Add axis aligned rectangles.

Makefile

@@ -2,8 +2,8 @@ CXX = g++
 
 CXXFLAGS  = -std=c++20 -Wall -Wextra -Wno-unused-parameter -march=native -O3 -flto -fopenmp
 
-DEPS = util.h vec3.h color.h ray.h camera.h hittable.h hittable_list.h sphere.h material.h lodepng.h moving_sphere.h bvh.h aabb.h texture.h
-OBJ = main.o material.o vec3.o lodepng.o sphere.o moving_sphere.o bvh.o
+DEPS = util.h vec3.h color.h ray.h camera.h hittable.h hittable_list.h sphere.h material.h lodepng.h moving_sphere.h bvh.h aabb.h texture.h aarect.h
+OBJ = main.o material.o vec3.o lodepng.o sphere.o moving_sphere.o bvh.o aarect.o
 
 TARGET = toytracer
 

aarect.cpp

@@ -0,0 +1,79 @@
+#include "aarect.h"
+
+bool Xy_rect::bounding_box(double t0, double t1, Aabb& output_box) const {
+    output_box = Aabb(Point3(x0, y0, k - 0.0001), Point3(x1, y1, k + 0.0001));
+    return true;
+}
+
+bool Xz_rect::bounding_box(double t0, double t1, Aabb& output_box) const {
+    output_box = Aabb(Point3(x0, k - 0.0001, z0), Point3(x1, k + 0.0001, z1));
+    return true;
+}
+
+bool Yz_rect::bounding_box(double t0, double t1, Aabb& output_box) const {
+    output_box = Aabb(Point3(k - 0.0001, y0, z0), Point3(k + 0.0001, y1, z1));
+    return true;
+}
+
+bool Xy_rect::hit(const Ray& r, double t0, double t1, hit_record& rec) const {
+    auto t = (k - r.origin().z()) / r.direction().z();
+    if (t < t0 || t > t1)
+        return false;
+
+    auto x = r.origin().x() + t * r.direction().x();
+    auto y = r.origin().y() + t * r.direction().y();
+    if (x < x0 || x > x1 || y < y0 || y > y1)
+        return false;
+
+    rec.u = (x - x0) / (x1 - x0);
+    rec.v = (y - y0) / (y1 - y0);
+    rec.t = t;
+
+    auto outward_normal = Vec3(0, 0, 1);
+    rec.set_face_normal(r, outward_normal);
+    rec.mat_ptr = mat_ptr;
+    rec.p = r.at(t);
+    return true;
+}
+
+bool Xz_rect::hit(const Ray& r, double t0, double t1, hit_record& rec) const {
+    auto t = (k - r.origin().y()) / r.direction().y();
+    if (t < t0 || t > t1)
+        return false;
+
+    auto x = r.origin().x() + t * r.direction().x();
+    auto z = r.origin().z() + t * r.direction().z();
+    if (x < x0 || x > x1 || z < z0 || z > z1)
+        return false;
+
+    rec.u = (x - x0) / (x1 - x0);
+    rec.v = (z - z0) / (z1 - z0);
+    rec.t = t;
+
+    auto outward_normal = Vec3(0, 1, 0);
+    rec.set_face_normal(r, outward_normal);
+    rec.mat_ptr = mat_ptr;
+    rec.p = r.at(t);
+    return true;
+}
+
+bool Yz_rect::hit(const Ray& r, double t0, double t1, hit_record& rec) const {
+    auto t = (k - r.origin().x()) / r.direction().x();
+    if (t < t0 || t > t1)
+        return false;
+
+    auto y = r.origin().y() + t * r.direction().y();
+    auto z = r.origin().z() + t * r.direction().z();
+    if (y < y0 || y > y1 || z < z0 || z > z1)
+        return false;
+
+    rec.u = (y - y0) / (y1 - y0);
+    rec.v = (z - z0) / (z1 - z0);
+    rec.t = t;
+
+    auto outward_normal = Vec3(1, 0, 0);
+    rec.set_face_normal(r, outward_normal);
+    rec.mat_ptr = mat_ptr;
+    rec.p = r.at(t);
+    return true;
+}

aarect.h

@@ -0,0 +1,55 @@
+#ifndef AARECT_H
+#define AARECT_H
+
+#include "hittable.h"
+#include "material.h"
+
+class Xy_rect : public Hittable {
+  public:
+    Xy_rect() {}
+
+    Xy_rect(double x0_, double x1_, double y0_, double y1_, double k_, std::shared_ptr<Material> mat)
+        : x0(x0_), x1(x1_), y0(y0_), y1(y1_), k(k_), mat_ptr(mat) {}
+
+    virtual bool hit(const Ray& r, double t0, double t1, hit_record& rec) const;
+
+    virtual bool bounding_box(double t0, double t1, Aabb& output_box) const;
+
+  private:
+    double x0, x1, y0, y1, k;
+    std::shared_ptr<Material> mat_ptr;
+};
+
+class Xz_rect : public Hittable {
+  public:
+    Xz_rect() {}
+
+    Xz_rect(double x0_, double x1_, double z0_, double z1_, double k_, std::shared_ptr<Material> mat)
+        : x0(x0_), x1(x1_), z0(z0_), z1(z1_), k(k_), mat_ptr(mat) {}
+
+    virtual bool hit(const Ray& r, double t0, double t1, hit_record& rec) const;
+
+    virtual bool bounding_box(double t0, double t1, Aabb& output_box) const;
+
+  private:
+    double x0, x1, z0, z1, k;
+    std::shared_ptr<Material> mat_ptr;
+};
+
+class Yz_rect : public Hittable {
+  public:
+    Yz_rect() {}
+
+    Yz_rect(double y0_, double y1_, double z0_, double z1_, double k_, std::shared_ptr<Material> mat)
+        : y0(y0_), y1(y1_), z0(z0_), z1(z1_), k(k_), mat_ptr(mat) {}
+
+    virtual bool hit(const Ray& r, double t0, double t1, hit_record& rec) const;
+
+    virtual bool bounding_box(double t0, double t1, Aabb& output_box) const;
+
+  private:
+    double y0, y1, z0, z1, k;
+    std::shared_ptr<Material> mat_ptr;
+};
+
+#endif // AARECT_H