Merge pull request #299 from Wallbraker/linux-openxr

Linux OpenXR support

CMakeLists.txt

@@ -25,6 +25,7 @@ option(LOVR_USE_OCULUS "Enable the LibOVR backend for the headset module (be sur
 option(LOVR_USE_VRAPI "Enable the VrApi backend for the headset module" OFF)
 option(LOVR_USE_PICO "Enable the Pico backend for the headset module" OFF)
 option(LOVR_USE_DESKTOP_HEADSET "Enable the keyboard/mouse backend for the headset module" ON)
+option(LOVR_USE_LINUX_EGL "Use the EGL graphics extension on Linux" OFF)
 
 option(LOVR_SYSTEM_ENET "Use the system-provided enet" OFF)
 option(LOVR_SYSTEM_GLFW "Use the system-provided glfw" OFF)
@@ -691,6 +692,12 @@ elseif(ANDROID)
     )
   endif()
 elseif(UNIX)
-  target_sources(lovr PRIVATE src/core/os_linux.c)
+  if(LOVR_USE_LINUX_EGL)
+    target_sources(lovr PRIVATE src/core/os_linux.c)
+    target_compile_definitions(lovr PRIVATE -DLOVR_LINUX_EGL)
+  else()
+    target_sources(lovr PRIVATE src/core/os_linux.c)
+    target_compile_definitions(lovr PRIVATE -DLOVR_LINUX_X11)
+  endif()
   target_compile_definitions(lovr PRIVATE -DLOVR_GL)
 endif()

src/api/l_math.c

@@ -110,6 +110,13 @@ static int l_lovrMathNewCurve(lua_State* L) {
       i += 3 + components;
       lua_pop(L, 3);
     }
+  } else if (top == 1 && lua_type(L, 1) == LUA_TNUMBER) {
+    float point[4] = { 0 };
+    int count = lua_tonumber(L, 1);
+    lovrAssert(count > 0, "Number of curve points must be positive");
+    for (int i = 0; i < count; i++) {
+      lovrCurveAddPoint(curve, point, i);
+    }
   } else {
     int pointIndex = 0;
     for (int i = 1; i <= top;) {

src/core/os_glfw.h

@@ -2,12 +2,26 @@
 
 #define GLFW_INCLUDE_NONE
 #include <GLFW/glfw3.h>
+
 #ifndef EMSCRIPTEN
-#ifdef _WIN32
-#define GLFW_EXPOSE_NATIVE_WIN32
-#define GLFW_EXPOSE_NATIVE_WGL
-#endif
-#include <GLFW/glfw3native.h>
+#  ifdef _WIN32
+#    define GLFW_EXPOSE_NATIVE_WIN32
+#    define GLFW_EXPOSE_NATIVE_WGL
+#  endif
+#  ifdef _WIN32
+#    define GLFW_EXPOSE_NATIVE_WIN32
+#    define GLFW_EXPOSE_NATIVE_WGL
+#  endif
+#  ifdef LOVR_LINUX_EGL
+#    define EGL_NO_X11
+#    include <EGL/egl.h>
+#    define GLFW_EXPOSE_NATIVE_EGL
+#  endif
+#  ifdef LOVR_LINUX_X11
+#    define GLFW_EXPOSE_NATIVE_X11
+#    define GLFW_EXPOSE_NATIVE_GLX
+#  endif
+#  include <GLFW/glfw3native.h>
 #endif
 
 static struct {
@@ -204,12 +218,18 @@ bool lovrPlatformCreateWindow(const WindowFlags* flags) {
     return false;
   }
 
+
+#ifdef LOVR_LINUX_EGL
+  glfwWindowHint(GLFW_CONTEXT_CREATION_API, GLFW_EGL_CONTEXT_API);
+#endif
   glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
   glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
   glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
   glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GLFW_TRUE);
   glfwWindowHint(GLFW_OPENGL_DEBUG_CONTEXT, flags->debug);
+#ifndef LOVR_LINUX_EGL
   glfwWindowHint(GLFW_CONTEXT_NO_ERROR, !flags->debug);
+#endif
   glfwWindowHint(GLFW_SAMPLES, flags->msaa);
   glfwWindowHint(GLFW_RESIZABLE, flags->resizable);
   glfwWindowHint(GLFW_SRGB_CAPABLE, GLFW_TRUE);
@@ -345,3 +365,56 @@ HGLRC lovrPlatformGetContext() {
   return glfwGetWGLContext(glfwState.window);
 }
 #endif
+
+#ifdef LOVR_LINUX_EGL
+PFNEGLGETPROCADDRESSPROC lovrPlatformGetEGLProcAddr(void)
+{
+  return (PFNEGLGETPROCADDRESSPROC)glfwGetProcAddress;
+}
+
+EGLDisplay lovrPlatformGetEGLDisplay(void)
+{
+  return glfwGetEGLDisplay();
+}
+
+EGLContext lovrPlatformGetEGLContext(void)
+{
+  return glfwGetEGLContext(glfwState.window);
+}
+
+EGLConfig lovrPlatformGetEGLConfig(void)
+{
+  EGLDisplay dpy = lovrPlatformGetEGLDisplay();
+  EGLContext ctx = lovrPlatformGetEGLContext();
+  EGLint cfg_id = -1;
+  EGLint num_cfgs = -1;
+  EGLConfig cfg = NULL;
+  PFNEGLQUERYCONTEXTPROC eglQueryContext = (PFNEGLQUERYCONTEXTPROC)glfwGetProcAddress("eglQueryContext");
+  PFNEGLCHOOSECONFIGPROC eglChooseConfig = (PFNEGLCHOOSECONFIGPROC)glfwGetProcAddress("eglChooseConfig");
+
+  eglQueryContext(dpy, ctx, EGL_CONFIG_ID, &cfg_id);
+  EGLint attrs [4] = {
+    EGL_CONFIG_ID, cfg_id,
+    EGL_NONE, EGL_NONE,
+  };
+  eglChooseConfig(dpy, attrs, &cfg, 1, &num_cfgs);
+  return cfg;
+}
+#endif
+
+#ifdef LOVR_LINUX_X11
+Display* lovrPlatformGetX11Display(void)
+{
+  return glfwGetX11Display();
+}
+
+GLXDrawable lovrPlatformGetGLXDrawable(void)
+{
+  return glfwGetGLXWindow(glfwState.window);
+}
+
+GLXContext lovrPlatformGetGLXContext(void)
+{
+  return glfwGetGLXContext(glfwState.window);
+}
+#endif

src/modules/headset/headset_openxr.c

@@ -24,6 +24,19 @@
   #define XR_USE_GRAPHICS_API_OPENGL_ES
   #define GRAPHICS_EXTENSION "XR_KHR_opengl_es_enable"
 #endif
+#if defined(LOVR_LINUX_X11)
+  #define XR_USE_PLATFORM_XLIB
+  typedef unsigned long XID;
+  typedef struct Display Display;
+  typedef XID GLXFBConfig;
+  typedef XID GLXDrawable;
+  typedef XID GLXContext;
+#endif
+#if defined(LOVR_LINUX_EGL)
+  #define XR_USE_PLATFORM_EGL
+  #define EGL_NO_X11
+  #include <EGL/egl.h>
+#endif
 #define XR_NO_PROTOTYPES
 #include <openxr/openxr.h>
 #include <openxr/openxr_platform.h>
@@ -46,6 +59,15 @@ struct ANativeActivity* lovrPlatformGetActivity(void);
 EGLDisplay lovrPlatformGetEGLDisplay(void);
 EGLContext lovrPlatformGetEGLContext(void);
 EGLConfig lovrPlatformGetEGLConfig(void);
+#elif defined(LOVR_LINUX_X11)
+Display* lovrPlatformGetX11Display(void);
+GLXDrawable lovrPlatformGetGLXDrawable(void);
+GLXContext lovrPlatformGetGLXContext(void);
+#elif defined(LOVR_LINUX_EGL)
+PFNEGLGETPROCADDRESSPROC lovrPlatformGetEGLProcAddr(void);
+EGLDisplay lovrPlatformGetEGLDisplay(void);
+EGLContext lovrPlatformGetEGLContext(void);
+EGLConfig lovrPlatformGetEGLConfig(void);
 #endif
 
 #define XR_FOREACH(X)\
@@ -183,6 +205,10 @@ static bool openxr_init(float supersample, float offset, uint32_t msaa) {
     enabledExtensionNames[enabledExtensionCount++] = XR_KHR_ANDROID_CREATE_INSTANCE_EXTENSION_NAME;
 #endif
 
+#ifdef LOVR_LINUX_EGL
+    enabledExtensionNames[enabledExtensionCount++] = "XR_MNDX_egl_enable";
+#endif
+
     enabledExtensionNames[enabledExtensionCount++] = GRAPHICS_EXTENSION;
 
     if (hasExtension(extensions, extensionCount, XR_EXT_HAND_TRACKING_EXTENSION_NAME)) {
@@ -326,6 +352,25 @@ static bool openxr_init(float supersample, float offset, uint32_t msaa) {
       .config = lovrPlatformGetEGLConfig(),
       .context = lovrPlatformGetEGLContext()
     };
+#elif defined(LOVR_LINUX_X11)
+    XrGraphicsBindingOpenGLXlibKHR graphicsBinding = {
+      .type = XR_TYPE_GRAPHICS_BINDING_OPENGL_XLIB_KHR,
+      .next = NULL,
+      .xDisplay = lovrPlatformGetX11Display(),
+      .visualid = 0,
+      .glxFBConfig = 0,
+      .glxDrawable = lovrPlatformGetGLXDrawable(),
+      .glxContext = lovrPlatformGetGLXContext(),
+    };
+#elif defined(LOVR_LINUX_EGL)
+    XrGraphicsBindingEGLMNDX graphicsBinding = {
+      .type = XR_TYPE_GRAPHICS_BINDING_EGL_MNDX,
+      .next = NULL,
+      .getProcAddress = lovrPlatformGetEGLProcAddr(),
+      .display = lovrPlatformGetEGLDisplay(),
+      .config = lovrPlatformGetEGLConfig(),
+      .context = lovrPlatformGetEGLContext(),
+    };
 #else
 #error "Unsupported OpenXR platform/graphics combination"
 #endif