view include/SDL_types.h @ 1287:15a89a0c52bf

Date: Tue, 15 Feb 2005 21:28:48 +0900 (JST) From: "Michael Leonhard" Subject: [SDL] resize bug on Win32 and patch This is my first post to this mailing list. In this email I will detail a bug in the behavior of resizable SDL windows on Win32. Then I will explain the solution and provide a patch. Symptoms: Under Windows, an SDL display created with the SDL_RESIZABLE flag exhibits quirky behavior when being maximized. The window is resized to the proper size, but it is shifted upwards about half the height of the title bar. Similarly, a window whose origin is above the top of the screen will spontaneously move its upper-left origin upon being resized. After two such resize-induced moves, the title bar will be entirely off the top edge of the screen. Subsequently, when the mouse is clicked and released on the window border, the window will shrink its height spontaneously. This height shrinkage occurs even if the user did not resize the border. To observe this curious situation, please invoke: SDL-1.2.8/test/testwm.exe -resize Cause: A pair of integers, SDL_windowX and SDL_windowY, are defined in video/wincommon/SDL_sysevents.c. They are used by the DirectX video driver and the DIB video driver: video/windx5/SDL_dx5video.c video/windib/SDL_dibvideo.c As I understand the source code, the primary use of these variables is to create a rectangle that represents the surface area in CLIENT SPACE. Client space refers to a coordinate system that originates at the upper left corner of a Win32 Window's drawable area. This is just inside the window border and title bar. This client space rectangle, called bounds, is subsequently converted to screen space with a call to AdjustWindowRectEx. The problem is found in SDL's handling of the WM_WINDOWPOSCHANGED message. According to MSDN, "The WM_WINDOWPOSCHANGED message is sent to a window whose size, position, or place in the Z order has changed as a result of a call to the SetWindowPos function or another window-management function." I have confirmed that this message is indeed being sent to the SDL window when the mouse is clicked on the window border, even if the window border is not dragged. In video/wincommon/SDL_sysevents.c, on line 464, in response to the WM_WINDOWPOSCHANGED message, the (potentially) new client rectangle is obtained. This rectangle is translated into screen coordinates and THEN assigned to the SDL_windowX and Y variables. Thus screen coordinates are being assigned to client coordinate variables. Once this is understood, the solution is apparent: assign SDL_windowX and Y before translating the rectangle to screen coordinates. This is accomplished by the following patch. -Mike_L
author Sam Lantinga <slouken@libsdl.org>
date Sun, 29 Jan 2006 08:50:06 +0000
parents 173c063d4f55
children c9b51268668f
line wrap: on
line source

/*
    SDL - Simple DirectMedia Layer
    Copyright (C) 1997-2004 Sam Lantinga

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Library General Public
    License as published by the Free Software Foundation; either
    version 2 of the License, or (at your option) any later version.

    This library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    Library General Public License for more details.

    You should have received a copy of the GNU Library General Public
    License along with this library; if not, write to the Free
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

    Sam Lantinga
    slouken@libsdl.org
*/

#ifdef SAVE_RCSID
static char rcsid =
 "@(#) $Id$";
#endif

/* General data types used by the SDL library */

#ifndef _SDL_types_h
#define _SDL_types_h

/* The number of elements in a table */
#define SDL_TABLESIZE(table)	(sizeof(table)/sizeof(table[0]))

/* Basic data types */
typedef enum {
	SDL_FALSE = 0,
	SDL_TRUE  = 1
} SDL_bool;

#ifdef H_MMBASIC /* mmbasic.h (Tru64 MME) */
/* Some of the basic types are already defined in mmbasic.h */
typedef signed char	Sint8;
typedef signed short	Sint16;
typedef signed int	Sint32;
#else
typedef unsigned char	Uint8;
typedef signed char	Sint8;
typedef unsigned short	Uint16;
typedef signed short	Sint16;
typedef unsigned int	Uint32;
typedef signed int	Sint32;
#endif

/* Figure out how to support 64-bit datatypes */
#if !defined(__STRICT_ANSI__)
#ifdef __osf__ /* Tru64 */
#define SDL_HAS_64BIT_TYPE	long
#elif defined(__GNUC__) || defined(__MWERKS__) || defined(__SUNPRO_C) || defined(__DECC) || defined(__WATCOMC__)
#define SDL_HAS_64BIT_TYPE	long long
#elif defined(_MSC_VER) /* VC++ */
#define SDL_HAS_64BIT_TYPE	__int64
#endif
#endif /* !__STRICT_ANSI__ */

/* The 64-bit type isn't available on EPOC/Symbian OS */
#ifdef __SYMBIAN32__
#undef SDL_HAS_64BIT_TYPE
#endif

/* The 64-bit datatype isn't supported on all platforms */
#ifdef SDL_HAS_64BIT_TYPE
#ifndef H_MMBASIC
typedef unsigned SDL_HAS_64BIT_TYPE Uint64;
#endif
typedef SDL_HAS_64BIT_TYPE Sint64;
#else
/* This is really just a hack to prevent the compiler from complaining */
typedef struct {
	Uint32 hi;
	Uint32 lo;
} Uint64, Sint64;
#endif

/* Make sure the types really have the right sizes */
#define SDL_COMPILE_TIME_ASSERT(name, x)               \
       typedef int SDL_dummy_ ## name[(x) * 2 - 1]

SDL_COMPILE_TIME_ASSERT(uint8, sizeof(Uint8) == 1);
SDL_COMPILE_TIME_ASSERT(sint8, sizeof(Sint8) == 1);
SDL_COMPILE_TIME_ASSERT(uint16, sizeof(Uint16) == 2);
SDL_COMPILE_TIME_ASSERT(sint16, sizeof(Sint16) == 2);
SDL_COMPILE_TIME_ASSERT(uint32, sizeof(Uint32) == 4);
SDL_COMPILE_TIME_ASSERT(sint32, sizeof(Sint32) == 4);
SDL_COMPILE_TIME_ASSERT(uint64, sizeof(Uint64) == 8);
SDL_COMPILE_TIME_ASSERT(sint64, sizeof(Sint64) == 8);

/* Check to make sure enums are the size of ints, for structure packing.
   For both Watcom C/C++ and Borland C/C++ the compiler option that makes
   enums having the size of an int must be enabled.
   This is "-b" for Borland C/C++ and "-ei" for Watcom C/C++ (v11).
*/
/* Enable enums always int in CodeWarrior (for MPW use "-enum int") */
#ifdef __MWERKS__
#pragma enumsalwaysint on
#endif

typedef enum {
	DUMMY_ENUM_VALUE
} SDL_DUMMY_ENUM;

SDL_COMPILE_TIME_ASSERT(enum, sizeof(SDL_DUMMY_ENUM) == sizeof(int));

#undef SDL_COMPILE_TIME_ASSERT

/* General keyboard/mouse state definitions */
enum { SDL_PRESSED = 0x01, SDL_RELEASED = 0x00 };

#endif