<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>08_深度缓存、透明度和混合</title>
<script type="text/javascript" src="Oak3D_v_0_5.js"></script>
<script id="shader-fs" type="x-shader/x-fragment">
precision mediump float;
varying vec2 vTextureCoord;
varying vec3 vLightWeighting;
uniform float uAlpha;
uniform sampler2D uSampler;
void main(void) {
vec4 textureColor = texture2D(uSampler, vec2(vTextureCoord.s, vTextureCoord.t));
gl_FragColor = vec4(textureColor.rgb * vLightWeighting, textureColor.a * uAlpha);
}
</script>
<script id="shader-vs" type="x-shader/x-vertex">
attribute vec3 aVertexPosition;
attribute vec3 aVertexNormal;
attribute vec2 aTextureCoord;
uniform mat4 uMVMatrix;
uniform mat4 uPMatrix;
uniform mat4 uNMatrix;
uniform vec3 uAmbientColor;
uniform vec3 uLightingDirection;
uniform vec3 uDirectionalColor;
uniform bool uUseLighting;
varying vec2 vTextureCoord;
varying vec3 vLightWeighting;
void main(void) {
gl_Position = uPMatrix * uMVMatrix * vec4(aVertexPosition, 1.0);
vTextureCoord = aTextureCoord;
if (!uUseLighting) {
vLightWeighting = vec3(1.0, 1.0, 1.0);
} else {
vec3 transformedNormal = (uNMatrix * vec4(aVertexNormal,1.0)).xyz;
float directionalLightWeighting = max(dot(transformedNormal, uLightingDirection), 0.0);
vLightWeighting = uAmbientColor + uDirectionalColor * directionalLightWeighting;
}
}
</script>
<script type="text/javascript">
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.vertexNormalAttribute = gl.getAttribLocation(shaderProgram, "aVertexNormal");
gl.enableVertexAttribArray(shaderProgram.vertexNormalAttribute);
shaderProgram.textureCoordAttribute = gl.getAttribLocation(shaderProgram, "aTextureCoord");
gl.enableVertexAttribArray(shaderProgram.textureCoordAttribute);
shaderProgram.pMatrixUniform = gl.getUniformLocation(shaderProgram, "uPMatrix");
shaderProgram.mvMatrixUniform = gl.getUniformLocation(shaderProgram, "uMVMatrix");
shaderProgram.nMatrixUniform = gl.getUniformLocation(shaderProgram, "uNMatrix");
shaderProgram.samplerUniform = gl.getUniformLocation(shaderProgram, "uSampler");
shaderProgram.useLightingUniform = gl.getUniformLocation(shaderProgram, "uUseLighting");
shaderProgram.ambientColorUniform = gl.getUniformLocation(shaderProgram, "uAmbientColor");
shaderProgram.lightingDirectionUniform = gl.getUniformLocation(shaderProgram, "uLightingDirection");
shaderProgram.directionalColorUniform = gl.getUniformLocation(shaderProgram, "uDirectionalColor");
shaderProgram.alphaUniform = gl.getUniformLocation(shaderProgram, "uAlpha");
}
function handleLoadedTexture(texture) {
gl.pixelStorei(gl.UNPACK_FLIP_Y_WEBGL, true);
gl.bindTexture(gl.TEXTURE_2D, texture);
gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, gl.RGBA, gl.UNSIGNED_BYTE, texture.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 glassTexture;
function initTexture() {
glassTexture = gl.createTexture();
glassTexture.image = new Image();
glassTexture.image.onload = function () {
handleLoadedTexture(glassTexture)
}
glassTexture.image.src = "glass.gif";
}
var mvMatrix;
var mvMatrixStack = [];
var pMatrix;
function mvPushMatrix() {
var copy = new okMat4();
mvMatrix.clone(copy);
mvMatrixStack.push(copy);
}
function mvPopMatrix() {
if (mvMatrixStack.length == 0) {
throw "Invalid popMatrix!";
}
mvMatrix = mvMatrixStack.pop();
}
function setMatrixUniforms() {
gl.uniformMatrix4fv(shaderProgram.pMatrixUniform, false, pMatrix.toArray());
gl.uniformMatrix4fv(shaderProgram.mvMatrixUniform, false, mvMatrix.toArray());
var normalMatrix = mvMatrix.inverse().transpose();
gl.uniformMatrix4fv(shaderProgram.nMatrixUniform, false, normalMatrix.toArray());
}
var xRot = 0;
var xSpeed = 3;
var yRot = 0;
var ySpeed = -3;
var z = -5.0;
var currentlyPressedKeys = {};
function handleKeyDown(event) {
currentlyPressedKeys[event.keyCode] = true;
}
function handleKeyUp(event) {
currentlyPressedKeys[event.keyCode] = false;
}
function handleKeys() {
if (currentlyPressedKeys[33]) {
// Page Up
z -= 0.05;
}
if (currentlyPressedKeys[34]) {
// Page Down
z += 0.05;
}
if (currentlyPressedKeys[37]) {
// Left cursor key
ySpeed -= 1;
}
if (currentlyPressedKeys[39]) {
// Right cursor key
ySpeed += 1;
}
if (currentlyPressedKeys[38]) {
// Up cursor key
xSpeed -= 1;
}
if (currentlyPressedKeys[40]) {
// Down cursor key
xSpeed += 1;
}
}
var cubeVertexPositionBuffer;
var cubeVertexNormalBuffer;
var cubeVertexTextureCoordBuffer;
var cubeVertexIndexBuffer;
function initBuffers() {
cubeVertexPositionBuffer = gl.createBuffer();
gl.bindBuffer(gl.ARRAY_BUFFER, cubeVertexPositionBuffer);
var 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;
cubeVertexNormalBuffer = gl.createBuffer();
gl.bindBuffer(gl.ARRAY_BUFFER, cubeVertexNormalBuffer);
var vertexNormals = [
// Front face
0.0, 0.0, 1.0,
0.0, 0.0, 1.0,
0.0, 0.0, 1.0,
0.0, 0.0, 1.0,
// Back face
0.0, 0.0, -1.0,
0.0, 0.0, -1.0,
0.0, 0.0, -1.0,
0.0, 0.0, -1.0,
// Top face
0.0, 1.0, 0.0,
0.0, 1.0, 0.0,
0.0, 1.0, 0.0,
0.0, 1.0, 0.0,
// Bottom face
0.0, -1.0, 0.0,
0.0, -1.0, 0.0,
0.0, -1.0, 0.0,
0.0, -1.0, 0.0,
// Right face
1.0, 0.0, 0.0,
1.0, 0.0, 0.0,
1.0, 0.0, 0.0,
1.0, 0.0, 0.0,
// Left face
-1.0, 0.0, 0.0,
-1.0, 0.0, 0.0,
-1.0, 0.0, 0.0,
-1.0, 0.0, 0.0
];
gl.bufferData(gl.ARRAY_BUFFER, new Float32Array(vertexNormals), gl.STATIC_DRAW);
cubeVertexNormalBuffer.itemSize = 3;
cubeVertexNormalBuffer.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;
}
function drawScene() {
gl.viewport(0, 0, gl.viewportWidth, gl.viewportHeight);
gl.clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT);
pMatrix = okMat4Proj(45, gl.viewportWidth / gl.viewportHeight, 0.1, 100.0);
mvMatrix = okMat4Trans(0.0, 0.0, z);
mvMatrix.rotX(OAK.SPACE_LOCAL, xRot, true);
mvMatrix.rotY(OAK.SPACE_LOCAL, yRot, true);
gl.bindBuffer(gl.ARRAY_BUFFER, cubeVertexPositionBuffer);
gl.vertexAttribPointer(shaderProgram.vertexPositionAttribute, cubeVertexPositionBuffer.itemSize, gl.FLOAT, false, 0, 0);
gl.bindBuffer(gl.ARRAY_BUFFER, cubeVertexNormalBuffer);
gl.vertexAttribPointer(shaderProgram.vertexNormalAttribute, cubeVertexNormalBuffer.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, glassTexture);
gl.uniform1i(shaderProgram.samplerUniform, 0);
var blending = document.getElementById("blending").checked;
if (blending) {
gl.blendFunc(gl.SRC_ALPHA, gl.ONE);
gl.enable(gl.BLEND);
gl.disable(gl.DEPTH_TEST);
gl.uniform1f(shaderProgram.alphaUniform, parseFloat(document.getElementById("alpha").value));
} else {
gl.disable(gl.BLEND);
gl.enable(gl.DEPTH_TEST);
}
var lighting = document.getElementById("lighting").checked;
gl.uniform1i(shaderProgram.useLightingUniform, lighting);
if (lighting) {
gl.uniform3f(
shaderProgram.ambientColorUniform,
parseFloat(document.getElementById("ambientR").value),
parseFloat(document.getElementById("ambientG").value),
parseFloat(document.getElementById("ambientB").value)
);
var lightingDirection = new okVec3(
parseFloat(document.getElementById("lightDirectionX").value),
parseFloat(document.getElementById("lightDirectionY").value),
parseFloat(document.getElementById("lightDirectionZ").value)
);
var adjustedLD = lightingDirection.normalize(false);
adjustedLD = okVec3MulVal(adjustedLD, -1.0);
gl.uniform3fv(shaderProgram.lightingDirectionUniform, adjustedLD.toArray());
gl.uniform3f(
shaderProgram.directionalColorUniform,
parseFloat(document.getElementById("directionalR").value),
parseFloat(document.getElementById("directionalG").value),
parseFloat(document.getElementById("directionalB").value)
);
}
gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, cubeVertexIndexBuffer);
setMatrixUniforms();
gl.drawElements(gl.TRIANGLES, cubeVertexIndexBuffer.numItems, gl.UNSIGNED_SHORT, 0);
}
var lastTime = 0;
function animate() {
var timeNow = new Date().getTime();
if (lastTime != 0) {
var elapsed = timeNow - lastTime;
xRot += (xSpeed * elapsed) / 1000.0;
yRot += (ySpeed * elapsed) / 1000.0;
}
lastTime = timeNow;
}
function tick() {
okRequestAnimationFrame(tick);
handleKeys();
drawScene();
animate();
}
function webGLStart() {
var canvas = document.getElementById("lesson08-canvas");
initGL(canvas);
initShaders();
initBuffers();
initTexture();
gl.clearColor(0.0, 0.0, 0.0, 1.0);
gl.enable(gl.DEPTH_TEST);
document.onkeydown = handleKeyDown;
document.onkeyup = handleKeyUp;
tick();
}
</script>
</head>
<body onload="webGLStart();">
<canvas id="lesson08-canvas" style="border: none;" width="500" height="500"></canvas>
<br />
<input type="checkbox" id="blending" checked /> 开启混合<br />
Alpha level <input type="text" id="alpha" value="0.5" /><br />
<br />
<input type="checkbox" id="lighting" checked /> 开启光照<br />
（使用方向键旋转立方体，使用<code>Page Up</code>键和<code>Page Down</code> 键来进行缩放）
<br />
<h2>平行光：</h2>
<table style="border: 0; padding: 10px;">
<tr>
<td><b>方向：</b>
<td>X: <input type="text" id="lightDirectionX" value="-0.25" />
<td>Y: <input type="text" id="lightDirectionY" value="-0.25" />
<td>Z: <input type="text" id="lightDirectionZ" value="-1.0" />
</tr>
<tr>
<td><b>颜色：</b>
<td>R: <input type="text" id="directionalR" value="0.8" />
<td>G: <input type="text" id="directionalG" value="0.8" />
<td>B: <input type="text" id="directionalB" value="0.8" />
</tr>
</table>
<h2>环境光</h2>
<table style="border: 0; padding: 10px;">
<tr>
<td><b>颜色</b>
<td>R: <input type="text" id="ambientR" value="0.2" />
<td>G: <input type="text" id="ambientG" value="0.2" />
<td>B: <input type="text" id="ambientB" value="0.2" />
</tr>
</table>
</body>
</html>
08、深度缓存、透明度和混合
创建日期：2024-06-21
更新日期：2025-01-12
简介
一个来自三线小城市的程序员开发经验总结。