1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
|
<!DOCTYPE html>
<head>
<meta charset="utf-8"/>
<title>Тройно махало</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 mat4 uNormalMatrix; // матрица за нормалните вектори
uniform bool uUseNormalMatrix; // дали матрицата се подава отвън
uniform bool uUseAmbient;
uniform vec3 uAmbientColor;
uniform bool uUseDiffuse;
uniform vec3 uDiffuseColor;
uniform vec3 uLightDir;
attribute vec3 aXYZ;
attribute vec3 aColor;
attribute vec3 aNormal;
varying vec3 vColor;
void main ()
{
mat4 mvMatrix = uViewMatrix * uModelMatrix;
vec4 pos = mvMatrix * vec4(aXYZ,1);
gl_Position = uProjectionMatrix * pos;
mat4 nMatrix = uUseNormalMatrix?uNormalMatrix:mvMatrix;
// околна светлина
if (uUseAmbient)
vColor = uAmbientColor*aColor;
else
vColor = aColor;
// дифузно отражение
vec3 light = normalize(-uLightDir);
vec3 normal = vec3(normalize(nMatrix*vec4(aNormal,0)));
if (uUseDiffuse)
{
vColor += aColor*uDiffuseColor*max(dot(normal,light),0.0);
}
// огледално отражение
vec3 reflectedLight = normalize(reflect(light,normal));
vec3 viewDir = normalize( pos.xyz/pos.w );
float cosa = max(dot(reflectedLight,viewDir),0.0);
vColor += vec3(1,1,1)*pow(cosa,50.0);
}
</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();
}
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");
uNormalMatrix = gl.getUniformLocation(glprog,"uNormalMatrix");
uUseNormalMatrix = gl.getUniformLocation(glprog,"uUseNormalMatrix");
aColor = gl.getAttribLocation(glprog,"aColor");
uAmbientColor = gl.getUniformLocation(glprog,"uAmbientColor");
uUseAmbient = gl.getUniformLocation(glprog,"uUseAmbient");
aNormal = gl.getAttribLocation(glprog,"aNormal");
uDiffuseColor = gl.getUniformLocation(glprog,"uDiffuseColor");
uUseDiffuse = gl.getUniformLocation(glprog,"uUseDiffuse");
uLightDir = gl.getUniformLocation(glprog,"uLightDir");
gl.enable(gl.DEPTH_TEST);
gl.clearColor(0.9,1,0.9,1);
identity();
perspective(30,gl.canvas.width/gl.canvas.height,1,40000);
gl.uniform1i(uUseNormalMatrix,false);
gl.uniform3f(uAmbientColor,0.3,0.3,0.3);
gl.uniform1i(uUseAmbient,true);
gl.uniform3f(uDiffuseColor,1,1,1);
gl.uniform1i(uUseDiffuse,true);
gl.uniform3f(uLightDir,0,0,-1);
// създаване на махало - масив от съответните елементи
pendulum = [];
}
var frame = 0;
function drawFrame()
{
frame++;
gl.clear(gl.COLOR_BUFFER_BIT+gl.DEPTH_BUFFER_BIT);
var a = 0.3*sin(frame/100);
lookAt([130*Math.cos(a),130*Math.sin(a),-36], [0,0,-36], [0,0,1]);
// рисуване на три навързани махала
// ...
requestAnimationFrame(drawFrame);
}
</script>
</head>
<body onload="start()">
<h2>Тройно махало</h2>
<noscript>
Искаме JavaScript, но няма!
</noscript>
<canvas id="picasso" width="600" height="400" style="border: solid;">
Искаме canvas, но няма!
</canvas>
</body>
|
