FreeGlut MacOS Support

CMakeLists.txt

@@ -10,6 +10,9 @@ set(CMAKE_MSVC_RUNTIME_LIBRARY "MultiThreaded$<$<CONFIG:Debug>:Debug>")
 # Declare Project where "GSM_TEMPLATE" is the project name
 project(GSM_TEMPLATE LANGUAGES C CXX)
 
+# Use FreeGlut on Macos (Requires X11 to be installed, but doesn't use it)
+option(USE_FREEGLUT "Use FreeGLUT on Mac (ignored on Windows)" ON)
+
 # Allow cmake to fetch web repositories
 include(FetchContent)
 
@@ -41,13 +44,28 @@ FetchContent_MakeAvailable(stb_image)
 
 
 # If using the Windows compiler
-if (MSVC)
+if (MSVC OR USE_FREEGLUT)
+
+  if (APPLE)
+
+    find_path(XQUARTZ_INCLUDE_DIR X11/Xlib.h
+      PATHS /opt/X11/include
+      NO_DEFAULT_PATH
+    )
+
+    if(NOT XQUARTZ_INCLUDE_DIR)
+      message(FATAL_ERROR "To use FreeGLUT on Mac, you need XQuartz installed.  Please install it from https://www.xquartz.org/ or set the USE_FREEGLUT cache option to OFF")
+    endif()
+
+  endif()
+
+  set(CMAKE_POLICY_VERSION_MINIMUM 3.16)
 
   # Download freeglut
 	FetchContent_Declare(
 		freeglut
 		GIT_REPOSITORY https://github.com/freeglut/freeglut.git
-		GIT_TAG "master"
+    GIT_TAG "v3.8.0"
 		GIT_SHALLOW TRUE
 		GIT_PROGRESS ON
 	)
@@ -56,6 +74,11 @@ if (MSVC)
 	set(FREEGLUT_BUILD_SHARED_LIBS OFF CACHE BOOL "" FORCE)
 	set(FREEGLUT_BUILD_STATIC_LIBS ON CACHE BOOL "" FORCE)
 
+  # Force Cocca on Mac
+  if(APPLE)
+    set(FREEGLUT_USE_X11 OFF CACHE BOOL "" FORCE)
+    set(FREEGLUT_COCOA ON CACHE BOOL "" FORCE)
+  endif()
 
 	FetchContent_MakeAvailable(freeglut)
 
@@ -76,8 +99,8 @@ endif()
 # Tell Cmake to find the locations of libraries
 find_package(OpenGL REQUIRED)
 
-# Only require glut if on macos
+# Only require glut if on macos and not using freeglut
-if (APPLE)
+if (APPLE AND NOT USE_FREEGLUT)
   find_package(GLUT REQUIRED)
 endif()
 # Define MY_SOURCES to be a list of all the source files for my game 
@@ -117,6 +140,37 @@ target_sources("${CMAKE_PROJECT_NAME}" PRIVATE ${MY_SOURCES})
 # If on mac
 if (APPLE)
 
+# FreeGlut for mac
+if (USE_FREEGLUT)
+
+
+target_sources("${CMAKE_PROJECT_NAME}" PRIVATE "${glad_SOURCE_DIR}/src/glad.c")
+target_include_directories("${CMAKE_PROJECT_NAME}" PUBLIC "${glad_SOURCE_DIR}/include")
+
+# Add our include files
+target_include_directories("${CMAKE_PROJECT_NAME}" PUBLIC 
+"${CMAKE_CURRENT_SOURCE_DIR}/include/"
+"${freeglut_SOURCE_DIR}/include"
+"${glad_SOURCE_DIR}/include"
+)
+
+target_compile_definitions("${CMAKE_PROJECT_NAME}" PUBLIC use_freeglut=TRUE)
+
+target_link_libraries("${CMAKE_PROJECT_NAME}" 
+  PRIVATE 
+  OpenGL::GL
+  freeglut_static
+  "-framework Cocoa"
+  "-framework IOKit"
+  "-framework CoreVideo"
+  "-lpthread"
+  stb_image
+  miniaudio
+)
+
+# Native GLUT for Mac
+else()
+
 # Add our include files
 target_include_directories("${CMAKE_PROJECT_NAME}" PUBLIC "${CMAKE_CURRENT_SOURCE_DIR}/include/")
 
@@ -138,6 +192,7 @@ target_link_libraries("${CMAKE_PROJECT_NAME}"
   stb_image
   miniaudio
 )
+endif()
 
 
 # If on windows

src/main.cpp

@@ -48,8 +48,6 @@
 // #
 // #############################################################################
 
-
-
 // Libraries
 #if defined(use_freeglut)
 #include <glad/glad.h>
@@ -61,8 +59,8 @@
 #include <miniaudio.h>
 
 // STD
-#include <math.h>
 #include <iostream>
+#include <math.h>
 #include <stdio.h>
 
 // Custom includes
@@ -76,14 +74,12 @@
 void ProcessKeys(unsigned char, int, int);
 void ProcessSpecialKeys(int, int, int);
 void MainLoop();
-void GlutLoopTimer(int);
 
 // Extended Functionality
 void UpdateViewPort();
 void DrawSprite();
 void LoadUserTextures();
 
-
 // Miniaudio Engine Declaration
 void CreateAudioEngine();
 ma_engine engine; // Miniaudio engine
@@ -97,6 +93,25 @@ unsigned int texID;
 ma_sound musicSound; // Miniaudio sound object
 int lastWinW = 0, lastWinH = 0;
 
+bool running = true;
+void CloseCallBack()
+{
+    running = false;
+}
+
+/**
+ * Main Loop Timer
+ * Wait 16.7ms then generate next frame (~60FPS)
+ */
+void GlutLoopTimer(int v)
+{
+    // Runs the function specified in glutDisplayFunc
+    glutPostRedisplay();
+
+    // Call the timer again in 16.7 seconds ~ 60 times per second
+    glutTimerFunc(16.7, GlutLoopTimer, v); // Creates a frame delay that is counted in miliseconds
+}
+
 /**
  * Main entry point of the application
  */
@@ -115,10 +130,11 @@ int main(int argc, char **argv)
     // Setup then create the window
     glutInitWindowSize(winW, winH); // window size
     glutInitWindowPosition(0, 0);
-	glutCreateWindow("Transform Example");
+    glutCreateWindow("Transform Example - Using Native Glut");
 
 // This line only needs to run when glad is in use
 #if defined(use_freeglut)
+	glutSetWindowTitle("Transform Example - using FreeGLUT");
     if (!gladLoadGL()) { }
 #endif
 
@@ -147,33 +163,40 @@ int main(int argc, char **argv)
     // Declare Special Keys Keyboard Interrupt
     glutSpecialFunc(ProcessSpecialKeys);
 
+#ifndef use_freeglut
     // Setup a timer to run the main loop at an interval
     // (This call will call the GlutLoopTimer() function immediately)
     glutTimerFunc(0, GlutLoopTimer, 0);
+#endif
 
-	std::cout << "Started";
+    std::cout << "Started" << std::endl;
     fflush(stdout);
     // Start the Glut Loop (Calls the funtions above repeatedly)
-	glutMainLoop();
 
-	std::cout << "exited";
+#if defined(use_freeglut)
+	// FreeGlut allows for manual updating of the main loop
+	// So we can call the main loop in a while loop and tell the loop when to stop
+
+	// Tell FreeGlut to do nothing on window X press
+    glutSetOption(GLUT_ACTION_ON_WINDOW_CLOSE, GLUT_ACTION_CONTINUE_EXECUTION);
+
+	// Run callback when window X is pressed
+    glutCloseFunc(CloseCallBack);
+
+	// Our loop, calls the funtion in glutDisplayFunc repeatedly until running = false 
+    while (running)
+        glutMainLoopEvent();
+
+#else
+    // Start the Glut Loop (Calls the funtions above repeatedly)
+    glutMainLoop();
+#endif
+
+    std::cout << "exited" << std::endl;
     fflush(stdout);
     return 0;
 }
 
-/**
- * Main Loop Timer
- * Wait 16.7ms then generate next frame (~60FPS)
- */
-void GlutLoopTimer(int v)
-{
-	// Runs the function specified in glutDisplayFunc
-	glutPostRedisplay();
-
-	// Call the timer again in 16.7 seconds ~ 60 times per second
-	glutTimerFunc(16.7, GlutLoopTimer, v); // Creates a frame delay that is counted in miliseconds
-}
-
 /**
  * Function to update the viewport to the size of the window
  */
@@ -202,26 +225,22 @@ void UpdateViewPort()
  */
 void ProcessSpecialKeys(int key, int x, int y)
 {
-	if (key == GLUT_KEY_LEFT)
+    if (key == GLUT_KEY_LEFT) {
-	{
         moveX = -10;
         movePressed = true;
     }
 
-	if (key == GLUT_KEY_RIGHT)
+    if (key == GLUT_KEY_RIGHT) {
-	{
         moveX = 10;
         movePressed = true;
     }
 
-	if (key == GLUT_KEY_UP)
+    if (key == GLUT_KEY_UP) {
-	{
         moveY = 10;
         movePressed = true;
     }
 
-	if (key == GLUT_KEY_DOWN)
+    if (key == GLUT_KEY_DOWN) {
-	{
         moveY = -10;
         movePressed = true;
     }
@@ -233,8 +252,7 @@ void ProcessSpecialKeys(int key, int x, int y)
  */
 void ProcessKeys(unsigned char key, int x, int y)
 {
-	switch (key)
+    switch (key) {
-	{
     case 'q':
         rotX += 1;
         break;
@@ -274,8 +292,7 @@ void ProcessKeys(unsigned char key, int x, int y)
 void CreateAudioEngine()
 {
     ma_result result = ma_engine_init(NULL, &engine);
-	if (result != MA_SUCCESS)
+    if (result != MA_SUCCESS) {
-	{
         std::cout << "Failed to setup the miniaudio engine\n";
         fflush(stdout);
     }
@@ -287,8 +304,7 @@ void CreateAudioEngine()
         0,
         NULL,
         NULL,
-		&musicSound
+        &musicSound);
-	);
 }
 
 /**
@@ -302,8 +318,7 @@ void MainLoop()
     int winH = glutGet(GLUT_WINDOW_HEIGHT);
 
     // If Changed, update the view port
-	if (winW != lastWinW || winH != lastWinH)
+    if (winW != lastWinW || winH != lastWinH) {
-	{
         UpdateViewPort();
     }
 
@@ -313,16 +328,14 @@ void MainLoop()
     glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);
 
     // If scale oneshot is set, scale the image
-	if (scalePressed)
+    if (scalePressed) {
-	{
         glScalef(scale, scale, scale);
         scalePressed = false;
         scale = 1;
     }
 
     // If rotation oneshot is set, rotate the image
-	if (rotPressed)
+    if (rotPressed) {
-	{
         glRotatef((GLfloat)rotX, 1.0, 0.0, 0.0);
         glRotatef((GLfloat)rotY, 0.0, 1.0, 0.0);
         glRotatef((GLfloat)rotZ, 0.0, 0.0, 1.0);
@@ -330,8 +343,7 @@ void MainLoop()
         rotX = rotY = rotZ = 0;
     }
     // If move oneshot is set, move the image and set move back to 0
-	if (movePressed)
+    if (movePressed) {
-	{
         glTranslatef(moveX, moveY, 0);
         movePressed = false;
         moveX = moveY = 0;
@@ -344,6 +356,11 @@ void MainLoop()
 
     // Swap buffers to display the new frame
     glutSwapBuffers();
+
+	// With freeglut, we can trigger screen update right after we are done
+#if defined(use_freeglut)
+    glutPostRedisplay();
+#endif
 }
 
 /**
@@ -364,7 +381,6 @@ void DrawSprite()
     glBegin(GL_POLYGON);
     {
 
-
         glTexCoord2f(0.0, 0.0);
         glVertex3f(-50, -50, 0);
         glTexCoord2f(1.0, 0.0);