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*
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/**
* @fileoverview This file contains functions for implementing picking.
* It puts them in the "picking" module on the o3djs object.
*
*
* This example shows one way to implement picking. Because O3D is shader
* agnostic we can't handle picking automatically since we have no way of
* knowing what the developer is going to do with their shaders. On the other
* hand, we can provide various functions that make it possible to do your own
* picking. Only you know which objects are pickable and which are not. For
* example if you are making an RTS game, only you would know that units are
* pickable but ground and explosions are not and that neither is your HUD.
* Similarly, only you would know how your shaders manipulate the vertices
* passed to them.
*
* It's possible that someone, maybe us, will create an engine to use o3d
* that given a bunch of restrictions and flags on the data it accepts can
* do picking in a more automatic way but that is not the goal of the o3d
* api. Its goal is to provide a LOW-LEVEL shader agnostic API.
*/
o3djs.provide('o3djs.picking');
o3djs.require('o3djs.math');
o3djs.require('o3djs.dump');
/**
* A Module for picking.
* @namespace
*/
o3djs.picking = o3djs.picking || {};
/**
* A ray.
* @type {{near: !o3djs.math.Vector3, far: !o3djs.math.Vector3}}
*/
o3djs.picking.Ray = goog.typedef;
/**
* Creates a new PickInfo.
* @param {!o3d.Element} element The Element that was picked.
* @param {!o3djs.picking.ShapeInfo} shapeInfo The ShapeInfo that was picked.
* @param {!o3d.RayIntersectionInfo} rayIntersectionInfo Information about the
* pick.
* @param {!o3djs.math.Vector3} worldIntersectionPosition world position of
* intersection.
* @return {!o3djs.picking.PickInfo} The new PickInfo.
*/
o3djs.picking.createPickInfo = function(element,
shapeInfo,
rayIntersectionInfo,
worldIntersectionPosition) {
return new o3djs.picking.PickInfo(element,
shapeInfo,
rayIntersectionInfo,
worldIntersectionPosition);
};
/**
* Creates a new ShapeInfo.
* @param {!o3d.Shape} shape Shape to keep info about.
* @param {!o3djs.picking.TransformInfo} parent Parent transform of the shape.
* @return {!o3djs.picking.ShapeInfo} The new ShapeInfo.
*/
o3djs.picking.createShapeInfo = function(shape, parent) {
return new o3djs.picking.ShapeInfo(shape, parent);
};
/**
* Creates a new TransformInfo.
* @param {!o3d.Transform} transform Transform to keep info about.
* @param {o3djs.picking.TransformInfo} parent Parent transform of the
* transform. Can be null.
* @return {!o3djs.picking.TransformInfo} The new TransformInfo.
*/
o3djs.picking.createTransformInfo = function(transform, parent) {
return new o3djs.picking.TransformInfo(transform, parent);
};
/**
* Convert a pixel position relative to the top left corner of the client area
* into the corresponding ray through the frustum in world space.
* @param {number} clientXPosition x position relative to client area.
* @param {number} clientYPosition y position relative to client area.
* @param {!o3djs.math.Matrix4} view View matrix to transform with.
* @param {!o3djs.math.Matrix4} projection Projection matrix to transform
* with.
* @param {number} clientWidth width of client area.
* @param {number} clientHeight height of client area.
* @return {!o3djs.picking.Ray} ray in world space.
*/
o3djs.picking.clientPositionToWorldRayEx = function(clientXPosition,
clientYPosition,
view,
projection,
clientWidth,
clientHeight) {
// compute the world position of a ray going through the view frustum
var inverseViewProjectionMatrix = o3djs.math.inverse(
o3djs.math.matrix4.composition(projection, view));
// normScreenX, normScreenY are in frustum coordinates.
var normScreenX = clientXPosition / (clientWidth * 0.5) - 1;
var normScreenY = -(clientYPosition / (clientHeight * 0.5) - 1);
// Apply inverse view-projection matrix to get the ray in world coordinates.
return {
near: o3djs.math.matrix4.transformPoint(
inverseViewProjectionMatrix, [normScreenX, normScreenY, 0]),
far: o3djs.math.matrix4.transformPoint(
inverseViewProjectionMatrix, [normScreenX, normScreenY, 1])
};
};
/**
* Convert a pixel position relative to the top left corner of the client area
* into the corresponding ray through the frustum in world space.
* @param {number} clientXPosition x position relative to client area.
* @param {number} clientYPosition y position relative to client area.
* @param {!o3d.DrawContext} drawContext DrawContext to get view and
* projection matrices from.
* @param {number} clientWidth width of client area.
* @param {number} clientHeight height of client area.
* @return {!o3djs.picking.Ray} ray in world space.
*/
o3djs.picking.clientPositionToWorldRay = function(clientXPosition,
clientYPosition,
drawContext,
clientWidth,
clientHeight) {
return o3djs.picking.clientPositionToWorldRayEx(
clientXPosition,
clientYPosition,
drawContext.view,
drawContext.projection,
clientWidth,
clientHeight);
};
/**
* A local dump function so we can easily comment it out.
* @param {string} msg Message to dump.
*/
o3djs.picking.dprint = function(msg) {
//o3djs.dump.dump(msg);
};
/**
* A local dump function so we can easily comment it out.
* @param {string} label Label to print before value.
* @param {!o3djs.math.Vector3} float3 Value to print.
* @param {string} prefix optional prefix for indenting.
*/
o3djs.picking.dprintPoint3 = function(label, float3, prefix) {
//o3djs.dump.dumpPoint3(label, float3, prefix);
};
/**
* A local dump function so we can easily comment it out.
* @param {string} label Label to put in front of dump.
* @param {!o3d.BoundingBox} boundingBox BoundingBox to dump.
* @param {string} opt_prefix optional prefix for indenting.
*/
o3djs.picking.dprintBoundingBox = function(label,
boundingBox,
opt_prefix) {
//o3djs.dump.dumpBoundingBox(label, boundingBox, opt_prefix);
};
/**
* A local dump function so we can easily comment it out.
* @param {string} label Label to print before value.
* @param {!o3d.RayIntersectionInfo} rayIntersectionInfo Value to print.
*/
o3djs.picking.dumpRayIntersectionInfo = function(label,
rayIntersectionInfo) {
o3djs.picking.dprint(label + ' : valid = ' +
rayIntersectionInfo.valid + ' : intersected = ' +
rayIntersectionInfo.intersected);
if (rayIntersectionInfo.intersected) {
o3djs.picking.dprint(
' : pos: ' +
rayIntersectionInfo.position[0] + ', ' +
rayIntersectionInfo.position[1] + ', ' +
rayIntersectionInfo.position[2] + ', ');
}
o3djs.picking.dprint('\n');
};
/**
* Creates a new PickInfo. Used to return picking information.
* @constructor
* @param {!o3d.Element} element The Element that was picked.
* @param {!o3djs.picking.ShapeInfo} shapeInfo The ShapeInfo that was picked.
* @param {!o3d.RayIntersectionInfo} rayIntersectionInfo Information about the
* pick.
* @param {!o3djs.math.Vector3} worldIntersectionPosition world position of
* intersection.
*/
o3djs.picking.PickInfo = function(element,
shapeInfo,
rayIntersectionInfo,
worldIntersectionPosition) {
/**
* The Element that was picked (Primitive).
* @type {!o3d.Element}
*/
this.element = element;
/**
* The ShapeInfo that was picked.
* @type {!o3djs.picking.ShapeInfo}
*/
this.shapeInfo = shapeInfo;
/**
* Information about the pick.
* @type {!o3d.RayIntersectionInfo}
*/
this.rayIntersectionInfo = rayIntersectionInfo;
/**
* The worldIntersectionPosition world position of intersection.
* @type {!o3djs.math.Vector3}
*/
this.worldIntersectionPosition = worldIntersectionPosition
};
/**
* Creates a new ShapeInfo. Used to store information about Shapes.
* @constructor
* @param {!o3d.Shape} shape Shape to keep info about.
* @param {!o3djs.picking.TransformInfo} parent Parent transform of the shape.
*/
o3djs.picking.ShapeInfo = function(shape, parent) {
/**
* The Shape for this ShapeInfo
* @type {!o3d.Shape}
*/
this.shape = shape;
/**
* The parent TransformInfo of this Shape.
* @type {!o3djs.picking.TransformInfo}
*/
this.parent = parent;
/**
* The bounding box for this Shape
* @type {o3d.BoundingBox}
*/
this.boundingBox = null;
this.update();
};
/**
* Gets the BoundingBox of the Shape in this ShapeInfo.
* @return {o3d.BoundingBox} The Shape's BoundingBox.
*/
o3djs.picking.ShapeInfo.prototype.getBoundingBox = function() {
return this.boundingBox;
};
/**
* Updates the BoundingBox of the Shape in this ShapeInfo.
*/
o3djs.picking.ShapeInfo.prototype.update = function() {
var elements = this.shape.elements;
if (elements.length > 0) {
this.boundingBox = elements[0].getBoundingBox(0);
for (var ee = 1; ee < elements.length; ee++) {
this.boundingBox = this.boundingBox.add(elements[ee].getBoundingBox(0));
}
}
};
/**
* Attempts to "pick" this Shape by checking for the intersection of a ray
* in world space to the triangles this shape uses.
* @param {!o3djs.picking.Ray} worldRay A ray in world space to pick against.
* @return {o3djs.picking.PickInfo} Information about the picking.
* null if the ray did not intersect any triangles.
*/
o3djs.picking.ShapeInfo.prototype.pick = function(worldRay) {
var worldMatrix = this.parent.transform.getUpdatedWorldMatrix()
var inverseWorldMatrix = o3djs.math.inverse(worldMatrix);
var relativeNear = o3djs.math.matrix4.transformPoint(
inverseWorldMatrix, worldRay.near);
var relativeFar = o3djs.math.matrix4.transformPoint(
inverseWorldMatrix, worldRay.far);
var rayIntersectionInfo =
this.boundingBox.intersectRay(relativeNear,
relativeFar);
o3djs.picking.dumpRayIntersectionInfo('SHAPE(box): ' + this.shape.name,
rayIntersectionInfo);
if (rayIntersectionInfo.intersected) {
var elements = this.shape.elements;
for (var e = 0; e < elements.length; e++) {
var element = elements[e];
rayIntersectionInfo = element.intersectRay(
0,
o3djs.base.o3d.State.CULL_CCW,
relativeNear,
relativeFar);
o3djs.picking.dumpRayIntersectionInfo(
'SHAPE(tris): ' + this.shape.name + ' : element ' + element.name,
rayIntersectionInfo);
// TODO: get closest element not just first element.
if (rayIntersectionInfo.intersected) {
var worldIntersectionPosition = o3djs.math.matrix4.transformPoint(
worldMatrix, rayIntersectionInfo.position);
return o3djs.picking.createPickInfo(element,
this,
rayIntersectionInfo,
worldIntersectionPosition);
}
}
}
return null;
};
/**
* Dumps info about a ShapeInfo
* @param {string} prefix optional prefix for indenting.
*/
o3djs.picking.ShapeInfo.prototype.dump = function(prefix) {
o3djs.picking.dprint(prefix + 'SHAPE: ' + this.shape.name + '\n');
o3djs.picking.dprintPoint3('bb min',
this.boundingBox.minExtent,
prefix + ' ');
o3djs.picking.dprintPoint3('bb max',
this.boundingBox.maxExtent,
prefix + ' ');
};
/**
* Creates a new TransformInfo. Used to store information about Transforms.
* @constructor
* @param {!o3d.Transform} transform Transform to keep info about.
* @param {o3djs.picking.TransformInfo} parent Parent transformInfo of the
* transform. Can be null.
*/
o3djs.picking.TransformInfo = function(transform, parent) {
this.childTransformInfos = {}; // Object of TransformInfo by id
this.shapeInfos = {}; // Object of ShapeInfo by id
/**
* The transform of this transform info.
* @type {!o3d.Transform}
*/
this.transform = transform;
/**
* The parent of this transform info.
* @type {o3djs.picking.TransformInfo}
*/
this.parent = parent;
this.boundingBox = null;
};
/**
* Gets the BoundingBox of the Transform in this TransformInfo.
* @return {o3d.BoundingBox} The Transform's BoundingBox.
*/
o3djs.picking.TransformInfo.prototype.getBoundingBox = function() {
return this.boundingBox;
};
/**
* Updates the shape and child lists for this TransformInfo and recomputes its
* BoundingBox.
*/
o3djs.picking.TransformInfo.prototype.update = function() {
var newChildTransformInfos = {};
var newShapeInfos = {};
var children = this.transform.children;
for (var c = 0; c < children.length; c++) {
var child = children[c];
var transformInfo = this.childTransformInfos[child.clientId];
if (!transformInfo) {
transformInfo = o3djs.picking.createTransformInfo(child, this);
} else {
// clear the boundingBox so we'll regenerate it.
transformInfo.boundingBox = null;
}
transformInfo.update();
newChildTransformInfos[child.clientId] = transformInfo;
}
var shapes = this.transform.shapes;
for (var s = 0; s < shapes.length; s++) {
var shape = shapes[s];
var shapeInfo = this.shapeInfos[shape.clientId];
if (!shapeInfo) {
shapeInfo = o3djs.picking.createShapeInfo(shape, this);
} else {
// unless the vertices or elements change there is no need to
// recompute this.
// shape.update();
}
newShapeInfos[shape.clientId] = shapeInfo;
}
// o3djs.picking.dprint(
// 'num Children: ' + children.length + '\n');
// o3djs.picking.dprint(
// 'num Shapes: ' + shapes.length + '\n');
this.childTransformInfos = newChildTransformInfos;
this.shapeInfos = newShapeInfos;
var boundingBox = null;
for (var key in newShapeInfos) {
var shapeInfo = newShapeInfos[key];
var box = shapeInfo.getBoundingBox().mul(this.transform.localMatrix);
if (!boundingBox) {
boundingBox = box;
} else if (box) {
boundingBox = boundingBox.add(box);
}
}
for (var key in newChildTransformInfos) {
var transformInfo = newChildTransformInfos[key];
// Note: If there is no shape at the leaf on this branch
// there will be no bounding box.
var box = transformInfo.getBoundingBox();
if (box) {
if (!boundingBox) {
boundingBox = box.mul(this.transform.localMatrix);
} else {
boundingBox = boundingBox.add(box.mul(this.transform.localMatrix));
}
}
}
this.boundingBox = boundingBox;
};
/**
* Attempts to "pick" this TransformInfo by checking for the intersection of a
* ray in world space to the boundingbox of the TransformInfo. If intesection
* is succesful recursively calls its children and shapes to try to find
* a single Shape that is hit by the ray.
* @param {!o3djs.picking.Ray} worldRay A ray in world space to pick against.
* @return {o3djs.picking.PickInfo} Information about the picking.
* null if the ray did not intersect any triangles.
*/
o3djs.picking.TransformInfo.prototype.pick = function(worldRay) {
if (this.boundingBox) {
var inverseWorldMatrix = o3djs.math.matrix4.identity();
if (this.parent) {
inverseWorldMatrix = o3djs.math.inverse(
this.parent.transform.getUpdatedWorldMatrix());
}
var relativeNear =
o3djs.math.matrix4.transformPoint(inverseWorldMatrix, worldRay.near);
var relativeFar =
o3djs.math.matrix4.transformPoint(inverseWorldMatrix, worldRay.far);
var rayIntersectionInfo =
this.boundingBox.intersectRay(relativeNear, relativeFar);
o3djs.picking.dumpRayIntersectionInfo(
'TRANSFORM(box): ' + this.transform.name, rayIntersectionInfo);
if (rayIntersectionInfo.intersected) {
var closestPickInfo = null;
var minDistance = -1;
for (var key in this.childTransformInfos) {
var transformInfo = this.childTransformInfos[key];
var pickInfo = transformInfo.pick(worldRay);
if (pickInfo) {
// is this closer than the last one?
var distance = o3djs.math.lengthSquared(
o3djs.math.subVector(worldRay.near,
pickInfo.worldIntersectionPosition));
if (!closestPickInfo || distance < minDistance) {
minDistance = distance;
closestPickInfo = pickInfo;
}
}
}
for (var key in this.shapeInfos) {
var shapeInfo = this.shapeInfos[key];
var pickInfo = shapeInfo.pick(worldRay);
if (pickInfo) {
// is this closer than the last one?
var distance = o3djs.math.lengthSquared(
o3djs.math.subVector(worldRay.near,
pickInfo.worldIntersectionPosition));
if (!closestPickInfo || distance < minDistance) {
minDistance = distance;
closestPickInfo = pickInfo;
}
}
}
return closestPickInfo;
}
}
return null;
};
/**
* Dumps info about a TransformInfo
* @param {string} prefix optional prefix for indenting.
*/
o3djs.picking.TransformInfo.prototype.dump = function(prefix) {
prefix = prefix || '';
o3djs.picking.dprint(prefix + 'TRANSFORM: ' + this.transform.name +
'\n');
if (this.boundingBox) {
o3djs.picking.dprintPoint3('bb min',
this.boundingBox.minExtent,
prefix + ' ');
o3djs.picking.dprintPoint3('bb max',
this.boundingBox.maxExtent,
prefix + ' ');
} else {
o3djs.picking.dprint(prefix + ' bb *NA*\n');
}
o3djs.picking.dprint(prefix + '--Shapes--\n');
for (var key in this.shapeInfos) {
var shapeInfo = this.shapeInfos[key];
shapeInfo.dump(prefix + ' ');
}
o3djs.picking.dprint(prefix + '--Children--\n');
for (var key in this.childTransformInfos) {
var transformInfo = this.childTransformInfos[key];
transformInfo.dump(prefix + ' ');
}
};