added glad generator and a glad runtime

tools/glad-0.1.14a0/glad/lang/d/loader/__init__.py

@@ -0,0 +1,90 @@
+
+LOAD_OPENGL_DLL = '''
+version(Windows) {
+    private import core.sys.windows.windows;
+} else {
+    private import core.sys.posix.dlfcn;
+}
+
+version(Windows) {
+    private __gshared HMODULE libGL;
+} else {
+    private __gshared void* libGL;
+}
+extern(System) private @nogc alias gladGetProcAddressPtrType = void* function(const(char)*);
+private __gshared gladGetProcAddressPtrType gladGetProcAddressPtr;
+
+%(pre)s
+bool %(init)s() @nogc {
+    version(Windows) {
+        libGL = LoadLibraryA("opengl32.dll");
+        if(libGL !is null) {
+            gladGetProcAddressPtr = cast(typeof(gladGetProcAddressPtr))GetProcAddress(
+                libGL, "wglGetProcAddress");
+            return gladGetProcAddressPtr !is null;
+        }
+
+        return false;
+    } else {
+        version(OSX) {
+            enum const(char)*[] NAMES = [
+                "../Frameworks/OpenGL.framework/OpenGL",
+                "/Library/Frameworks/OpenGL.framework/OpenGL",
+                "/System/Library/Frameworks/OpenGL.framework/OpenGL",
+                "/System/Library/Frameworks/OpenGL.framework/Versions/Current/OpenGL"
+            ];
+        } else {
+            enum const(char)*[] NAMES = ["libGL.so.1", "libGL.so"];
+        }
+
+        foreach(name; NAMES) {
+            libGL = dlopen(name, RTLD_NOW | RTLD_GLOBAL);
+            if(libGL !is null) {
+                version(OSX) {
+                    return true;
+                } else {
+                    gladGetProcAddressPtr = cast(typeof(gladGetProcAddressPtr))dlsym(libGL,
+                        "glXGetProcAddressARB");
+                    return gladGetProcAddressPtr !is null;
+                }
+            }
+        }
+
+        return false;
+    }
+}
+
+%(pre)s
+void* %(proc)s(const(char)* namez) @nogc {
+    if(libGL is null) return null;
+    void* result;
+
+    if(gladGetProcAddressPtr !is null) {
+        result = gladGetProcAddressPtr(namez);
+    }
+    if(result is null) {
+        version(Windows) {
+            result = GetProcAddress(libGL, namez);
+        } else {
+            result = dlsym(libGL, namez);
+        }
+    }
+
+    return result;
+}
+
+%(pre)s
+void %(terminate)s() @nogc {
+    version(Windows) {
+        if(libGL !is null) {
+            FreeLibrary(libGL);
+            libGL = null;
+        }
+    } else {
+        if(libGL !is null) {
+            dlclose(libGL);
+            libGL = null;
+        }
+    }
+}
+'''