From 9e961569128cdc7f84ae9c30cda5375f580e50db Mon Sep 17 00:00:00 2001
From: Geoffrey McRae <geoff@hostfission.com>
Date: Mon, 25 Jan 2021 16:04:33 +1100
Subject: [PATCH] [client] egl: use eglGetPlatformDisplay(EXT) if possible

---
 client/renderers/EGL/dynprocs.c |  4 +++
 client/renderers/EGL/dynprocs.h |  7 ++++-
 client/renderers/EGL/egl.c      | 54 +++++++++++++++++----------------
 3 files changed, 38 insertions(+), 27 deletions(-)

diff --git a/client/renderers/EGL/dynprocs.c b/client/renderers/EGL/dynprocs.c
index 65727d22..44079f4b 100644
--- a/client/renderers/EGL/dynprocs.c
+++ b/client/renderers/EGL/dynprocs.c
@@ -23,6 +23,10 @@ struct EGLDynProcs g_dynprocs = {0};
 
 void egl_dynProcsInit(void)
 {
+  g_dynprocs.eglGetPlatformDisplay = (eglGetPlatformDisplayEXT_t)
+    eglGetProcAddress("eglGetPlatformDisplay");
+  g_dynprocs.eglGetPlatformDisplayEXT = (eglGetPlatformDisplayEXT_t)
+    eglGetProcAddress("eglGetPlatformDisplayEXT");
   g_dynprocs.glEGLImageTargetTexture2DOES = (glEGLImageTargetTexture2DOES_t)
     eglGetProcAddress("glEGLImageTargetTexture2DOES");
 };
diff --git a/client/renderers/EGL/dynprocs.h b/client/renderers/EGL/dynprocs.h
index eaefb163..73b1aa83 100644
--- a/client/renderers/EGL/dynprocs.h
+++ b/client/renderers/EGL/dynprocs.h
@@ -20,10 +20,15 @@ Place, Suite 330, Boston, MA 02111-1307 USA
 #include <SDL2/SDL_egl.h>
 #include <GL/gl.h>
 
-typedef void (*glEGLImageTargetTexture2DOES_t)(GLenum target, GLeglImageOES image);
+typedef EGLDisplay (*eglGetPlatformDisplayEXT_t)(EGLenum platform,
+    void *native_display, const EGLint *attrib_list);
+typedef void (*glEGLImageTargetTexture2DOES_t)(GLenum target,
+    GLeglImageOES image);
 
 struct EGLDynProcs
 {
+  eglGetPlatformDisplayEXT_t     eglGetPlatformDisplay;
+  eglGetPlatformDisplayEXT_t     eglGetPlatformDisplayEXT;
   glEGLImageTargetTexture2DOES_t glEGLImageTargetTexture2DOES;
 };
 
diff --git a/client/renderers/EGL/egl.c b/client/renderers/EGL/egl.c
index 4ba93eac..f2d24896 100644
--- a/client/renderers/EGL/egl.c
+++ b/client/renderers/EGL/egl.c
@@ -506,43 +506,28 @@ bool egl_render_startup(void * opaque, SDL_Window * window)
     return false;
   }
 
-  bool useNative = false;
-  {
-    const char *client_exts = eglQueryString(NULL, EGL_EXTENSIONS);
-    if (strstr(client_exts, "EGL_KHR_platform_base") != NULL)
-      useNative = true;
-  }
+  egl_dynProcsInit();
 
-  DEBUG_INFO("use native: %s", useNative ? "true" : "false");
+  EGLNativeDisplayType native;
+  EGLenum platform;
 
   switch(wminfo.subsystem)
   {
     case SDL_SYSWM_X11:
-    {
-      if (!useNative)
-        this->display = eglGetPlatformDisplay(EGL_PLATFORM_X11_KHR, wminfo.info.x11.display, NULL);
-      else
-      {
-        EGLNativeDisplayType native = (EGLNativeDisplayType)wminfo.info.x11.display;
-        this->display = eglGetDisplay(native);
-      }
+      native           = (EGLNativeDisplayType)wminfo.info.x11.display;
+      platform         = EGL_PLATFORM_X11_KHR;
       this->nativeWind = (EGLNativeWindowType)wminfo.info.x11.window;
       break;
-    }
 
 #if defined(SDL_VIDEO_DRIVER_WAYLAND)
     case SDL_SYSWM_WAYLAND:
     {
       int width, height;
       SDL_GetWindowSize(window, &width, &height);
-      if (!useNative)
-        this->display = eglGetPlatformDisplay(EGL_PLATFORM_WAYLAND_KHR, wminfo.info.wl.display, NULL);
-      else
-      {
-        EGLNativeDisplayType native = (EGLNativeDisplayType)wminfo.info.wl.display;
-        this->display = eglGetDisplay(native);
-      }
-      this->nativeWind = (EGLNativeWindowType)wl_egl_window_create(wminfo.info.wl.surface, width, height);
+      native           = (EGLNativeDisplayType)wminfo.info.wl.display;
+      platform         = EGL_PLATFORM_WAYLAND_KHR;
+      this->nativeWind = (EGLNativeWindowType)wl_egl_window_create(
+          wminfo.info.wl.surface, width, height);
       break;
     }
 #endif
@@ -552,6 +537,25 @@ bool egl_render_startup(void * opaque, SDL_Window * window)
       return false;
   }
 
+  const char *early_exts = eglQueryString(NULL, EGL_EXTENSIONS);
+  if (strstr(early_exts, "EGL_KHR_platform_base") != NULL &&
+      g_dynprocs.eglGetPlatformDisplay)
+  {
+    DEBUG_INFO("Using eglGetPlatformDisplay");
+    this->display = g_dynprocs.eglGetPlatformDisplay(platform, native, NULL);
+  }
+  else if (strstr(early_exts, "EGL_EXT_platform_base") != NULL &&
+      g_dynprocs.eglGetPlatformDisplayEXT)
+  {
+    DEBUG_INFO("Using eglGetPlatformDisplayEXT");
+    this->display = g_dynprocs.eglGetPlatformDisplayEXT(platform, native, NULL);
+  }
+  else
+  {
+    DEBUG_INFO("Using eglGetDisplay");
+    this->display = eglGetDisplay(native);
+  }
+
   if (this->display == EGL_NO_DISPLAY)
   {
     DEBUG_ERROR("eglGetDisplay failed");
@@ -640,8 +644,6 @@ bool egl_render_startup(void * opaque, SDL_Window * window)
   const char *client_exts = eglQueryString(this->display, EGL_EXTENSIONS);
   const char *vendor      = (const char *)glGetString(GL_VENDOR);
 
-  egl_dynProcsInit();
-
   DEBUG_INFO("EGL       : %d.%d", maj, min);
   DEBUG_INFO("Vendor    : %s", vendor);
   DEBUG_INFO("Renderer  : %s", glGetString(GL_RENDERER));