AS3 Library and LibraryManager for Assets and Other AS3 Utilities
May 26, 2008 — drawkTink posted a great library manager for using external assets in your flash projects. When you start getting deep in projects you end up either having to roll your own that might end up being project specific, or you can just grab this from Tink and it is nice and standardized now for you.
Here’s and example of our Library & LibraryManager classes that we use in some of our Flex and AS 3.0 projects to manage our external assets stored in SWF’s.
The classes enabled you to create multiple libraries of embedded (retaining and giving access to code) or loaded SWF’s.
You can create instance of Library wherever you want, but you can also create them through the LibraryManager giving you a single class to gain access to all your Library instances.
As you develop more and more flash/flex projects with AS3 these types of utilities come in handy. Another that comes to mind is Arthur Debert’s BulkLoader and polygonal labs Data Structures for Game Developers that are all great kits.
Add Tink’s Library and LibraryManager to your arsenal today! Thanks Tink.
+ skyB;
var ambientIllumination:Number = .1;
var canvas:BlankClip;
var theta:Number = 0;
var mouseIsDown:Boolean = false;
var mouseDownTheta:Number = 0;
var mouseDownX:Number = 0;
public function RayTracer()
{
outputBitmapData = new BitmapData(BUFFER_WIDTH, BUFFER_HEIGHT, false);
outputBitmap = new Bitmap(outputBitmapData);
addChild(outputBitmap);
//outputBitmap.smoothing = true;
outputBitmap.width= 320;
outputBitmap.height = 240;
canvas = new BlankClip;
addChild(canvas);
canvas.buttonMode = true;
canvas.useHandCursor = true;
frameTimeTxt = new TextField();
frameTimeTxt.defaultTextFormat = new TextFormat("Arial");
frameTimeTxt.x = 8;
frameTimeTxt.y = 8;
frameTimeTxt.width = 640;
frameTimeTxt.textColor = 0xFFFFFF;
frameTimeTxt.selectable = false;
addChild(frameTimeTxt);
t = 0;
addEventListener(Event.ENTER_FRAME, update, false, 0, true);
canvas.addEventListener(MouseEvent.MOUSE_DOWN, mouseDownHandler);
canvas.addEventListener(MouseEvent.MOUSE_UP, mouseUpHandler);
}
public function mouseDownHandler(e:*):void
{
mouseIsDown = true;
mouseDownX = stage.mouseX;
mouseDownTheta = theta;
}
public function mouseUpHandler(e:*):void
{
mouseIsDown = false;
}
public function update(e:*)
{
// start frame timer and update global time
var timer:Number = getTimer();
t += dt;
// handle mouse rotation
if( mouseIsDown ) theta = mouseDownTheta - .0015 * (stage.mouseX - mouseDownX);
theta += dt;
// do some funky animation
sphereCenterX[0] = .5*Math.sin(theta*5);
sphereCenterZ[0] =1 + .5*Math.cos(theta*5);
sphereCenterX[1] = .5*Math.sin(theta*5 + 2 * Math.PI / 3);
sphereCenterZ[1] = 1 + .5*Math.cos(theta*5 + 2 * Math.PI / 3);
sphereCenterX[2] = .5*Math.sin(theta*5 + 4 * Math.PI / 3);
sphereCenterZ[2] = 1 + .5*Math.cos(theta*5 + 4 * Math.PI / 3);
// reused variables
var x:int;
var y:int;
var i:int;
var j:int;
var r:int;
var g:int;
var b:int;
var dx:Number;
var dy:Number;
var rayDirX:Number;
var rayDirY:Number;
var rayDirZ:Number;
var rayDirMag:Number;
var reflectRayDirX:Number;
var reflectRayDirY:Number;
var reflectRayDirZ:Number;
var intersectionX:Number;
var intersectionY:Number;
var intersectionZ:Number;
var reflectIntersectionX:Number;
var reflectIntersectionY:Number;
var reflectIntersectionZ:Number;
var rayToSphereCenterX:Number;
var rayToSphereCenterY:Number;
var rayToSphereCenterZ:Number;
var lengthRTSC2:Number;
var closestApproach:Number;
var halfCord2:Number;
var dist:Number;
var normalX:Number;
var normalY:Number;
var normalZ:Number;
var normalMag:Number;
var illumination:Number;
var reflectIllumination:Number;
var reflectR:Number;
var reflectG:Number;
var reflectB:Number;
// setup light dir
var lightDirX:Number = .3;
var lightDirY:Number = -1;
var lightDirZ:Number = -.5;
var lightDirMag:Number = 1/Math.sqrt(lightDirX*lightDirX +lightDirY*lightDirY +lightDirZ*lightDirZ);
lightDirX *= lightDirMag;
lightDirY *= lightDirMag;
lightDirZ *= lightDirMag;
// vars used to in intersection tests
var closestIntersectionDist:Number;
var closestSphereIndex:int;
var reflectClosestSphereIndex:int;
// compute screen space bounding circles
//canvas.graphics.clear();
//canvas.graphics.lineStyle(1, 0xFF0000, .25);
for(i = 0; i < numSpheres; ++i)
{
sphere2dX[i] = (BUFFER_WIDTH / 2 + FOV * sphereCenterX[i] / sphereCenterZ[i]);
sphere2dY[i] = (BUFFER_HEIGHT /2 + FOV * sphereCenterY[i] / sphereCenterZ[i]);
sphere2dR[i] = (3 * FOV * sphereRadius[i] / sphereCenterZ[i]);
//canvas.graphics.drawCircle(sphere2dX[i]*BUFFER_SCALEDDOWN, sphere2dY[i]*BUFFER_SCALEDDOWN, sphere2dR[i]*BUFFER_SCALEDDOWN);
sphere2dR[i] *= sphere2dR[i]; // store the squared value
}
// write to each pixel
outputBitmapData.lock();
for(y = 0; y < BUFFER_HEIGHT; ++y)
{
for(x = 0; x < BUFFER_WIDTH; ++x)
{
// compute ray direction
rayDirX = x - HALF_BUFFER_WIDTH;
rayDirY = y - HALF_BUFFER_HEIGHT;
rayDirZ = FOV;
rayDirMag = 1/Math.sqrt(rayDirX * rayDirX + rayDirY * rayDirY +rayDirZ * rayDirZ);
rayDirX *= rayDirMag;
rayDirY *= rayDirMag;
rayDirZ *= rayDirMag;
/// trace the primary ray ///
closestIntersectionDist = Number.POSITIVE_INFINITY;
closestSphereIndex = -1
for(i = 0; i < numSpheres; ++i)
{
// check against screen space bounding circle
dx = x - sphere2dX[i];
dy = y - sphere2dY[i];
if( dx * dx + dy * dy > sphere2dR[i] ) continue;
// begin actual ray tracing if its inside the bounding circle
lengthRTSC2 = sphereCenterX[i] * sphereCenterX[i] +
sphereCenterY[i] * sphereCenterY[i] +
sphereCenterZ[i] * sphereCenterZ[i];
closestApproach = sphereCenterX[i] * rayDirX +
sphereCenterY[i] * rayDirY +
sphereCenterZ[i] * rayDirZ;
if( closestApproach < 0 ) // intersection behind the origin
continue;
halfCord2 = sphereRadius[i] * sphereRadius[i] - lengthRTSC2 + (closestApproach * closestApproach);
if( halfCord2 < 0 ) // ray misses the sphere
continue;
// ray hits the sphere
dist = closestApproach - Math.sqrt(halfCord2);
if( dist < closestIntersectionDist )
{
closestIntersectionDist = dist;
closestSphereIndex=i;
}
}
/// end of trace primary ray ///
// primary ray doesn't hit anything
if( closestSphereIndex == - 1)
{
outputBitmapData.setPixel(x, y, skyColor);
}
else // primary ray hits a sphere.. calculate shading, shadow and reflection
{
// location of ray-sphere intersection
intersectionX = rayDirX * closestIntersectionDist;
intersectionY = rayDirY * closestIntersectionDist;
intersectionZ = rayDirZ * closestIntersectionDist;
// sphere normal at intersection point
normalX = intersectionX - sphereCenterX[closestSphereIndex];
normalY = intersectionY - sphereCenterY[closestSphereIndex];
normalZ = intersectionZ - sphereCenterZ[closestSphereIndex];
normalX /= sphereRadius[closestSphereIndex]; // could be multiply by precacluated 1/rad
normalY /= sphereRadius[closestSphereIndex];
normalZ /= sphereRadius[closestSphereIndex];
// diffuse illumination coef
illumination = normalX * lightDirX +
normalY * lightDirY +
normalZ * lightDirZ;
if( illumination < ambientIllumination )
illumination = ambientIllumination;
/// trace a shadow ray ///
var isInShadow:Boolean = false;
for(j = 0; j < numSpheres; ++j)
{
if( j == closestSphereIndex ) continue;
rayToSphereCenterX = sphereCenterX[j] - intersectionX;
rayToSphereCenterY = sphereCenterY[j] - intersectionY;
rayToSphereCenterZ = sphereCenterZ[j] - intersectionZ;
lengthRTSC2 = rayToSphereCenterX * rayToSphereCenterX +
rayToSphereCenterY * rayToSphereCenterY +
rayToSphereCenterZ * rayToSphereCenterZ;
closestApproach = rayToSphereCenterX * lightDirX +
rayToSphereCenterY * lightDirY +
rayToSphereCenterZ * lightDirZ;
if( closestApproach < 0 ) // intersection behind the origin
continue;
halfCord2 = sphereRadius[j] * sphereRadius[j] - lengthRTSC2 + (closestApproach * closestApproach);
if( halfCord2 < 0 ) // ray misses the sphere
continue;
isInShadow = true;
break;
}
/// end of shadow ray ///
if( isInShadow ) illumination *= .5;
/// trace reflected ray ///
if( sphereReflects[closestSphereIndex] )
{
// calculate reflected ray direction
var reflectCoef:Number = 2 * (rayDirX * normalX + rayDirY * normalY + rayDirZ * normalZ);
reflectRayDirX = rayDirX - normalX * reflectCoef;
reflectRayDirY = rayDirY - normalY * reflectCoef;
reflectRayDirZ = rayDirZ - normalZ * reflectCoef;
closestIntersectionDist = Number.POSITIVE_INFINITY;
reflectClosestSphereIndex = -1
for(j = 0; j < numSpheres; ++j)
{
if( j == closestSphereIndex ) continue;
rayToSphereCenterX = sphereCenterX[j] - intersectionX;
rayToSphereCenterY = sphereCenterY[j] - intersectionY;
rayToSphereCenterZ = sphereCenterZ[j] - intersectionZ;
lengthRTSC2 = rayToSphereCenterX * rayToSphereCenterX +
rayToSphereCenterY * rayToSphereCenterY +
rayToSphereCenterZ * rayToSphereCenterZ;
closestApproach = rayToSphereCenterX * reflectRayDirX +
rayToSphereCenterY * reflectRayDirY +
rayToSphereCenterZ * reflectRayDirZ;
if( closestApproach < 0 ) // intersection behind the origin
continue;
halfCord2 = sphereRadius[j] * sphereRadius[j] - lengthRTSC2 + (closestApproach * closestApproach);
if( halfCord2 < 0 ) // ray misses the sphere
continue;
// ray hits the sphere
dist = closestApproach - Math.sqrt(halfCord2);
if( dist < closestIntersectionDist )
{
closestIntersectionDist = dist;
reflectClosestSphereIndex=j;
}
} // end loop through spheres for reflect ray
if( reflectClosestSphereIndex == - 1) // reflected ray misses
{
r = sphereR[closestSphereIndex] * illumination;
g = sphereG[closestSphereIndex] * illumination;
b = sphereB[closestSphereIndex] * illumination;
}
else
{
//trace("ref hit");
// location of ray-sphere intersection
reflectIntersectionX = reflectRayDirX * closestIntersectionDist + intersectionX;
reflectIntersectionY = reflectRayDirY * closestIntersectionDist + intersectionY;
reflectIntersectionZ = reflectRayDirZ * closestIntersectionDist + intersectionZ;
// sphere normal at intersection point
normalX = reflectIntersectionX - sphereCenterX[reflectClosestSphereIndex];
normalY = reflectIntersectionY - sphereCenterY[reflectClosestSphereIndex];
normalZ = reflectIntersectionZ - sphereCenterZ[reflectClosestSphereIndex];
normalX /= sphereRadius[reflectClosestSphereIndex]; // could be multiply by precacluated 1/rad
normalY /= sphereRadius[reflectClosestSphereIndex];
normalZ /= sphereRadius[reflectClosestSphereIndex];
// diffuse illumination coef
reflectIllumination = normalX * lightDirX +
normalY * lightDirY +
normalZ * lightDirZ;
if( reflectIllumination < ambientIllumination )
reflectIllumination = ambientIllumination;
r = sphereR[closestSphereIndex] * illumination + .5 * sphereR[reflectClosestSphereIndex] * reflectIllumination;
g = sphereG[closestSphereIndex] * illumination + .5 * sphereG[reflectClosestSphereIndex] * reflectIllumination;
b = sphereB[closestSphereIndex] * illumination + .5 * sphereB[reflectClosestSphereIndex] * reflectIllumination;
if( r > 255 ) r = 255;
if( g > 255 ) g = 255;
if( b > 255 ) b = 255;
} // end if reflected ray hits
} /// end if reflects
else // primary ray doesn't reflect
{
r = sphereR[closestSphereIndex] * illumination;
g = sphereG[closestSphereIndex] * illumination;
b = sphereB[closestSphereIndex] * illumination;
}
outputBitmapData.setPixel(x, y, (r<<16) + (g<<