Add functions resembling SDL_iconv_utf8_* macros

Author: suve

units/sdl2.pas

@@ -203,6 +203,8 @@ interface
 
 implementation
 
+uses Strings;
+
 // Macros from "sdl_version.h"
 procedure SDL_VERSION(out x: TSDL_Version);
 begin
@@ -427,6 +429,24 @@ function SDL_SHAPEMODEALPHA(mode: TWindowShapeMode): Boolean;
   Result := (mode = ShapeModeDefault) or (mode = ShapeModeBinarizeAlpha) or (mode = ShapeModeReverseBinarizeAlpha);
 end;
 
+// from "sdl_stdinc.h"
+
+// Note: We're using FPC's Strings.strlen() here, not SDL_strlen().
+function SDL_iconv_utf8_locale(str: PAnsiChar): PAnsiChar; cdecl;
+begin
+  Result := SDL_iconv_string('', 'UTF-8', str, Strings.strlen(str)+1)
+end;
+
+function SDL_iconv_utf8_ucs2(str: PAnsiChar): pcUint16; cdecl;
+begin
+	Result := pcUint16(SDL_iconv_string('UCS-2-INTERNAL', 'UTF-8', str, Strings.strlen(str)+1))
+end;
+
+function SDL_iconv_utf8_ucs4(str: PAnsiChar): pcUint32; cdecl;
+begin
+	Result := pcUint32(SDL_iconv_string('UCS-4-INTERNAL', 'UTF-8', str, Strings.strlen(str)+1))
+end;
+
 //from "sdl_video.h"
 
 function SDL_WINDOWPOS_UNDEFINED_DISPLAY(X: Variant): Variant;

units/sdlstdinc.inc

@@ -114,3 +114,8 @@ procedure SDL_free(mem: Pointer); cdecl;
  *)
 function SDL_iconv_string(tocode, fromcode, inbuf: PAnsiChar; inbytesleft: csize_t): PAnsiChar; cdecl
   external SDL_LibName {$IFDEF DELPHI} {$IFDEF MACOS} name '_SDL_iconv_string' {$ENDIF} {$ENDIF};
+
+// These are macros in the original C headers, we will reimplement them as simple Pascal functions.
+function SDL_iconv_utf8_locale(str: PAnsiChar): PAnsiChar; cdecl;
+function SDL_iconv_utf8_ucs2(str: PAnsiChar): pcUint16; cdecl;
+function SDL_iconv_utf8_ucs4(str: PAnsiChar): pcUint32; cdecl;