src/events/SDL_mouse.c
author Ryan C. Gordon
Wed, 29 Nov 2006 10:30:05 +0000
branchSDL-1.2
changeset 3900 ce3a2bd11305
parent 1525 23a347cfbed8
child 1662 782fd950bd46
child 1895 c121d94672cb
child 4159 a1b03ba2fcd0
permissions -rw-r--r--
Wrapped some macro params in parentheses for alloca wrappers.
Thansk, Suzuki Masahiro.
     1 /*
     2     SDL - Simple DirectMedia Layer
     3     Copyright (C) 1997-2006 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 Uint8  SDL_ButtonState = 0;
    38 
    39 
    40 /* Public functions */
    41 int SDL_MouseInit(void)
    42 {
    43 	/* The mouse is at (0,0) */
    44 	SDL_MouseX = 0;
    45 	SDL_MouseY = 0;
    46 	SDL_DeltaX = 0;
    47 	SDL_DeltaY = 0;
    48 	SDL_ButtonState = 0;
    49 
    50 	/* That's it! */
    51 	return(0);
    52 }
    53 void SDL_MouseQuit(void)
    54 {
    55 }
    56 
    57 /* We lost the mouse, so post button up messages for all pressed buttons */
    58 void SDL_ResetMouse(void)
    59 {
    60 	Uint8 i;
    61 	for ( i = 0; i < sizeof(SDL_ButtonState)*8; ++i ) {
    62 		if ( SDL_ButtonState & SDL_BUTTON(i) ) {
    63 			SDL_PrivateMouseButton(SDL_RELEASED, i, 0, 0);
    64 		}
    65 	}
    66 }
    67 
    68 Uint8 SDL_GetMouseState (int *x, int *y)
    69 {
    70 	if ( x ) {
    71 		*x = SDL_MouseX;
    72 	}
    73 	if ( y ) {
    74 		*y = SDL_MouseY;
    75 	}
    76 	return(SDL_ButtonState);
    77 }
    78 
    79 Uint8 SDL_GetRelativeMouseState (int *x, int *y)
    80 {
    81 	if ( x )
    82 		*x = SDL_DeltaX;
    83 	if ( y )
    84 		*y = SDL_DeltaY;
    85 	SDL_DeltaX = 0;
    86 	SDL_DeltaY = 0;
    87 	return(SDL_ButtonState);
    88 }
    89 
    90 static void ClipOffset(Sint16 *x, Sint16 *y)
    91 {
    92 	/* This clips absolute mouse coordinates when the apparent
    93 	   display surface is smaller than the real display surface.
    94 	 */
    95 	if ( SDL_VideoSurface->offset ) {
    96 		*y -= SDL_VideoSurface->offset/SDL_VideoSurface->pitch;
    97 		*x -= (SDL_VideoSurface->offset%SDL_VideoSurface->pitch)/
    98 				SDL_VideoSurface->format->BytesPerPixel;
    99 	}
   100 }
   101 
   102 /* These are global for SDL_eventloop.c */
   103 int SDL_PrivateMouseMotion(Uint8 buttonstate, int relative, Sint16 x, Sint16 y)
   104 {
   105 	int posted;
   106 	Uint16 X, Y;
   107 	Sint16 Xrel;
   108 	Sint16 Yrel;
   109 
   110 	/* Don't handle mouse motion if there's no cursor surface */
   111 	if ( SDL_VideoSurface == NULL ) {
   112 		return(0);
   113 	}
   114 
   115 	/* Default buttonstate is the current one */
   116 	if ( ! buttonstate ) {
   117 		buttonstate = SDL_ButtonState;
   118 	}
   119 
   120 	Xrel = x;
   121 	Yrel = y;
   122 	if ( relative ) {
   123 		/* Push the cursor around */
   124 		x = (SDL_MouseX+x);
   125 		y = (SDL_MouseY+y);
   126 	} else {
   127 		/* Do we need to clip {x,y} ? */
   128 		ClipOffset(&x, &y);
   129 	}
   130 
   131 	/* Mouse coordinates range from 0 - width-1 and 0 - height-1 */
   132 	if ( x < 0 )
   133 		X = 0;
   134 	else
   135 	if ( x >= SDL_VideoSurface->w )
   136 		X = SDL_VideoSurface->w-1;
   137 	else
   138 		X = (Uint16)x;
   139 
   140 	if ( y < 0 )
   141 		Y = 0;
   142 	else
   143 	if ( y >= SDL_VideoSurface->h )
   144 		Y = SDL_VideoSurface->h-1;
   145 	else
   146 		Y = (Uint16)y;
   147 
   148 	/* If not relative mode, generate relative motion from clamped X/Y.
   149 	   This prevents lots of extraneous large delta relative motion when
   150 	   the screen is windowed mode and the mouse is outside the window.
   151 	*/
   152 	if ( ! relative ) {
   153 		Xrel = X-SDL_MouseX;
   154 		Yrel = Y-SDL_MouseY;
   155 	}
   156 
   157 	/* Drop events that don't change state */
   158 	if ( ! Xrel && ! Yrel ) {
   159 #if 0
   160 printf("Mouse event didn't change state - dropped!\n");
   161 #endif
   162 		return(0);
   163 	}
   164 
   165 	/* Update internal mouse state */
   166 	SDL_ButtonState = buttonstate;
   167 	SDL_MouseX = X;
   168 	SDL_MouseY = Y;
   169 	SDL_DeltaX += Xrel;
   170 	SDL_DeltaY += Yrel;
   171         SDL_MoveCursor(SDL_MouseX, SDL_MouseY);
   172 
   173 	/* Post the event, if desired */
   174 	posted = 0;
   175 	if ( SDL_ProcessEvents[SDL_MOUSEMOTION] == SDL_ENABLE ) {
   176 		SDL_Event event;
   177 		SDL_memset(&event, 0, sizeof(event));
   178 		event.type = SDL_MOUSEMOTION;
   179 		event.motion.state = buttonstate;
   180 		event.motion.x = X;
   181 		event.motion.y = Y;
   182 		event.motion.xrel = Xrel;
   183 		event.motion.yrel = Yrel;
   184 		if ( (SDL_EventOK == NULL) || (*SDL_EventOK)(&event) ) {
   185 			posted = 1;
   186 			SDL_PushEvent(&event);
   187 		}
   188 	}
   189 	return(posted);
   190 }
   191 
   192 int SDL_PrivateMouseButton(Uint8 state, Uint8 button, Sint16 x, Sint16 y)
   193 {
   194 	SDL_Event event;
   195 	int posted;
   196 	int move_mouse;
   197 	Uint8 buttonstate;
   198 
   199 	SDL_memset(&event, 0, sizeof(event));
   200 
   201 	/* Check parameters */
   202 	if ( x || y ) {
   203 		ClipOffset(&x, &y);
   204 		move_mouse = 1;
   205 		/* Mouse coordinates range from 0 - width-1 and 0 - height-1 */
   206 		if ( x < 0 )
   207 			x = 0;
   208 		else
   209 		if ( x >= SDL_VideoSurface->w )
   210 			x = SDL_VideoSurface->w-1;
   211 
   212 		if ( y < 0 )
   213 			y = 0;
   214 		else
   215 		if ( y >= SDL_VideoSurface->h )
   216 			y = SDL_VideoSurface->h-1;
   217 	} else {
   218 		move_mouse = 0;
   219 	}
   220 	if ( ! x )
   221 		x = SDL_MouseX;
   222 	if ( ! y )
   223 		y = SDL_MouseY;
   224 
   225 	/* Figure out which event to perform */
   226 	buttonstate = SDL_ButtonState;
   227 	switch ( state ) {
   228 		case SDL_PRESSED:
   229 			event.type = SDL_MOUSEBUTTONDOWN;
   230 			buttonstate |= SDL_BUTTON(button);
   231 			break;
   232 		case SDL_RELEASED:
   233 			event.type = SDL_MOUSEBUTTONUP;
   234 			buttonstate &= ~SDL_BUTTON(button);
   235 			break;
   236 		default:
   237 			/* Invalid state -- bail */
   238 			return(0);
   239 	}
   240 
   241 	/* Update internal mouse state */
   242 	SDL_ButtonState = buttonstate;
   243 	if ( move_mouse ) {
   244 		SDL_MouseX = x;
   245 		SDL_MouseY = y;
   246 		SDL_MoveCursor(SDL_MouseX, SDL_MouseY);
   247 	}
   248 
   249 	/* Post the event, if desired */
   250 	posted = 0;
   251 	if ( SDL_ProcessEvents[event.type] == SDL_ENABLE ) {
   252 		event.button.state = state;
   253 		event.button.button = button;
   254 		event.button.x = x;
   255 		event.button.y = y;
   256 		if ( (SDL_EventOK == NULL) || (*SDL_EventOK)(&event) ) {
   257 			posted = 1;
   258 			SDL_PushEvent(&event);
   259 		}
   260 	}
   261 	return(posted);
   262 }
   263