overte/examples/grab.js
Andrew Meadows a3c5ea1b58 Merge pull request #5088 from sethalves/actions
spring action with rotation and position target, rework grab script to use it
2015-06-11 13:23:57 -07:00

340 lines
12 KiB
JavaScript

// grab.js
// examples
//
// Created by Eric Levin on May 1, 2015
// Copyright 2015 High Fidelity, Inc.
//
// Grab's physically moveable entities with the mouse, by applying a spring force.
//
// Distributed under the Apache License, Version 2.0.
// See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
//
var MOVE_TIMESCALE = 0.1;
var INV_MOVE_TIMESCALE = 1.0 / MOVE_TIMESCALE;
var MAX_SOLID_ANGLE = 0.01; // objects that appear smaller than this can't be grabbed
var CLOSE_ENOUGH = 0.001;
var ZERO_VEC3 = { x: 0, y: 0, z: 0 };
var ANGULAR_DAMPING_RATE = 0.40;
// NOTE: to improve readability global variable names start with 'g'
var gIsGrabbing = false;
var gGrabbedEntity = null;
var gActionID = null;
var gEntityProperties;
var gStartPosition;
var gStartRotation;
var gCurrentPosition;
var gOriginalGravity = ZERO_VEC3;
var gPlaneNormal = ZERO_VEC3;
// gMaxGrabDistance is a function of the size of the object.
var gMaxGrabDistance;
// gGrabMode defines the degrees of freedom of the grab target positions
// relative to gGrabStartPosition options include:
// xzPlane (default)
// verticalCylinder (SHIFT)
// rotate (CONTROL)
// Modes to eventually support?:
// xyPlane
// yzPlane
// polar
// elevationAzimuth
var gGrabMode = "xzplane";
// gGrabOffset allows the user to grab an object off-center. It points from ray's intersection
// with the move-plane to object center (at the moment the grab is initiated). Future target positions
// are relative to the ray's intersection by the same offset.
var gGrabOffset = { x: 0, y: 0, z: 0 };
var gTargetPosition;
var gTargetRotation;
var gLiftKey = false; // SHIFT
var gRotateKey = false; // CONTROL
var gInitialMouse = { x: 0, y: 0 };
var gPreviousMouse = { x: 0, y: 0 };
var gMouseCursorLocation = { x: 0, y: 0 };
var gMouseAtRotateStart = { x: 0, y: 0 };
var gBeaconHeight = 0.10;
// var gAngularVelocity = ZERO_VEC3;
// TODO: play sounds again when we aren't leaking AudioInjector threads
// var grabSound = SoundCache.getSound("https://hifi-public.s3.amazonaws.com/eric/sounds/CloseClamp.wav");
// var releaseSound = SoundCache.getSound("https://hifi-public.s3.amazonaws.com/eric/sounds/ReleaseClamp.wav");
// var VOLUME = 0.0;
var gBeaconHeight = 0.10;
var BEACON_COLOR = {
red: 200,
green: 200,
blue: 200
};
var BEACON_WIDTH = 2;
var gBeacon = Overlays.addOverlay("line3d", {
color: BEACON_COLOR,
alpha: 1,
visible: false,
lineWidth: BEACON_WIDTH
});
function updateDropLine(position) {
Overlays.editOverlay(gBeacon, {
visible: true,
start: {
x: position.x,
y: position.y + gBeaconHeight,
z: position.z
},
end: {
x: position.x,
y: position.y - gBeaconHeight,
z: position.z
}
});
}
function mouseIntersectionWithPlane(pointOnPlane, planeNormal, event) {
var cameraPosition = Camera.getPosition();
var localPointOnPlane = Vec3.subtract(pointOnPlane, cameraPosition);
var distanceFromPlane = Vec3.dot(localPointOnPlane, planeNormal);
var MIN_DISTANCE_FROM_PLANE = 0.001;
if (Math.abs(distanceFromPlane) < MIN_DISTANCE_FROM_PLANE) {
// camera is touching the plane
return pointOnPlane;
}
var pickRay = Camera.computePickRay(event.x, event.y);
var dirDotNorm = Vec3.dot(pickRay.direction, planeNormal);
var MIN_RAY_PLANE_DOT = 0.00001;
var localIntersection;
var useMaxForwardGrab = false;
if (Math.abs(dirDotNorm) > MIN_RAY_PLANE_DOT) {
var distanceToIntersection = distanceFromPlane / dirDotNorm;
if (distanceToIntersection > 0 && distanceToIntersection < gMaxGrabDistance) {
// ray points into the plane
localIntersection = Vec3.multiply(pickRay.direction, distanceFromPlane / dirDotNorm);
} else {
// ray intersects BEHIND the camera or else very far away
// so we clamp the grab point to be the maximum forward position
useMaxForwardGrab = true;
}
} else {
// ray points perpendicular to grab plane
// so we map the grab point to the maximum forward position
useMaxForwardGrab = true;
}
if (useMaxForwardGrab) {
// we re-route the intersection to be in front at max distance.
var rayDirection = Vec3.subtract(pickRay.direction, Vec3.multiply(planeNormal, dirDotNorm));
rayDirection = Vec3.normalize(rayDirection);
localIntersection = Vec3.multiply(rayDirection, gMaxGrabDistance);
localIntersection = Vec3.sum(localIntersection, Vec3.multiply(planeNormal, distanceFromPlane));
}
var worldIntersection = Vec3.sum(cameraPosition, localIntersection);
return worldIntersection;
}
function computeNewGrabPlane() {
if (!gIsGrabbing) {
return;
}
var maybeResetMousePosition = false;
if (gGrabMode !== "rotate") {
gMouseAtRotateStart = gMouseCursorLocation;
} else {
maybeResetMousePosition = true;
}
gGrabMode = "xzPlane";
gPointOnPlane = gCurrentPosition;
gPlaneNormal = { x: 0, y: 1, z: 0 };
if (gLiftKey) {
if (!gRotateKey) {
gGrabMode = "verticalCylinder";
// a new planeNormal will be computed each move
}
} else if (gRotateKey) {
gGrabMode = "rotate";
}
gPointOnPlane = Vec3.subtract(gCurrentPosition, gGrabOffset);
var xzOffset = Vec3.subtract(gPointOnPlane, Camera.getPosition());
xzOffset.y = 0;
gXzDistanceToGrab = Vec3.length(xzOffset);
if (gGrabMode !== "rotate" && maybeResetMousePosition) {
// we reset the mouse position whenever we stop rotating
Window.setCursorPosition(gMouseAtRotateStart.x, gMouseAtRotateStart.y);
}
}
function mousePressEvent(event) {
if (!event.isLeftButton) {
return;
}
gInitialMouse = {x: event.x, y: event.y };
gPreviousMouse = {x: event.x, y: event.y };
var pickRay = Camera.computePickRay(event.x, event.y);
var pickResults = Entities.findRayIntersection(pickRay, true); // accurate picking
if (!pickResults.intersects) {
// didn't click on anything
return;
}
if (!pickResults.properties.collisionsWillMove) {
// only grab dynamic objects
return;
}
var clickedEntity = pickResults.entityID;
var entityProperties = Entities.getEntityProperties(clickedEntity)
gStartPosition = entityProperties.position;
gStartRotation = entityProperties.rotation;
var cameraPosition = Camera.getPosition();
gBeaconHeight = Vec3.length(entityProperties.dimensions);
gMaxGrabDistance = gBeaconHeight / MAX_SOLID_ANGLE;
if (Vec3.distance(gStartPosition, cameraPosition) > gMaxGrabDistance) {
// don't allow grabs of things far away
return;
}
Entities.editEntity(clickedEntity, { gravity: ZERO_VEC3 });
gIsGrabbing = true;
gGrabbedEntity = clickedEntity;
gCurrentPosition = entityProperties.position;
gOriginalGravity = entityProperties.gravity;
gTargetPosition = gStartPosition;
// compute the grab point
var nearestPoint = Vec3.subtract(gStartPosition, cameraPosition);
var distanceToGrab = Vec3.dot(nearestPoint, pickRay.direction);
nearestPoint = Vec3.multiply(distanceToGrab, pickRay.direction);
gPointOnPlane = Vec3.sum(cameraPosition, nearestPoint);
// compute the grab offset
gGrabOffset = Vec3.subtract(gStartPosition, gPointOnPlane);
computeNewGrabPlane();
updateDropLine(gStartPosition);
// TODO: play sounds again when we aren't leaking AudioInjector threads
//Audio.playSound(grabSound, { position: entityProperties.position, volume: VOLUME });
}
function mouseReleaseEvent() {
if (gIsGrabbing) {
if (Vec3.length(gOriginalGravity) != 0) {
Entities.editEntity(gGrabbedEntity, { gravity: gOriginalGravity });
}
gIsGrabbing = false
Entities.deleteAction(gGrabbedEntity, gActionID);
gActionID = null;
Overlays.editOverlay(gBeacon, { visible: false });
// TODO: play sounds again when we aren't leaking AudioInjector threads
//Audio.playSound(releaseSound, { position: entityProperties.position, volume: VOLUME });
}
}
function mouseMoveEvent(event) {
if (!gIsGrabbing) {
return;
}
// see if something added/restored gravity
var entityProperties = Entities.getEntityProperties(gGrabbedEntity);
if (Vec3.length(entityProperties.gravity) != 0) {
gOriginalGravity = entityProperties.gravity;
}
var actionArgs = {};
if (gGrabMode === "rotate") {
var deltaMouse = { x: 0, y: 0 };
var dx = event.x - gInitialMouse.x;
var dy = event.y - gInitialMouse.y;
var orientation = Camera.getOrientation();
var dragOffset = Vec3.multiply(dx, Quat.getRight(orientation));
dragOffset = Vec3.sum(dragOffset, Vec3.multiply(-dy, Quat.getUp(orientation)));
var axis = Vec3.cross(dragOffset, Quat.getFront(orientation));
axis = Vec3.normalize(axis);
var ROTATE_STRENGTH = 0.4; // magic number tuned by hand
var angle = ROTATE_STRENGTH * Math.sqrt((dx * dx) + (dy * dy));
var deltaQ = Quat.angleAxis(angle, axis);
// var qZero = entityProperties.rotation;
var qZero = gStartRotation;
var qOne = Quat.multiply(deltaQ, qZero);
actionArgs = {targetRotation: qOne, angularTimeScale: 0.1};
} else {
var newTargetPosition;
if (gGrabMode === "verticalCylinder") {
// for this mode we recompute the plane based on current Camera
var planeNormal = Quat.getFront(Camera.getOrientation());
planeNormal.y = 0;
planeNormal = Vec3.normalize(planeNormal);
var pointOnCylinder = Vec3.multiply(planeNormal, gXzDistanceToGrab);
pointOnCylinder = Vec3.sum(Camera.getPosition(), pointOnCylinder);
newTargetPosition = mouseIntersectionWithPlane(pointOnCylinder, planeNormal, event);
} else {
var cameraPosition = Camera.getPosition();
newTargetPosition = mouseIntersectionWithPlane(gPointOnPlane, gPlaneNormal, event);
var relativePosition = Vec3.subtract(newTargetPosition, cameraPosition);
var distance = Vec3.length(relativePosition);
if (distance > gMaxGrabDistance) {
// clamp distance
relativePosition = Vec3.multiply(relativePosition, gMaxGrabDistance / distance);
newTargetPosition = Vec3.sum(relativePosition, cameraPosition);
}
}
gTargetPosition = Vec3.sum(newTargetPosition, gGrabOffset);
actionArgs = {targetPosition: gTargetPosition, linearTimeScale: 0.1};
}
gPreviousMouse = { x: event.x, y: event.y };
gMouseCursorLocation = { x: Window.getCursorPositionX(), y: Window.getCursorPositionY() };
if (!gActionID) {
gActionID = Entities.addAction("spring", gGrabbedEntity, actionArgs);
} else {
Entities.updateAction(gGrabbedEntity, gActionID, actionArgs);
}
updateDropLine(gTargetPosition);
}
function keyReleaseEvent(event) {
if (event.text === "SHIFT") {
gLiftKey = false;
}
if (event.text === "CONTROL") {
gRotateKey = false;
}
computeNewGrabPlane();
}
function keyPressEvent(event) {
if (event.text === "SHIFT") {
gLiftKey = true;
}
if (event.text === "CONTROL") {
gRotateKey = true;
}
computeNewGrabPlane();
}
Controller.mouseMoveEvent.connect(mouseMoveEvent);
Controller.mousePressEvent.connect(mousePressEvent);
Controller.mouseReleaseEvent.connect(mouseReleaseEvent);
Controller.keyPressEvent.connect(keyPressEvent);
Controller.keyReleaseEvent.connect(keyReleaseEvent);