Merge branch 'master' into sdl2.0

src/debug.h

@@ -1,4 +1,49 @@
 #define DEBUG
+#define VERBOSE
+
+/*
+* Enable verbose logging if requested on platforms that support it.
+*
+* Verbose logging adds metadata to printf, including the source file location
+* from where printf was called and the time it was called at runtime.
+*/
+#if defined(DEBUG) && defined(VERBOSE) && defined(__GNUC__)
+#include <stdio.h>
+#include <time.h>
+
+#define printf(args...) do { \
+    time_t now = time(NULL); \
+    printf("\n### %s, line %d in %s() @ %s", __FILE__, __LINE__, __FUNCTION__, ctime(&now)); \
+    printf(args); \
+} while(0)
+#endif
+
+
+/*
+* Define a convenience macro DEBUG_PRINTF().  This macro resolves to printf()
+* if and only if DEBUG is enabled, otherwise resolves to nothing.  In other
+* words,
+*
+*   DEBUG_PRINTF("Hello, world!\n");
+*
+* ... is equivalent to:
+*
+*   #if defined(DEBUG)
+*   printf("Hello, world!\n");
+*   #endif
+*
+* (To be precise, the semicolon falls outside of the #if test, but an empty
+* semicolon resolves to nothing in standard C.)
+*
+* If VERBOSE logging is enabled, DEBUG_PRINTF should resolve to the verbose
+* version of printf() defined earlier in this file.
+*/
+#if defined(DEBUG)
+#define DEBUG_PRINTF(...) printf(__VA_ARGS__)
+#else
+#define DEBUG_PRINTF(...)
+#endif
+
 
 #ifdef __ANDROID__
 #include <android/log.h>