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<!DOCTYPE html>
<head>
<meta charset="utf-8"/>
<title>Сенчестият град</title>
<script src="webgl-fmi.js"></script>
<script id="vshader" type="x-shader/x-vertex">
uniform mat4 uProjectionMatrix;
uniform mat4 uViewMatrix;
uniform mat4 uModelMatrix;
uniform vec3 uAmbientColor;
uniform vec3 uDiffuseColor;
uniform vec3 uLightDir;
attribute vec3 aXYZ;
attribute vec3 aColor;
attribute vec3 aNormal;
varying vec3 vColor;
void main ()
{
mat4 mvMatrix = uViewMatrix * uModelMatrix;
gl_Position = uProjectionMatrix * mvMatrix * vec4(aXYZ,1);
vec3 light = normalize(-uLightDir);
vec3 normal = vec3(normalize(mvMatrix*vec4(aNormal,0)));
vColor = uAmbientColor*aColor+aColor*uDiffuseColor*max(dot(normal,light),0.0);
}
</script>
<script id="fshader" type="x-shader/x-fragment">
precision mediump float;
varying vec3 vColor;
void main( )
{
gl_FragColor = vec4(vColor,1);
}
</script>
<script>
function start( )
{
var canvas = document.getElementById("picasso");
canvas.addEventListener('webglcontextlost',function(event){event.preventDefault();},false);
canvas.addEventListener('webglcontextrestored',function(){init();},false);
init();
drawFrame();
}
var N=20;
var building=[]; // глобален масив за параметрите на сградите
function drawCube()
{
useMatrix();
gl.drawArrays(gl.TRIANGLES,0,36);
}
function init()
{
gl = getContext("picasso");
glprog = getProgram("vshader","fshader");
aXYZ = gl.getAttribLocation(glprog,"aXYZ");
uProjectionMatrix = gl.getUniformLocation(glprog,"uProjectionMatrix");
uViewMatrix = gl.getUniformLocation(glprog,"uViewMatrix");
uModelMatrix = gl.getUniformLocation(glprog,"uModelMatrix");
aColor = gl.getAttribLocation(glprog,"aColor");
uAmbientColor = gl.getUniformLocation(glprog,"uAmbientColor");
aNormal = gl.getAttribLocation(glprog,"aNormal");
uDiffuseColor = gl.getUniformLocation(glprog,"uDiffuseColor");
uLightDir = gl.getUniformLocation(glprog,"uLightDir");
gl.enable(gl.DEPTH_TEST); // включваме тест за дълбочина
gl.clearColor(1,1,1,1);
identity();
perspective(30,gl.canvas.width/gl.canvas.height,1,40000);
// куб 1x1x1
var v = [ [+0.5,-0.5,-0.5], [+0.5,+0.5,-0.5],
[-0.5,+0.5,-0.5], [-0.5,-0.5,-0.5],
[+0.5,-0.5,+0.5], [+0.5,+0.5,+0.5],
[-0.5,+0.5,+0.5], [-0.5,-0.5,+0.5] ];
var n = [ [1,0,0], [-1,0,0],
[0,1,0], [0,-1,0],
[0,0,1], [0,0,-1] ];
var data = [].concat(
v[0],n[0],v[1],n[0],v[4],n[0],
v[4],n[0],v[1],n[0],v[5],n[0],
v[6],n[1],v[2],n[1],v[7],n[1],
v[7],n[1],v[2],n[1],v[3],n[1],
v[5],n[2],v[1],n[2],v[6],n[2],
v[6],n[2],v[1],n[2],v[2],n[2],
v[4],n[3],v[7],n[3],v[0],n[3],
v[0],n[3],v[7],n[3],v[3],n[3],
v[4],n[4],v[5],n[4],v[7],n[4],
v[7],n[4],v[5],n[4],v[6],n[4],
v[0],n[5],v[3],n[5],v[1],n[5],
v[1],n[5],v[3],n[5],v[2],n[5] );
var buf = gl.createBuffer();
gl.bindBuffer(gl.ARRAY_BUFFER,buf);
gl.bufferData(gl.ARRAY_BUFFER, new Float32Array(data), gl.STATIC_DRAW);
gl.enableVertexAttribArray(aXYZ);
gl.vertexAttribPointer(aXYZ,3,gl.FLOAT,false,6*FLOATS,0*FLOATS);
gl.enableVertexAttribArray(aNormal);
gl.vertexAttribPointer(aNormal,3,gl.FLOAT,false,6*FLOATS,3*FLOATS);
gl.vertexAttrib3f(aColor,0.5,0.8,1);
gl.uniform3f(uAmbientColor,0.2,0,0);
gl.uniform3f(uDiffuseColor,1,1,1);
gl.uniform3f(uLightDir,0,0,-1);
// инициализиране на сградите
for (var x=0; x<N; x++)
{
building[x]=[];
for (var y=0; y<N; y++)
building[x][y] = {
height: random(5,10),
speed: random(1/50,1/500),
offset: random(0,2*Math.PI) };
}
}
var frame = 0;
function drawFrame()
{
frame++;
gl.clear(gl.COLOR_BUFFER_BIT+gl.DEPTH_BUFFER_BIT);
lookAt([20*Math.cos(frame/300),20*Math.sin(frame/300),20+15*Math.sin(frame/100)], [0,0,2-2*Math.sin(frame/100)], [0,0,1]);
// рисуване на града
for (var x=0; x<N; x++)
for (var y=0; y<N; y++)
{
var b = building[x][y];
var z = b.height*(0.5+0.4*Math.cos(b.offset+b.speed*frame));
identity();
translate([x-N/2,y-N/2,z/2]);
scale([1,1,z]);
drawCube(frame);
}
requestAnimationFrame(drawFrame);
}
</script>
</head>
<body onload="start()">
<h2>Сенчестият град</h2>
<noscript>
Искаме JavaScript, но няма!
</noscript>
<canvas id="picasso" width="600" height="400" style="border: solid;">
Искаме canvas, но няма!
</canvas>
</body>
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