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<!DOCTYPE html>
<head>
<meta charset="utf-8"/>
<title>Пирамида</title>
<script src="webgl-fmi.js"></script>
<script id="vshader" type="x-shader/x-vertex">
uniform mat4 uProjectionMatrix;
uniform mat4 uViewMatrix;
uniform mat4 uModelMatrix;
attribute vec3 aXYZ;
void main ()
{
gl_Position = uProjectionMatrix * uViewMatrix * uModelMatrix * vec4(aXYZ,1);
}
</script>
<script id="fshader" type="x-shader/x-fragment">
precision mediump float;
uniform vec3 uColor;
void main( )
{
gl_FragColor = vec4(uColor,1);
}
</script>
<script>
// рисуване на куба
function cube()
{
useMatrix();
gl.drawArrays(gl.LINE_LOOP,0,4);
gl.drawArrays(gl.LINE_LOOP,4,4);
gl.drawArrays(gl.LINES,8,8);
}
function start( )
{
gl = getContext("picasso");
glprog = getProgram("vshader","fshader");
aXYZ = gl.getAttribLocation(glprog,"aXYZ");
uColor = gl.getUniformLocation(glprog,"uColor");
uProjectionMatrix = gl.getUniformLocation(glprog,"uProjectionMatrix");
uViewMatrix = gl.getUniformLocation(glprog,"uViewMatrix");
uModelMatrix = gl.getUniformLocation(glprog,"uModelMatrix");
gl.clearColor(1,1,1,1);
gl.clear(gl.COLOR_BUFFER_BIT);
var proj = perspMatrix(30,gl.canvas.width/gl.canvas.height,1,40000);
gl.uniformMatrix4fv(uProjectionMatrix,false,proj);
// гледна точка, с която пирамидата трябва да изглежда относително центрирана (поправете я)
var view = viewMatrix([90,12,30], [0,-25,-5], [0,1,0]);
gl.uniformMatrix4fv(uViewMatrix,false,view);
// куб 1x1x1
var data = [ 0.5,-0.5,0.5, // предна стена
0.5,0.5,0.5,
-0.5,0.5,0.5,
-0.5,-0.5,0.5,
0.5,-0.5,-0.5, // задна стена
0.5,0.5,-0.5,
-0.5,0.5,-0.5,
-0.5,-0.5,-0.5,
0.5,-0.5,0.5, // десни хоризонтални ръбове
0.5,-0.5,-0.5,
0.5,0.5,0.5,
0.5,0.5,-0.5,
-0.5,0.5,0.5, // леви хоризонтални ръбове
-0.5,0.5,-0.5,
-0.5,-0.5,0.5,
-0.5,-0.5,-0.5
];
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,0,0);
gl.uniform3f(uColor,0,0,1);
// рисуване на най-горния етаж на пирамида
// допълнете тук рисуването на останалите етажи
identity();
cube();
function scaleXZ(value) {
glmatnew = true;
glmat[0] += value
glmat[5] = 1
glmat[10] += value
glmat[15] = 1
}
function translateY(value) {
glmatnew = true;
glmat[12] = 0 ;
glmat[13] += value ;
glmat[14] = 0 ;
glmat[15] = 1 ;
}
for (var i = 0; i < 30; i++) {
scaleXZ(2); translateY(-1); cube();
}
}
</script>
</head>
<body onload="start()">
<h2>Пирамида</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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