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RotatingCube: Add RotatingCube[.html, .js]

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John
2022-07-12 13:18:10 -05:00
parent 3386f7f249
commit c179df0fa3
3 changed files with 192 additions and 0 deletions
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7
.vscode/launch.json vendored
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@@ -22,6 +22,13 @@
"request": "launch",
"reAttach": true,
"file": "${workspaceFolder}/Pendulum/Pendulum.html"
},
{
"name": "RotatingCube",
"type": "firefox",
"request": "launch",
"reAttach": true,
"file": "${workspaceFolder}/RotatingCube/RotatingCube.html"
}
]
}

19
RotatingCube/RotatingCube.html Normal file
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@@ -0,0 +1,19 @@
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8" />
<title>Draw cube with specification of face color</title>
</head>
<body onload="main()">
<canvas id="webgl" width="400" height="400">
Please use a browser that supports "canvas"
</canvas>
<script src="../lib/webgl-utils.js"></script>
<script src="../lib/webgl-debug.js"></script>
<script src="../lib/cuon-utils.js"></script>
<script src="../lib/cuon-matrix.js"></script>
<script src="RotatingCube.js"></script>
</body>
</html>

166
RotatingCube/RotatingCube.js Normal file
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@@ -0,0 +1,166 @@
// ColoredCube.js (c) 2012 matsuda
const vertex_shader = `
attribute vec4 a_Position;
attribute vec4 a_Color;
uniform mat4 u_MvpMatrix;
varying vec4 v_Color;
void main()
{
gl_Position = u_MvpMatrix * a_Position;
v_Color = a_Color;
} `;
const fragment_shader = `
#ifdef GL_ES
precision mediump float;
#endif
varying vec4 v_Color;
void main()
{
gl_FragColor = v_Color;
} `;
function main()
{
// Retrieve <canvas> element
var canvas = document.getElementById('webgl');
// Get the rendering context for WebGL
var gl = getWebGLContext(canvas);
if (!gl)
{
console.log('Failed to get the rendering context for WebGL');
return;
}
// Initialize shaders
if (!initShaders(gl, vertex_shader, fragment_shader))
{
console.log('Failed to intialize shaders.');
return;
}
// Set the vertex information
var n = initVertexBuffers(gl);
if (n < 0)
{
console.log('Failed to set the vertex information');
return;
}
// Set the clear color and enable the depth test
gl.clearColor(0.0, 0.0, 0.0, 1.0);
gl.enable(gl.DEPTH_TEST);
// Get the storage location of u_MvpMatrix
var u_MvpMatrix = gl.getUniformLocation(gl.program, 'u_MvpMatrix');
if (!u_MvpMatrix)
{
console.log('Failed to get the storage location of u_MvpMatrix');
return;
}
// Set the eye point and the viewing volume
var mvpMatrix = new Matrix4();
mvpMatrix.setOrtho(-2, 2, -2, 2, -2, 2);
// Pass the model view projection matrix to u_MvpMatrix
gl.uniformMatrix4fv(u_MvpMatrix, false, mvpMatrix.elements);
// Clear color and depth buffer
gl.clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT);
// Draw the cube
gl.drawElements(gl.TRIANGLES, n, gl.UNSIGNED_BYTE, 0);
}
function initVertexBuffers(gl)
{
// Create a cube
// v6----- v5
// /| /|
// v1------v0|
// | | | |
// | |v7---|-|v4
// |/ |/
// v2------v3
var vertices = new Float32Array([ // Vertex coordinates
1.0, 1.0, 1.0, -1.0, 1.0, 1.0, -1.0,-1.0, 1.0, 1.0,-1.0, 1.0, // v0-v1-v2-v3 front
1.0, 1.0, 1.0, 1.0,-1.0, 1.0, 1.0,-1.0,-1.0, 1.0, 1.0,-1.0, // v0-v3-v4-v5 right
1.0, 1.0, 1.0, 1.0, 1.0,-1.0, -1.0, 1.0,-1.0, -1.0, 1.0, 1.0, // v0-v5-v6-v1 up
-1.0, 1.0, 1.0, -1.0, 1.0,-1.0, -1.0,-1.0,-1.0, -1.0,-1.0, 1.0, // v1-v6-v7-v2 left
-1.0,-1.0,-1.0, 1.0,-1.0,-1.0, 1.0,-1.0, 1.0, -1.0,-1.0, 1.0, // v7-v4-v3-v2 down
1.0,-1.0,-1.0, -1.0,-1.0,-1.0, -1.0, 1.0,-1.0, 1.0, 1.0,-1.0 // v4-v7-v6-v5 back
]);
var colors = new Float32Array([ // Colors
0.4, 0.4, 1.0, 0.4, 0.4, 1.0, 0.4, 0.4, 1.0, 0.4, 0.4, 1.0, // v0-v1-v2-v3 front(blue)
0.4, 1.0, 0.4, 0.4, 1.0, 0.4, 0.4, 1.0, 0.4, 0.4, 1.0, 0.4, // v0-v3-v4-v5 right(green)
1.0, 0.4, 0.4, 1.0, 0.4, 0.4, 1.0, 0.4, 0.4, 1.0, 0.4, 0.4, // v0-v5-v6-v1 up(red)
1.0, 1.0, 0.4, 1.0, 1.0, 0.4, 1.0, 1.0, 0.4, 1.0, 1.0, 0.4, // v1-v6-v7-v2 left
1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, // v7-v4-v3-v2 down
0.4, 1.0, 1.0, 0.4, 1.0, 1.0, 0.4, 1.0, 1.0, 0.4, 1.0, 1.0 // v4-v7-v6-v5 back
]);
var indices = new Uint8Array([ // Indices of the vertices
0, 1, 2, 0, 2, 3, // front
4, 5, 6, 4, 6, 7, // right
8, 9,10, 8,10,11, // up
12,13,14, 12,14,15, // left
16,17,18, 16,18,19, // down
20,21,22, 20,22,23 // back
]);
// Create a buffer object
var indexBuffer = gl.createBuffer();
if (!indexBuffer)
return -1;
// Write the vertex coordinates and color to the buffer object
if (!initArrayBuffer(gl, vertices, 3, gl.FLOAT, 'a_Position'))
return -1;
if (!initArrayBuffer(gl, colors, 3, gl.FLOAT, 'a_Color'))
return -1;
// Write the indices to the buffer object
gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, indexBuffer);
gl.bufferData(gl.ELEMENT_ARRAY_BUFFER, indices, gl.STATIC_DRAW);
return indices.length;
}
function initArrayBuffer(gl, data, num, type, attribute)
{
var buffer = gl.createBuffer(); // Create a buffer object
if (!buffer)
{
console.log('Failed to create the buffer object');
return false;
}
// Write date into the buffer object
gl.bindBuffer(gl.ARRAY_BUFFER, buffer);
gl.bufferData(gl.ARRAY_BUFFER, data, gl.STATIC_DRAW);
// Assign the buffer object to the attribute variable
var a_attribute = gl.getAttribLocation(gl.program, attribute);
if (a_attribute < 0)
{
console.log('Failed to get the storage location of ' + attribute);
return false;
}
gl.vertexAttribPointer(a_attribute, num, type, false, 0, 0);
// Enable the assignment of the buffer object to the attribute variable
gl.enableVertexAttribArray(a_attribute);
return true;
}