Enable compilation with cuda

Author: heyshb

CMakeLists.txt

@@ -4,7 +4,10 @@ set(CMAKE_CXX_STANDARD 14)
 
 add_subdirectory(third_party)
 
+find_package(CUDA REQUIRED)
+
 set(rt_root_dir "ray-tracing-cuda")
 file(GLOB_RECURSE rt_srcs "${rt_root_dir}/*.cc")
 add_library(rt STATIC "${rt_srcs}")
-target_link_libraries(rt glm)
+target_link_libraries(rt glm)
+target_include_directories(rt PUBLIC "${rt_root_dir}" "${CUDA_INCLUDE_DIRS}")

ray-tracing-cuda/hitable.h ray-tracing-cuda/hitable.cuhray-tracing-cuda/hitable.h renamed to ray-tracing-cuda/hitable.cuh

@@ -2,6 +2,8 @@
 
 struct HitRecord;
 
+#include <cuda_runtime.h>
+
 #include <memory>
 
 #include "material.h"
@@ -15,6 +17,6 @@ struct HitRecord {
 
 class Hitable {
  public:
-  virtual bool Hit(const Ray &ray, std::pair<double, double> t_range,
-                   HitRecord *out) const = 0;
+  __device__ virtual bool Hit(const Ray &ray, std::pair<double, double> t_range,
+                              HitRecord *out) const = 0;
 };

ray-tracing-cuda/hitable_list.cc

@@ -0,0 +1,24 @@
+#include "hitable_list.h"
+
+using std::pair;
+
+__device__ bool HitableList::Hit(const Ray &ray, pair<double, double> t_range,
+                                 HitRecord *out) const {
+  HitRecord hit_record;
+  bool ok = false;
+  for (int i = 0; i < list_len_; i++) {
+    auto ret = list_[i]->Hit(ray, t_range, &hit_record);
+    if (!ret) continue;
+    if (!ok) {
+      *out = hit_record;
+      ok = true;
+    } else {
+      if (out->t > hit_record.t) {
+        *out = hit_record;
+      }
+    }
+  }
+  return ok;
+}
+
+void HitableList::Append(Hitable *obj) { list_[list_len_++] = obj; }

ray-tracing-cuda/hitable_list.h

@@ -0,0 +1,20 @@
+#pragma once
+
+#include <memory>
+#include <vector>
+
+#include "hitable.cuh"
+
+class HitableList : public Hitable {
+ public:
+  const static int kMaxHitables = 32;
+
+  __device__ bool Hit(const Ray &ray, std::pair<double, double> t_range,
+                      HitRecord *out) const override;
+
+  void Append(Hitable *obj);
+
+ private:
+  Hitable *list_[kMaxHitables];
+  int list_len_ = 0;
+};

ray-tracing-cuda/main.cu

@@ -0,0 +1 @@
+int main() { return 0; }

ray-tracing-cuda/material.cc

@@ -1,5 +1,6 @@
 #include "material.h"
 
-glm::vec3 Material::Emit(double u, double v, const glm::vec3 &p) const {
+__device__ glm::vec3 Material::Emit(double u, double v,
+                                    const glm::vec3 &p) const {
   return glm::vec3(0);
 }

ray-tracing-cuda/material.h

@@ -4,12 +4,13 @@ class Material;
 
 #include <glm/glm.hpp>
 
-#include "hitable.h"
+#include "hitable.cuh"
 #include "ray.h"
 
 class Material {
  public:
-  virtual bool Scatter(const Ray &ray, const HitRecord &record,
-                       std::pair<glm::vec3, Ray> *out) const = 0;
-  virtual glm::vec3 Emit(double u, double v, const glm::vec3 &p) const;
+  __device__ virtual bool Scatter(const Ray &ray, const HitRecord &record,
+                                  std::pair<glm::vec3, Ray> *out) const = 0;
+  __device__ virtual glm::vec3 Emit(double u, double v,
+                                    const glm::vec3 &p) const;
 };

ray-tracing-cuda/sphere.h

@@ -2,7 +2,7 @@
 
 #include <utility>
 
-#include "hitable.h"
+#include "hitable.cuh"
 #include "material.h"
 
 class Sphere : public Hitable {