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 */
SDL_MouseInit(void)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 }
SDL_MouseQuit(void)53 void SDL_MouseQuit(void)
54 {
55 }
56
57 /* We lost the mouse, so post button up messages for all pressed buttons */
SDL_ResetMouse(void)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
SDL_GetMouseState(int * x,int * y)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
SDL_GetRelativeMouseState(int * x,int * y)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
ClipOffset(Sint16 * x,Sint16 * y)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 */
SDL_PrivateMouseMotion(Uint8 buttonstate,int relative,Sint16 x,Sint16 y)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
SDL_PrivateMouseButton(Uint8 state,Uint8 button,Sint16 x,Sint16 y)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
264