vulkan: locate shaders in srcdir

If running from inside out-of-tree build, the shaders were not located -
now look them up in srcdir (if the the formerly looked shader directory
doesn't exist).

Author: MartinPulec

configure.ac

@@ -3528,7 +3528,8 @@ AC_SUBST(TEST_OBJS)
 AC_SUBST(TOREMOVE)
 
 # -------------------------------------------------------------------------------------------------
-# Finally, substitute things into the Makefile and config.h
+# Print summary + set it to AUTOCONF_RESULT
+# -------------------------------------------------------------------------------------------------
 
 start_section() {
         printf "$1\n$2:"
@@ -3664,6 +3665,12 @@ RES_STR=`printf "$RESULT" | sed 's/$/\\\\n/' | tr -d '\n'`
 
 AC_DEFINE_UNQUOTED([AUTOCONF_RESULT], "$RES_STR", [Autoconf result])
 
+# -------------------------------------------------------------------------------------------------
+# Finally, substitute things into the Makefile and config.h
+# -------------------------------------------------------------------------------------------------
+
+AC_DEFINE_UNQUOTED([SRCDIR], "$srcdir", [path to src directory])
+
 AC_CONFIG_HEADERS([src/config.h])
 AC_CONFIG_FILES([Makefile])
 AC_OUTPUT

src/video_display/vulkan/vulkan_display.cpp

@@ -3,7 +3,7 @@
  * @author Martin Bela      <[email protected]>
  */
 /*
- * Copyright (c) 2021-2023 CESNET, z. s. p. o.
+ * Copyright (c) 2021-2025 CESNET
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -41,13 +41,21 @@
 #include <cmath>
 #include <cstdint>
 #include <cstring>
+#include <filesystem>
 #include <fstream>
 #include <iostream>
 #include <memory>
 #include <tuple>
 #include <utility>
 #include <vector>
 #include "debug.h"
+#include "utils/fs.h"
+
+#ifdef HAVE_CONFIG_H
+#include "config.h" // for SRCDIR
+#else
+#define SRCDIR ".."
+#endif // HAVE_CONFIG_H
 
 #define MOD_NAME "[vulkan] "
 
@@ -652,4 +660,22 @@ void VulkanDisplay::window_parameters_changed(WindowParameters new_parameters) {
         }
 }
 
+std::string
+get_shader_path()
+{
+        constexpr char suffix[] = "/share/ultragrid/vulkan_shaders";
+        // note that get_install_root returns bin/.. if run from build,
+        // which will not contain the shaders for out-of-tree builds
+        const char *path = get_install_root();
+        if (path != nullptr) {
+                std::string path_to_shaders = std::string(path) + suffix;
+                std::filesystem::directory_entry dir{ std::filesystem::path(
+                    path_to_shaders) };
+                if (dir.exists()) {
+                        return path_to_shaders;
+                }
+        }
+        return std::string(SRCDIR) + suffix;
+}
+
 } //namespace vulkan_display

src/video_display/vulkan/vulkan_display.hpp

@@ -3,7 +3,7 @@
  * @author Martin Bela      <[email protected]>
  */
 /*
- * Copyright (c) 2021-2023 CESNET, z. s. p. o.
+ * Copyright (c) 2021-2025 CESNET
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -201,4 +201,6 @@ class VulkanDisplay {
         bool destroyed = false;
 };
 
+std::string get_shader_path();
+
 } //vulkan_display

src/video_display/vulkan/vulkan_sdl2.cpp

@@ -60,7 +60,6 @@
 #include "video_display.h"
 #include "video_display/splashscreen.h"
 #include "video.h"
-#include "utils/fs.h"
 //remove leaking macros
 #undef min
 #undef max
@@ -776,9 +775,7 @@ void* display_vulkan_init(module* parent, const char* fmt, unsigned int flags) {
         SDL_Vulkan_GetInstanceExtensions(s->window, &extension_count, required_extensions.data());
         assert(extension_count > 0);
 
-        const char *path = get_install_root();
-        std::string path_to_shaders{ path ? path : ".." };
-        path_to_shaders = path_to_shaders + "/share/ultragrid/vulkan_shaders";
+        std::string path_to_shaders = vkd::get_shader_path();
         LOG(LOG_LEVEL_INFO) << MOD_NAME "Path to shaders: " << path_to_shaders << '\n';
         try {
                 vkd::VulkanInstance instance;

src/video_display/vulkan/vulkan_sdl3.cpp

@@ -59,7 +59,6 @@
 #include "video_display.h"
 #include "video_display/splashscreen.h"
 #include "video.h"
-#include "utils/fs.h"
 //remove leaking macros
 #undef min
 #undef max
@@ -805,9 +804,7 @@ void* display_vulkan_init(module* parent, const char* fmt, unsigned int flags) {
         std::vector<const char*> required_extensions(extensions, extensions + extension_count);
         assert(extension_count > 0);
 
-        const char *path = get_install_root();
-        std::string path_to_shaders{ path ? path : ".." };
-        path_to_shaders = path_to_shaders + "/share/ultragrid/vulkan_shaders";
+        std::string path_to_shaders = vkd::get_shader_path();
         LOG(LOG_LEVEL_INFO) << MOD_NAME "Path to shaders: " << path_to_shaders << '\n';
         try {
                 vkd::VulkanInstance instance;