From bc1073a020c99ed89967a6b00a9eeb4ab2e160dc Mon Sep 17 00:00:00 2001
From: ladevieq <ladevie.quentin@gmail.com>
Date: Thu, 18 Mar 2021 23:28:20 +0100
Subject: Display frame time & add aabb ray hit function for future BVH
 implementation

---
 include/aabb.hpp     | 13 +++++++++++++
 shaders/compute.comp | 28 ++++++++++++++++++++++++++++
 src/main.cpp         | 37 ++++++++++++++++++-------------------
 3 files changed, 59 insertions(+), 19 deletions(-)
 create mode 100644 include/aabb.hpp

diff --git a/include/aabb.hpp b/include/aabb.hpp
new file mode 100644
index 0000000..9ec1f3f
--- /dev/null
+++ b/include/aabb.hpp
@@ -0,0 +1,13 @@
+#ifndef __AABB_HPP_
+#define __AABB_HPP_
+
+#include "vec3.hpp"
+
+class AABB {
+    AABB(vec3 min_point, vec3 max_point): minimum(min_point), maximum(max_point) {}
+
+    vec3 minimum;
+    vec3 maximum;
+};
+
+#endif // !__AABB_HPP_
diff --git a/shaders/compute.comp b/shaders/compute.comp
index b70b021..3510d52 100644
--- a/shaders/compute.comp
+++ b/shaders/compute.comp
@@ -34,6 +34,11 @@ struct sphere {
     float[3] padding;
 };
 
+struct aabb {
+    vec4 min;
+    vec4 max;
+};
+
 struct camera {
     vec4 position;
 
@@ -88,6 +93,29 @@ float rand(vec2 co) {
     return fract(sin(dot(co.xy ,vec2(12.9898,78.233))) * 43758.5453);
 }
 
+bool hit_aabb(aabb b, ray r, float min_t, float max_t) {
+    for (int axis_index = 0; axis_index < 3; axis_index++) {
+        float inv_dir = 1.f / r.direction[axis_index];
+        float t0 = (b.min[axis_index] - r.origin[axis_index]) * inv_dir;
+        float t1 = (b.max[axis_index] - r.origin[axis_index]) * inv_dir;
+
+        if (inv_dir < 0.f) {
+            float temp = t0;
+            t0 = t1;
+            t1 = t0;
+        }
+
+        min_t = max(t0, min_t);
+        max_t = min(t1, max_t);
+
+        if (max_t < min_t) {
+            return false;
+        }
+    }
+
+    return true;
+}
+
 bool hit_sphere(sphere s, ray r, float min_t, float max_t, out hit_info info) {
     vec3 origin_center = r.origin - s.position.xyz;
 
diff --git a/src/main.cpp b/src/main.cpp
index 56e924d..553191a 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -19,24 +19,6 @@
 #include <Windows.h>
 #endif
 
-void gui(input_data* mapped_input_data, bool &reset_accumulation) {
-    ImGui::NewFrame();
-
-    ImGui::SetNextWindowPos({ 0.f, 0.f });
-    ImGui::SetNextWindowSize({ 0.f, 0.f });
-    ImGui::Begin("Debug", NULL, ImGuiWindowFlags_NoMove | ImGuiWindowFlags_NoResize | ImGuiWindowFlags_NoTitleBar);
-
-    if (ImGui::SliderInt("samples per pixel", (int32_t*)&mapped_input_data->samples_per_pixel, 1, 1000)) {
-        reset_accumulation = true;
-    }
-
-    ImGui::SliderInt("bounces", (int32_t*)&mapped_input_data->max_bounce, 2, 250);
-
-    ImGui::End();
-
-    ImGui::EndFrame();
-}
-
 int main() {
     RENDERDOC_API_1_1_2 *rdoc_api = NULL;
 
@@ -185,7 +167,24 @@ int main() {
 
         wnd.events.clear();
 
-        gui((input_data*)renderer.compute_shader_buffer.alloc_info.pMappedData, reset_accumulation);
+        // GUI
+        ImGui::NewFrame();
+
+        ImGui::SetNextWindowPos({ 0.f, 0.f });
+        ImGui::SetNextWindowSize({ 0.f, 0.f });
+        ImGui::Begin("Debug", NULL, ImGuiWindowFlags_NoMove | ImGuiWindowFlags_NoResize | ImGuiWindowFlags_NoTitleBar);
+
+        ImGui::Text("frame time %f ms\n", delta_time);
+
+        if (ImGui::SliderInt("samples per pixel", (int32_t*)&((input_data*) renderer.compute_shader_buffer.alloc_info.pMappedData)->samples_per_pixel, 1, 1000)) {
+            reset_accumulation = true;
+        }
+
+        ImGui::SliderInt("bounces", (int32_t*)&((input_data*) renderer.compute_shader_buffer.alloc_info.pMappedData)->max_bounce, 2, 250);
+
+        ImGui::End();
+
+        ImGui::EndFrame();
 
         // To start a frame capture, call StartFrameCapture.
         // You can specify NULL, NULL for the device to capture on if you have only one device and
-- 
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