more improvements in builds setup

- moved slang shaders to spvshaders to separate software and hardware
  shaders
- split Makefile.am into Makefile.am, src/Makefile.am and
  src/spvshaders/Makefile.am
- build shaders as DATA primary, instead of both PROGRAMS and SCRIPTS,
  which greatly simplifies building. Before that, we had to first build
  them as PROGRAMS, and then copy them as SCRIPTS to remove executable
  extensions (i.e. ".exe" for Windows)
- changed final executable dir from enginedir to bindir, which makes
  automake see it as an exec instead of data
- compute relative paths from C++, which makes it possible to change
  dirs arbitrarily when running make while still having a relocatable
  executable
- updated README.md to reflect changes in dirs
- use AX_COMPARE_VERSION() to simplify checking if Vulkan headers
  version is correct
- factored out most of paths computation in engine::path_utils::Paths

6 files changed, 115 insertions, 16 deletions

diff --git a/src/Makefile.am b/src/Makefile.am
new file mode 100644
index 0000000..00e76ac
--- /dev/null
+++ b/src/Makefile.am
@@ -0,0 +1,61 @@
+include ../common.am
+
+bin_PROGRAMS = engine
+
+engine_SOURCES = \
+	engine.cpp \
+	renderer.hpp renderer.cpp \
+	obj_parser.hpp obj_parser.cpp \
+	vulkan_utils.hpp \
+	path_utils.hpp path_utils.cpp \
+	stb_image.h \
+	stb_image.cpp \
+	fb/fb.hpp \
+	fb/chfb.hpp fb/chfb.cpp \
+	fb/pixfb.hpp fb/pixfb.cpp \
+	math/utils.hpp \
+	math/vector.hpp \
+	math/mat4.hpp \
+	math/quat.hpp \
+	math/tform.hpp \
+	o3d/mesh.hpp o3d/mesh.cpp \
+	o3d/obj3d.hpp \
+	o3d/vertex.hpp \
+	o3d/deriv_vertex.hpp \
+	o3d/tri.hpp \
+	o3d/tri_deriv.hpp \
+	o3d/polygon.hpp \
+	o3d/camera.hpp \
+	o3d/scene.hpp \
+	ctrl/keyboard.hpp \
+	ctrl/mouse.hpp \
+	shaders/shaders.hpp \
+	shaders/simple_shaders.hpp shaders/simple_shaders.cpp
+
+if DEBUG
+BINDIR_CXX = $(abs_builddir)
+SPVSHADERSDIR_CXX = $(abs_builddir)/spvshaders
+PKGDATADIR_CXX = $(abs_top_srcdir)
+else
+BINDIR_CXX = $(bindir)
+SPVSHADERSDIR_CXX = $(spvshadersdir)
+PKGDATADIR_CXX = $(pkgdatadir)
+endif
+
+engine_CPPFLAGS = -std=gnu++23 -Wall -Wextra -I'$(srcdir)/src' \
+	-DBINDIR='"$(BINDIR_CXX)"' \
+	-DPKGDATADIR='"$(PKGDATADIR_CXX)"' \
+	-DSPVSHADERSDIR='"$(SPVSHADERSDIR_CXX)"' \
+	$(GLFW3_CFLAGS) $(VULKAN_CFLAGS)
+if !DEBUG
+engine_CPPFLAGS += -DNDEBUG
+endif
+engine_LDFLAGS = -std=gnu++23 -Wall -Wextra
+engine_LDADD = $(GLFW3_LIBS) $(VULKAN_LIBS)
+
+if HAVE_NCURSES
+engine_CPPFLAGS += $(NCURSES_CFLAGS)
+engine_LDADD    += $(NCURSES_LIBS)
+endif
+
+engine-stb_image.$(OBJEXT): CXXFLAGS += -Wno-unused-but-set-variable
diff --git a/src/engine.cpp b/src/engine.cpp
index a9991c4..1f57bd7 100644
--- a/src/engine.cpp
+++ b/src/engine.cpp
@@ -194,7 +194,7 @@ static void render_software(Renderer<FrameBuffer, Shaders>& renderer, const Matr
 #ifdef HAVE_NCURSES
 #define MKEY_ESC 27
 
-static int main_term(const std::filesystem::path& files_root, Scene& scene) {
+static int main_term(const engine::path_utils::Paths& paths, Scene& scene) {
     // init
     std::setlocale(LC_ALL, "");
     initscr();
@@ -206,7 +206,7 @@ static int main_term(const std::filesystem::path& files_root, Scene& scene) {
     curs_set(0);
 
     int texture_w, texture_h, texture_channels;
-    const auto texture_path = std::filesystem::path(files_root).append(ASSETS_TEXTURES_DIR "/viking_room.png");
+    const auto texture_path = paths.assets_textures() / "viking_room.png";
 #ifdef _WIN32
     const auto texture_path_wcstr = texture_path.c_str();
     const auto texture_path_cstr_size = stbi_convert_wchar_to_utf8(nullptr, 0, texture_path_wcstr);
@@ -907,7 +907,7 @@ static void generate_mipmaps(VkCommandBuffer cmd_buf, VkPhysicalDevice physical_
     }
 }
 
-static int main_graphical(const std::filesystem::path& files_root, Scene& scene) {
+static int main_graphical(const engine::path_utils::Paths& paths, Scene& scene) {
     // init window
     glfwInit();
     glfwWindowHint(GLFW_CLIENT_API, GLFW_NO_API);
@@ -1581,7 +1581,7 @@ static int main_graphical(const std::filesystem::path& files_root, Scene& scene)
         // reading shader file
         auto shader_module = [&] {
             auto shader_code = [&] {
-                const auto shader_path = std::filesystem::path(files_root).append(SHADERS_DIR "/shader.spv");
+                const auto shader_path = paths.spvshaders() / "shader.spv";
                 const auto shader_file_name = shader_path.c_str();
                 std::ifstream shader_file(shader_file_name, std::ios::ate | std::ios::binary);
                 if (!shader_file.is_open()) {
@@ -1832,7 +1832,7 @@ static int main_graphical(const std::filesystem::path& files_root, Scene& scene)
     // create texture image
     auto [texture_img, texture_mip_lvls, texture_img_device_mem, texture_w, texture_h, texture_pixels] = [&] {
         int w, h, channels;
-        const auto texture_path = std::filesystem::path(files_root).append(ASSETS_TEXTURES_DIR "/viking_room.png");
+        const auto texture_path = paths.assets_textures() / "viking_room.png";
 #ifdef _WIN32
         const auto texture_path_wcstr = texture_path.c_str();
         const auto texture_path_cstr_size = stbi_convert_wchar_to_utf8(nullptr, 0, texture_path_wcstr);
@@ -2892,12 +2892,7 @@ static void parse_args(const std::vector<std::string_view>& args, Mode& mode) {
 }
 
 int main(int argc, char *argv[]) {
-    const auto exe_path_opt = engine::path_utils::exe_path();
-    if (!exe_path_opt) {
-        std::cerr << "cannot find path of executable" << std::endl;
-        exit(1);
-    }
-    const auto files_root = (*exe_path_opt).parent_path();
+    const auto paths = engine::path_utils::Paths();
 
     Mode mode = Mode::graphical;
     parse_args(convert_args(argc, argv), mode);
@@ -2920,7 +2915,7 @@ int main(int argc, char *argv[]) {
             case GameType::suzanne:
                 return {
                     {
-                        engine::parse_object(std::filesystem::path(files_root).append(ASSETS_OBJS_DIR "/suzanne.obj")),
+                        engine::parse_object(paths.assets_objs() / "suzanne.obj"),
                         {
                             Vector3(0.f, 0.f, 0.f),
                             Quaternion::one(),
@@ -2939,7 +2934,7 @@ int main(int argc, char *argv[]) {
                         }
                     },
                     {
-                        engine::parse_object(std::filesystem::path(files_root).append(ASSETS_OBJS_DIR "/suzanne.obj")),
+                        engine::parse_object(paths.assets_objs() / "suzanne.obj"),
                         {
                             Vector3(0.f, 1.f, 0.f),
                             Quaternion::one(),
@@ -2950,7 +2945,7 @@ int main(int argc, char *argv[]) {
             case GameType::test:
                 return {
                     {
-                        engine::parse_object(std::filesystem::path(files_root).append(ASSETS_OBJS_DIR "/viking_room.obj")),
+                        engine::parse_object(paths.assets_objs() / "viking_room.obj"),
                         {
                             Vector3(0.f, .5f, 0.f),
                             Quaternion::look_towards({ -1.f, 0.f, 0.f }, { 0.f, 0.f, 1.f }).conjugate(),
@@ -2969,13 +2964,13 @@ int main(int argc, char *argv[]) {
         return EXIT_SUCCESS;
     case Mode::term:
 #ifdef HAVE_NCURSES
-        return main_term(files_root, scene);
+        return main_term(paths, scene);
 #else
         std::cerr << "Error: ncurses was not enabled during compilation." << std::endl;
         return EXIT_FAILURE;
 #endif
     case Mode::graphical:
-        return main_graphical(files_root, scene);
+        return main_graphical(paths, scene);
     default:
         std::unreachable();
     }
diff --git a/src/path_utils.cpp b/src/path_utils.cpp
index df35ef1..94bbba5 100644
--- a/src/path_utils.cpp
+++ b/src/path_utils.cpp
@@ -1,4 +1,5 @@
 #include "path_utils.hpp"
+#include <iostream>
 #include <optional>
 #include <filesystem>
 #ifdef _WIN32
@@ -18,3 +19,16 @@ std::optional<std::filesystem::path> engine::path_utils::exe_path() noexcept {
 # error "operating system not supported"
 #endif
 }
+
+engine::path_utils::Paths::Paths() noexcept {
+    const auto exe_path_opt = engine::path_utils::exe_path();
+    if (!exe_path_opt) {
+        std::cerr << "cannot find path of executable" << std::endl;
+        exit(1);
+    }
+    const auto files_root = (*exe_path_opt).parent_path();
+
+    m_assets_objs = files_root / std::filesystem::relative(PKGDATADIR "/assets/objs", BINDIR);
+    m_assets_textures = files_root / std::filesystem::relative(PKGDATADIR "/assets/textures", BINDIR);
+    m_spvshaders = files_root / std::filesystem::relative(SPVSHADERSDIR, BINDIR);
+}
diff --git a/src/path_utils.hpp b/src/path_utils.hpp
index e87aad6..76567bc 100644
--- a/src/path_utils.hpp
+++ b/src/path_utils.hpp
@@ -8,6 +8,26 @@ namespace engine::path_utils {
 
 std::optional<std::filesystem::path> exe_path() noexcept;
 
+class Paths {
+    public:
+        Paths() noexcept;
+
+        const std::filesystem::path& assets_objs() const & noexcept {
+            return m_assets_objs;
+        }
+
+        const std::filesystem::path& assets_textures() const & noexcept {
+            return m_assets_textures;
+        }
+
+        const std::filesystem::path& spvshaders() const & noexcept {
+            return m_spvshaders;
+        }
+
+    private:
+        std::filesystem::path m_assets_objs, m_assets_textures, m_spvshaders;
+};
+
 }
 
 #endif // PATH_UTILS_HPP
diff --git a/src/spvshaders/Makefile.am b/src/spvshaders/Makefile.am
new file mode 100644
index 0000000..5a5a362
--- /dev/null
+++ b/src/spvshaders/Makefile.am
@@ -0,0 +1,9 @@
+include ../../common.am
+
+spvshaders_DATA = shader.spv
+CLEANFILES = shader.spv
+
+shader_spv_SLANGFLAGS = -target spirv -profile spirv_1_4 -emit-spirv-directly -fvk-use-entrypoint-name -entry vert_main -entry frag_main
+
+shader.spv: $(srcdir)/shader.slang
+	$(SLANGC) $(shader_spv_SLANGFLAGS) -o $@ $<
diff --git a/src/shaders/shader.slang b/src/spvshaders/shader.slang
index 245df4b..245df4b 100644
--- a/src/shaders/shader.slang
+++ b/src/spvshaders/shader.slang