Merge pull request #29 from Free-Pascal-meets-SDL-Website/usectypes

Use ctypes unit for c-type definitions if FPC is used for compilation

Compare issue #26 for discussion and details about this PR.

Main features:

- map all variables/parameters/return values consistently against native C types by using ctypes unit (FPC) or our new ctypes.inc (Delphi + others)
- use one naming style (style from ctypes unit) throughout the whole project (cint instead of a mixture of Integer/Int/SInt32/UInt32/...)
- prevent access violations or unpredictable behaviour by using/expecting accidently wrong memory size of data types (see e.g. C's int on different platforms)
- makes the code much more comprehensible and tracking of memory related bugs much easier

Necessity:

As a Pascal developer you need to know the exact C variable type of every parameter of the parameter list of a function, instead of what we believe the C function is asking for. E.g. prior to this update C's int was often translated to SInt32, which will work well most often, but as a Pascal developer it is hidden to you, that the platform dependent int is actually expected. This may raise bugs when developing for a system where int does not correspond to SInt32.

Author: Free-Pascal-meets-SDL-Website

units/ctypes.inc

@@ -0,0 +1,97 @@
+// C data types
+
+{
+  Simple DirectMedia Layer
+  Copyright (C) 1997-2013 Sam Lantinga <[email protected]>
+
+  Pascal-Header-Conversion
+  Copyright (C) 2012-2020 Tim Blume aka End/EV1313
+
+  SDL2-for-Pascal
+  Copyright (C) 2020-2021 PGD Community
+
+  This file is part of the project above. It has solely the purpose
+  to map common C data types correctly by Pascal compilers.
+
+  FPC: Most C data types are found in the native ctypes unit.
+  Delphi + others: Relies on this file for C data type mapping.
+
+  These native C types should be strictly separated from
+  types defined by SDL which can be found in sdlstdinc.inc.
+}
+
+{$IFNDEF FPC}
+type
+  DWord = LongWord;
+
+  pcint = ^cint;
+  cint = Integer;
+  {$EXTERNALSYM cint}
+
+  pcint8 = ^cint8;
+  cint8 = ShortInt;
+  {$EXTERNALSYM cint8}
+
+  pcuint8 = ^cuint8;
+  cuint8 = Byte;
+  {$EXTERNALSYM cuint8}
+
+  pcint16 = ^cint16;
+  cint16 = SmallInt;
+  {$EXTERNALSYM cint16}
+
+  pcuint16 = ^cuint16;
+  cuint16 = Word;
+  {$EXTERNALSYM cuint16}
+
+  pcint32 = ^cint32;
+  cint32 = LongInt;
+  {$EXTERNALSYM cint32}
+
+  pcuint32 = ^cuint32;
+  cuint32 = LongWord;
+  {$EXTERNALSYM cuint32}
+
+  {$IFNDEF Has_Int64}
+     pcint64 = ^cint64;
+     cint64 = record
+       hi: cuint32;
+       lo: cuint32;
+     end;
+    {$EXTERNALSYM cint64}
+
+    pcuint64 = ^cuint64;
+    cuint64 = record
+      hi: cuint32;
+      lo: cuint32;
+    end;
+    {$EXTERNALSYM cuint64}
+  {$ELSE}
+    pcint64 = ^cint64;
+    cint64 = Int64;
+    {$EXTERNALSYM cint64}
+
+    pcuint64 = ^cuint64;
+    cuint64 = UInt64;
+    {$EXTERNALSYM cuint64}
+  {$ENDIF}
+
+  {$IFNDEF WIN64}
+    csize_t = cuint32;
+  {$ELSE}
+    csize_t = cuint64;
+  {$ENDIF}
+  {$EXTERNALSYM SIZE_T}
+
+  pcfloat = ^cfloat;
+  cfloat = Single;
+  {$EXTERNALSYM cfloat}
+{$ENDIF}
+
+{ Data types for all compilers }
+type
+  PUInt8Array = ^TUInt8Array;
+  TUInt8Array = array [0..MAXINT shr 1] of cuint8;
+
+  ppcuint8 = ^pcuint8;
+

units/sdl.inc

@@ -1,7 +1,7 @@
 //from "sdl.h"
 
 type
-  TSDL_Init = type UInt32;
+  TSDL_Init = type cuint32;
 
 const
   SDL_INIT_TIMER          = TSDL_Init($00000001);
@@ -40,13 +40,13 @@ const
  *  signal handlers for some commonly ignored fatal signals (like SIGSEGV).
  *}
 
-function SDL_Init(flags: TSDL_Init): SInt32 cdecl; external SDL_LibName {$IFDEF DELPHI} {$IFDEF MACOS} name '_SDL_Init' {$ENDIF} {$ENDIF};
+function SDL_Init(flags: TSDL_Init): cint32 cdecl; external SDL_LibName {$IFDEF DELPHI} {$IFDEF MACOS} name '_SDL_Init' {$ENDIF} {$ENDIF};
 
 {**
  *  This function initializes specific SDL subsystems
  *}
 
-function SDL_InitSubSystem(flags: TSDL_Init): SInt32 cdecl; external SDL_LibName {$IFDEF DELPHI} {$IFDEF MACOS} name '_SDL_InitSubSystem' {$ENDIF} {$ENDIF};
+function SDL_InitSubSystem(flags: TSDL_Init): cint32 cdecl; external SDL_LibName {$IFDEF DELPHI} {$IFDEF MACOS} name '_SDL_InitSubSystem' {$ENDIF} {$ENDIF};
 
 {**
  *  This function cleans up specific SDL subsystems
@@ -61,7 +61,7 @@ procedure SDL_QuitSubSystem(flags: TSDL_Init) cdecl; external SDL_LibName {$IFDE
  *  If flags is 0, it returns a mask of all initialized subsystems.
  *}
 
-function SDL_WasInit(flags: TSDL_Init): UInt32 cdecl; external SDL_LibName {$IFDEF DELPHI} {$IFDEF MACOS} name '_SDL_WasInit' {$ENDIF} {$ENDIF};
+function SDL_WasInit(flags: TSDL_Init): cuint32 cdecl; external SDL_LibName {$IFDEF DELPHI} {$IFDEF MACOS} name '_SDL_WasInit' {$ENDIF} {$ENDIF};
 
 {**
  *  This function cleans up all initialized subsystems. You should

units/sdl2.pas

@@ -97,11 +97,17 @@ interface
 
   {$IFDEF WINDOWS}
     uses
+      {$IFDEF FPC}
+      ctypes,
+      {$ENDIF}
       Windows;
   {$ENDIF}
 
   {$IF DEFINED(UNIX) AND NOT DEFINED(ANDROID)}
     uses
+      {$IFDEF FPC}
+      ctypes,
+      {$ENDIF}
       {$IFDEF DARWIN}
       CocoaAll;
       {$ELSE}
@@ -135,6 +141,8 @@ interface
     {$ENDIF}
   {$ENDIF}
 
+
+{$I ctypes.inc}  // C data types
 {$I sdlstdinc.inc}
 {$I sdlversion.inc}
 {$I sdlerror.inc}
@@ -183,7 +191,7 @@ procedure SDL_VERSION(out x: TSDL_Version);
   x.patch := SDL_PATCHLEVEL;
 end;
 
-function SDL_VERSIONNUM(X,Y,Z: UInt32): Cardinal;
+function SDL_VERSIONNUM(X,Y,Z: cuint32): Cardinal;
 begin
   Result := X*1000 + Y*100 + Z;
 end;
@@ -201,7 +209,7 @@ function SDL_VERSION_ATLEAST(X,Y,Z: Cardinal): Boolean;
 end;
 
 //from "sdl_mouse.h"
-function SDL_Button(button: SInt32): SInt32;
+function SDL_Button(button: cint32): cint32;
 begin
   Result := 1 shl (button - 1); 
 end;
@@ -237,39 +245,39 @@ function SDL_PointInRect(const p: PSDL_Point; const r: PSDL_Rect): Boolean;
 
 //from "sdl_rwops.h"
 
-function SDL_RWsize(ctx: PSDL_RWops): SInt64;
+function SDL_RWsize(ctx: PSDL_RWops): cint64;
 begin
   Result := ctx^.size(ctx);
 end;
 
-function SDL_RWseek(ctx: PSDL_RWops; offset: SInt64; whence: SInt32): SInt64;
+function SDL_RWseek(ctx: PSDL_RWops; offset: cint64; whence: cint32): cint64;
 begin
   Result := ctx^.seek(ctx,offset,whence);
 end;
 
-function SDL_RWtell(ctx: PSDL_RWops): SInt64;
+function SDL_RWtell(ctx: PSDL_RWops): cint64;
 begin
   Result := ctx^.seek(ctx, 0, RW_SEEK_CUR);
 end;
 
-function SDL_RWread(ctx: PSDL_RWops; ptr: Pointer; size: size_t; n: size_t): size_t;
+function SDL_RWread(ctx: PSDL_RWops; ptr: Pointer; size: csize_t; n: csize_t): csize_t;
 begin
   Result := ctx^.read(ctx, ptr, size, n);
 end;
 
-function SDL_RWwrite(ctx: PSDL_RWops; ptr: Pointer; size: size_t; n: size_t): size_t;
+function SDL_RWwrite(ctx: PSDL_RWops; ptr: Pointer; size: csize_t; n: csize_t): csize_t;
 begin
   Result := ctx^.write(ctx, ptr, size, n);
 end;
 
-function SDL_RWclose(ctx: PSDL_RWops): SInt32;
+function SDL_RWclose(ctx: PSDL_RWops): cint32;
 begin
   Result := ctx^.close(ctx);
 end;
 
 //from "sdl_audio.h"
 
-function SDL_LoadWAV(_file: PAnsiChar; spec: PSDL_AudioSpec; audio_buf: PPUInt8; audio_len: PUInt32): PSDL_AudioSpec;
+function SDL_LoadWAV(_file: PAnsiChar; spec: PSDL_AudioSpec; audio_buf: ppcuint8; audio_len: pcuint32): PSDL_AudioSpec;
 begin
   Result := SDL_LoadWAV_RW(SDL_RWFromFile(_file, 'rb'), 1, spec, audio_buf, audio_len);
 end;
@@ -349,7 +357,7 @@ function SDL_LoadBMP(_file: PAnsiChar): PSDL_Surface;
 end;
 
 function SDL_SaveBMP(const surface: PSDL_Surface; const filename: AnsiString
-  ): sInt32;
+  ): cint32;
 begin
    Result := SDL_SaveBMP_RW(surface, SDL_RWFromFile(PAnsiChar(filename), 'wb'), 1)
 end;
@@ -393,23 +401,23 @@ function SDL_WINDOWPOS_ISCENTERED(X: Variant): Variant;
 
 //from "sdl_events.h"
 
-function SDL_GetEventState(type_: TSDL_EventType): UInt8;
+function SDL_GetEventState(type_: TSDL_EventType): cuint8;
 begin
   Result := SDL_EventState(type_, SDL_QUERY);
 end;
 
 // from "sdl_timer.h"
-function SDL_TICKS_PASSED(const A, B: UInt32): Boolean;
+function SDL_TICKS_PASSED(const A, B: cuint32): Boolean;
 begin
-   Result := ((Int64(B) - Int64(A)) <= 0)
+   Result := ((cint64(B) - cint64(A)) <= 0)
 end;
 
 // from "sdl_gamecontroller.h"
   {**
    *  Load a set of mappings from a file, filtered by the current SDL_GetPlatform()
    *}
 function SDL_GameControllerAddMappingsFromFile(const FilePath: PAnsiChar
-  ): SInt32;
+  ): cint32;
 begin
   Result := SDL_GameControllerAddMappingsFromRW(SDL_RWFromFile(FilePath, 'rb'), 1)
 end;