\n        webgl.compileShader(fs);\n\n        if(!webgl.getShaderParameter(vs, webgl.COMPILE_STATUS)) {\n            alert('error');\n        }\n\n        if(!webgl.getShaderParameter(fs, webgl.COMPILE_STATUS)) {\n            alert('error');\n        }\n\n        var program = webgl.createProgram();\n\n        webgl.attachShader(program, vs);\n        webgl.attachShader(program, fs);\n\n        webgl.linkProgram(program);\n        webgl.useProgram(program);\n\n        var aPosition = webgl.getAttribLocation(program, 'aPosition');\n        var aColor = webgl.getAttribLocation(program, 'aColor');\n\n        webgl.enableVertexAttribArray(aPosition);\n\n        webgl.enable(webgl.DEPTH_TEST);\n\n        var aPo = [\n            -0.2, -0.2, -0.5,\n            0.2, -0.2, -0.5,\n            0.2, 0.2, -0.5,\n            -0.2, 0.2, -0.5\n        ];\n\n        var aIndex = [0, 1, 2, 0, 2, 3];\n\n        webgl.bindBuffer(webgl.ARRAY_BUFFER, webgl.createBuffer());\n        webgl.bufferData(webgl.ARRAY_BUFFER, new Float32Array(aPo), webgl.STATIC_DRAW);\n        webgl.vertexAttribPointer(aPosition, 3, webgl.FLOAT, false, 0, 0);\n\n        webgl.vertexAttrib3f(aColor, 1, 0, 0);\n\n        webgl.bindBuffer(webgl.ELEMENT_ARRAY_BUFFER, webgl.createBuffer());\n        webgl.bufferData(webgl.ELEMENT_ARRAY_BUFFER, new Uint16Array(aIndex), webgl.STATIC_DRAW);\n\n        \/\/ \u5148\u753b\u4e00\u4e2az\u8f74\u662f-0.1\u7684\u77e9\u5f62\uff0c\u989c\u8272\u662f\u7ea2\u8272\n        webgl.drawElements(webgl.TRIANGLES, 6, webgl.UNSIGNED_SHORT, 0);\n\n        aPo = [\n            0, -0.4, -0.8,\n            0.4, -0.4, -0.8,\n            0.4, 0, -0.8,\n            0, 0, -0.8\n        ];\n\n        webgl.bindBuffer(webgl.ARRAY_BUFFER, webgl.createBuffer());\n        webgl.bufferData(webgl.ARRAY_BUFFER, new Float32Array(aPo), webgl.STATIC_DRAW);\n        webgl.vertexAttribPointer(aPosition, 3, webgl.FLOAT, false, 0, 0);\n\n        webgl.vertexAttrib3f(aColor, 0, 1, 0);\n\n        \/\/ \u518d\u753b\u4e00\u4e2az\u8f74\u662f-0.2\u7684\u77e9\u5f62\uff0c\u989c\u8272\u662f\u7eff\u8272\n        webgl.drawElements(webgl.TRIANGLES, 6, webgl.UNSIGNED_SHORT, 0);\n<\/code><\/pre>\n<p>\u8fd9\u91cc\u6211\u4eec\u53d1\u73b0\uff0c\u8fd9\u91cc\u7684\u88c1\u526a\u7a7a\u95f4\u662f\u6309\u7167\u5de6\u624b\u5750\u6807\u7cfb\u6765\u7684\u3002\u88c1\u526a\u7a7a\u95f4\u5c31\u662f\u7528\u6765\u628a\u8d85\u8fc7\u5750\u6807\u7a7a\u95f4\u7684\u4e1c\u897f\u5207\u5272\u6389(-1 ~ 1)\uff0c\u5176\u4e2d\u88c1\u526a\u7a7a\u95f4\u7684z\u5750\u6807\u5c31\u662f\u6309\u7167\u5de6\u624b\u5750\u6807\u7cfb\u6765\u7684\u3002<\/p>\n<p>\u65e0\u8bba\u662fPMatrix(\u900f\u89c6\u6295\u5f71\u77e9\u9635)\u8fd8\u662fOMatrix(\u6b63\u89c6\u6295\u5f71\u77e9\u9635)\uff0c\u5b83\u4eec\u90fd\u4f1a\u64cd\u4f5c\u88c1\u526a\u7a7a\u95f4\uff0c\u5176\u4e2d\u6709\u4e00\u6b65\u5c31\u662f\u5c06\u5de6\u624b\u5750\u6807\u7cfb\u7ed9\u8f6c\u6362\u4e3a\u53f3\u624b\u5750\u6807\u7cfb\uff1a<\/p>\n<p><center><br \/>\n1  0  0  0<br \/>\n0  1  0  0<br \/>\n0  0  -1  0<br \/>\n0  0  0  1<br \/>\n<\/center><\/p>\n<p>\u6211\u4eec\u53ea\u9700\u8981\u5c06z\u8f74\u53cd\u8f6c\uff0c\u5c31\u53ef\u4ee5\u5f97\u5230\u5c06\u88c1\u526a\u7a7a\u95f4\u7531\u5de6\u624b\u5750\u6807\u7cfb\u8f6c\u53d8\u4e3a\u53f3\u624b\u5750\u6807\u7cfb\u4e86\u3002<\/p>\n<pre><code class=\"language-javascript line-numbers\">var oC = document.getElementById('c');\n        var webgl = oC.getContext('webgl');\n\n        var vsScript = document.getElementById('shader-vs').innerText;\n        var fsScript = document.getElementById('shader-fs').innerText;\n\n        var vs = webgl.createShader(webgl.VERTEX_SHADER);\n        var fs = webgl.createShader(webgl.FRAGMENT_SHADER);\n\n        webgl.shaderSource(vs, vsScript);\n        webgl.shaderSource(fs, fsScript);\n\n        webgl.compileShader(vs);\n        webgl.compileShader(fs);\n\n        if(!webgl.getShaderParameter(vs, webgl.COMPILE_STATUS)) {\n            alert('error');\n        }\n\n        if(!webgl.getShaderParameter(fs, webgl.COMPILE_STATUS)) {\n            alert('error');\n        }\n\n        var program = webgl.createProgram();\n\n        webgl.attachShader(program, vs);\n        webgl.attachShader(program, fs);\n\n        webgl.linkProgram(program);\n        webgl.useProgram(program);\n\n        var aPosition = webgl.getAttribLocation(program, 'aPosition');\n        var aColor = webgl.getAttribLocation(program, 'aColor');\n\n        webgl.enableVertexAttribArray(aPosition);\n\n        var uMatrix = webgl.getUniformLocation(program, 'uMatrix');\n\n        webgl.uniformMatrix4fv(uMatrix, false, [\n            1,  0,  0,  0,\n            0,  1,  0,  0,\n            0,  0,  -1,  0,\n            0,  0,  0,  1\n        ])\n\n        webgl.enable(webgl.DEPTH_TEST);\n\n        var aPo = [\n            -0.2, -0.2, -0.5,\n            0.2, -0.2, -0.5,\n            0.2, 0.2, -0.5,\n            -0.2, 0.2, -0.5\n        ];\n\n        var aIndex = [0, 1, 2, 0, 2, 3];\n\n        webgl.bindBuffer(webgl.ARRAY_BUFFER, webgl.createBuffer());\n        webgl.bufferData(webgl.ARRAY_BUFFER, new Float32Array(aPo), webgl.STATIC_DRAW);\n        webgl.vertexAttribPointer(aPosition, 3, webgl.FLOAT, false, 0, 0);\n\n        webgl.vertexAttrib3f(aColor, 1, 0, 0);\n\n        webgl.bindBuffer(webgl.ELEMENT_ARRAY_BUFFER, webgl.createBuffer());\n        webgl.bufferData(webgl.ELEMENT_ARRAY_BUFFER, new Uint16Array(aIndex), webgl.STATIC_DRAW);\n\n        \/\/ \u5148\u753b\u4e00\u4e2az\u8f74\u662f-0.1\u7684\u77e9\u5f62\uff0c\u989c\u8272\u662f\u7ea2\u8272\n        webgl.drawElements(webgl.TRIANGLES, 6, webgl.UNSIGNED_SHORT, 0);\n\n        aPo = [\n            0, -0.4, -0.8,\n            0.4, -0.4, -0.8,\n            0.4, 0, -0.8,\n            0, 0, -0.8\n        ];\n\n        webgl.bindBuffer(webgl.ARRAY_BUFFER, webgl.createBuffer());\n        webgl.bufferData(webgl.ARRAY_BUFFER, new Float32Array(aPo), webgl.STATIC_DRAW);\n        webgl.vertexAttribPointer(aPosition, 3, webgl.FLOAT, false, 0, 0);\n\n        webgl.vertexAttrib3f(aColor, 0, 1, 0);\n\n        \/\/ \u518d\u753b\u4e00\u4e2az\u8f74\u662f-0.2\u7684\u77e9\u5f62\uff0c\u989c\u8272\u662f\u7eff\u8272\n        webgl.drawElements(webgl.TRIANGLES, 6, webgl.UNSIGNED_SHORT, 0);\n<\/code><\/pre>\n<h4>4. \u7ed3\u8bed<\/h4>\n<p>\u81f3\u4e8e\u5177\u4f53\u7684PMatrix\u548cOMatrix\u662f\u600e\u4e48\u6765\u7684\uff0cMatrix\u80fd\u5426\u8fdb\u884c\u4e00\u4e9b\u4f18\u5316\uff0c\u53ef\u4ee5\u591a\u505a\u51e0\u4e2a\u4f8b\u5b50\u6d4b\u8bd5\u4ee5\u4e0b\u3002<\/p>\n<p>code enjoy!   \u0669(\u0e51\u275b\u1d17\u275b\u0e51)\u06f6<\/p>\n<p>\u4f5c\u8005\uff1aindeex<\/p>\n<p>\u94fe\u63a5\uff1a<a class=\"wp-editor-md-post-content-link\" href=\"http:\/\/indeex.cc\/\">http:\/\/indeex.cc<\/a><\/p>\n<p>\u8457\u4f5c\u6743\u5f52\u4f5c\u8005\u6240\u6709\u3002\u5546\u4e1a\u8f6c\u8f7d\u8bf7\u8054\u7cfb\u4f5c\u8005\u83b7\u5f97\u6388\u6743\uff0c\u975e\u5546\u4e1a\u8f6c\u8f7d\u8bf7\u6ce8\u660e\u51fa\u5904\u3002<\/p>\n<hr \/>\n","protected":false},"excerpt":{"rendered":"<p>1. \u77e9\u9635\u7684\u6765\u6e90 \u82f1\u6587matrix\u5c31\u662f\u77e9\u9635\u7684\u610f\u601d\uff0c\u7b80\u5355\u7684\u8bf4\uff0c\u77e9\u9635\u7528\u6765\u6539\u53d8\u9876\u70b9\u4f4d\u7f6e\u4fe1\u606f\u7684\uff0c\u5148\u7262\u8bb0\u8fd9\u53e5\u8bdd<a href=\"https:\/\/blog.indeex.club\/index.php\/2017\/11\/02\/%e7%9f%a9%e9%98%b5\/\" class=\"read-more\">Read More<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[3],"tags":[4],"_links":{"self":[{"href":"https:\/\/blog.indeex.club\/index.php\/wp-json\/wp\/v2\/posts\/115"}],"collection":[{"href":"https:\/\/blog.indeex.club\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blog.indeex.club\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blog.indeex.club\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/blog.indeex.club\/index.php\/wp-json\/wp\/v2\/comments?post=115"}],"version-history":[{"count":1,"href":"https:\/\/blog.indeex.club\/index.php\/wp-json\/wp\/v2\/posts\/115\/revisions"}],"predecessor-version":[{"id":120,"href":"https:\/\/blog.indeex.club\/index.php\/wp-json\/wp\/v2\/posts\/115\/revisions\/120"}],"wp:attachment":[{"href":"https:\/\/blog.indeex.club\/index.php\/wp-json\/wp\/v2\/media?parent=115"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blog.indeex.club\/index.php\/wp-json\/wp\/v2\/categories?post=115"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blog.indeex.club\/index.php\/wp-json\/wp\/v2\/tags?post=115"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}