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graphic-o3d-samples-archive-textures.htm / htm
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<!--
In this tutorial, we show how to progressively load in textures from a tar.gz archive.
-->
<!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>
Progressive Texture Loading
</title>
<script type="text/javascript" src="o3djs/base.js"></script>
<script type="text/javascript">
o3djs.require('o3djs.util');
o3djs.require('o3djs.math');
o3djs.require('o3djs.io');
o3djs.require('o3djs.rendergraph');
o3djs.require('o3djs.primitives');
o3djs.require('o3djs.effect');
// Events
// Run the init() once the page has finished loading.
window.onload = init;
// global variables
var g_o3d;
var g_math;
var g_client;
var g_pack;
var g_viewInfo;
var g_finished = false; // for selenium testing
var g_fileCount = 0;
var g_textureCount = 0;
// This is for offsetting our textures from each other as they arrive
var g_x = -200.0;
var g_y = -200.0;
function makeShape(texture, effect) {
// Create a Material for the effect.
var myMaterial = g_pack.createObject('Material');
// Set the material's drawList for opaque objects.
myMaterial.drawList = g_viewInfo.performanceDrawList;
// Apply our effect to this material.
myMaterial.effect = effect;
// Create the parameters the effect needs on the material.
effect.createUniformParameters(myMaterial);
// Creates a quad.
var myShape = o3djs.primitives.createPlane(g_pack,
myMaterial,
300, // width
300, // height
1, // quads across
1); // quads down
// Get the material's sampler parameter and put a sampler on it.
var sampler_param = myMaterial.getParam('texSampler0');
var sampler = g_pack.createObject('Sampler');
sampler_param.value = sampler;
// Set the texture to use.
sampler.texture = texture;
// adjust the scale of our transform to match the aspect ratio of
// the texture. Of course we could also have waited until now to build
// our plane and set its width and height to match instead of scaling
// here.
var textureWidth = texture.width;
var textureHeight = texture.height;
var hScale = 1;
var vScale = 1;
if (textureWidth > textureHeight) {
vScale = textureHeight / textureWidth;
} else if (textureHeight > textureWidth) {
hScale = textureWidth / textureHeight;
}
// We now attach our quad to the root of the transform graph.
// We do this after the texture has loaded, otherwise we'd be attempting
// to display something invalid.
// Make a transform for each quad.
var transform = g_pack.createObject('Transform');
transform.translate(g_x, 0, g_y);
transform.scale(hScale, 1, vScale);
transform.addShape(myShape);
transform.parent = g_client.root;
// Diagonally offset the next texture we load
g_x += 5.0;
g_y += 5.0;
return myShape;
}
Creates the client area.
function init() {
o3djs.util.makeClients(initStep2);
}
Initializes O3D, loads the effect, and loads a tar.gz archive containing
a bunch of image files. We'll create textures from them as they come in.
parameter: {Array} clientElements Array of o3d object elements.
function initStep2(clientElements) {
// Initialize global variables and libraries.
var o3dElement = clientElements[0];
g_o3d = o3dElement.o3d;
g_math = o3djs.math;
g_client = o3dElement.client;
// Create a pack to manage our resources/assets
g_pack = g_client.createPack();
// Create the render graph for a view.
g_viewInfo = o3djs.rendergraph.createBasicView(
g_pack,
g_client.root,
g_client.renderGraphRoot);
// Set up an orthographic projection.
g_viewInfo.drawContext.projection = g_math.matrix4.orthographic(
-g_client.width * 0.5,
g_client.width * 0.5,
-g_client.height * 0.5,
g_client.height * 0.5,
0.1,
1000);
// Move the camera above the origin looking down.
g_viewInfo.drawContext.view = g_math.matrix4.lookAt(
[0, 500, 0], // eye
[0, 0, 0], // target
[0, 0, -1]); // up
// Create and load the effect.
var effect = g_pack.createObject('Effect');
o3djs.effect.loadEffect(effect, 'shaders/texture-only.shader');
// Start a request for loading the tar.gz archive containing a bunch of
// image files. We'll then make textures from each one...
var loadInfo = o3djs.io.loadArchiveAdvanced(
g_pack,
'./assets/archive_textures.tar.gz',
onFileAvailable,
function(request, exception) {
// We are finished with the request so remove it.
g_pack.removeObject(request);
// Check for errors.
if (!exception) {
g_finished = true;
} else {
alert('Failed to load archive!\n' + exception);
}
});
// This is called for each file in the archive as it arrives
function onFileAvailable(rawData) {
// Create a texture from the RawData object that was just made available.
var texture = g_pack.createTextureFromRawData(rawData, true);
// Free the raw data object immediately since we're done with it.
// If we don't call this the RawData will stay around so we can use it
// later. For this app we won't need it later so we discard it now.
rawData.discard();
// Verify that the texture was created correctly and count it if so...
if (texture) g_textureCount++; // for selenium testing
// Display progress information.
var n = loadInfo.getTotalBytesDownloaded();
var streamLength = loadInfo.getTotalKnownBytesToStreamSoFar();
var progressInfo = n + ' bytes of ' + streamLength;
var fileInfo = 'file name = ' + rawData.uri
+ ' :: length = ' + rawData.length + ' bytes';
var info = document.getElementById('info');
var textureInfo = 'texture = ' + texture.width + 'x' + texture.height;
// If the page is reloaded before all of the textures have been created,
// IE will still invoke this call-back (even after the 'info' element has
// been removed).
if (info) {
info.innerHTML = info.innerHTML + progressInfo + " :: " + fileInfo +
" :: " + textureInfo + "<br>";
}
g_fileCount++;
if (texture) {
var shape = makeShape(texture, effect);
}
}
}
</script>
</head>
<body>
<h1>Progressive archive loading</h1>
This tutorial shows how to load textures progressively from a compressed archive.
<br><br/>
<!-- Start of O3D plugin -->
<div id="o3d" style="width: 600px; height: 600px"></div>
<!-- End of O3D plugin -->
<br><br/>
<!-- This div is for logging the progress of the progressive loading -->
<div id="info">
<h1>File Loading Progress</h1>
</div>
</body>
</html>
(C) Æliens
20/2/2008
You may not copy or print any of this material without explicit permission of the author or the publisher.
In case of other copyright issues, contact the author.
