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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.
*/
/**
* @fileoverview This file contains various functions for helping setup
* elements for o3d
*/
o3djs.provide('o3djs.element');
o3djs.require('o3djs.math');
/**
* A Module for element functions.
* @namespace
*/
o3djs.element = o3djs.element || {};
/**
* Sets the bounding box and z sort point of an element.
* @param {!o3d.Element} element Element to set bounding box and z sort point
* on.
*/
o3djs.element.setBoundingBoxAndZSortPoint = function(element) {
var boundingBox = element.getBoundingBox(0);
var minExtent = boundingBox.minExtent;
var maxExtent = boundingBox.maxExtent;
element.boundingBox = boundingBox;
element.cull = true;
element.zSortPoint = o3djs.math.divVectorScalar(
o3djs.math.addVector(minExtent, maxExtent), 2);
};
/**
* Adds missing texture coordinate streams to a primitive.
*
* This is very application specific but if it's a primitive
* and if it uses a collada material the material builder
* assumes 1 TEXCOORD stream per texture. In other words if you have
* both a specular texture AND a diffuse texture the builder assumes
* you have 2 TEXCOORD streams. This assumption is often false.
*
* To work around this we check how many streams the material
* expects and if there are not enough UVs streams we duplicate the
* last TEXCOORD stream until there are, making a BIG assumption that
* that will work.
*
* The problem is maybe you have 4 textures and each of them share
* texture coordinates. There is information in the collada file about
* what stream to connect each texture to.
*
* @param {!o3d.Element} element Element to add streams to.
*/
o3djs.element.addMissingTexCoordStreams = function(element) {
// TODO: We should store that info. The conditioner should either
// make streams that way or pass on the info so we can do it here.
if (element.isAClassName('o3d.Primitive')) {
var material = /** @type {!o3d.Material} */ (element.material);
var streamBank = element.streamBank;
var lightingType = o3djs.effect.getColladaLightingType(material);
if (lightingType) {
var numTexCoordStreamsNeeded =
o3djs.effect.getNumTexCoordStreamsNeeded(material);
// Count the number of TEXCOORD streams the streamBank has.
var streams = streamBank.vertexStreams;
var lastTexCoordStream = null;
var numTexCoordStreams = 0;
for (var ii = 0; ii < streams.length; ++ii) {
var stream = streams[ii];
if (stream.semantic == o3djs.base.o3d.Stream.TEXCOORD) {
lastTexCoordStream = stream;
++numTexCoordStreams;
}
}
// Add any missing TEXCOORD streams. It might be more efficient for
// the GPU to create an effect that doesn't need the extra streams
// but this is a more generic solution because it means we can reuse
// the same effect.
for (var ii = numTexCoordStreams;
ii < numTexCoordStreamsNeeded;
++ii) {
streamBank.setVertexStream(
lastTexCoordStream.semantic,
lastTexCoordStream.semanticIndex + ii - numTexCoordStreams + 1,
lastTexCoordStream.field,
lastTexCoordStream.startIndex);
}
}
}
};
/**
* Copies an element and streambank or buffers so the two will share
* streambanks, vertex and index buffers.
* @param {!o3d.Pack} pack Pack to manage created objects.
* @param {!o3d.Element} sourceElement The element to copy.
* @return {!o3d.Element} the new copy of sourceElement.
*/
o3djs.element.duplicateElement = function(pack, sourceElement) {
var newElement = pack.createObject(sourceElement.className);
newElement.copyParams(sourceElement);
// TODO: If we get the chance to parameterize the primitive's settings
// we can delete this code since copyParams will handle it.
// For now it only handles primitives by doing it manually.
if (sourceElement.isAClassName('o3d.Primitive')) {
newElement.indexBuffer = sourceElement.indexBuffer;
newElement.startIndex = sourceElement.startIndex;
newElement.primitiveType = sourceElement.primitiveType;
newElement.numberVertices = sourceElement.numberVertices;
newElement.numberPrimitives = sourceElement.numberPrimitives;
}
return newElement;
};
/**
* Gets the normal for specific triangle in a Primitive in that Primitive's
* local space.
*
* NOTE: THIS FUNCTION IS SLOW! If you want to do collisions you should use a
* different solution.
*
* @param {!o3d.Primitive} primitive Primitive to get normal from. The
* primitive MUST be a TRIANGLELIST or a TRIANGLESTRIP and it must have a
* POSITION,0 stream.
* @param {number} index Index of triangle.
* @param {boolean} opt_winding The winding of the triangles of the
* Primitive. False = Clockwise, True = Counterclockwise. The default is
* false. This is only used for Primitives that have no normals.
* @return {!o3djs.math.Vector3} The normal for the triangle.
*/
o3djs.element.getNormalForTriangle = function(primitive, index, opt_winding) {
// Check that we can do this
var primitiveType = primitive.primitiveType;
if (primitiveType != o3djs.base.o3d.Primitive.TRIANGLELIST &&
primitiveType != o3djs.base.o3d.Primitive.TRIANGLESTRIP) {
throw 'primitive is not a TRIANGLELIST or TRIANGLESTRIP';
}
var indexBuffer = primitive.indexBuffer;
var vertexIndex = (primitiveType == o3djs.base.o3d.Primitive.TRIANGLELIST) ?
(index * 3) : (index + 2);
var vertexIndices;
if (indexBuffer) {
var indexField = indexBuffer.fields[0];
vertexIndices = indexField.getAt(vertexIndex, 3);
} else {
vertexIndices = [vertexIndex, vertexIndex + 1, vertexIndex + 2]
}
var normalStream = primitive.streamBank.getVertexStream(
o3djs.base.o3d.Stream.NORMAL, 0);
if (normalStream) {
var normalField = normalStream.field;
// Look up the 3 normals that make the triangle.
var summedNormal = [0, 0, 0];
for (var ii = 0; ii < 3; ++ii) {
var normal = normalField.getAt(vertexIndices[ii], 1);
summedNormal = o3djs.math.addVector(summedNormal, normal);
}
return o3djs.math.normalize(summedNormal);
} else {
var positionStream = primitive.streamBank.getVertexStream(
o3djs.base.o3d.Stream.POSITION, 0);
if (!positionStream) {
throw 'no POSITION,0 stream in primitive';
}
var positionField = positionStream.field;
// Lookup the 3 positions that make the triangle.
var positions = [];
for (var ii = 0; ii < 3; ++ii) {
positions[ii] = positionField.getAt(vertexIndices[ii], 1);
}
// Compute a face normal from the positions.
var v0 = o3djs.math.normalize(o3djs.math.subVector(positions[1],
positions[0]));
var v1 = o3djs.math.normalize(o3djs.math.subVector(positions[2],
positions[1]));
return opt_winding ? o3djs.math.cross(v1, v0) : o3djs.math.cross(v0, v1);
}
};
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