From b0d6d609d64dcf71845801233d1d3680b9d50288 Mon Sep 17 00:00:00 2001
From: Akihiko Odaki <akihiko.odaki@gmail.com>
Date: Wed, 8 Dec 2021 15:24:55 +0900
Subject: [PATCH] Improve library detections

Now it automatically finds files from Qt 5 and supports the upstream
ANGLE on Windows and macOS.
---
 meson.build           | 36 +++++++++++++++++++++++++++++-------
 src/dispatch_common.c |  5 +++--
 src/dispatch_common.h |  2 +-
 src/meson.build       |  2 +-
 4 files changed, 34 insertions(+), 11 deletions(-)

diff --git a/meson.build b/meson.build
index 76af8c59..c5a589b0 100644
--- a/meson.build
+++ b/meson.build
@@ -165,25 +165,47 @@ endif
 # Dependencies
 dl_dep = cc.find_library('dl', required: false)
 gl_dep = dependency('gl', required: false)
-egl_dep = dependency('egl', required: false)
-elg_headers_dep = egl_dep.partial_dependency(compile_args: true, includes: true)
 
 # Optional dependencies for tests
 x11_dep = dependency('x11', required: false)
 x11_headers_dep = x11_dep.partial_dependency(compile_args: true, includes: true)
 
-# GLES v2 and v1 may have pkg-config files, courtesy of downstream
-# packagers; let's check those first, and fall back to find_library()
-# if we fail
+# We have multiple checks for EGL and GLES v2/v1 to support different providers:
+# 1. pkg-config for Mesa
+# 2. find_library() for ANGLE, which do not support pkg-config nor CMake.
+#    Note that Microsoft's "link" requires "lib" prefix.
+# 3. CMake for Qt 5, which bundles ANGLE.
+egl_dep = dependency('egl', required: false)
+if not egl_dep.found()
+  egl_dep = cc.find_library('EGL', required: false)
+endif
+if not egl_dep.found() and host_machine == 'windows'
+  egl_dep = cc.find_library('libEGL.dll', required: false)
+endif
+if not egl_dep.found()
+  egl_dep = dependency('Qt5Gui', modules: 'Qt5::Gui_EGL', required: false)
+endif
+
 gles2_dep = dependency('glesv2', required: false)
 if not gles2_dep.found()
-  gles2_dep = cc.find_library('libGLESv2', required: false)
+  gles2_dep = cc.find_library('GLESv2', required: false)
+endif
+if not gles2_dep.found() and host_machine == 'windows'
+  gles2_dep = cc.find_library('libGLESv2.dll', required: false)
+endif
+if not gles2_dep.found()
+  egl_dep = dependency('Qt5Gui', modules: 'Qt5::Gui_GLESv2', required: false)
 endif
 
 gles1_dep = dependency('glesv1_cm', required: false)
 if not gles1_dep.found()
-  gles1_dep = cc.find_library('libGLESv1_CM', required: false)
+  gles1_dep = cc.find_library('GLESv1_CM', required: false)
 endif
+if not gles1_dep.found() and host_machine == 'windows'
+  gles1_dep = cc.find_library('libGLESv1_CM.dll', required: false)
+endif
+
+elg_headers_dep = egl_dep.partial_dependency(compile_args: true, includes: true)
 
 # On windows, the DLL has to have all of its functions
 # resolved at link time, so we have to link directly against
diff --git a/src/dispatch_common.c b/src/dispatch_common.c
index 153eb7c5..5841a7ed 100644
--- a/src/dispatch_common.c
+++ b/src/dispatch_common.c
@@ -175,9 +175,10 @@
 
 #if defined(__APPLE__)
 #define GLX_LIB "/opt/X11/lib/libGL.1.dylib"
+#define EGL_LIB "libEGL.dylib"
 #define OPENGL_LIB "/System/Library/Frameworks/OpenGL.framework/Versions/Current/OpenGL"
-#define GLES1_LIB "libGLESv1_CM.so"
-#define GLES2_LIB "libGLESv2.so"
+#define GLES1_LIB "libGLESv1_CM.dylib"
+#define GLES2_LIB "libGLESv2.dylib"
 #elif defined(__ANDROID__)
 #define GLX_LIB "libGLESv2.so"
 #define EGL_LIB "libEGL.so"
diff --git a/src/dispatch_common.h b/src/dispatch_common.h
index a1369431..55388a82 100644
--- a/src/dispatch_common.h
+++ b/src/dispatch_common.h
@@ -28,7 +28,7 @@
 #define PLATFORM_HAS_GLX ENABLE_GLX
 #define PLATFORM_HAS_WGL 1
 #elif defined(__APPLE__)
-#define PLATFORM_HAS_EGL 0 
+#define PLATFORM_HAS_EGL ENABLE_EGL
 #define PLATFORM_HAS_GLX ENABLE_GLX
 #define PLATFORM_HAS_WGL 0
 #elif defined(ANDROID)
diff --git a/src/meson.build b/src/meson.build
index da581ee9..177022a1 100644
--- a/src/meson.build
+++ b/src/meson.build
@@ -55,7 +55,7 @@ endif
 # Maintain compatibility with autotools; see: https://github.com/anholt/libepoxy/issues/108
 darwin_versions = [1, '1.0']
 
-epoxy_deps = [ dl_dep, ]
+epoxy_deps = [ dl_dep, egl_dep ]
 if host_system == 'windows'
   epoxy_deps += [ opengl32_dep, gdi32_dep ]
 endif