src/events/SDL_mouse.c
author Ryan C. Gordon <icculus@icculus.org>
Thu, 01 Jun 2017 00:39:07 -0400
branchSDL-1.2
changeset 11056 1138bf8c009a
parent 6137 4720145f848b
permissions -rw-r--r--
SDL_ResetMouse was using a bogus mouse button, causing a "<< -1" shift.

Note that we got rid of SDL_ResetMouse() entirely for SDL 2.0, but for 1.2,
this is a small fix that doesn't otherwise alter behavior in any serious way.

Fixes Bugzilla #3593.
     1 /*
     2     SDL - Simple DirectMedia Layer
     3     Copyright (C) 1997-2012 Sam Lantinga
     4 
     5     This library is free software; you can redistribute it and/or
     6     modify it under the terms of the GNU Lesser General Public
     7     License as published by the Free Software Foundation; either
     8     version 2.1 of the License, or (at your option) any later version.
     9 
    10     This library is distributed in the hope that it will be useful,
    11     but WITHOUT ANY WARRANTY; without even the implied warranty of
    12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    13     Lesser General Public License for more details.
    14 
    15     You should have received a copy of the GNU Lesser General Public
    16     License along with this library; if not, write to the Free Software
    17     Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
    18 
    19     Sam Lantinga
    20     slouken@libsdl.org
    21 */
    22 #include "SDL_config.h"
    23 
    24 /* General mouse handling code for SDL */
    25 
    26 #include "SDL_events.h"
    27 #include "SDL_events_c.h"
    28 #include "../video/SDL_cursor_c.h"
    29 #include "../video/SDL_sysvideo.h"
    30 
    31 
    32 /* These are static for our mouse handling code */
    33 static Sint16 SDL_MouseX = 0;
    34 static Sint16 SDL_MouseY = 0;
    35 static Sint16 SDL_DeltaX = 0;
    36 static Sint16 SDL_DeltaY = 0;
    37 static Sint16 SDL_MouseMaxX = 0;
    38 static Sint16 SDL_MouseMaxY = 0;
    39 static Uint8  SDL_ButtonState = 0;
    40 
    41 
    42 /* Public functions */
    43 int SDL_MouseInit(void)
    44 {
    45 	/* The mouse is at (0,0) */
    46 	SDL_MouseX = 0;
    47 	SDL_MouseY = 0;
    48 	SDL_DeltaX = 0;
    49 	SDL_DeltaY = 0;
    50 	SDL_MouseMaxX = 0;
    51 	SDL_MouseMaxY = 0;
    52 	SDL_ButtonState = 0;
    53 
    54 	/* That's it! */
    55 	return(0);
    56 }
    57 void SDL_MouseQuit(void)
    58 {
    59 }
    60 
    61 /* We lost the mouse, so post button up messages for all pressed buttons */
    62 void SDL_ResetMouse(void)
    63 {
    64 	Uint8 i;
    65 	for ( i = 1; i < sizeof(SDL_ButtonState)*8; ++i ) {
    66 		if ( SDL_ButtonState & SDL_BUTTON(i) ) {
    67 			SDL_PrivateMouseButton(SDL_RELEASED, i, 0, 0);
    68 		}
    69 	}
    70 }
    71 
    72 Uint8 SDL_GetMouseState (int *x, int *y)
    73 {
    74 	if ( x ) {
    75 		*x = SDL_MouseX;
    76 	}
    77 	if ( y ) {
    78 		*y = SDL_MouseY;
    79 	}
    80 	return(SDL_ButtonState);
    81 }
    82 
    83 Uint8 SDL_GetRelativeMouseState (int *x, int *y)
    84 {
    85 	if ( x )
    86 		*x = SDL_DeltaX;
    87 	if ( y )
    88 		*y = SDL_DeltaY;
    89 	SDL_DeltaX = 0;
    90 	SDL_DeltaY = 0;
    91 	return(SDL_ButtonState);
    92 }
    93 
    94 static void ClipOffset(Sint16 *x, Sint16 *y)
    95 {
    96 	/* This clips absolute mouse coordinates when the apparent
    97 	   display surface is smaller than the real display surface.
    98 	 */
    99 	if ( SDL_VideoSurface && SDL_VideoSurface->offset ) {
   100 		*y -= SDL_VideoSurface->offset/SDL_VideoSurface->pitch;
   101 		*x -= (SDL_VideoSurface->offset%SDL_VideoSurface->pitch)/
   102 				SDL_VideoSurface->format->BytesPerPixel;
   103 	}
   104 }
   105 
   106 void SDL_SetMouseRange(int maxX, int maxY)
   107 {
   108 	SDL_MouseMaxX = (Sint16)maxX;
   109 	SDL_MouseMaxY = (Sint16)maxY;
   110 }
   111 
   112 /* These are global for SDL_eventloop.c */
   113 int SDL_PrivateMouseMotion(Uint8 buttonstate, int relative, Sint16 x, Sint16 y)
   114 {
   115 	int posted;
   116 	Uint16 X, Y;
   117 	Sint16 Xrel;
   118 	Sint16 Yrel;
   119 
   120 	/* Default buttonstate is the current one */
   121 	if ( ! buttonstate ) {
   122 		buttonstate = SDL_ButtonState;
   123 	}
   124 
   125 	Xrel = x;
   126 	Yrel = y;
   127 	if ( relative ) {
   128 		/* Push the cursor around */
   129 		x = (SDL_MouseX+x);
   130 		y = (SDL_MouseY+y);
   131 	} else {
   132 		/* Do we need to clip {x,y} ? */
   133 		ClipOffset(&x, &y);
   134 	}
   135 
   136 	/* Mouse coordinates range from 0 - width-1 and 0 - height-1 */
   137 	if ( x < 0 )
   138 		X = 0;
   139 	else
   140 	if ( x >= SDL_MouseMaxX )
   141 		X = SDL_MouseMaxX-1;
   142 	else
   143 		X = (Uint16)x;
   144 
   145 	if ( y < 0 )
   146 		Y = 0;
   147 	else
   148 	if ( y >= SDL_MouseMaxY )
   149 		Y = SDL_MouseMaxY-1;
   150 	else
   151 		Y = (Uint16)y;
   152 
   153 	/* If not relative mode, generate relative motion from clamped X/Y.
   154 	   This prevents lots of extraneous large delta relative motion when
   155 	   the screen is windowed mode and the mouse is outside the window.
   156 	*/
   157 	if ( ! relative ) {
   158 		Xrel = X-SDL_MouseX;
   159 		Yrel = Y-SDL_MouseY;
   160 	}
   161 
   162 	/* Drop events that don't change state */
   163 	if ( ! Xrel && ! Yrel ) {
   164 #if 0
   165 printf("Mouse event didn't change state - dropped!\n");
   166 #endif
   167 		return(0);
   168 	}
   169 
   170 	/* Update internal mouse state */
   171 	SDL_ButtonState = buttonstate;
   172 	SDL_MouseX = X;
   173 	SDL_MouseY = Y;
   174 	SDL_DeltaX += Xrel;
   175 	SDL_DeltaY += Yrel;
   176         SDL_MoveCursor(SDL_MouseX, SDL_MouseY);
   177 
   178 	/* Post the event, if desired */
   179 	posted = 0;
   180 	if ( SDL_ProcessEvents[SDL_MOUSEMOTION] == SDL_ENABLE ) {
   181 		SDL_Event event;
   182 		SDL_memset(&event, 0, sizeof(event));
   183 		event.type = SDL_MOUSEMOTION;
   184 		event.motion.state = buttonstate;
   185 		event.motion.x = X;
   186 		event.motion.y = Y;
   187 		event.motion.xrel = Xrel;
   188 		event.motion.yrel = Yrel;
   189 		if ( (SDL_EventOK == NULL) || (*SDL_EventOK)(&event) ) {
   190 			posted = 1;
   191 			SDL_PushEvent(&event);
   192 		}
   193 	}
   194 	return(posted);
   195 }
   196 
   197 int SDL_PrivateMouseButton(Uint8 state, Uint8 button, Sint16 x, Sint16 y)
   198 {
   199 	SDL_Event event;
   200 	int posted;
   201 	int move_mouse;
   202 	Uint8 buttonstate;
   203 
   204 	SDL_memset(&event, 0, sizeof(event));
   205 
   206 	/* Check parameters */
   207 	if ( x || y ) {
   208 		ClipOffset(&x, &y);
   209 		move_mouse = 1;
   210 		/* Mouse coordinates range from 0 - width-1 and 0 - height-1 */
   211 		if ( x < 0 )
   212 			x = 0;
   213 		else
   214 		if ( x >= SDL_MouseMaxX )
   215 			x = SDL_MouseMaxX-1;
   216 
   217 		if ( y < 0 )
   218 			y = 0;
   219 		else
   220 		if ( y >= SDL_MouseMaxY )
   221 			y = SDL_MouseMaxY-1;
   222 	} else {
   223 		move_mouse = 0;
   224 	}
   225 	if ( ! x )
   226 		x = SDL_MouseX;
   227 	if ( ! y )
   228 		y = SDL_MouseY;
   229 
   230 	/* Figure out which event to perform */
   231 	buttonstate = SDL_ButtonState;
   232 	switch ( state ) {
   233 		case SDL_PRESSED:
   234 			event.type = SDL_MOUSEBUTTONDOWN;
   235 			buttonstate |= SDL_BUTTON(button);
   236 			break;
   237 		case SDL_RELEASED:
   238 			event.type = SDL_MOUSEBUTTONUP;
   239 			buttonstate &= ~SDL_BUTTON(button);
   240 			break;
   241 		default:
   242 			/* Invalid state -- bail */
   243 			return(0);
   244 	}
   245 
   246 	/* Update internal mouse state */
   247 	SDL_ButtonState = buttonstate;
   248 	if ( move_mouse ) {
   249 		SDL_MouseX = x;
   250 		SDL_MouseY = y;
   251 		SDL_MoveCursor(SDL_MouseX, SDL_MouseY);
   252 	}
   253 
   254 	/* Post the event, if desired */
   255 	posted = 0;
   256 	if ( SDL_ProcessEvents[event.type] == SDL_ENABLE ) {
   257 		event.button.state = state;
   258 		event.button.button = button;
   259 		event.button.x = x;
   260 		event.button.y = y;
   261 		if ( (SDL_EventOK == NULL) || (*SDL_EventOK)(&event) ) {
   262 			posted = 1;
   263 			SDL_PushEvent(&event);
   264 		}
   265 	}
   266 	return(posted);
   267 }
   268