Fix bugs

Assignments/Assignment3/sampler.h

@@ -0,0 +1,112 @@
+#pragma once
+#include <cstddef>
+#include <vector>
+#include "random_sampler_wrapper.hpp"
+#include "math/vec2.h"
+#include "math/vec3fa.h"
+
+class MLTRandomSampler : public embree::RandomSamplerWrapper {
+private:
+  size_t index;
+  std::vector<float> data;
+  std::vector<float> new_data;
+  std::vector<size_t> last_changed;
+  size_t time;
+  size_t last_large_step;
+  float small_step_size;
+  float large_step_probability;
+  bool large_step;
+
+  float normalize(float x) {
+    if (x < 0.0) {
+      return x + 1.0;
+    } else if (x >= 1.0) {
+      return x - 1.0;
+    }
+    return x;
+  }
+
+public:
+  MLTRandomSampler() {
+    
+  }
+  MLTRandomSampler(float small_step_size, float large_step_probability)
+      : index(0), data({}), last_changed({}), time(0), last_large_step(0),
+        small_step_size(small_step_size),
+        large_step_probability(large_step_probability) {}
+
+  void init(int id) override { RandomSampler_init(sampler, id); }
+
+  void accept() {
+    time++;
+    for (size_t i = 0; i < new_data.size(); i++) {
+      if (i >= data.size()) {
+        data.push_back(new_data[i]);
+        last_changed.push_back(time);
+      } else {
+        data.at(i) = new_data.at(i);
+        last_changed.at(i) = time;
+      }
+    }
+    if (large_step)
+      last_large_step = time;
+    index = 0;
+    new_data.clear();
+  }
+  
+  void new_ray(bool l) {
+    large_step = l;
+  }
+
+  bool is_large_step() { return large_step; }
+
+  float get1D() override {
+    if (is_large_step()) {
+      float r = RandomSampler_get1D(sampler);
+      new_data.push_back(r);
+      index++;
+      return r;
+    } else {
+      if (index >= data.size()) {
+        float r = RandomSampler_get1D(sampler);
+        data.push_back(r);
+        last_changed.push_back(time);
+        new_data.push_back(r);
+        index++;
+        return r;
+      }
+      // printf("%d, %d\n", index, last_large_step);
+      if (last_changed.at(index) < last_large_step) {
+        float r = RandomSampler_get1D(sampler);
+        data.at(index) = r;
+        last_changed.at(index) = time;
+        new_data.push_back(r);
+        index++;
+        return r;
+      } else {
+        size_t steps = time - last_changed.at(index);
+        float d = data.at(index);
+        for (size_t i = 0; i < steps; i++) {
+          float r = RandomSampler_get1D(sampler);
+          float o = r * small_step_size - (small_step_size / 2.0);
+          d = normalize(d + o);
+        }
+        data.at(index) = d;
+        last_changed.at(index) = time;
+        
+        float r = RandomSampler_get1D(sampler);
+        float o = r * small_step_size - (small_step_size / 2.0);
+        d = normalize(d + o);
+
+        new_data.push_back(d);
+        // printf("%f, %f\n", data.at(index), d);
+        index++;
+        return d;
+      }
+    }
+  }
+
+  embree::Vec2f get2D() override { return embree::Vec2f(get1D(), get1D()); }
+
+  embree::Vec3fa get3D() override { return embree::Vec3fa(get1D(), get1D(), get1D()); }
+};