import toxi.geom.Vec3D; import toxi.geom.Matrix4x4; class HelixPattern extends SCPattern { // Stores a line in point + vector form private class Line { private final PVector origin; private final PVector vector; Line(PVector pt, PVector v) { origin = pt; vector = v.get(); vector.normalize(); } PVector getPoint() { return origin; } PVector getVector() { return vector; } PVector getPointAt(final float t) { return PVector.add(origin, PVector.mult(vector, t)); } boolean isColinear(final PVector pt) { PVector projected = projectPoint(pt); return projected.x==pt.x && projected.y==pt.y && projected.z==pt.z; } float getTValue(final PVector pt) { PVector subtraction = PVector.sub(pt, origin); return subtraction.dot(vector); } PVector projectPoint(final PVector pt) { return getPointAt(getTValue(pt)); } PVector rotatePoint(final PVector p, final float t) { final PVector o = origin; final PVector v = vector; final float cost = cos(t); final float sint = sin(t); float x = (o.x*(v.y*v.y + v.z*v.z) - v.x*(o.y*v.y + o.z*v.z - v.x*p.x - v.y*p.y - v.z*p.z))*(1 - cost) + p.x*cost + (-o.z*v.y + o.y*v.z - v.z*p.y + v.y*p.z)*sint; float y = (o.y*(v.x*v.x + v.z*v.z) - v.y*(o.x*v.x + o.z*v.z - v.x*p.x - v.y*p.y - v.z*p.z))*(1 - cost) + p.y*cost + (o.z*v.x - o.x*v.z + v.z*p.x - v.x*p.z)*sint; float z = (o.z*(v.x*v.x + v.y*v.y) - v.z*(o.x*v.x + o.y*v.y - v.x*p.x - v.y*p.y - v.z*p.z))*(1 - cost) + p.z*cost + (-o.y*v.x + o.x*v.y - v.y*p.x + v.x*p.y)*sint; return new PVector(x, y, z); } } private class Helix { private final Line axis; private final float period; // period of coil private final float rotationPeriod; // animation period private final float radius; // radius of coil private final float girth; // girth of coil private final PVector referencePoint; private float phase; private PVector phaseNormal; Helix(Line axis, float period, float radius, float girth, float phase, float rotationPeriod) { this.axis = axis; this.period = period; this.radius = radius; this.girth = girth; this.phase = phase; this.rotationPeriod = rotationPeriod; // Generate a normal that will rotate to // produce the helical shape. PVector pt = new PVector(0, 1, 0); if (this.axis.isColinear(pt)) { pt = new PVector(0, 0, 1); if (this.axis.isColinear(pt)) { pt = new PVector(0, 1, 1); } } this.referencePoint = pt; // The normal is calculated by the cross product of the axis // and a random point that is not colinear with it. phaseNormal = axis.getVector().cross(referencePoint); phaseNormal.normalize(); phaseNormal.mult(radius); } Line getAxis() { return axis; } PVector getPhaseNormal() { return phaseNormal; } float getPhase() { return phase; } void step(double deltaMs) { // Rotate if (rotationPeriod != 0) { this.phase = (phase + ((float)deltaMs / (float)rotationPeriod) * TWO_PI); } } PVector pointOnToroidalAxis(float t) { PVector p = axis.getPointAt(t); PVector middle = PVector.add(p, phaseNormal); return axis.rotatePoint(middle, (t / period) * TWO_PI + phase); } private float myDist(PVector p1, PVector p2) { final float x = p2.x-p1.x; final float y = p2.y-p1.y; final float z = p2.z-p1.z; return sqrt(x*x + y*y + z*z); } color colorOfPoint(final PVector p) { final float t = axis.getTValue(p); final PVector axisPoint = axis.getPointAt(t); // For performance reasons, cut out points that are outside of // the tube where the toroidal coil lives. if (abs(myDist(p, axisPoint) - radius) > girth*.5f) { return color(0,0,0); } // Find the appropriate point for the current rotation // of the helix. PVector toroidPoint = axisPoint; toroidPoint.add(phaseNormal); toroidPoint = axis.rotatePoint(toroidPoint, (t / period) * TWO_PI + phase); // The rotated point represents the middle of the girth of // the helix. Figure out if the current point is inside that // region. float d = myDist(p, toroidPoint); // Soften edges by fading brightness. float b = constrain(100*(1 - ((d-.5*girth)/(girth*.5))), 0, 100); return color((lx.getBaseHuef() + (360*(phase / TWO_PI)))%360, 80, b); } } private class BasePairInfo { Line line; float colorPhase1; float colorPhase2; BasePairInfo(Line line, float colorPhase1, float colorPhase2) { this.line = line; this.colorPhase1 = colorPhase1; this.colorPhase2 = colorPhase2; } } private final Helix h1; private final Helix h2; private final BasePairInfo[] basePairs; private final BasicParameter helix1On = new BasicParameter("H1ON", 1); private final BasicParameter helix2On = new BasicParameter("H2ON", 1); private final BasicParameter basePairsOn = new BasicParameter("BPON", 1); private static final float helixCoilPeriod = 100; private static final float helixCoilRadius = 50; private static final float helixCoilGirth = 30; private static final float helixCoilRotationPeriod = 5000; private static final float spokePeriod = 40; private static final float spokeGirth = 20; private static final float spokePhase = 10; private static final float spokeRadius = helixCoilRadius - helixCoilGirth*.5f; private static final float tMin = -200; private static final float tMax = 200; public HelixPattern(GLucose glucose) { super(glucose); addParameter(helix1On); addParameter(helix2On); addParameter(basePairsOn); PVector origin = new PVector(100, 50, 55); PVector axis = new PVector(1,0,0); h1 = new Helix( new Line(origin, axis), helixCoilPeriod, helixCoilRadius, helixCoilGirth, 0, helixCoilRotationPeriod); h2 = new Helix( new Line(origin, axis), helixCoilPeriod, helixCoilRadius, helixCoilGirth, PI, helixCoilRotationPeriod); basePairs = new BasePairInfo[(int)floor((tMax - tMin)/spokePeriod)]; } private void calculateSpokes() { float colorPhase = PI/6; for (float t = tMin + spokePhase; t < tMax; t += spokePeriod) { int spokeIndex = (int)floor((t - tMin)/spokePeriod); PVector h1point = h1.pointOnToroidalAxis(t); PVector spokeCenter = h1.getAxis().getPointAt(t); PVector spokeVector = PVector.sub(h1point, spokeCenter); Line spokeLine = new Line(spokeCenter, spokeVector); basePairs[spokeIndex] = new BasePairInfo(spokeLine, colorPhase * spokeIndex, colorPhase * (spokeIndex + 1)); } } private color calculateSpokeColor(final PVector pt) { // Find the closest spoke's t-value and calculate its // axis. Until everything animates in the model reference // frame, this has to be calculated at every step because // the helices rotate. Line axis = h1.getAxis(); float t = axis.getTValue(pt) + spokePhase; int spokeIndex = (int)floor((t - tMin + spokePeriod/2) / spokePeriod); if (spokeIndex < 0 || spokeIndex >= basePairs.length) { return color(0,0,0); } BasePairInfo basePair = basePairs[spokeIndex]; Line spokeLine = basePair.line; PVector pointOnSpoke = spokeLine.projectPoint(pt); float d = PVector.dist(pt, pointOnSpoke); float b = (PVector.dist(pointOnSpoke, spokeLine.getPoint()) < spokeRadius) ? constrain(100*(1 - ((d-.5*spokeGirth)/(spokeGirth*.5))), 0, 100) : 0.f; float phase = spokeLine.getTValue(pointOnSpoke) < 0 ? basePair.colorPhase1 : basePair.colorPhase2; return color((lx.getBaseHuef() + (360*(phase / TWO_PI)))%360, 80.f, b); } void run(double deltaMs) { boolean h1on = helix1On.getValue() > 0.5; boolean h2on = helix2On.getValue() > 0.5; boolean spokesOn = (float)basePairsOn.getValue() > 0.5; h1.step(deltaMs); h2.step(deltaMs); calculateSpokes(); for (Point p : model.points) { PVector pt = new PVector(p.x,p.y,p.z); color h1c = h1.colorOfPoint(pt); color h2c = h2.colorOfPoint(pt); color spokeColor = calculateSpokeColor(pt); if (!h1on) { h1c = color(0,0,0); } if (!h2on) { h2c = color(0,0,0); } if (!spokesOn) { spokeColor = color(0,0,0); } // The helices are positioned to not overlap. If that changes, // a better blending formula is probably needed. colors[p.index] = blendColor(blendColor(h1c, h2c, ADD), spokeColor, ADD); } } }