Added SDL_RWprintf() and SDL_RWvprintf() to do formatted printing to an SDL_rwops stream

Fixes https://github.com/libsdl-org/SDL/issues/2390

src/dynapi/SDL_dynapi.c

@@ -144,6 +144,16 @@ static void SDL_InitDynamicAPI(void);
         va_end(ap);                                                                                                                       \
         return retval;                                                                                                                    \
     }                                                                                                                                     \
+    _static size_t SDLCALL SDL_RWprintf##name(SDL_RWops *context, SDL_PRINTF_FORMAT_STRING const char *fmt, ...)                          \
+    {                                                                                                                                     \
+        size_t retval;                                                                                                                    \
+        va_list ap;                                                                                                                       \
+        initcall;                                                                                                                         \
+        va_start(ap, fmt);                                                                                                                \
+        retval = jump_table.SDL_RWvprintf(context, fmt, ap);                                                                              \
+        va_end(ap);                                                                                                                       \
+        return retval;                                                                                                                    \
+    }                                                                                                                                     \
     _static void SDLCALL SDL_Log##name(SDL_PRINTF_FORMAT_STRING const char *fmt, ...)                                                     \
     {                                                                                                                                     \
         va_list ap;                                                                                                                       \
@@ -285,6 +295,16 @@ static int SDLCALL SDL_swprintf_LOGSDLCALLS(SDL_OUT_Z_CAP(maxlen) wchar_t *buf,
     va_end(ap);
     return retval;
 }
+_static size_t SDLCALL SDL_RWprintf_LOGSDLCALLS(SDL_RWops *context, SDL_PRINTF_FORMAT_STRING const char *fmt, ...)
+{
+    size_t retval;
+    va_list ap;
+    SDL_Log_REAL("SDL3CALL SDL_RWprintf");
+    va_start(ap, fmt);
+    retval = SDL_RWvprintf_REAL(context, fmt, ap);
+    va_end(ap);
+    return retval;
+}
 static void SDLCALL SDL_Log_LOGSDLCALLS(SDL_PRINTF_FORMAT_STRING const char *fmt, ...)
 {
     va_list ap;

src/dynapi/SDL_dynapi.sym

@@ -922,6 +922,8 @@ SDL3_0.0.0 {
     SDL_ClearProperty;
     SDL_EnterAppMainCallbacks;
     SDL_CleanupEvent;
+    SDL_RWprintf;
+    SDL_RWvprintf;
     # extra symbols go here (don't modify this line)
   local: *;
 };

src/dynapi/SDL_dynapi_overrides.h

@@ -947,3 +947,5 @@
 #define SDL_ClearProperty SDL_ClearProperty_REAL
 #define SDL_EnterAppMainCallbacks SDL_EnterAppMainCallbacks_REAL
 #define SDL_CleanupEvent SDL_CleanupEvent_REAL
+#define SDL_RWprintf SDL_RWprintf_REAL
+#define SDL_RWvprintf SDL_RWvprintf_REAL

src/dynapi/SDL_dynapi_procs.h

@@ -43,6 +43,7 @@ SDL_DYNAPI_PROC(int,SDL_asprintf,(char **a, SDL_PRINTF_FORMAT_STRING const char
 SDL_DYNAPI_PROC(int,SDL_snprintf,(SDL_OUT_Z_CAP(b) char *a, size_t b, SDL_PRINTF_FORMAT_STRING const char *c, ...),(a,b,c),return)
 SDL_DYNAPI_PROC(int,SDL_swprintf,(SDL_OUT_Z_CAP(b) wchar_t *a, size_t b, SDL_PRINTF_FORMAT_STRING const wchar_t *c, ...),(a,b,c),return)
 SDL_DYNAPI_PROC(int,SDL_sscanf,(const char *a, SDL_SCANF_FORMAT_STRING const char *b, ...),(a,b),return)
+SDL_DYNAPI_PROC(size_t,SDL_RWprintf,(SDL_RWops *a, SDL_PRINTF_FORMAT_STRING const char *b, ...),(a,b),return)
 #endif
 
 #ifdef SDL_CreateThread
@@ -979,3 +980,4 @@ SDL_DYNAPI_PROC(SDL_PropertiesID,SDL_GetWindowProperties,(SDL_Window *a),(a),ret
 SDL_DYNAPI_PROC(int,SDL_ClearProperty,(SDL_PropertiesID a, const char *b),(a,b),return)
 SDL_DYNAPI_PROC(int,SDL_EnterAppMainCallbacks,(int a, char *b[], SDL_AppInit_func c, SDL_AppIterate_func d, SDL_AppEvent_func e, SDL_AppQuit_func f),(a,b,c,d,e,f),return)
 SDL_DYNAPI_PROC(void,SDL_CleanupEvent,(SDL_Event *a),(a),)
+SDL_DYNAPI_PROC(size_t,SDL_RWvprintf,(SDL_RWops *a, const char *b, va_list c),(a,b,c),return)

src/file/SDL_rwops.c

@@ -808,6 +808,35 @@ size_t SDL_RWwrite(SDL_RWops *context, const void *ptr, size_t size)
     return bytes;
 }
 
+size_t SDL_RWprintf(SDL_RWops *context, SDL_PRINTF_FORMAT_STRING const char *fmt, ...)
+{
+    va_list ap;
+    int size;
+    char *string = NULL;
+    size_t bytes;
+
+    va_start(ap, fmt);
+    size = SDL_vasprintf(&string, fmt, ap);
+    va_end(ap);
+
+    bytes = SDL_RWwrite(context, string, size);
+    SDL_free(string);
+    return bytes;
+}
+
+size_t SDL_RWvprintf(SDL_RWops *context, const char *fmt, va_list ap)
+{
+    int size;
+    char *string = NULL;
+    size_t bytes;
+
+    size = SDL_vasprintf(&string, fmt, ap);
+
+    bytes = SDL_RWwrite(context, string, size);
+    SDL_free(string);
+    return bytes;
+}
+
 int SDL_RWclose(SDL_RWops *context)
 {
     if (!context) {