Commit | Line | Data |
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fd8a39b0 SG |
1 | import toxi.geom.Vec3D; |
2 | import toxi.geom.Matrix4x4; | |
3 | ||
4 | class HelixPattern extends SCPattern { | |
5 | ||
6 | // Stores a line in point + vector form | |
7 | private class Line { | |
8 | private final PVector origin; | |
9 | private final PVector vector; | |
10 | ||
11 | Line(PVector pt, PVector v) { | |
12 | origin = pt; | |
13 | vector = v.get(); | |
14 | vector.normalize(); | |
15 | } | |
16 | ||
17 | PVector getPoint() { | |
18 | return origin; | |
19 | } | |
20 | ||
21 | PVector getVector() { | |
22 | return vector; | |
23 | } | |
24 | ||
25 | PVector getPointAt(float t) { | |
26 | PVector pt = PVector.mult(vector, t); | |
27 | pt.add(origin); | |
28 | return pt; | |
29 | } | |
30 | ||
31 | boolean isColinear(PVector pt) { | |
32 | PVector projected = projected(pt); | |
33 | return projected.x==pt.x && projected.y==pt.y && projected.z==pt.z; | |
34 | } | |
35 | ||
36 | float getTValue(PVector pt) { | |
37 | PVector subtraction = PVector.sub(pt, origin); | |
38 | return subtraction.dot(vector); | |
39 | } | |
40 | ||
41 | PVector projected(PVector pt) { | |
42 | return getPointAt(getTValue(pt)); | |
43 | } | |
44 | ||
45 | PVector rotatePoint(PVector pt, float rads) { | |
46 | Vec3D axisVec3D = new Vec3D(vector.x, vector.y, vector.z); | |
47 | Matrix4x4 mat = new Matrix4x4(); | |
48 | mat.rotateAroundAxis(axisVec3D, rads); | |
49 | Vec3D ptVec3D = new Vec3D(pt.x, pt.y, pt.z); | |
50 | Vec3D rotatedPt = mat.applyTo(ptVec3D); | |
51 | return new PVector(rotatedPt.x, rotatedPt.y, rotatedPt.z); | |
52 | } | |
53 | } | |
54 | ||
55 | private class Helix { | |
56 | private final Line axis; | |
57 | private final float period; | |
58 | private final float rotationPeriod; | |
59 | private final float radius; | |
60 | private final float girth; | |
61 | private final PVector referencePoint; | |
62 | private float phase; | |
63 | private PVector phaseNormal; | |
64 | ||
65 | Helix(Line axis, float period, float radius, float girth, float phase, float rotationPeriod) { | |
66 | this.axis = axis; | |
67 | this.period = period; | |
68 | this.radius = radius; | |
69 | this.girth = girth; | |
70 | this.phase = phase; | |
71 | this.rotationPeriod = rotationPeriod; | |
72 | ||
73 | // Generate a normal that will rotate to | |
74 | // produce the helical shape. | |
75 | PVector pt = new PVector(0, 1, 0); | |
76 | if (this.axis.isColinear(pt)) { | |
77 | pt = new PVector(0, 0, 1); | |
78 | if (this.axis.isColinear(pt)) { | |
79 | pt = new PVector(0, 1, 1); | |
80 | } | |
81 | } | |
82 | ||
83 | this.referencePoint = pt; | |
84 | this.phase = phase; | |
85 | ||
86 | setPhaseNormalFromPhase(); | |
87 | } | |
88 | ||
89 | private void setPhaseNormalFromPhase() { | |
90 | phaseNormal = axis.getVector().cross(axis.rotatePoint(referencePoint, phase)); | |
91 | phaseNormal.normalize(); | |
92 | phaseNormal.mult(radius); | |
93 | } | |
94 | ||
95 | private void setPhase(float phase) { | |
96 | this.phase = phase; | |
97 | setPhaseNormalFromPhase(); | |
98 | } | |
99 | ||
100 | void step(int deltaMs) { | |
101 | setPhase(phase + (deltaMs / rotationPeriod) * TWO_PI); | |
102 | } | |
103 | ||
104 | PVector pointOnToroidalAxis(float t) { | |
105 | PVector p = axis.getPointAt(t); | |
106 | PVector middle = PVector.add(p, phaseNormal); | |
107 | return axis.rotatePoint(middle, (t / period) * TWO_PI); | |
108 | } | |
109 | ||
110 | color colorOfPoint(PVector p) { | |
111 | // Calculate the projection of this point to the axis. | |
112 | PVector projectedPoint = axis.projected(p); | |
113 | ||
114 | // Find the appropriate point for the current rotation | |
115 | // of the helix. | |
116 | float t = axis.getTValue(projectedPoint); | |
117 | PVector toroidPoint = pointOnToroidalAxis(t); | |
118 | ||
119 | // The rotated point represents the middle of the girth of | |
120 | // the helix. Figure out if the current point is inside that | |
121 | // region. | |
122 | float d = PVector.dist(p, toroidPoint); | |
c27cb078 | 123 | boolean inToroid = d < girth; |
fd8a39b0 | 124 | |
c27cb078 SG |
125 | // Soften edges by fading brightness |
126 | float b = constrain(100*(1 - ((d-.5*girth)/(girth*.5))), 0, 100); | |
127 | return color((lx.getBaseHuef() + (360*(phase / TWO_PI)))%360, (inToroid ? 80 : 0), b); | |
fd8a39b0 SG |
128 | } |
129 | } | |
130 | ||
131 | private final Helix h1; | |
132 | private final Helix h2; | |
133 | ||
134 | private final BasicParameter helix1On = new BasicParameter("H1ON", 1); | |
135 | private final BasicParameter helix2On = new BasicParameter("H2ON", 1); | |
136 | ||
137 | public HelixPattern(GLucose glucose) { | |
138 | super(glucose); | |
139 | ||
140 | addParameter(helix1On); | |
141 | addParameter(helix2On); | |
142 | ||
143 | h1 = new Helix( | |
144 | new Line(new PVector(100, 50, 70), new PVector(1,0,0)), | |
145 | 700, // period | |
146 | 50, // radius | |
147 | 30, // girth | |
148 | 0, // phase | |
149 | 10000); // rotation period (ms) | |
150 | h2 = new Helix( | |
151 | new Line(new PVector(100, 50, 70), new PVector(1,0,0)), | |
152 | 700, | |
153 | 50, | |
154 | 30, | |
155 | PI, | |
156 | 10000); | |
157 | ||
158 | // TODO(shaheen) calculate line segments between | |
159 | // toroidal points selected by stepping the | |
160 | // parameterized t value. select base pairs and | |
161 | // associated colors. lerp between colors for each | |
162 | // base pair to produce a DNA effect. | |
c27cb078 | 163 | |
fd8a39b0 SG |
164 | } |
165 | ||
166 | void run(int deltaMs) { | |
167 | boolean h1on = helix1On.getValue() > 0.5; | |
168 | boolean h2on = helix2On.getValue() > 0.5; | |
169 | ||
170 | h1.step(deltaMs); | |
171 | h2.step(deltaMs); | |
172 | ||
173 | for (Point p : model.points) { | |
174 | color h1c = color(0,0,0); | |
175 | color h2c = color(0,0,0); | |
176 | ||
177 | if (h1on) { | |
178 | h1c = h1.colorOfPoint(new PVector(p.x,p.y,p.z)); | |
179 | } | |
180 | ||
181 | if (h2on) { | |
182 | h2c = h2.colorOfPoint(new PVector(p.x,p.y,p.z)); | |
183 | } | |
184 | ||
185 | // The helices are positioned to not overlap. If that changes, | |
186 | // a better blending formula is probably needed. | |
187 | colors[p.index] = blendColor(h1c, h2c, ADD); | |
188 | } | |
189 | } | |
190 | } | |
191 |