Convert noise_math.h into C++20 module

CMakeLists.txt

@@ -1,20 +1,19 @@
-cmake_minimum_required(VERSION 3.22)
+cmake_minimum_required(VERSION 3.28 FATAL_ERROR)
 project(perlin-shadows)
 
 set(CMAKE_CXX_STANDARD 23)
 
-include_directories(src)
-
 link_libraries(-lGL -lglut -lGLEW -lGLU)
 
-add_executable(perlin-shadows
+add_executable(${CMAKE_PROJECT_NAME})
+target_sources(${CMAKE_PROJECT_NAME}
+	PRIVATE
 		src/constants.h
 		src/final.cpp
 		src/geography.cpp
 		src/geography.h
 		src/grid.cpp
 		src/grid.h
-        src/noise_math.h
 		src/renderer.cpp
 		src/renderer.h
 		src/camera.cpp
@@ -25,6 +24,9 @@ add_executable(perlin-shadows
 		src/point_light.h
 		src/renderable.cpp
 		src/renderable.h
+	PRIVATE
+		FILE_SET modules TYPE CXX_MODULES FILES
+		src/noise.cppm
 )
 
 file(READ src/shader/phong.vert PHONG_VERT)
@@ -36,4 +38,5 @@ file(READ src/shader/shadow.frag SHADOW_FRAG)
 file(READ src/shader/shadow.geom SHADOW_GEOM)
 configure_file(src/point_light.in.h src/point_light.h @ONLY)
 
+include_directories(src)
 target_include_directories(perlin-shadows PUBLIC "${CMAKE_CURRENT_BINARY_DIR}/src")

src/grid.cpp

@@ -4,9 +4,11 @@
 #include <vector>
 
 #include "constants.h"
-#include "noise_math.h"
+
+import noise;
 
 using namespace std;
+using namespace noise;
 
 random_device Grid::device_;
 default_random_engine::result_type Grid::base_random_{0};

src/noise.cppm

@@ -1,4 +1,6 @@
-#pragma once
+export module noise;
+
+export namespace noise {
 
 // Based on Ken Perlin's smoother step function:
 // https://en.wikipedia.org/wiki/Smoothstep#Variations Returns value in range
@@ -21,3 +23,5 @@
                                           const float bound_1) {
   return bound_0 + SmootherStep(x) * (bound_1 - bound_0);
 }
+
+}  // namespace noise