Call GLFW functions via a dynamic dispatch table.

This allows us to use GLFW without needing to introduce a link-time dependency on the library, which in turn enables us to get GLFW through Python. PiperOrigin-RevId: 470100999 Change-Id: I27c84ad3310afdbebd582ab0033b6a963ba6307e
2022-08-25 15:41:14 -07:00
parent d26501c0f3
commit 3240596c3a
7 changed files with 294 additions and 94 deletions
@@ -0,0 +1,117 @@
+// Copyright 2022 DeepMind Technologies Limited
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "glfw_dispatch.h"
+
+#ifdef mjGLFW_DYNAMIC_SYMBOLS
+  #ifdef _MSC_VER
+    #include <windows.h>
+    #include <libloaderapi.h>
+  #else
+    #include <dlfcn.h>
+  #endif
+#endif
+
+#include <cstdlib>
+#include <iostream>
+
+namespace mujoco {
+const struct Glfw& Glfw(void* dlhandle) {
+  {
+    static const void* init_dlhandle = dlhandle;
+    if (dlhandle && dlhandle != init_dlhandle) {
+      std::cerr << "dlhandle is specified when GLFW dispatch table is already "
+                   "initialized\n";
+      abort();
+    }
+  }
+
+  static const struct Glfw glfw = [&]() {
+    struct Glfw glfw;
+
+#ifdef mjGLFW_DYNAMIC_SYMBOLS
+  #ifdef _MSC_VER
+    if (!dlhandle) dlhandle = LoadLibraryA("glfw3.dll");
+    if (!dlhandle) {
+      std::cerr << "cannot obtain a shared object handle\n";
+      abort();
+    }
+    #define mjGLFW_RESOLVE_SYMBOL(func)                   \
+      glfw.func = reinterpret_cast<decltype(glfw.func)>(  \
+          GetProcAddress(reinterpret_cast<HMODULE>(dlhandle), #func))
+  #else
+    if (!dlhandle) dlhandle = dlopen("nullptr", RTLD_GLOBAL | RTLD_NOW);
+    if (!dlhandle) {
+      std::cerr << "cannot obtain a shared object handle\n";
+      abort();
+    }
+    #define mjGLFW_RESOLVE_SYMBOL(func) \
+      glfw.func = reinterpret_cast<decltype(glfw.func)>(dlsym(dlhandle, #func))
+  #endif
+#else
+  #define mjGLFW_RESOLVE_SYMBOL(func) glfw.func = &func
+#endif
+
+#define mjGLFW_INITIALIZE_SYMBOL(func)                  \
+  if (!(mjGLFW_RESOLVE_SYMBOL(func))) {                 \
+    std::cerr << "cannot dlsym " #func "\n"; \
+    abort();                                            \
+  }
+
+    // go/keep-sorted start
+    mjGLFW_INITIALIZE_SYMBOL(glfwCreateWindow);
+    mjGLFW_INITIALIZE_SYMBOL(glfwGetCursorPos);
+    mjGLFW_INITIALIZE_SYMBOL(glfwGetFramebufferSize);
+    mjGLFW_INITIALIZE_SYMBOL(glfwGetKey);
+    mjGLFW_INITIALIZE_SYMBOL(glfwGetMonitorPhysicalSize);
+    mjGLFW_INITIALIZE_SYMBOL(glfwGetMouseButton);
+    mjGLFW_INITIALIZE_SYMBOL(glfwGetPrimaryMonitor);
+    mjGLFW_INITIALIZE_SYMBOL(glfwGetTime);
+    mjGLFW_INITIALIZE_SYMBOL(glfwGetVideoMode);
+    mjGLFW_INITIALIZE_SYMBOL(glfwGetWindowMonitor);
+    mjGLFW_INITIALIZE_SYMBOL(glfwGetWindowPos);
+    mjGLFW_INITIALIZE_SYMBOL(glfwGetWindowSize);
+    mjGLFW_INITIALIZE_SYMBOL(glfwGetWindowUserPointer);
+    mjGLFW_INITIALIZE_SYMBOL(glfwInit);
+    mjGLFW_INITIALIZE_SYMBOL(glfwMakeContextCurrent);
+    mjGLFW_INITIALIZE_SYMBOL(glfwPollEvents);
+    mjGLFW_INITIALIZE_SYMBOL(glfwSetClipboardString);
+    mjGLFW_INITIALIZE_SYMBOL(glfwSetCursorPosCallback);
+    mjGLFW_INITIALIZE_SYMBOL(glfwSetDropCallback);
+    mjGLFW_INITIALIZE_SYMBOL(glfwSetKeyCallback);
+    mjGLFW_INITIALIZE_SYMBOL(glfwSetMouseButtonCallback);
+    mjGLFW_INITIALIZE_SYMBOL(glfwSetScrollCallback);
+    mjGLFW_INITIALIZE_SYMBOL(glfwSetWindowMonitor);
+    mjGLFW_INITIALIZE_SYMBOL(glfwSetWindowRefreshCallback);
+    mjGLFW_INITIALIZE_SYMBOL(glfwSetWindowSizeCallback);
+    mjGLFW_INITIALIZE_SYMBOL(glfwSetWindowTitle);
+    mjGLFW_INITIALIZE_SYMBOL(glfwSetWindowUserPointer);
+    mjGLFW_INITIALIZE_SYMBOL(glfwSwapBuffers);
+    mjGLFW_INITIALIZE_SYMBOL(glfwSwapInterval);
+    mjGLFW_INITIALIZE_SYMBOL(glfwTerminate);
+    mjGLFW_INITIALIZE_SYMBOL(glfwWindowHint);
+    mjGLFW_INITIALIZE_SYMBOL(glfwWindowShouldClose);
+    // go/keep-sorted end
+
+#undef mjGLFW_INITIALIZE_SYMBOL
+
+#if defined(mjGLFW_DYNAMIC_SYMBOLS) && !defined(_MSC_VER)
+    dlclose(dlhandle);
+#endif
+
+    return glfw;
+  }();
+  return glfw;
+}
+}  // namespace mujoco