Test out an optional render callback

examples/core/core_basic_window.c

@@ -28,6 +28,18 @@
 
 #include "raylib.h"
 
+bool RunFrame(void)
+{
+    if (WindowShouldClose())
+        return false;
+
+    ClearBackground(RAYWHITE);
+
+    DrawText("Congrats! You created your first window!", 190, 200, 20, LIGHTGRAY);
+
+    return true;
+}
+
 //------------------------------------------------------------------------------------
 // Program main entry point
 //------------------------------------------------------------------------------------
@@ -44,24 +56,7 @@ int main(void)
     //--------------------------------------------------------------------------------------
 
     // Main game loop
-    while (!WindowShouldClose())    // Detect window close button or ESC key
-    {
-        // Update
-        //----------------------------------------------------------------------------------
-        // TODO: Update your variables here
-        //----------------------------------------------------------------------------------
-
-        // Draw
-        //----------------------------------------------------------------------------------
-        BeginDrawing();
-
-            ClearBackground(RAYWHITE);
-
-            DrawText("Congrats! You created your first window!", 190, 200, 20, LIGHTGRAY);
-
-        EndDrawing();
-        //----------------------------------------------------------------------------------
-    }
+    RunGameLoop(RunFrame);
 
     // De-Initialization
     //--------------------------------------------------------------------------------------

src/platforms/rcore_desktop_glfw.c

@@ -1432,6 +1432,33 @@ static void DeallocateWrapper(void *block, void *user)
     RL_FREE(block);
 }
 
+void WindowRefreshCallback(GLFWwindow* window)
+{
+    if (window != platform.handle || CORE.Window.updateCallback == NULL)
+    {
+        return;
+    }
+    
+    CORE.Window.updateCallback();
+
+    rlDrawRenderBatchActive();
+    SwapScreenBuffer();
+    CORE.Time.current = GetTime();
+    CORE.Time.draw = CORE.Time.current - CORE.Time.previous;
+    CORE.Time.previous = CORE.Time.current;
+
+    SwapScreenBuffer();                  // Copy back buffer to front buffer (screen)
+
+    // Frame time control system
+    CORE.Time.current = GetTime();
+    CORE.Time.draw = CORE.Time.current - CORE.Time.previous;
+    CORE.Time.previous = CORE.Time.current;
+
+    CORE.Time.frame = CORE.Time.update + CORE.Time.draw;
+
+    CORE.Time.frameCounter++;
+}
+
 // Initialize platform: graphics, inputs and more
 int InitPlatform(void)
 {
@@ -1808,6 +1835,7 @@ int InitPlatform(void)
     glfwSetWindowIconifyCallback(platform.handle, WindowIconifyCallback);
     glfwSetWindowFocusCallback(platform.handle, WindowFocusCallback);
     glfwSetDropCallback(platform.handle, WindowDropCallback);
+    glfwSetWindowRefreshCallback(platform.handle, WindowRefreshCallback);
     if (FLAG_IS_SET(CORE.Window.flags, FLAG_WINDOW_HIGHDPI)) glfwSetWindowContentScaleCallback(platform.handle, WindowContentScaleCallback);
 
     // Set input callback events

src/raylib.h

@@ -987,6 +987,7 @@ extern "C" {            // Prevents name mangling of functions
 // Window-related functions
 RLAPI void InitWindow(int width, int height, const char *title);  // Initialize window and OpenGL context
 RLAPI void CloseWindow(void);                                     // Close window and unload OpenGL context
+RLAPI void RunGameLoop(bool(*processFrame)(void));                // (Optional), Run an automatic game loop using the defined callback, calls Begin/EndDrawing for you.
 RLAPI bool WindowShouldClose(void);                               // Check if application should close (KEY_ESCAPE pressed or windows close icon clicked)
 RLAPI bool IsWindowReady(void);                                   // Check if window has been initialized successfully
 RLAPI bool IsWindowFullscreen(void);                              // Check if window is currently fullscreen

src/rcore.c

@@ -318,6 +318,8 @@ typedef struct CoreData {
         char **dropFilepaths;               // Store dropped files paths pointers (provided by GLFW)
         unsigned int dropFileCount;         // Count dropped files strings
 
+        bool(*updateCallback)(void);        // Optional user defined callback to draw a frame
+
     } Window;
     struct {
         const char *basePath;               // Base path for data storage
@@ -737,6 +739,39 @@ void CloseWindow(void)
     TRACELOG(LOG_INFO, "Window closed successfully");
 }
 
+static bool RunLoop = false;
+
+void ProcessSingleFrame(void)
+{
+    BeginDrawing();
+    RunLoop = CORE.Window.updateCallback();
+    EndDrawing();
+
+#if defined(SUPPORT_CUSTOM_FRAME_CONTROL)
+    SwapBuffers();
+    PollInputEvents();
+#endif
+}
+
+#if defined(PLATFORM_WEB)
+#include <emscripten.h>
+#endif
+
+void RunGameLoop(bool(*processFrame)(void))
+{    
+    RunLoop = true;
+    CORE.Window.updateCallback = processFrame;
+
+#if defined(PLATFORM_WEB)
+    emscripten_set_main_loop(ProcessSingleFrame, 0, 1);
+#else
+    while (RunLoop)
+    {
+        ProcessSingleFrame();
+    }
+#endif
+}
+
 // Check if window has been initialized successfully
 bool IsWindowReady(void)
 {