[2853] | 1 | #include "common.h"
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| 2 | #include "SampleGenerator.h"
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| 3 | #include "Halton.h"
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| 4 |
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| 5 | using namespace std;
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| 6 |
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| 7 | //SampleGenerator::SampleGenerator() {}
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| 8 |
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| 9 | SampleGenerator::SampleGenerator(int numSamples, float radius):
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| 10 | mNumSamples(numSamples), mRadius(radius)
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| 11 | {}
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| 12 |
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| 13 |
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| 14 | PoissonDiscSampleGenerator::PoissonDiscSampleGenerator(int numSamples, float radius):
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| 15 | SampleGenerator(numSamples, radius)
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| 16 | {}
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| 17 |
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| 18 |
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| 19 | void PoissonDiscSampleGenerator::Generate(Sample2 *samples) const
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| 20 | {
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| 21 | static HaltonSequence halton;
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| 22 | float r[2];
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| 23 |
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| 24 | // generates poisson distribution on disc
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| 25 | float minDist = 2.0f / sqrt((float)mNumSamples);
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| 26 |
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| 27 | //cout << "minDist before= " << minDist << endl;
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| 28 |
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| 29 | for (int i = 0; i < mNumSamples; ++ i)
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| 30 | {
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| 31 | int tries = 0, totalTries = 0;
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| 32 |
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| 33 | // repeat until valid sample was found
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| 34 | while (1)
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| 35 | {
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| 36 | ++ tries;
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| 37 | ++ totalTries;
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| 38 |
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| 39 | halton.GetNext(2, r);
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| 40 |
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| 41 | const float rx = r[0] * 2.0f - 1.0f;
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| 42 | const float ry = r[1] * 2.0f - 1.0f;
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| 43 |
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| 44 | // check if in disk, else exit early
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| 45 | if (rx * rx + ry * ry > 1)
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| 46 | continue;
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| 47 |
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| 48 | bool sampleValid = true;
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| 49 |
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| 50 | // check poisson property
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| 51 | for (int j = 0; ((j < i) && sampleValid); ++ j)
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| 52 | {
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| 53 | const float dist =
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| 54 | sqrt((samples[j].x - rx) * (samples[j].x - rx) +
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| 55 | (samples[j].y - ry) * (samples[j].y - ry));
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| 56 |
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| 57 | if (dist < minDist)
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| 58 | sampleValid = false;
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| 59 | }
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| 60 |
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| 61 | if (sampleValid)
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| 62 | {
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| 63 | samples[i].x = rx;
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| 64 | samples[i].y = ry;
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| 65 | break;
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| 66 | }
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| 67 |
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| 68 | if (tries > 2000)
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| 69 | {
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| 70 | minDist *= 0.9f;
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| 71 | tries = 0;
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| 72 | }
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| 73 | }
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| 74 |
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| 75 | //cout << "sample: " << samples[i].x << " " << i << " " << samples[i].y << " r: " << sqrt(samples[i].x * samples[i].x + samples[i].y * samples[i].y) << " tries: " << totalTries << endl;
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| 76 | }
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| 77 |
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| 78 | //cout << "minDist after= " << minDist << endl;
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| 79 | } |
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