Add SetTraceLogCallback to enable users setting custom logging (#597)

examples/core/core_custom_logging.c

@@ -0,0 +1,90 @@
+/*******************************************************************************************
+*
+*   raylib [core] example - Custom logging
+*
+*   Welcome to raylib!
+*
+*   To test examples, just press F6 and execute raylib_compile_execute script
+*   Note that compiled executable is placed in the same folder as .c file
+*
+*   You can find all basic examples on C:\raylib\raylib\examples folder or
+*   raylib official webpage: www.raylib.com
+*
+*   Enjoy using raylib. :)
+*
+*   This example has been created using raylib 2.0 (www.raylib.com)
+*   raylib is licensed under an unmodified zlib/libpng license (View raylib.h for details)
+*
+*   Copyright (c) 2018 Ramon Santamaria (@raysan5) and Pablo Marcos Oltra (@pamarcos)
+*
+********************************************************************************************/
+
+#include "raylib.h"
+
+#include <stdio.h>                  // Required for: fopen(), fclose(), fputc(), fwrite(), printf(), fprintf(), funopen()
+#include <time.h>                   // Required for: time_t, tm, time(), localtime(), strftime()
+
+void logCustom(int msgType, const char *text, va_list args)
+{
+	char timeStr[64];
+	time_t now = time(NULL);
+	struct tm *tm_info = localtime(&now);
+
+	strftime(timeStr, sizeof(timeStr), "%Y-%m-%d %H:%M:%S", tm_info);
+	printf("[%s] ", timeStr);
+
+	switch (msgType)
+	{
+		case LOG_INFO: printf("[INFO] : "); break;
+		case LOG_ERROR: printf("[ERROR]: "); break;
+		case LOG_WARNING: printf("[WARN] : "); break;
+		case LOG_DEBUG: printf("[DEBUG]: "); break;
+		default: break;
+	}
+	vprintf(text, args);
+	printf("\n");
+}
+
+int main(int argc, char* argv[])
+{
+	// Initialization
+	//--------------------------------------------------------------------------------------
+	int screenWidth = 800;
+	int screenHeight = 450;
+
+	// First thing we do is setting our custom logger to ensure everything raylib logs
+	// will use our own logger instead of its internal one
+	SetTraceLogCallback(logCustom);
+
+	InitWindow(screenWidth, screenHeight, "raylib [core] example - custom logging");
+
+	SetTargetFPS(60);
+	//--------------------------------------------------------------------------------------
+
+	// Main game loop
+	while (!WindowShouldClose())    // Detect window close button or ESC key
+	{
+		// Update
+		//----------------------------------------------------------------------------------
+		// TODO: Update your variables here
+		//----------------------------------------------------------------------------------
+
+		// Draw
+		//----------------------------------------------------------------------------------
+		BeginDrawing();
+
+		ClearBackground(RAYWHITE);
+
+		DrawText("Check out the console output to see the custom logger in action!", 60, 200, 20, LIGHTGRAY);
+
+		EndDrawing();
+		//----------------------------------------------------------------------------------
+	}
+
+	// De-Initialization
+	//--------------------------------------------------------------------------------------
+	CloseWindow();        // Close window and OpenGL context
+	//--------------------------------------------------------------------------------------
+
+	return 0;
+}