Move trace logging to tracelog.h.

Pixel-wise, comprehensive, beautiful trace logging.

8 files changed, 74 insertions, 24 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index a197031..fc3e6f3 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -12,9 +12,9 @@ set(CMAKE_VERBOSE_MAKEFILE on)
 
 # main executable
 
-add_executable(rt main.cpp vec.h bitmap.h ray.h bitfont.h hitlist.h object.h sphere.h viewport.h aa.h material.h material_diffusive.h material_diffusive.cpp material_reflective.h material_reflective.cpp material_dielectric.cpp material_dielectric.h)
+add_executable(rt main.cpp vec.h bitmap.h ray.h bitfont.h hitlist.h object.h sphere.h viewport.h aa.h material.h material_diffusive.h material_diffusive.cpp material_reflective.h material_reflective.cpp material_dielectric.cpp material_dielectric.h tracelog.h)
 add_executable(image_output main_image_output.cpp vec.h bitmap.h bitfont.h hitlist.h object.h sphere.h viewport.h)
-add_executable(simple_scanner main_simple_scanner.cpp vec.h bitmap.h ray.h timer.h bitfont.h hitlist.h object.h sphere.h viewport.h aa.h material.h material_diffusive.h material_diffusive.cpp material_reflective.h material_reflective.cpp material_dielectric.cpp material_dielectric.h)
+add_executable(simple_scanner main_simple_scanner.cpp vec.h bitmap.h ray.h timer.h bitfont.h hitlist.h object.h sphere.h viewport.h aa.h material.h material_diffusive.h material_diffusive.cpp material_reflective.h material_reflective.cpp material_dielectric.cpp material_dielectric.h tracelog.h)
 
 # googletest
 
diff --git a/hitlist.h b/hitlist.h
index 1ad040a..ab9cca3 100644
--- a/hitlist.h
+++ b/hitlist.h
@@ -11,6 +11,7 @@
 #include "ray.h"
 #include "vec.h"
 #include "object.h"
+#include "tracelog.h"
 #include <cstdlib>
 #include <memory>
 #include <limits>
@@ -22,15 +23,6 @@
 //#define T_NORM_VISUAL
 #define T_DIFFUSE
 
-// log ray traces to stderr
-//#define LOG_TRACE
-
-#ifdef LOG_TRACE
-#define TRACELOG(...) (fprintf(stderr, __VA_ARGS__))
-#else
-#define TRACELOG(...)
-#endif
-
 // A world, T is color depth
 class hitlist {
     std::vector<std::shared_ptr<object>> objects;
@@ -50,9 +42,10 @@ public:
     pixel<T> color(ray3d r, random_uv_gen_3d &ruvg, uint_fast32_t max_recursion_depth = 64) const {
         assert(r.decay().is_one());
         TRACELOG("+++ start tracing (limit=%zu)\n", max_recursion_depth);
-        TRACELOG("    ray: [%10f,%10f,%10f], decay=[%10f,%10f,%10f]\n",
+        TRACELOG("    ray: [%-10f,%-10f,%-10f], decay=[%-10f,%-10f,%-10f]\n",
                  r.direction().x, r.direction().y, r.direction().z, r.decay().x, r.decay().y, r.decay().z);
         while (max_recursion_depth-- > 0) {
+            TRACELOG("    step start (remaining: %lu)\n", max_recursion_depth + 1);
             // Detect hits
             bool hit = false;
             double hit_t = std::numeric_limits<double>::infinity();
@@ -77,7 +70,8 @@ public:
 #ifdef LOG_TRACE
                 const auto _hit_p_ = r.at(hit_t);
                 const auto _rn_ = dot(r.direction(), hit_obj->normal_vector(_hit_p_));
-                TRACELOG("    hit object <%p> at [%10f,%10f,%10f], t=%10f, surface=%10f (%s)\n",
+                TRACELOG("    hit object %s <%p> at [%-10f,%-10f,%-10f], t=%-10f, surface=%-10f (%s)\n",
+                         typeid(*hit_obj).name(),
                          hit_obj.get(), _hit_p_.x, _hit_p_.y, _hit_p_.z,
                          hit_t, _rn_, (_rn_ < 0) ? "outside" : "inside");
 #endif
@@ -94,7 +88,7 @@ public:
 #ifdef T_DIFFUSE
                 const auto &materi = hit_obj->material();
                 if (materi.scatter(r, *hit_obj, hit_t, ruvg)) {
-                    TRACELOG("    scattered: [%10f,%10f,%10f], decay=[%10f,%10f,%10f]\n",
+                    TRACELOG("    scattered ray: [%-10f,%-10f,%-10f], decay=[%-10f,%-10f,%-10f]\n",
                              r.direction().x, r.direction().y, r.direction().z,
                              r.decay().x, r.decay().y, r.decay().z);
                     continue; // The ray is scatted by an object. Continue processing the scattered ray.
@@ -105,6 +99,7 @@ public:
 #endif
             }
 
+            TRACELOG("    hit infinity (light source)\n");
             // Does not hit anything. Get background color (infinity)
             const auto u = (r.direction().y + 1.0) * 0.5;
             const auto c = mix(
@@ -113,19 +108,15 @@ public:
                     1.0 - u,
                     u
             );
+
+            TRACELOG("--- finish (hit infinity)\n");
 #ifdef T_DIFFUSE
-#ifdef LOG_TRACE
-            const auto co = pixel8b::from(r.hit(c));
-            TRACELOG("    result: [%d, %d, %d]\n", co.r, co.g, co.b);
-            TRACELOG("--- finish (reached infinity)\n");
-#endif
             return r.hit(c);
 #else
-            TRACELOG("--- finish (hit)\n");
             return c;
 #endif
         }
-        TRACELOG("--- finish (max search depth)\n");
+        TRACELOG("--- finish (trace step limit reached) [XX]\n");
         return pixel<T>::black(); // reached recursion time limit, very little light
     }
 };
diff --git a/material_dielectric.cpp b/material_dielectric.cpp
index ed8e4eb..61e34ec 100644
--- a/material_dielectric.cpp
+++ b/material_dielectric.cpp
@@ -3,6 +3,7 @@
 //
 
 #include "material_dielectric.h"
+#include "tracelog.h"
 
 bool material_dielectric::scatter(ray3d &r, const object &hit_obj, double hit_t, random_uv_gen_3d &ruvg) const {
     const auto hit_p = r.at(hit_t);
@@ -22,9 +23,11 @@ bool material_dielectric::scatter(ray3d &r, const object &hit_obj, double hit_t,
     // determine reflection or refraction using Schlick's Approximation.
     if (reflectance(cos1, ri_) > ruvg.range01_scalar()) {
         // reflect
+        TRACELOG("    reflect (dielectric material, schlick, ri=%-10f)\n", ri_);
         r2 = n.reflect(r.direction());
     } else {
         // refract
+        TRACELOG("    refract (dielectric material, schlick, ri=%-10f)\n", ri_);
         r2 = n.refract<true>(r.direction(), ri_);
     }
     r.direction(r2.unit_vec());
diff --git a/material_diffusive.cpp b/material_diffusive.cpp
index b3f0207..58c9c45 100644
--- a/material_diffusive.cpp
+++ b/material_diffusive.cpp
@@ -4,6 +4,7 @@
 
 #include "vec.h"
 #include "material_diffusive.h"
+#include "tracelog.h"
 
 
 bool material_diffuse_lambertian::scatter(ray3d &r, const object &hit_obj, double hit_t, random_uv_gen_3d &ruvg) const {
@@ -16,6 +17,7 @@ bool material_diffuse_lambertian::scatter(ray3d &r, const object &hit_obj, doubl
     r.decay(albedo); // lose some light when diffused
     r.source(hit_point);
     r.direction((diffuse_target - hit_point).unit_vec()); // the new diffused ray we trace on
+    TRACELOG("    reflected (diffusive, lambertian material)\n");
     return true;
 }
 
@@ -52,6 +54,7 @@ bool material_diffuse_simple::scatter(ray3d &r, const object &hit_obj, double hi
     r.decay(albedo); // lose some light when diffused
     r.source(hit_point);
     r.direction((diffuse_target - hit_point).unit_vec()); // the new diffused ray we trace on
+    TRACELOG("    reflected (diffusive, simple material)\n");
     return true;
 }
 
@@ -80,6 +83,7 @@ material_diffuse_hemispherical::scatter(ray3d &r, const object &hit_obj, double
     r.decay(albedo); // lose some light when diffused
     r.source(hit_point);
     r.direction((diffuse_target - hit_point).unit_vec()); // the new diffused ray we trace on
+    TRACELOG("    reflected (diffusive, hemispherical material)\n");
     return true;
 }
 
diff --git a/material_reflective.cpp b/material_reflective.cpp
index aa0d361..6cffcf3 100644
--- a/material_reflective.cpp
+++ b/material_reflective.cpp
@@ -5,6 +5,7 @@
 #include "vec.h"
 #include "material.h"
 #include "material_reflective.h"
+#include "tracelog.h"
 
 // perfectly-smooth reflective
 template<>
@@ -15,7 +16,16 @@ bool material_reflective_<false>::scatter(ray3d &r, const object &hit_obj, doubl
     r.source(hit_point);
     r.direction(reflected);
     r.decay(albedo);
-    return dot(reflected, nv) > 0;
+    const auto alive = dot(reflected, nv) > 0;
+#ifdef LOG_TRACE
+    if (!alive) {
+        TRACELOG("    absorbed (perfectly smooth material) (reflected: [%-10f,%-10f,%-10f], nv: [%-10f,%-10f,%-10f])\n",
+                 reflected.x, reflected.y, reflected.z, nv.x, nv.y, nv.z);
+    } else {
+        TRACELOG("    reflected (perfectly smooth material)\n");
+    }
+#endif
+    return alive;
 }
 
 // fuzzy reflective
@@ -27,5 +37,14 @@ bool material_reflective_<true>::scatter(ray3d &r, const object &hit_obj, double
     r.source(hit_point);
     r.direction(reflected.unit_vec());
     r.decay(albedo);
-    return dot(reflected, nv) > 0;
+    const auto alive = dot(reflected, nv) > 0;
+#ifdef LOG_TRACE
+    if (!alive) {
+        TRACELOG("    absorbed (fuzzy reflective material) (reflected: [%-10f,%-10f,%-10f], nv: [%-10f,%-10f,%-10f])\n",
+                 reflected.x, reflected.y, reflected.z, nv.x, nv.y, nv.z);
+    } else {
+        TRACELOG("    reflected (fuzzy reflective material)\n");
+    }
+#endif
+    return alive;
 }
\ No newline at end of file
diff --git a/tracelog.h b/tracelog.h
new file mode 100644
index 0000000..cee85d4
--- /dev/null
+++ b/tracelog.h
@@ -0,0 +1,17 @@
+//
+// Created by Keuin on 2022/4/16.
+//
+
+#ifndef RT_TRACELOG_H
+#define RT_TRACELOG_H
+
+// log ray traces to stderr
+//#define LOG_TRACE
+
+#ifdef LOG_TRACE
+#define TRACELOG(...) (fprintf(stderr, __VA_ARGS__))
+#else
+#define TRACELOG(...)
+#endif
+
+#endif //RT_TRACELOG_H
diff --git a/vec.h b/vec.h
index d2dece0..e3e15b8 100644
--- a/vec.h
+++ b/vec.h
@@ -10,6 +10,7 @@
 #include <ostream>
 #include <cassert>
 #include <algorithm>
+#include "tracelog.h"
 
 static inline bool eq(int a, int b) {
     return a == b;
@@ -134,8 +135,10 @@ struct vec3 {
             // TODO test TIR
             if (Enable_TIR) {
                 // ri_inv < sin(a1), cannot refract, must reflect (Total Internal Reflection)
+                TRACELOG("    reflect (TIR, d=%f)\n", d);
                 return reflect(r1);
             } else {
+                TRACELOG("    refract (forced, d=%f)\n", d);
                 d = -d; // abs, just make the sqrt has a real solution
             }
         }
diff --git a/viewport.h b/viewport.h
index 85d17f5..2924582 100644
--- a/viewport.h
+++ b/viewport.h
@@ -10,6 +10,7 @@
 #include "ray.h"
 #include "vec.h"
 #include "hitlist.h"
+#include "tracelog.h"
 #include <cstdlib>
 #include <memory>
 #include <limits>
@@ -97,7 +98,19 @@ public:
                 const auto dir = r + off; // direction vector from camera to current pixel on screen
                 ray3d ray{viewpoint, dir}; // from camera to pixel (on the viewport)
                 const auto pixel = world.color<T>(ray, ruvg);
-                image.set(i + img_hw, -j + img_hh, pixel);
+                const auto x_ = i + img_hw, y_ = -j + img_hh;
+                image.set(x_, y_, pixel);
+
+#ifdef LOG_TRACE
+                const auto ret = pixel;
+                const auto ret8b = pixel8b::from(ret);
+                const auto ret8bg2 = pixel8b::from(ret.gamma2());
+                TRACELOG(" ^  apply to pixel: (%d, %d), color: [%f, %f, %f] (8bit: [%d, %d, %d], 8bit-gamma2: [%d, %d, %d])\n",
+                         x_, y_,
+                         (double) ret.r, (double) ret.g, (double) ret.b,
+                         ret8b.r, ret8b.g, ret8b.b,
+                         ret8bg2.r, ret8bg2.g, ret8bg2.b);
+#endif
             }
         }
         return image;