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<!--
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modification, are permitted provided that the following conditions are
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-->
<!--
This sample shows how to place an O3D area in a page and draw simple
3D shape in it.
-->
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<title>
Hello Cube: Primitives
</title>
<script type="text/javascript" src="../o3d-webgl/base.js"></script>
<script type="text/javascript" src="../o3djs/base.js"></script>
<script type="text/javascript" id="o3dscript">
o3djs.base.o3d = o3d;
o3djs.require('o3djs.webgl');
o3djs.require('o3djs.math');
o3djs.require('o3djs.rendergraph');
// Events
// Run the init() function once the page has finished loading.
// Run the uninit() function when the page has is unloaded.
window.onload = init;
window.onunload = uninit;
// global variables
var g_o3d;
var g_math;
var g_client;
var g_pack;
var g_clock = 0;
var g_timeMult = 1;
var g_cubeTransform;
var g_cubePrimitive;
var g_material;
var g_finished = false; // for selenium testing
/**
* Changes the primitive type of the displayed cube. Some primitive types will
* only draw a partial cube.
* @param {string} type The desired primitive type.
*/
function changePrimitive(type) {
var indicesArray;
var primitiveType;
var numberPrimitives;
// All of the indices arrays below reference the same set of 8 vertices,
// defined below in the createCube method.
switch (type) {
case 'PointList':
primitiveType = g_o3d.Primitive.POINTLIST;
numberPrimitives = 8;
indicesArray = [0, 1, 2, 3, 4, 5, 6, 7];
break;
case 'LineList':
primitiveType = g_o3d.Primitive.LINELIST;
numberPrimitives = 12;
indicesArray = [
0, 1,
1, 3,
3, 2,
2, 0,
6, 7,
7, 5,
5, 4,
4, 6,
2, 4,
3, 5,
0, 6,
1, 7
];
break;
case 'LineStrip':
primitiveType = g_o3d.Primitive.LINESTRIP;
numberPrimitives = 8;
// Forms an incomplete cube, where indices 0 and 1 are the first segment,
// 1 and 3 are the second segement, 3 and 5 are the third, and so forth.
indicesArray = [0, 1, 3, 5, 7, 6, 4, 2, 0];
break;
case 'TriangleList':
primitiveType = g_o3d.Primitive.TRIANGLELIST;
numberPrimitives = 12;
indicesArray = [
0, 1, 2, // face 1
2, 1, 3,
2, 3, 4, // face 2
4, 3, 5,
4, 5, 6, // face 3
6, 5, 7,
6, 7, 0, // face 4
0, 7, 1,
1, 7, 3, // face 5
3, 7, 5,
6, 0, 4, // face 6
4, 0, 2
];
break;
case 'TriangleStrip':
primitiveType = g_o3d.Primitive.TRIANGLESTRIP;
numberPrimitives = 8;
// Forms a cube missing two faces. Indices (0, 1, 2) forms the first
// triangle, (1, 2, 3) forms the second triangle, and so forth.
indicesArray = [0, 1, 2, 3, 4, 5, 6, 7, 0, 1];
break;
case 'TriangleFan':
primitiveType = g_o3d.Primitive.TRIANGLEFAN;
numberPrimitives = 6;
// Forms a half cube, missing three faces. Indices (2, 0, 1) forms the
// first triangle, (2, 1, 3) is the second, (2, 3, 5) is the third, etc.
indicesArray = [2, 0, 1, 3, 5, 4, 6, 0];
break;
default:
alert('Invalid selection type!');
return;
}
g_cubePrimitive.primitiveType = primitiveType;
g_cubePrimitive.numberPrimitives = numberPrimitives;
g_cubePrimitive.indexBuffer.set(indicesArray);
}
/**
* Changes the fill mode on the state associated with the cube material.
* @param {string} type The desired fill mode.
*/
function changeFillMode(mode_string) {
var mode = o3d.State.SOLID;
switch (mode_string) {
case 'Point':
mode = o3d.State.POINT;
break;
case 'Wireframe':
mode = o3d.State.WIREFRAME;
break;
case 'Solid':
default:
mode = o3d.State.SOLID;
break;
}
g_material.state.getStateParam('FillMode').value = mode;
}
/**
* Creates an O3D shape representing a cube. The shape consists of
* a single primitive with eight vertices.
*
* @param {o3d.Material} material the material used by the primitive.
* @return {o3d.Shape} The Shape object created.
*/
function createCube(material) {
// Create a Shape object for the mesh.
var cubeShape = g_pack.createObject('Shape');
// Create the Primitive that will contain the geometry data for
// the cube.
var cubePrimitive = g_pack.createObject('Primitive');
g_cubePrimitive = cubePrimitive;
// Create a StreamBank to hold the streams of vertex data.
var streamBank = g_pack.createObject('StreamBank');
// Assign the material that was passed in to the primitive.
cubePrimitive.material = material;
// Assign the Primitive to the Shape.
cubePrimitive.owner = cubeShape;
// Assign the StreamBank to the Primitive.
cubePrimitive.streamBank = streamBank;
// Generate the draw element for the cube primitive.
cubePrimitive.createDrawElement(g_pack, null);
// Create a javascript array that stores the X, Y and Z coordinates of each
// of the 8 corners of the cube.
var positionArray = [
-0.5, -0.5, 0.5, // vertex 0
0.5, -0.5, 0.5, // vertex 1
-0.5, 0.5, 0.5, // vertex 2
0.5, 0.5, 0.5, // vertex 3
-0.5, 0.5, -0.5, // vertex 4
0.5, 0.5, -0.5, // vertex 5
-0.5, -0.5, -0.5, // vertex 6
0.5, -0.5, -0.5 // vertex 7
];
// Create buffers containing the vertex data.
var positionsBuffer = g_pack.createObject('VertexBuffer');
var positionsField = positionsBuffer.createField('FloatField', 3);
positionsBuffer.set(positionArray);
cubePrimitive.indexBuffer = g_pack.createObject('IndexBuffer');
// Associate the positions Buffer with the StreamBank.
streamBank.setVertexStream(
g_o3d.Stream.POSITION, // semantic: This stream stores vertex positions
0, // semantic index: First (and only) position stream
positionsField, // field: the field this stream uses.
0); // start_index: How many elements to skip in the
// field.
return cubeShape;
}
/**
* This method gets called every time O3D renders a frame. Here's where
* we update the cube's transform to make it spin.
* @param {o3d.RenderEvent} renderEvent The render event object that gives
* us the elapsed time since the last time a frame was rendered.
*/
function renderCallback(renderEvent) {
g_clock += renderEvent.elapsedTime * g_timeMult;
// Rotate the cube around the Y axis.
g_cubeTransform.identity();
g_cubeTransform.rotateY(2.0 * g_clock);
}
/**
* Creates the client area.
*/
function init() {
o3djs.webgl.makeClients(initStep2);
}
/**
* Initializes O3D, creates the cube and sets up the transform and
* render graphs.
* @param {Array} clientElements Array of o3d object elements.
*/
function initStep2(clientElements) {
// Initializes global variables and libraries.
var o3dElement = clientElements[0];
g_client = o3dElement.client;
g_o3d = o3dElement.o3d;
g_math = o3djs.math;
// Create a pack to manage the objects created.
g_pack = g_client.createPack();
// Create the render graph for a view.
var viewInfo = o3djs.rendergraph.createBasicView(
g_pack,
g_client.root,
g_client.renderGraphRoot,
[1, 1, 1, 1]);
// Set up a perspective projection.
viewInfo.drawContext.projection = g_math.matrix4.perspective(
g_math.degToRad(30), // 30 degree fov.
g_client.width / g_client.height,
1, // Near plane.
5000); // Far plane.
// Set up our view transformation to look towards the world origin where the
// cube is located.
viewInfo.drawContext.view = g_math.matrix4.lookAt([0, 1, 5], // eye
[0, 0, 0], // target
[0, 1, 0]); // up
// Create an Effect object and initialize it using the shaders from the
// text area.
var myEffect = g_pack.createObject('Effect');
var vertexShaderString = document.getElementById('vshader').value;
var pixelShaderString = document.getElementById('pshader').value;
myEffect.loadVertexShaderFromString(vertexShaderString);
myEffect.loadPixelShaderFromString(pixelShaderString);
// Create a Material for the mesh.
g_material = g_pack.createObject('Material');
// Set the material's drawList.
g_material.drawList = viewInfo.performanceDrawList;
g_material.state = g_pack.createObject('State');
// Turn off culling.
viewInfo.performanceDrawPassInfo.state.getStateParam('CullMode').value =
g_o3d.State.CULL_NONE;
// Apply our effect to this material. The effect tells the 3D hardware
// which shaders to use.
g_material.effect = myEffect;
// Create the Shape for the cube mesh and assign its material.
var cubeShape = createCube(g_material);
// Render with line lists to begin with.
changePrimitive('LineList');
changeFillMode('Solid');
// Create a new transform and parent the Shape under it.
g_cubeTransform = g_pack.createObject('Transform');
g_cubeTransform.addShape(cubeShape);
// Parent the cube's transform to the client root.
g_cubeTransform.parent = g_client.root;
// Set our render callback for animation.
// This sets a function to be executed every time a frame is rendered.
g_client.setRenderCallback(renderCallback);
g_finished = true; // for selenium testing.
}
/**
* Removes any callbacks so they don't get called after the page has unloaded.
*/
function uninit() {
if (g_client) {
g_client.cleanup();
}
}
</script>
</head>
<body>
<h1>Hello Cube - Primitives</h1>
This example shows how to display a cube in O3D using different primitive types.
<br/>
<!-- Start of O3D plugin -->
<div id="o3d" style="width: 600px; height: 600px;"></div>
<form name="default_form" action="#" method="get">
<p>
Primitive type:
<select onchange="changePrimitive(this.options[this.selectedIndex].value);">
<option value="PointList">PointList</option>
<option value="LineList" selected>LineList</option>
<option value="LineStrip">LineStrip</option>
<option value="TriangleList">TriangleList</option>
<option value="TriangleStrip">TriangleStrip</option>
<option value="TriangleFan">TriangleFan</option>
</select>
</p>
<p>
Fill mode:
<select onchange="changeFillMode(this.options[this.selectedIndex].value);">
<option value="Point">Point</option>
<option value="Wireframe">Wireframe</option>
<option value="Solid" selected>Solid</option>
</select>
</p>
</form>
<!-- End of O3D plugin -->
<!-- Don't render the textarea -->
<div style="display:none">
<!-- Start of effect -->
<textarea id="vshader">
attribute vec4 position;
uniform mat4 world;
uniform mat4 view;
uniform mat4 projection;
varying vec4 pos;
/**
* The vertex shader simply transforms the input vertices to screen space.
*/
void main() {
// Multiply the vertex positions by the worldViewProjection matrix to
// transform them to screen space.
gl_Position = projection * view * world * position;
// Make points larger, so they can been seen.
gl_PointSize = 5.0;
pos = position;
}
</textarea>
<textarea id="pshader">
varying vec4 pos;
/**
* The fragment shader derives color based on the position.
*/
void main() {
gl_FragColor = pos;
}
</textarea>
<!-- End of effect -->
</div>
</body>
</html>
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