Ciao a tutti,
Ho disegnato un rettangolo orizzontale e lo vorrei spostare in verticale spostando i vertici, non facendolo ruotare.
Ho creato una funzione ChangePosition ma non va! qualcuno sa dirmi cosa ho sbagliato?
Grazie
<html>
<head>
<script id="shader-fs" type="x-shader/x-fragment">
#ifdef GL_ES
precision highp float;
varying vec4 vColor;
#endif
void main(void) {
gl_FragColor = vec4(1.0,1.0,1.0,1.0);
gl_FragColor=vColor;
}
</script>
<script id="shader-vs" type="x-shader/x-vertex">
attribute vec3 aVertexPosition;
attribute vec4 aVertexColor;
uniform mat4 uMVMatrix;
uniform mat4 uPMatrix;
varying vec4 vColor;
void main(void) {
gl_Position = uPMatrix * uMVMatrix * vec4(aVertexPosition, 1.0);
vColor=aVertexColor;
}
</script>
<script type="text/javascript" src="Sylvester.js"></script>
<script type="text/javascript" src="glUtils.js"></script>
<script type="text/javascript" src="MatriUtilityFunc.js"></script>
<script type="text/javascript">
var k=0; //matrici vettori spostati
function ChangePosition()
{
k++;
var position;
switch(k%2)
{
case 0:
position = [
-0.5, 1.0, 0.0,
-0.5, -1.0, 0.0,
0.5, 1.0, 1.0,
0.5, -1.0, 0.0
];
break;
case 1:
position = [
2.0, 0.05, 0.0,
-2.0, 0.05, 0.0,
2.0, -0.05, 0.0,
-2.0, -0.05, 0.0
];
break;
}
gl.bindBuffer(gl.ARRAY_BUFFER, squareVertexPositionBuffer);
gl.bufferData(gl.ARRAY_BUFFER, new Float32Array(vertices), gl.STATIC_DRAW);
squareVertexPositionBuffer.itemSize = 3;
squareVertexPositionBuffer.numItems = 4;
}
var i=0; //matrici colori multipli
function ChangeColor()
{
i++;
var colors;
switch(i%3)
{
case 0:
colors = [
1.0, 0.0, 0.0,1.0,
0.0, 1.0, 0.0,1.0,
0.0, 0.0, 1.0,1.0,
1.0, 0.0, 0.0,1.0
];
break;
case 1:
colors = [
0.0, 0.0, 1.0,1.0,
1.0, 0.0, 0.0,1.0,
0.0, 1.0, 0.0,1.0,
1.0, 0.0, 0.0,1.0
];
break;
case 2:
colors = [
0.0, 1.0, 0.0,1.0,
0.0, 0.0, 1.0,1.0,
1.0, 0.0, 0.0,1.0,
1.0, 0.0, 0.0,1.0
];
break;
}
gl.bindBuffer(gl.ARRAY_BUFFER, squareVertexColorBuffer);
gl.bufferData(gl.ARRAY_BUFFER, new Float32Array(colors), gl.STATIC_DRAW);
}
var gl;
function initGL(canvas) {
try {
gl = canvas.getContext("experimental-webgl");
gl.viewportWidth = canvas.width;
gl.viewportHeight = canvas.height;
} catch(e) {
}
if (!gl) {
alert("Impossibile Inizializzare WebGL.Devi avere un Browser con webgl abilitato per vedere qualcosa!");
}
gl.clearColor(0.0, 0.0, 0.0, 1.0);
gl.clearDepth(1.0);
gl.enable(gl.DEPTH_TEST);
gl.depthFunc(gl.LEQUAL);
}
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("Non posso inizializzare gli shader");
}
gl.useProgram(shaderProgram);
shaderProgram.vertexPositionAttribute = gl.getAttribLocation(shaderProgram, "aVertexPosition");
vertexColorAttribute=gl.getAttribLocation(shaderPr ogram,"aVertexColor");
gl.enableVertexAttribArray(vertexColorAttribute);
gl.enableVertexAttribArray(shaderProgram.vertexPos itionAttribute);
shaderProgram.pMatrixUniform = gl.getUniformLocation(shaderProgram, "uPMatrix");
shaderProgram.mvMatrixUniform = gl.getUniformLocation(shaderProgram, "uMVMatrix");
}
var squareVertexPositionBuffer;
var squareVertexColorBuffer;
function initBuffers() {
squareVertexPositionBuffer = gl.createBuffer();
gl.bindBuffer(gl.ARRAY_BUFFER, squareVertexPositionBuffer);
//vertici quadrato
vertices = [
1.0, 0.05, 0.0, // 1
-1.0, 0.05, 0.0, // 2
1.0, -0.05, 0.0, // 3
-1.0, -0.05, 0.0 // 4
];
gl.bufferData(gl.ARRAY_BUFFER, new Float32Array(vertices), gl.STATIC_DRAW);
squareVertexPositionBuffer.itemSize = 3;
squareVertexPositionBuffer.numItems = 4;
//colore vertici quadrato verde statico
squareVertexColorBuffer = gl.createBuffer();
gl.bindBuffer(gl.ARRAY_BUFFER, squareVertexColorBuffer);
var colors = [
0.0, 0.0, 1.0,1.0,
0.0, 0.0, 1.0,1.0,
0.0, 0.0, 1.0,1.0,
0.0, 0.0, 1.0,1.0
];
gl.bufferData(gl.ARRAY_BUFFER, new Float32Array(colors), gl.STATIC_DRAW);
}
function drawScene() {
gl.viewport(0, 0, gl.viewportWidth, gl.viewportHeight); //1
gl.clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT); //2
perspective(45, gl.viewportWidth / gl.viewportHeight, 0.1, 100.0); //3
loadIdentity(); //4
mvPushMatrix();
mvRotate(alfa, [0,0,1]);
mvTranslate([0.0, 0.0, -7.0]); //5
gl.bindBuffer(gl.ARRAY_BUFFER, squareVertexPositionBuffer); //6
gl.vertexAttribPointer(shaderProgram.vertexPositio nAttribute, squareVertexPositionBuffer.itemSize, gl.FLOAT, false, 0, 0);
gl.bindBuffer(gl.ARRAY_BUFFER,squareVertexColorBuf fer);
gl.vertexAttribPointer(vertexColorAttribute,4,gl.F LOAT,false,0,0);
setMatrixUniforms(); //8
gl.drawArrays(gl.TRIANGLE_STRIP, 0, squareVertexPositionBuffer.numItems); //9
}
function Start() {
var canvas = document.getElementById("Mycanvas");
initGL(canvas);
initShaders();
initBuffers();
setInterval(tick, 45);
//setInterval(ChangeColor, 300) automatico senza bottone
}
var alfa=0; //variabile angolo
function IncrementRotation()
{
alfa+=2;
}
function tick()
{
drawScene();
//IncrementRotation(); gira in automatico
}
</script>
</head>
<body onload="setTimeout(Start,1000);">
<canvas id="Mycanvas" width="800" height="400"></canvas>
<input type="button" value="Cambia colore" onclick="setInterval(ChangeColor, 300)">
<input type="button" value="Ruota" onclick="IncrementRotation()">
<input type="button" value="Cambia posizione" onclick="ChangePosition()">
</body>
</html>
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