<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>13_片源级光照和多program对象</title>
<script type="text/javascript" src="Oak3D_v_0_5.js"></script>
<script id="per-vertex-lighting-fs" type="x-shader/x-fragment">
precision mediump float;
varying vec2 vTextureCoord;
varying vec3 vLightWeighting;
uniform bool uUseTextures;
uniform sampler2D uSampler;
void main(void) {
vec4 fragmentColor;
if (uUseTextures) {
fragmentColor = texture2D(uSampler, vec2(vTextureCoord.s, vTextureCoord.t));
} else {
fragmentColor = vec4(1.0, 1.0, 1.0, 1.0);
}
gl_FragColor = vec4(fragmentColor.rgb * vLightWeighting, fragmentColor.a);
}
</script>
<script id="per-vertex-lighting-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 uPointLightingLocation;
uniform vec3 uPointLightingColor;
uniform bool uUseLighting;
varying vec2 vTextureCoord;
varying vec3 vLightWeighting;
void main(void) {
vec4 mvPosition = uMVMatrix * vec4(aVertexPosition, 1.0);
gl_Position = uPMatrix * mvPosition;
vTextureCoord = aTextureCoord;
if (!uUseLighting) {
vLightWeighting = vec3(1.0, 1.0, 1.0);
} else {
vec3 lightDirection = normalize(uPointLightingLocation - mvPosition.xyz);
vec3 transformedNormal = (uNMatrix * vec4(aVertexNormal,1.0)).xyz;
float directionalLightWeighting = max(dot(transformedNormal, lightDirection), 0.0);
vLightWeighting = uAmbientColor + uPointLightingColor * directionalLightWeighting;
}
}
</script>
<script id="per-fragment-lighting-fs" type="x-shader/x-fragment">
precision mediump float;
varying vec2 vTextureCoord;
varying vec3 vTransformedNormal;
varying vec4 vPosition;
uniform bool uUseLighting;
uniform bool uUseTextures;
uniform vec3 uAmbientColor;
uniform vec3 uPointLightingLocation;
uniform vec3 uPointLightingColor;
uniform sampler2D uSampler;
void main(void) {
vec3 lightWeighting;
if (!uUseLighting) {
lightWeighting = vec3(1.0, 1.0, 1.0);
} else {
vec3 lightDirection = normalize(uPointLightingLocation - vPosition.xyz);
float directionalLightWeighting = max(dot(normalize(vTransformedNormal), lightDirection), 0.0);
lightWeighting = uAmbientColor + uPointLightingColor * directionalLightWeighting;
}
vec4 fragmentColor;
if (uUseTextures) {
fragmentColor = texture2D(uSampler, vec2(vTextureCoord.s, vTextureCoord.t));
} else {
fragmentColor = vec4(1.0, 1.0, 1.0, 1.0);
}
gl_FragColor = vec4(fragmentColor.rgb * lightWeighting, fragmentColor.a);
}
</script>
<script id="per-fragment-lighting-vs" type="x-shader/x-vertex">
attribute vec3 aVertexPosition;
attribute vec3 aVertexNormal;
attribute vec2 aTextureCoord;
uniform mat4 uMVMatrix;
uniform mat4 uPMatrix;
uniform mat4 uNMatrix;
varying vec2 vTextureCoord;
varying vec3 vTransformedNormal;
varying vec4 vPosition;
void main(void) {
vPosition = uMVMatrix * vec4(aVertexPosition, 1.0);
gl_Position = uPMatrix * vPosition;
vTextureCoord = aTextureCoord;
vTransformedNormal = (uNMatrix * vec4(aVertexNormal, 1.0)).xyz;
}
</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;
}
function createProgram(fragmentShaderID, vertexShaderID) {
var fragmentShader = getShader(gl, fragmentShaderID);
var vertexShader = getShader(gl, vertexShaderID);
var program = gl.createProgram();
gl.attachShader(program, vertexShader);
gl.attachShader(program, fragmentShader);
gl.linkProgram(program);
if (!gl.getProgramParameter(program, gl.LINK_STATUS)) {
alert("Could not initialise shaders");
}
program.vertexPositionAttribute = gl.getAttribLocation(program, "aVertexPosition");
gl.enableVertexAttribArray(program.vertexPositionAttribute);
program.vertexNormalAttribute = gl.getAttribLocation(program, "aVertexNormal");
gl.enableVertexAttribArray(program.vertexNormalAttribute);
program.textureCoordAttribute = gl.getAttribLocation(program, "aTextureCoord");
gl.enableVertexAttribArray(program.textureCoordAttribute);
program.pMatrixUniform = gl.getUniformLocation(program, "uPMatrix");
program.mvMatrixUniform = gl.getUniformLocation(program, "uMVMatrix");
program.nMatrixUniform = gl.getUniformLocation(program, "uNMatrix");
program.samplerUniform = gl.getUniformLocation(program, "uSampler");
program.useTexturesUniform = gl.getUniformLocation(program, "uUseTextures");
program.useLightingUniform = gl.getUniformLocation(program, "uUseLighting");
program.ambientColorUniform = gl.getUniformLocation(program, "uAmbientColor");
program.pointLightingLocationUniform = gl.getUniformLocation(program, "uPointLightingLocation");
program.pointLightingColorUniform = gl.getUniformLocation(program, "uPointLightingColor");
return program;
}
var currentProgram;
var perVertexProgram;
var perFragmentProgram;
function initShaders() {
perVertexProgram = createProgram("per-vertex-lighting-fs", "per-vertex-lighting-vs");
perFragmentProgram = createProgram("per-fragment-lighting-fs", "per-fragment-lighting-vs");
}
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 moonTexture;
var crateTexture;
function initTextures() {
moonTexture = gl.createTexture();
moonTexture.image = new Image();
moonTexture.image.onload = function () {
handleLoadedTexture(moonTexture)
}
moonTexture.image.src = "moon.gif";
crateTexture = gl.createTexture();
crateTexture.image = new Image();
crateTexture.image.onload = function () {
handleLoadedTexture(crateTexture)
}
crateTexture.image.src = "crate.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(currentProgram.pMatrixUniform, false, pMatrix.toArray());
gl.uniformMatrix4fv(currentProgram.mvMatrixUniform, false, mvMatrix.toArray());
var normalMatrix = mvMatrix.inverse().transpose();
gl.uniformMatrix4fv(currentProgram.nMatrixUniform, false, normalMatrix.toArray());
}
function degToRad(degrees) {
return degrees * Math.PI / 180;
}
var cubeVertexPositionBuffer;
var cubeVertexNormalBuffer;
var cubeVertexTextureCoordBuffer;
var cubeVertexIndexBuffer;
var moonVertexPositionBuffer;
var moonVertexNormalBuffer;
var moonVertexTextureCoordBuffer;
var moonVertexIndexBuffer;
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;
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;
var latitudeBands = 30;
var longitudeBands = 30;
var radius = 1;
var vertexPositionData = [];
var normalData = [];
var textureCoordData = [];
for (var latNumber = 0; latNumber <= latitudeBands; latNumber++) {
var theta = latNumber * Math.PI / latitudeBands;
var sinTheta = Math.sin(theta);
var cosTheta = Math.cos(theta);
for (var longNumber = 0; longNumber <= longitudeBands; longNumber++) {
var phi = longNumber * 2 * Math.PI / longitudeBands;
var sinPhi = Math.sin(phi);
var cosPhi = Math.cos(phi);
var x = cosPhi * sinTheta;
var y = cosTheta;
var z = sinPhi * sinTheta;
var u = 1 - (longNumber / longitudeBands);
var v = 1 - (latNumber / latitudeBands);
normalData.push(x);
normalData.push(y);
normalData.push(z);
textureCoordData.push(u);
textureCoordData.push(v);
vertexPositionData.push(radius * x);
vertexPositionData.push(radius * y);
vertexPositionData.push(radius * z);
}
}
var indexData = [];
for (var latNumber = 0; latNumber < latitudeBands; latNumber++) {
for (var longNumber = 0; longNumber < longitudeBands; longNumber++) {
var first = (latNumber * (longitudeBands + 1)) + longNumber;
var second = first + longitudeBands + 1;
indexData.push(first);
indexData.push(second);
indexData.push(first + 1);
indexData.push(second);
indexData.push(second + 1);
indexData.push(first + 1);
}
}
moonVertexNormalBuffer = gl.createBuffer();
gl.bindBuffer(gl.ARRAY_BUFFER, moonVertexNormalBuffer);
gl.bufferData(gl.ARRAY_BUFFER, new Float32Array(normalData), gl.STATIC_DRAW);
moonVertexNormalBuffer.itemSize = 3;
moonVertexNormalBuffer.numItems = normalData.length / 3;
moonVertexTextureCoordBuffer = gl.createBuffer();
gl.bindBuffer(gl.ARRAY_BUFFER, moonVertexTextureCoordBuffer);
gl.bufferData(gl.ARRAY_BUFFER, new Float32Array(textureCoordData), gl.STATIC_DRAW);
moonVertexTextureCoordBuffer.itemSize = 2;
moonVertexTextureCoordBuffer.numItems = textureCoordData.length / 2;
moonVertexPositionBuffer = gl.createBuffer();
gl.bindBuffer(gl.ARRAY_BUFFER, moonVertexPositionBuffer);
gl.bufferData(gl.ARRAY_BUFFER, new Float32Array(vertexPositionData), gl.STATIC_DRAW);
moonVertexPositionBuffer.itemSize = 3;
moonVertexPositionBuffer.numItems = vertexPositionData.length / 3;
moonVertexIndexBuffer = gl.createBuffer();
gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, moonVertexIndexBuffer);
gl.bufferData(gl.ELEMENT_ARRAY_BUFFER, new Uint16Array(indexData), gl.STREAM_DRAW);
moonVertexIndexBuffer.itemSize = 1;
moonVertexIndexBuffer.numItems = indexData.length;
}
var moonAngle = 180;
var cubeAngle = 0;
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);
var perFragmentLighting = document.getElementById("per-fragment").checked;
if (perFragmentLighting) {
currentProgram = perFragmentProgram;
} else {
currentProgram = perVertexProgram;
}
gl.useProgram(currentProgram);
var lighting = document.getElementById("lighting").checked;
gl.uniform1i(currentProgram.useLightingUniform, lighting);
if (lighting) {
gl.uniform3f(
currentProgram.ambientColorUniform,
parseFloat(document.getElementById("ambientR").value),
parseFloat(document.getElementById("ambientG").value),
parseFloat(document.getElementById("ambientB").value)
);
gl.uniform3f(
currentProgram.pointLightingLocationUniform,
parseFloat(document.getElementById("lightPositionX").value),
parseFloat(document.getElementById("lightPositionY").value),
parseFloat(document.getElementById("lightPositionZ").value)
);
gl.uniform3f(
currentProgram.pointLightingColorUniform,
parseFloat(document.getElementById("pointR").value),
parseFloat(document.getElementById("pointG").value),
parseFloat(document.getElementById("pointB").value)
);
}
var textures = document.getElementById("textures").checked;
gl.uniform1i(currentProgram.useTexturesUniform, textures);
mvMatrix = okMat4Trans(0, 0, -5);
mvMatrix.rotX(OAK.SPACE_LOCAL, 30, true);
mvPushMatrix();
mvMatrix.rotY(OAK.SPACE_LOCAL, moonAngle, true);
mvMatrix.translate(OAK.SPACE_LOCAL, 2, 0, 0, true);
gl.activeTexture(gl.TEXTURE0);
gl.bindTexture(gl.TEXTURE_2D, moonTexture);
gl.uniform1i(currentProgram.samplerUniform, 0);
gl.bindBuffer(gl.ARRAY_BUFFER, moonVertexPositionBuffer);
gl.vertexAttribPointer(currentProgram.vertexPositionAttribute, moonVertexPositionBuffer.itemSize, gl.FLOAT, false, 0, 0);
gl.bindBuffer(gl.ARRAY_BUFFER, moonVertexTextureCoordBuffer);
gl.vertexAttribPointer(currentProgram.textureCoordAttribute, moonVertexTextureCoordBuffer.itemSize, gl.FLOAT, false, 0, 0);
gl.bindBuffer(gl.ARRAY_BUFFER, moonVertexNormalBuffer);
gl.vertexAttribPointer(currentProgram.vertexNormalAttribute, moonVertexNormalBuffer.itemSize, gl.FLOAT, false, 0, 0);
gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, moonVertexIndexBuffer);
setMatrixUniforms();
gl.drawElements(gl.TRIANGLES, moonVertexIndexBuffer.numItems, gl.UNSIGNED_SHORT, 0);
mvPopMatrix();
mvPushMatrix();
mvMatrix.rotY(OAK.SPACE_LOCAL, cubeAngle, true);
mvMatrix.translate(OAK.SPACE_LOCAL, 1.25, 0, 0, true);
gl.bindBuffer(gl.ARRAY_BUFFER, cubeVertexPositionBuffer);
gl.vertexAttribPointer(currentProgram.vertexPositionAttribute, cubeVertexPositionBuffer.itemSize, gl.FLOAT, false, 0, 0);
gl.bindBuffer(gl.ARRAY_BUFFER, cubeVertexNormalBuffer);
gl.vertexAttribPointer(currentProgram.vertexNormalAttribute, cubeVertexNormalBuffer.itemSize, gl.FLOAT, false, 0, 0);
gl.bindBuffer(gl.ARRAY_BUFFER, cubeVertexTextureCoordBuffer);
gl.vertexAttribPointer(currentProgram.textureCoordAttribute, cubeVertexTextureCoordBuffer.itemSize, gl.FLOAT, false, 0, 0);
gl.activeTexture(gl.TEXTURE0);
gl.bindTexture(gl.TEXTURE_2D, crateTexture);
gl.uniform1i(currentProgram.samplerUniform, 0);
gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, cubeVertexIndexBuffer);
setMatrixUniforms();
gl.drawElements(gl.TRIANGLES, cubeVertexIndexBuffer.numItems, gl.UNSIGNED_SHORT, 0);
mvPopMatrix();
}
var lastTime = 0;
function animate() {
var timeNow = new Date().getTime();
if (lastTime != 0) {
var elapsed = timeNow - lastTime;
moonAngle += 0.05 * elapsed;
cubeAngle += 0.05 * elapsed;
}
lastTime = timeNow;
}
function tick() {
okRequestAnimationFrame(tick);
drawScene();
animate();
}
function webGLStart() {
var canvas = document.getElementById("lesson13-canvas");
initGL(canvas);
initShaders();
initBuffers();
initTextures();
gl.clearColor(0.0, 0.0, 0.0, 1.0);
gl.enable(gl.DEPTH_TEST);
tick();
}
</script>
</head>
<body onload="webGLStart();">
<canvas id="lesson13-canvas" style="border: none;" width="500" height="500"></canvas>
<br />
<input type="checkbox" id="lighting" checked />启用光照<br />
<input type="checkbox" id="per-fragment" checked />启用逐片元光照<br />
<input type="checkbox" id="textures" checked />启用纹理贴图<br />
<br />
<h2>点光源：</h2>
<table style="border: 0; padding: 10px;">
<tr>
<td><b>位置：</b>
<td>X: <input type="text" id="lightPositionX" value="0.0" />
<td>Y: <input type="text" id="lightPositionY" value="0.0" />
<td>Z: <input type="text" id="lightPositionZ" value="-5.0" />
</tr>
<tr>
<td><b>颜色：</b>
<td>R: <input type="text" id="pointR" value="0.8" />
<td>G: <input type="text" id="pointG" value="0.8" />
<td>B: <input type="text" id="pointB" 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>
13、片源级光照和多program对象
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。