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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 */
SDL_MouseInit(void)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 }
SDL_MouseQuit(void)57 void SDL_MouseQuit(void)
58 {
59 }
60 
61 /* We lost the mouse, so post button up messages for all pressed buttons */
SDL_ResetMouse(void)62 void SDL_ResetMouse(void)
63 {
64 	Uint8 i;
65 	for ( i = 0; 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 
SDL_GetMouseState(int * x,int * y)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 
SDL_GetRelativeMouseState(int * x,int * y)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 
ClipOffset(Sint16 * x,Sint16 * y)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 
SDL_SetMouseRange(int maxX,int maxY)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 */
SDL_PrivateMouseMotion(Uint8 buttonstate,int relative,Sint16 x,Sint16 y)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 
SDL_PrivateMouseButton(Uint8 state,Uint8 button,Sint16 x,Sint16 y)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 
269