From 18edd4eb50fb1036419f68a9cb55ef7767f668c6 Mon Sep 17 00:00:00 2001
From: Danilo Spinella <danyspin97@protonmail.com>
Date: Thu, 13 Feb 2020 19:16:31 +0100
Subject: [PATCH] meson: Add option to use system vulkan headers

---
 meson.build       | 19 +++++++++++++++++--
 meson_options.txt |  1 +
 src/meson.build   |  3 ++-
 3 files changed, 20 insertions(+), 3 deletions(-)

diff --git a/meson.build b/meson.build
index adb9dae0..f20b3e2e 100644
--- a/meson.build
+++ b/meson.build
@@ -108,9 +108,15 @@ endif
 
 inc_common = [
     include_directories('include'),
-    include_directories('modules/Vulkan-Headers/include'),
 ]
 
+dep_vulkan = dependency('vulkan', required: get_option('use_system_vulkan'))
+if not dep_vulkan.found()
+  inc_common += [
+      include_directories('modules/Vulkan-Headers/include')
+  ]
+endif
+
 # Check for generic C arguments
 c_args = []
 foreach a : ['-Werror=implicit-function-declaration',
@@ -184,7 +190,16 @@ endif
 
 dep_pthread = cc.find_library('pthread')
 
-vk_api_xml = files('modules/Vulkan-Headers/registry/vk.xml')
+if dep_vulkan.found()
+  datadir = get_option('datadir')
+  if not datadir.startswith('/')
+    datadir = get_option('prefix') / datadir
+  endif
+  vk_api_xml = files(datadir / 'vulkan/registry/vk.xml')
+else
+  vk_api_xml = files('modules/Vulkan-Headers/registry/vk.xml')
+endif
+
 vk_layer_table_helpers = []
 
 vk_enum_to_str = custom_target(
diff --git a/meson_options.txt b/meson_options.txt
index cf87a716..9d1d8279 100644
--- a/meson_options.txt
+++ b/meson_options.txt
@@ -1 +1,2 @@
 option('glibcxx_asserts', type : 'boolean', value : false)
+option('use_system_vulkan', type : 'feature', value : 'disabled', description: 'Use system vulkan headers instead of the provided ones')
diff --git a/src/meson.build b/src/meson.build
index 196b810b..3095632d 100644
--- a/src/meson.build
+++ b/src/meson.build
@@ -66,7 +66,8 @@ vklayer_mesa_overlay = shared_library(
     vulkan_wsi_deps, 
     libimgui_core_dep, 
     dep_dl,
-    dep_pthread],
+    dep_pthread,
+    dep_vulkan],
   include_directories : inc_common,
   link_args : cc.get_supported_link_arguments(['-Wl,-Bsymbolic-functions', '-Wl,-z,relro']),
   install : true