Add support for OpenGL Example keyboard input (Windows only) by creating a Win32 Subclass proc to retrieve native keyboard messages. Who wants to do the same thing for macOS?

Author: callumlinden

CMakeLists.txt

@@ -407,11 +407,11 @@ if (BUILD_EXAMPLES)
             opengl-example
             dullahan
             opengl32
+            comctl32
             ${CEF_LIBRARY}
             ${CEF_DLL_LIBRARY}
             ${THIRD-PARTY-PREFIX}/${GLFW_FOLDER}/${GLFW_LIB_PATH}
         )
-
         SET_PROPERTY(DIRECTORY PROPERTY VS_STARTUP_PROJECT "opengl-example")
     elseif(IS_MACOS)
         find_library (OPENGL_FRAMEWORK OpenGL)
@@ -447,6 +447,10 @@ if (BUILD_EXAMPLES)
     endif()
 endif()
 
+if(CMAKE_CONFIGURATION_TYPES)
+    set(CMAKE_CONFIGURATION_TYPES "Release")
+endif()
+
 # Install the Dullahan library and host executable
 
 if( USE_SPOTIFY_CEF )

examples/opengl-example/src/opengl-example.cpp

@@ -74,13 +74,10 @@ void openglExample::resizeCallback(int width, int height)
         mDullahan->setSize(width, height);
     }
 }
+
 void openglExample::handleKeyEvent(int key, int scancode, int action, int mods)
 {
-    // Dullahan only has keyboard functions for native OS events
-    // I don't know if you can get msg, wparam, lparam etc. in GLFW
-    // Might have to forego keyboard input for the moment
-
-    // keey the ESC key to exit as well as File -> Quit since it's useful
+    // keep the ESC key to exit as well as File -> Quit since it's useful
     if (action == GLFW_PRESS)
     {
         if (key == GLFW_KEY_ESCAPE)
@@ -201,6 +198,21 @@ void openglExample::mouseScrollCallback(double xoffset, double yoffset)
 
 }
 
+#if defined(WIN32)
+// Windows subclass procedure for handling keyboard events using native
+// Windows messages and parameters which is what Dullahan requires.
+LRESULT CALLBACK openglExample::keyEventSubClassProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam, UINT_PTR uIdSubclass, DWORD_PTR dwRefData)
+{
+    if (uMsg == WM_CHAR || uMsg == WM_KEYDOWN || uMsg == WM_KEYUP)
+    {
+        openglExample* parent = (openglExample*)dwRefData;
+        parent->mDullahan->nativeKeyboardEventWin(uMsg, (uint32_t)wParam, lParam);
+    }
+
+    return DefSubclassProc(hWnd, uMsg, wParam, lParam);
+}
+#endif
+
 bool openglExample::init()
 {
     if (! glfwInit())
@@ -224,6 +236,13 @@ bool openglExample::init()
     // store this to so the static callbacks can get to an instance
     glfwSetWindowUserPointer(mWindow, this);
 
+    // Create a Windows subclass procedure for handling keyboard events using
+    // native Windows messages and parameters which is what Dullahan requires.
+    #if defined(WIN32)
+    HWND hwnd = glfwGetWin32Window(mWindow);
+    SetWindowSubclass(hwnd, keyEventSubClassProc, 0x01, (DWORD_PTR)this);
+    #endif
+
     glfwSetErrorCallback(errorCallback);
     glfwMakeContextCurrent(mWindow);
     gladLoadGL();

examples/opengl-example/src/opengl-example.h

@@ -35,12 +35,21 @@
 #include "imgui_impl_opengl2.h"
 
 #include <glad/glad.h>
+#if defined(WIN32)
+#undef APIENTRY
+#define GLFW_EXPOSE_NATIVE_WIN32
+#include <GLFW/glfw3.h>
+#include <GLFW/glfw3native.h>
+#include <commctrl.h>
+#elif
 #define GLFW_INCLUDE_NONE
 #include <GLFW/glfw3.h>
+#endif
 
 class dullahan;
 
-class openglExample {
+class openglExample
+{
     public:
         openglExample();
 
@@ -96,20 +105,29 @@ class openglExample {
         void generatePickTexture();
         bool mousePosToTexturePos(int* tx, int* ty);
 
-        // Used to marshall staticfunction callbacks to a instance of the app class
-        static void resizeCallbackStatic(GLFWwindow* window, int width, int height) {
+        // Used to marshall static function callbacks to a instance of the app class
+        static void resizeCallbackStatic(GLFWwindow* window, int width, int height)
+        {
             static_cast<openglExample*>(glfwGetWindowUserPointer(window))->resizeCallback(width, height);
         }
-        static void keyCallbackStatic(GLFWwindow* window, int key, int scancode, int action, int mods) {
+        static void keyCallbackStatic(GLFWwindow* window, int key, int scancode, int action, int mods)
+        {
             static_cast<openglExample*>(glfwGetWindowUserPointer(window))->handleKeyEvent(key, scancode, action, mods);
         }
-        static void mouseButtonCallbackStatic(GLFWwindow* window, int button, int action, int mods) {
+        static void mouseButtonCallbackStatic(GLFWwindow* window, int button, int action, int mods)
+        {
             static_cast<openglExample*>(glfwGetWindowUserPointer(window))->mouseButtonCallback(button, action, mods);
         }
-        static void mouseMoveCallbackStatic(GLFWwindow* window, double xpos, double ypos) {
+        static void mouseMoveCallbackStatic(GLFWwindow* window, double xpos, double ypos)
+        {
             static_cast<openglExample*>(glfwGetWindowUserPointer(window))->mouseMoveCallback(xpos, ypos);
         }
-        static void mouseScrollCallbackStatic(GLFWwindow* window, double xoffset, double yoffset) {
+        static void mouseScrollCallbackStatic(GLFWwindow* window, double xoffset, double yoffset)
+        {
             static_cast<openglExample*>(glfwGetWindowUserPointer(window))->mouseScrollCallback(xoffset, yoffset);
         }
+
+        #if defined(WIN32)
+        static LRESULT CALLBACK keyEventSubClassProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam, UINT_PTR uIdSubclass, DWORD_PTR dwRefData);
+        #endif
 };