Простейшая 3D программа — различия между версиями

Материал из Department of Theoretical and Applied Mechanics
Перейти к: навигация, поиск
м (Замена текста — «<source lang="(.*)" first-line="(.*)">» на «<syntaxhighlight lang="$1" line start="$2" enclose="div">»)
м (Замена текста — «</source>» на «</syntaxhighligh>»)
Строка 384: Строка 384:
 
     webGLStart();
 
     webGLStart();
 
}
 
}
</source>
+
</syntaxhighligh>
 
Файл '''"WebGL_Example_v4.html"'''
 
Файл '''"WebGL_Example_v4.html"'''
 
<syntaxhighlight lang="html" line start="1" enclose="div">
 
<syntaxhighlight lang="html" line start="1" enclose="div">
Строка 436: Строка 436:
  
 
</html>
 
</html>
</source>
+
</syntaxhighligh>
 
</toggledisplay>
 
</toggledisplay>
  

Версия 18:55, 8 марта 2015

Виртуальная лаборатория > Простейшая 3D программа

Здесь расположена простейшая 3D программа, написанная на чистом WebGL.


Чтобы работало управление, нужно щелкнуть окно программы.


Скачать WebGL_Example_v4.zip

Текст программы на языке JavaScript (разработчик Цветков Денис): <toggledisplay status=hide showtext="Показать↓" hidetext="Скрыть↑" linkstyle="font-size:default"> Файл "WebGL_Example_v4.js" <syntaxhighlight lang="javascript" line start="1" enclose="div"> // Куб на чистом WebGL // Версия 4.0 от 24.08.2014

function Main_WebGL_example() {

   var gl;
   function initGL(canvas) {
       try {
           gl = canvas.getContext("experimental-webgl");
           gl.viewportWidth = canvas.width;
           gl.viewportHeight = canvas.height;
       } catch (e) {
       }
       if (!gl) {
           alert("Could not initialise WebGL, sorry :-(");
       }
   }
   function getShader(gl, id) {
       var shaderScript = document.getElementById(id);
       if (!shaderScript) {
           return null;
       }
       var str = "";
       var k = shaderScript.firstChild;
       while (k) {
           if (k.nodeType == 3) {
               str += k.textContent;
           }
           k = k.nextSibling;
       }
       var shader;
       if (shaderScript.type == "x-shader/x-fragment") {
           shader = gl.createShader(gl.FRAGMENT_SHADER);
       } else if (shaderScript.type == "x-shader/x-vertex") {
           shader = gl.createShader(gl.VERTEX_SHADER);
       } else {
           return null;
       }
       gl.shaderSource(shader, str);
       gl.compileShader(shader);
       if (!gl.getShaderParameter(shader, gl.COMPILE_STATUS)) {
           alert(gl.getShaderInfoLog(shader));
           return null;
       }
       return shader;
   }


   var shaderProgram;
   function initShaders() {
       var fragmentShader = getShader(gl, "shader-fs");
       var vertexShader = getShader(gl, "shader-vs");
       shaderProgram = gl.createProgram();
       gl.attachShader(shaderProgram, vertexShader);
       gl.attachShader(shaderProgram, fragmentShader);
       gl.linkProgram(shaderProgram);
       if (!gl.getProgramParameter(shaderProgram, gl.LINK_STATUS)) {
           alert("Could not initialise shaders");
       }
       gl.useProgram(shaderProgram);
       shaderProgram.vertexPositionAttribute = gl.getAttribLocation(shaderProgram, "aVertexPosition");
       gl.enableVertexAttribArray(shaderProgram.vertexPositionAttribute);
       shaderProgram.textureCoordAttribute = gl.getAttribLocation(shaderProgram, "aTextureCoord");
       gl.enableVertexAttribArray(shaderProgram.textureCoordAttribute);
       shaderProgram.pMatrixUniform = gl.getUniformLocation(shaderProgram, "uPMatrix");
       shaderProgram.mvMatrixUniform = gl.getUniformLocation(shaderProgram, "uMVMatrix");
       shaderProgram.samplerUniform = gl.getUniformLocation(shaderProgram, "uSampler");
   }


   function handleLoadedTexture(textures) {
       gl.pixelStorei(gl.UNPACK_FLIP_Y_WEBGL, true);
       gl.bindTexture(gl.TEXTURE_2D, textures[0]);
       gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, gl.RGBA, gl.UNSIGNED_BYTE, textures[0].image);
       gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.NEAREST);
       gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.NEAREST);
       gl.bindTexture(gl.TEXTURE_2D, textures[1]);
       gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, gl.RGBA, gl.UNSIGNED_BYTE, textures[1].image);
       gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.LINEAR);
       gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR);
       gl.bindTexture(gl.TEXTURE_2D, textures[2]);
       gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, gl.RGBA, gl.UNSIGNED_BYTE, textures[2].image);
       gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.LINEAR);
       gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR_MIPMAP_NEAREST);
       gl.generateMipmap(gl.TEXTURE_2D);
       gl.bindTexture(gl.TEXTURE_2D, null);
   }


   var crateTextures = Array();
   function initTexture() {
       var crateImage = new Image();
       for (var i=0; i < 3; i++) {
           var texture = gl.createTexture();
           texture.image = crateImage;
           crateTextures.push(texture);
       }
       crateImage.onload = function () {
           handleLoadedTexture(crateTextures)
       }
       crateImage.src = "teormeh.png";
   }


   var mvMatrix = mat4.create();
   var mvMatrixStack = [];
   var pMatrix = mat4.create();
   //function mvPushMatrix() {
   //    var copy = mat4.create();
   //    mat4.set(mvMatrix, copy);
   //    mvMatrixStack.push(copy);
   //}
   //
   //function mvPopMatrix() {
   //    if (mvMatrixStack.length == 0) {
   //        throw "Invalid popMatrix!";
   //    }
   //    mvMatrix = mvMatrixStack.pop();
   //}


   function setMatrixUniforms() {
       gl.uniformMatrix4fv(shaderProgram.pMatrixUniform, false, pMatrix);
       gl.uniformMatrix4fv(shaderProgram.mvMatrixUniform, false, mvMatrix);
   }


   function degToRad(degrees) {
       return degrees * Math.PI / 180;
   }


   var xRot = 0;
   var xSpeed = 0;
   var yRot = 0;
   var ySpeed = 0;
   var z = -4.0;
   var filter = 1;


   var currentlyPressedKeys = {};
   function handleKeyDown(event) {
       currentlyPressedKeys[event.keyCode] = true;
       if (String.fromCharCode(event.keyCode) == "F") {
           filter += 1;
           if (filter == 3) {
               filter = 0;
           }
       }
       if (event.keyCode == "36") {                            // TODO удалить
           mat4.identity(rotate_buf);
       }
   }


   function handleKeyUp(event) {
       currentlyPressedKeys[event.keyCode] = false;
   }


   function handleKeys() {
       if (currentlyPressedKeys[33]) {z += 0.05;}          // Page Up
       if (currentlyPressedKeys[34]) {z -= 0.05;}          // Page Down
       if (currentlyPressedKeys[37]) {ySpeed -= 2;}    // Влево
       if (currentlyPressedKeys[39]) {ySpeed += 2;}    // Вправо
       if (currentlyPressedKeys[38]) {xSpeed -= 2;}    // Вверх
       if (currentlyPressedKeys[40]) {xSpeed += 2;}    // Вниз
   }


   var cubeVertexPositionBuffer;
   var cubeVertexTextureCoordBuffer;
   var cubeVertexIndexBuffer;
   function initBuffers() {
       cubeVertexPositionBuffer = gl.createBuffer();
       gl.bindBuffer(gl.ARRAY_BUFFER, cubeVertexPositionBuffer);
       vertices = [
           // Front face
           -1.0, -1.0,  1.0,
           1.0, -1.0,  1.0,
           1.0,  1.0,  1.0,
           -1.0,  1.0,  1.0,
           // Back face
           -1.0, -1.0, -1.0,
           -1.0,  1.0, -1.0,
           1.0,  1.0, -1.0,
           1.0, -1.0, -1.0,
           // Top face
           -1.0,  1.0, -1.0,
           -1.0,  1.0,  1.0,
           1.0,  1.0,  1.0,
           1.0,  1.0, -1.0,
           // Bottom face
           -1.0, -1.0, -1.0,
           1.0, -1.0, -1.0,
           1.0, -1.0,  1.0,
           -1.0, -1.0,  1.0,
           // Right face
           1.0, -1.0, -1.0,
           1.0,  1.0, -1.0,
           1.0,  1.0,  1.0,
           1.0, -1.0,  1.0,
           // Left face
           -1.0, -1.0, -1.0,
           -1.0, -1.0,  1.0,
           -1.0,  1.0,  1.0,
           -1.0,  1.0, -1.0,
       ];
       gl.bufferData(gl.ARRAY_BUFFER, new Float32Array(vertices), gl.STATIC_DRAW);
       cubeVertexPositionBuffer.itemSize = 3;
       cubeVertexPositionBuffer.numItems = 24;
       cubeVertexTextureCoordBuffer = gl.createBuffer();
       gl.bindBuffer(gl.ARRAY_BUFFER, cubeVertexTextureCoordBuffer);
       var textureCoords = [
           // Front face
           0.0, 0.0,
           1.0, 0.0,
           1.0, 1.0,
           0.0, 1.0,
           // Back face
           1.0, 0.0,
           1.0, 1.0,
           0.0, 1.0,
           0.0, 0.0,
           // Top face
           0.0, 1.0,
           0.0, 0.0,
           1.0, 0.0,
           1.0, 1.0,
           // Bottom face
           1.0, 1.0,
           0.0, 1.0,
           0.0, 0.0,
           1.0, 0.0,
           // Right face
           1.0, 0.0,
           1.0, 1.0,
           0.0, 1.0,
           0.0, 0.0,
           // Left face
           0.0, 0.0,
           1.0, 0.0,
           1.0, 1.0,
           0.0, 1.0,
       ];
       gl.bufferData(gl.ARRAY_BUFFER, new Float32Array(textureCoords), gl.STATIC_DRAW);
       cubeVertexTextureCoordBuffer.itemSize = 2;
       cubeVertexTextureCoordBuffer.numItems = 24;
       cubeVertexIndexBuffer = gl.createBuffer();
       gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, cubeVertexIndexBuffer);
       var cubeVertexIndices = [
           0, 1, 2,      0, 2, 3,    // Front face
           4, 5, 6,      4, 6, 7,    // Back face
           8, 9, 10,     8, 10, 11,  // Top face
           12, 13, 14,   12, 14, 15, // Bottom face
           16, 17, 18,   16, 18, 19, // Right face
           20, 21, 22,   20, 22, 23  // Left face
       ]
       gl.bufferData(gl.ELEMENT_ARRAY_BUFFER, new Uint16Array(cubeVertexIndices), gl.STATIC_DRAW);
       cubeVertexIndexBuffer.itemSize = 1;
       cubeVertexIndexBuffer.numItems = 36;
   }
   var rotate_buf = mat4.create();
   function drawScene() {
       gl.viewport(0, 0, gl.viewportWidth, gl.viewportHeight);
       gl.clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT);
       mat4.perspective(pMatrix, 45, gl.viewportWidth / gl.viewportHeight, 0.1, 100.0);
       mat4.identity(mvMatrix);


       mat4.translate(mvMatrix, mvMatrix, [0, 0, z]);
       var new_rotate = mat4.create();
       mat4.rotateX(new_rotate, new_rotate, degToRad(xRot));
       mat4.rotateY(new_rotate, new_rotate, degToRad(yRot));


       mat4.multiply(rotate_buf, new_rotate, rotate_buf);
       mat4.multiply(mvMatrix, mvMatrix, rotate_buf);


       gl.bindBuffer(gl.ARRAY_BUFFER, cubeVertexPositionBuffer);
       gl.vertexAttribPointer(shaderProgram.vertexPositionAttribute, cubeVertexPositionBuffer.itemSize, gl.FLOAT, false, 0, 0);
       gl.bindBuffer(gl.ARRAY_BUFFER, cubeVertexTextureCoordBuffer);
       gl.vertexAttribPointer(shaderProgram.textureCoordAttribute, cubeVertexTextureCoordBuffer.itemSize, gl.FLOAT, false, 0, 0);


       gl.activeTexture(gl.TEXTURE0);
       gl.bindTexture(gl.TEXTURE_2D, crateTextures[filter]);
       gl.uniform1i(shaderProgram.samplerUniform, 0);
       gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, cubeVertexIndexBuffer);
       setMatrixUniforms();
       gl.drawElements(gl.TRIANGLES, cubeVertexIndexBuffer.numItems, gl.UNSIGNED_SHORT, 0);
   }
   function animate() {
       xRot = xSpeed;
       yRot = ySpeed;
       xSpeed = ySpeed = 0;
   }
   function tick() {
       requestAnimFrame(tick);
       handleKeys();
       drawScene();
       animate();
   }
   function webGLStart() {
       var canvas = document.getElementById("WebGL_canvas");
       initGL(canvas);
       initShaders();
       initBuffers();
       initTexture();
       gl.clearColor(0.95, 0.95, 1.0, 1.0);
       gl.enable(gl.DEPTH_TEST);
       document.onkeydown = handleKeyDown;
       document.onkeyup = handleKeyUp;
       tick();
   }
   // Запуск программы
   webGLStart();

} </syntaxhighligh> Файл "WebGL_Example_v4.html" <syntaxhighlight lang="html" line start="1" enclose="div"> <!DOCTYPE html> <html> <head>

   <meta charset="UTF-8" />
   <title>WebGL Example</title>
   <script type="text/javascript" src="gl-matrix.js"></script>
   <script type="text/javascript" src="webgl-utils.js"></script>
   <script id="shader-fs" type="x-shader/x-fragment">
       precision mediump float;
       varying vec2 vTextureCoord;
       uniform sampler2D uSampler;
       void main(void) {
       gl_FragColor = texture2D(uSampler, vec2(vTextureCoord.s, vTextureCoord.t));
       }
   </script>
   <script id="shader-vs" type="x-shader/x-vertex">
       attribute vec3 aVertexPosition;
       attribute vec2 aTextureCoord;
       uniform mat4 uMVMatrix;
       uniform mat4 uPMatrix;
       varying vec2 vTextureCoord;


       void main(void) {
       gl_Position = uPMatrix * uMVMatrix * vec4(aVertexPosition, 1.0);
       vTextureCoord = aTextureCoord;
       }
   </script>
   <script src="WebGL_Example_v4.js"></script>

</head>

<body onload="Main_WebGL_example();"> <canvas id="WebGL_canvas" style="border: none;" width="500" height="500"></canvas>

  • Стрелочки - поворот куба
  • [Home] - вернуть куб в исходное положение
  • [Page Up]/[Page Down] - приближение/отдаление

</body>

</html> </syntaxhighligh> </toggledisplay>