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<!--
Copyright 2009, Google Inc.
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are
met:
* Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above
copyright notice, this list of conditions and the following disclaimer
in the documentation and/or other materials provided with the
distribution.
* Neither the name of Google Inc. nor the names of its
contributors may be used to endorse or promote products derived from
this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-->
<!--
This sample shows how to use simple circle texture for shadows.
-->
<!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>
Old School Shadows.
</title>
<link rel="stylesheet" type="text/css" href="assets/style.css" />
<!-- Include sample javascript library functions-->
<script type="text/javascript" src="o3djs/base.js"></script>
<!-- Our javascript code -->
<script type="text/javascript" id="o3dscript">
o3djs.require('o3djs.util');
o3djs.require('o3djs.math');
o3djs.require('o3djs.rendergraph');
o3djs.require('o3djs.primitives');
o3djs.require('o3djs.material');
// Constants
var SHADOW_SIZE = 5;
// Events
// init() once the page has finished loading.
// unload() when the page is unloaded.
window.onload = init;
window.onunload = unload;
// global variables
var g_o3dElement;
var g_o3d;
var g_math;
var g_client;
var g_viewInfo;
var g_pack;
var g_root;
var g_clock = 0;
var g_timeMult = 1;
var g_globalParams;
var g_shadowDrawPassInfo;
var g_o3dWidth;
var g_o3dHeight;
var g_o3dElement;
var g_transforms = [];
/**
* Creates the client area.
*/
function init() {
o3djs.util.makeClients(initStep2);
}
/**
* Initializes O3D and creates one shape.
* @param {Array} clientElements Array of o3d object elements.
*/
function initStep2(clientElements) {
// Initializes global variables and libraries.
g_o3dElement = clientElements[0];
g_o3d = g_o3dElement.o3d;
g_math = o3djs.math;
g_client = g_o3dElement.client;
// Creates a pack to manage our resources/assets
g_pack = g_client.createPack();
g_root = g_pack.createObject('Transform');
g_viewInfo = o3djs.rendergraph.createBasicView(
g_pack,
g_root,
g_client.renderGraphRoot);
// Make another draw pass just for the shadows so they get
// drawn last. We don't need to pass any extra info to createDrawPass
// because we are using the same drawContext and because we want it to
// happen last, both of which are the default.
g_shadowDrawPassInfo = g_viewInfo.createDrawPass(
g_o3d.DrawList.BY_PERFORMANCE);
// Get the state object the shadow draw pass and set states for the shadows.
var state = g_shadowDrawPassInfo.state;
// The following settings turn on blending for all objects using the
// shadow DrawList
state.getStateParam('AlphaBlendEnable').value = true;
state.getStateParam('SourceBlendFunction').value =
o3djs.base.o3d.State.BLENDFUNC_SOURCE_ALPHA;
state.getStateParam('DestinationBlendFunction').value =
o3djs.base.o3d.State.BLENDFUNC_INVERSE_SOURCE_ALPHA;
state.getStateParam('AlphaTestEnable').value = true;
state.getStateParam('AlphaComparisonFunction').value =
o3djs.base.o3d.State.CMP_GREATER;
// Make the shadow not write to the ZBuffer, otherwise they will interfere
// with each other. Try commenting this line out to see what happens. Look
// closely when 2 shadows overlap. It's easier to see the problem
// if you make the shadows larger. Set the shadow size to 15
state.getStateParam('ZWriteEnable').value = false;
// This setting pulls the shadow in front of the ground plane even though
// they are at the same position in space. Comment this 2 lines out
// to see what happens if you don't use this setting.
state.getStateParam('PolygonOffset1').value = -1;
state.getStateParam('PolygonOffset2').value = -1;
// Setup the view and projection matrices.
var eye = [15, 25, 50];
var target = [0, 10, 0];
var up = [0, 1, 0];
g_viewInfo.drawContext.view = g_math.matrix4.lookAt(eye, target, up);
g_viewInfo.drawContext.projection = g_math.matrix4.perspective(
g_math.degToRad(45), // field of view.
g_client.width / g_client.height, // aspect ratio
0.1, // Near plane.
5000); // Far plane.
// Load a small circle texture.
o3djs.io.loadTexture(
g_pack,
o3djs.util.getAbsoluteURI('assets/old-school-shadow.png'),
initStep3);
}
function initStep3(texture, exception) {
if (exception) {
alert(exception);
return;
}
// This material is used for the spheres.
var sphereMaterial = o3djs.material.createBasicMaterial(
g_pack,
g_viewInfo,
[1, 1, 1, 1]);
sphereMaterial.getParam('specularFactor').value = 0.4;
// The material for the ground.
var checkerMaterial = o3djs.material.createCheckerMaterial(
g_pack,
g_viewInfo);
// Make a material to use for the shadow. A standard constant shader will
// be fine.
var shadowMaterial = o3djs.material.createConstantMaterial(
g_pack,
g_viewInfo,
texture,
true);
shadowMaterial.drawList = g_shadowDrawPassInfo.drawList;
// Setup the lighting for the ground and spheres.
g_globalParams = o3djs.material.createAndBindStandardParams(g_pack);
g_globalParams.lightWorldPos.value = [30, 60, 40];
g_globalParams.lightColor.value = [1, 1, 1, 1];
// Create a ground plane.
var shape = o3djs.primitives.createPlane(
g_pack, checkerMaterial, 100, 100, 10, 10);
var transform = g_pack.createObject('Transform');
transform.parent = g_root;
transform.addShape(shape);
// Create a sphere.
var sphere = o3djs.primitives.createSphere(
g_pack, sphereMaterial, 2.5, 24, 48,
g_math.matrix4.translation([0, 2.5, 0]));
// Create a plane for the shadow.
var shadow = o3djs.primitives.createPlane(g_pack, shadowMaterial,
SHADOW_SIZE, SHADOW_SIZE, 1, 1);
// Instance 100 spheres with shadows.
for (var ii = 0; ii < 100; ++ii) {
var transform = g_pack.createObject('Transform');
g_transforms.push(transform);
transform.parent = g_root;
transform.addShape(sphere);
// Give each sphere a pseudo random color.
transform.createParam('diffuse', 'ParamFloat4').value = [
(ii * 1.71) % 1,
(ii * 2.09) % 1,
(ii * 6.31) % 1,
1];
var shadowTransform = g_pack.createObject('Transform');
shadowTransform.parent = transform;
shadowTransform.addShape(shadow);
}
// Setup a render callback for per frame processing.
g_client.setRenderCallback(onRender);
window.g_finished = true; // for selenium testing.
}
/**
* Called every frame.
* @param {!o3d.RenderEvent} renderEvent Rendering Information.
*/
function onRender(renderEvent) {
var elapsedTime = renderEvent.elapsedTime;
g_clock += elapsedTime * g_timeMult;
moveThings();
};
/**
* Moves all the sphere transforms in some pattern that is a function of
* g_clock so we can force it to a predictable state for testing.
*/
function moveThings() {
for (var ii = 0; ii < g_transforms.length; ++ii) {
var transform = g_transforms[ii];
var xSpeed = g_clock * 0.25 + ii * 1.1;
var ySpeed = g_clock * 0.27 + ii * 0.5;
transform.identity();
transform.translate(40 * Math.sin(xSpeed),
0,
40 * Math.cos(ySpeed));
var scale = (Math.sin(g_clock * 0.29 + ii * 20.7) + 1) * 0.5 + 0.3;
transform.scale(scale, scale, scale);
}
}
/**
* Remove any callbacks so they don't get called after the page has unloaded.
*/
function unload() {
if (g_client) {
g_client.cleanup();
}
}
</script>
</head>
<body>
<h1>Old School Shadows</h1>
<div id="o3d" style="width: 800px; height: 600px"></div>
</body>
</html>
|
