1 /*
2 Copyright (C) 1997-2020 Sam Lantinga <slouken@libsdl.org>
3
4 This software is provided 'as-is', without any express or implied
5 warranty. In no event will the authors be held liable for any damages
6 arising from the use of this software.
7
8 Permission is granted to anyone to use this software for any purpose,
9 including commercial applications, and to alter it and redistribute it
10 freely.
11 */
12
13 /* Usage:
14 * Spacebar to begin recording a gesture on all touches.
15 * s to save all touches into "./gestureSave"
16 * l to load all touches from "./gestureSave"
17 */
18
19 #include "SDL.h"
20 #include <stdlib.h> /* for exit() */
21
22 #ifdef __EMSCRIPTEN__
23 #include <emscripten/emscripten.h>
24 #endif
25
26 #include "SDL_test.h"
27 #include "SDL_test_common.h"
28
29 #define WIDTH 640
30 #define HEIGHT 480
31 #define BPP 4
32
33 /* MUST BE A POWER OF 2! */
34 #define EVENT_BUF_SIZE 256
35
36 #define VERBOSE 0
37
38 static SDLTest_CommonState *state;
39 static SDL_Event events[EVENT_BUF_SIZE];
40 static int eventWrite;
41 static int colors[7] = {0xFF,0xFF00,0xFF0000,0xFFFF00,0x00FFFF,0xFF00FF,0xFFFFFF};
42 static int quitting = 0;
43
44 typedef struct
45 {
46 float x, y;
47 } Point;
48
49 typedef struct
50 {
51 float ang, r;
52 Point p;
53 } Knob;
54
55 static Knob knob = { 0.0f, 0.1f, { 0.0f, 0.0f } };
56
57
58 static void
setpix(SDL_Surface * screen,float _x,float _y,unsigned int col)59 setpix(SDL_Surface *screen, float _x, float _y, unsigned int col)
60 {
61 Uint32 *pixmem32;
62 Uint32 colour;
63 Uint8 r, g, b;
64 const int x = (int)_x;
65 const int y = (int)_y;
66 float a;
67
68 if ( (x < 0) || (x >= screen->w) || (y < 0) || (y >= screen->h) ) {
69 return;
70 }
71
72 pixmem32 = (Uint32 *) screen->pixels + y * screen->pitch / BPP + x;
73
74 SDL_memcpy(&colour, pixmem32, screen->format->BytesPerPixel);
75
76 SDL_GetRGB(colour,screen->format,&r,&g,&b);
77
78 /* r = 0;g = 0; b = 0; */
79 a = (float) ((col >> 24) & 0xFF);
80 if (a == 0) {
81 a = 0xFF; /* Hack, to make things easier. */
82 }
83
84 a = (a == 0.0f) ? 1 : (a / 255.0f);
85 r = (Uint8) (r * (1 - a) + ((col >> 16) & 0xFF) * a);
86 g = (Uint8) (g * (1 - a) + ((col >> 8) & 0xFF) * a);
87 b = (Uint8) (b * (1 - a) + ((col >> 0) & 0xFF) * a);
88 colour = SDL_MapRGB(screen->format, r, g, b);
89
90 *pixmem32 = colour;
91 }
92
93 static void
drawLine(SDL_Surface * screen,float x0,float y0,float x1,float y1,unsigned int col)94 drawLine(SDL_Surface *screen, float x0, float y0, float x1, float y1, unsigned int col)
95 {
96 float t;
97 for (t = 0; t < 1; t += (float) (1.0f / SDL_max(SDL_fabs(x0 - x1), SDL_fabs(y0 - y1)))) {
98 setpix(screen, x1 + t * (x0 - x1), y1 + t * (y0 - y1), col);
99 }
100 }
101
102 static void
drawCircle(SDL_Surface * screen,float x,float y,float r,unsigned int c)103 drawCircle(SDL_Surface *screen, float x, float y, float r, unsigned int c)
104 {
105 float tx,ty, xr;
106 for (ty = (float) -SDL_fabs(r); ty <= (float) SDL_fabs((int) r); ty++) {
107 xr = (float) SDL_sqrt(r * r - ty * ty);
108 if (r > 0) { /* r > 0 ==> filled circle */
109 for(tx = -xr + 0.5f; tx <= xr - 0.5f; tx++) {
110 setpix(screen, x + tx, y + ty, c);
111 }
112 } else {
113 setpix(screen, x - xr + 0.5f, y + ty, c);
114 setpix(screen, x + xr - 0.5f, y + ty, c);
115 }
116 }
117 }
118
119 static void
drawKnob(SDL_Surface * screen,const Knob * k)120 drawKnob(SDL_Surface *screen, const Knob *k)
121 {
122 drawCircle(screen, k->p.x * screen->w, k->p.y * screen->h, k->r * screen->w, 0xFFFFFF);
123 drawCircle(screen, (k->p.x + k->r / 2 * SDL_cosf(k->ang)) * screen->w,
124 (k->p.y + k->r / 2 * SDL_sinf(k->ang)) * screen->h, k->r / 4 * screen->w, 0);
125 }
126
127 static void
DrawScreen(SDL_Window * window)128 DrawScreen(SDL_Window *window)
129 {
130 SDL_Surface *screen = SDL_GetWindowSurface(window);
131 int i;
132
133 if (!screen) {
134 return;
135 }
136
137 SDL_FillRect(screen, NULL, SDL_MapRGB(screen->format, 75, 75, 75));
138
139 /* draw Touch History */
140 for (i = eventWrite; i < eventWrite + EVENT_BUF_SIZE; ++i) {
141 const SDL_Event *event = &events[i & (EVENT_BUF_SIZE - 1)];
142 const float age = (float)(i - eventWrite) / EVENT_BUF_SIZE;
143 float x, y;
144 unsigned int c, col;
145
146 if ( (event->type == SDL_FINGERMOTION) ||
147 (event->type == SDL_FINGERDOWN) ||
148 (event->type == SDL_FINGERUP) ) {
149 x = event->tfinger.x;
150 y = event->tfinger.y;
151
152 /* draw the touch: */
153 c = colors[event->tfinger.fingerId % 7];
154 col = ((unsigned int) (c * (0.1f + 0.85f))) | (unsigned int) (0xFF * age) << 24;
155
156 if (event->type == SDL_FINGERMOTION) {
157 drawCircle(screen, x * screen->w, y * screen->h, 5, col);
158 } else if (event->type == SDL_FINGERDOWN) {
159 drawCircle(screen, x * screen->w, y * screen->h, -10, col);
160 }
161 }
162 }
163
164 if (knob.p.x > 0) {
165 drawKnob(screen, &knob);
166 }
167
168 SDL_UpdateWindowSurface(window);
169 }
170
171 static void
loop(void)172 loop(void)
173 {
174 SDL_Event event;
175 SDL_RWops *stream;
176 int i;
177
178 while (SDL_PollEvent(&event)) {
179 SDLTest_CommonEvent(state, &event, &quitting);
180
181 /* Record _all_ events */
182 events[eventWrite & (EVENT_BUF_SIZE-1)] = event;
183 eventWrite++;
184
185 switch (event.type) {
186 case SDL_KEYDOWN:
187 switch (event.key.keysym.sym) {
188 case SDLK_i: {
189 for (i = 0; i < SDL_GetNumTouchDevices(); ++i) {
190 const SDL_TouchID id = SDL_GetTouchDevice(i);
191 SDL_Log("Fingers Down on device %"SDL_PRIs64": %d", id, SDL_GetNumTouchFingers(id));
192 }
193 break;
194 }
195
196 case SDLK_SPACE:
197 SDL_RecordGesture(-1);
198 break;
199
200 case SDLK_s:
201 stream = SDL_RWFromFile("gestureSave", "w");
202 SDL_Log("Wrote %i templates", SDL_SaveAllDollarTemplates(stream));
203 SDL_RWclose(stream);
204 break;
205
206 case SDLK_l:
207 stream = SDL_RWFromFile("gestureSave", "r");
208 SDL_Log("Loaded: %i", SDL_LoadDollarTemplates(-1, stream));
209 SDL_RWclose(stream);
210 break;
211 }
212 break;
213
214 #if VERBOSE
215 case SDL_FINGERMOTION:
216 SDL_Log("Finger: %"SDL_PRIs64",x: %f, y: %f",event.tfinger.fingerId,
217 event.tfinger.x,event.tfinger.y);
218 break;
219
220 case SDL_FINGERDOWN:
221 SDL_Log("Finger: %"SDL_PRIs64" down - x: %f, y: %f",
222 event.tfinger.fingerId,event.tfinger.x,event.tfinger.y);
223 break;
224
225 case SDL_FINGERUP:
226 SDL_Log("Finger: %"SDL_PRIs64" up - x: %f, y: %f",
227 event.tfinger.fingerId,event.tfinger.x,event.tfinger.y);
228 break;
229 #endif
230
231 case SDL_MULTIGESTURE:
232 #if VERBOSE
233 SDL_Log("Multi Gesture: x = %f, y = %f, dAng = %f, dR = %f",
234 event.mgesture.x, event.mgesture.y,
235 event.mgesture.dTheta, event.mgesture.dDist);
236 SDL_Log("MG: numDownTouch = %i",event.mgesture.numFingers);
237 #endif
238
239 knob.p.x = event.mgesture.x;
240 knob.p.y = event.mgesture.y;
241 knob.ang += event.mgesture.dTheta;
242 knob.r += event.mgesture.dDist;
243 break;
244
245 case SDL_DOLLARGESTURE:
246 SDL_Log("Gesture %"SDL_PRIs64" performed, error: %f",
247 event.dgesture.gestureId, event.dgesture.error);
248 break;
249
250 case SDL_DOLLARRECORD:
251 SDL_Log("Recorded gesture: %"SDL_PRIs64"",event.dgesture.gestureId);
252 break;
253 }
254 }
255
256 for (i = 0; i < state->num_windows; ++i) {
257 if (state->windows[i]) {
258 DrawScreen(state->windows[i]);
259 }
260 }
261
262 #ifdef __EMSCRIPTEN__
263 if (quitting) {
264 emscripten_cancel_main_loop();
265 }
266 #endif
267 }
268
main(int argc,char * argv[])269 int main(int argc, char* argv[])
270 {
271 state = SDLTest_CommonCreateState(argv, SDL_INIT_VIDEO);
272 if (!state) {
273 return 1;
274 }
275
276 state->window_title = "Gesture Test";
277 state->window_w = WIDTH;
278 state->window_h = HEIGHT;
279 state->skip_renderer = SDL_TRUE;
280
281 if (!SDLTest_CommonDefaultArgs(state, argc, argv) || !SDLTest_CommonInit(state)) {
282 SDLTest_CommonQuit(state);
283 return 1;
284 }
285
286 #ifdef __EMSCRIPTEN__
287 emscripten_set_main_loop(loop, 0, 1);
288 #else
289 while (!quitting) {
290 loop();
291 }
292 #endif
293
294 SDLTest_CommonQuit(state);
295 return 0;
296 }
297
298