1/*
2  Copyright (C) 1997-2014 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/*  Usage:
13 *  Spacebar to begin recording a gesture on all touches.
14 *  s to save all touches into "./gestureSave"
15 *  l to load all touches from "./gestureSave"
16 */
17
18#include <stdio.h>
19#include <math.h>
20
21#include "SDL.h"
22#include "SDL_touch.h"
23#include "SDL_gesture.h"
24
25/* Make sure we have good macros for printing 32 and 64 bit values */
26#ifndef PRIs32
27#define PRIs32 "d"
28#endif
29#ifndef PRIu32
30#define PRIu32 "u"
31#endif
32#ifndef PRIs64
33#ifdef __WIN32__
34#define PRIs64 "I64"
35#else
36#define PRIs64 "lld"
37#endif
38#endif
39#ifndef PRIu64
40#ifdef __WIN32__
41#define PRIu64 "I64u"
42#else
43#define PRIu64 "llu"
44#endif
45#endif
46
47#define WIDTH 640
48#define HEIGHT 480
49#define BPP 4
50#define DEPTH 32
51
52/* MUST BE A POWER OF 2! */
53#define EVENT_BUF_SIZE 256
54
55
56#define VERBOSE 0
57
58static SDL_Window *window;
59static SDL_Event events[EVENT_BUF_SIZE];
60static int eventWrite;
61
62
63static int colors[7] = {0xFF,0xFF00,0xFF0000,0xFFFF00,0x00FFFF,0xFF00FF,0xFFFFFF};
64
65typedef struct {
66  float x,y;
67} Point;
68
69typedef struct {
70  float ang,r;
71  Point p;
72} Knob;
73
74static Knob knob;
75
76void handler (int sig)
77{
78  SDL_Log ("exiting...(%d)", sig);
79  exit (0);
80}
81
82void perror_exit (char *error)
83{
84  perror (error);
85  handler (9);
86}
87
88void setpix(SDL_Surface *screen, float _x, float _y, unsigned int col)
89{
90  Uint32 *pixmem32;
91  Uint32 colour;
92  Uint8 r,g,b;
93  int x = (int)_x;
94  int y = (int)_y;
95  float a;
96
97  if(x < 0 || x >= screen->w) return;
98  if(y < 0 || y >= screen->h) return;
99
100  pixmem32 = (Uint32*) screen->pixels  + y*screen->pitch/BPP + x;
101
102  SDL_memcpy(&colour,pixmem32,screen->format->BytesPerPixel);
103
104  SDL_GetRGB(colour,screen->format,&r,&g,&b);
105  /* r = 0;g = 0; b = 0; */
106  a = (float)((col>>24)&0xFF);
107  if(a == 0) a = 0xFF; /* Hack, to make things easier. */
108  a /= 0xFF;
109  r = (Uint8)(r*(1-a) + ((col>>16)&0xFF)*(a));
110  g = (Uint8)(g*(1-a) + ((col>> 8)&0xFF)*(a));
111  b = (Uint8)(b*(1-a) + ((col>> 0)&0xFF)*(a));
112  colour = SDL_MapRGB( screen->format,r, g, b);
113
114
115  *pixmem32 = colour;
116}
117
118void drawLine(SDL_Surface *screen,float x0,float y0,float x1,float y1,unsigned int col) {
119  float t;
120  for(t=0;t<1;t+=(float)(1.f/SDL_max(SDL_fabs(x0-x1),SDL_fabs(y0-y1))))
121    setpix(screen,x1+t*(x0-x1),y1+t*(y0-y1),col);
122}
123
124void drawCircle(SDL_Surface* screen,float x,float y,float r,unsigned int c)
125{
126  float tx,ty;
127  float xr;
128  for(ty = (float)-SDL_fabs(r);ty <= (float)SDL_fabs((int)r);ty++) {
129    xr = (float)sqrt(r*r - ty*ty);
130    if(r > 0) { /* r > 0 ==> filled circle */
131      for(tx=-xr+.5f;tx<=xr-.5;tx++) {
132    setpix(screen,x+tx,y+ty,c);
133      }
134    }
135    else {
136      setpix(screen,x-xr+.5f,y+ty,c);
137      setpix(screen,x+xr-.5f,y+ty,c);
138    }
139  }
140}
141
142void drawKnob(SDL_Surface* screen,Knob k) {
143  drawCircle(screen,k.p.x*screen->w,k.p.y*screen->h,k.r*screen->w,0xFFFFFF);
144  drawCircle(screen,(k.p.x+k.r/2*SDL_cosf(k.ang))*screen->w,
145                (k.p.y+k.r/2*SDL_sinf(k.ang))*screen->h,k.r/4*screen->w,0);
146}
147
148void DrawScreen(SDL_Surface* screen)
149{
150  int i;
151#if 1
152  SDL_FillRect(screen, NULL, 0);
153#else
154  int x, y;
155  for(y = 0;y < screen->h;y++)
156    for(x = 0;x < screen->w;x++)
157    setpix(screen,(float)x,(float)y,((x%255)<<16) + ((y%255)<<8) + (x+y)%255);
158#endif
159
160  /* draw Touch History */
161  for(i = eventWrite; i < eventWrite+EVENT_BUF_SIZE; ++i) {
162    const SDL_Event *event = &events[i&(EVENT_BUF_SIZE-1)];
163    float age = (float)(i - eventWrite) / EVENT_BUF_SIZE;
164    float x, y;
165    unsigned int c, col;
166
167    if(event->type == SDL_FINGERMOTION ||
168       event->type == SDL_FINGERDOWN ||
169       event->type == SDL_FINGERUP) {
170      x = event->tfinger.x;
171      y = event->tfinger.y;
172
173      /* draw the touch: */
174      c = colors[event->tfinger.fingerId%7];
175      col = ((unsigned int)(c*(.1+.85))) | (unsigned int)(0xFF*age)<<24;
176
177      if(event->type == SDL_FINGERMOTION)
178    drawCircle(screen,x*screen->w,y*screen->h,5,col);
179      else if(event->type == SDL_FINGERDOWN)
180    drawCircle(screen,x*screen->w,y*screen->h,-10,col);
181    }
182  }
183
184  if(knob.p.x > 0)
185    drawKnob(screen,knob);
186
187  SDL_UpdateWindowSurface(window);
188}
189
190SDL_Surface* initScreen(int width,int height)
191{
192  if (!window) {
193    window = SDL_CreateWindow("Gesture Test",
194                              SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED,
195                              width, height, SDL_WINDOW_RESIZABLE);
196  }
197  if (!window) {
198    return NULL;
199  }
200  return SDL_GetWindowSurface(window);
201}
202
203int main(int argc, char* argv[])
204{
205  SDL_Surface *screen;
206  SDL_Event event;
207  SDL_bool quitting = SDL_FALSE;
208  SDL_RWops *stream;
209
210  /* Enable standard application logging */
211  SDL_LogSetPriority(SDL_LOG_CATEGORY_APPLICATION, SDL_LOG_PRIORITY_INFO);
212
213  /* gesture variables */
214  knob.r = .1f;
215  knob.ang = 0;
216
217  if (SDL_Init(SDL_INIT_VIDEO) < 0 ) return 1;
218
219  if (!(screen = initScreen(WIDTH,HEIGHT)))
220    {
221      SDL_Quit();
222      return 1;
223    }
224
225  while(!quitting) {
226    while(SDL_PollEvent(&event))
227      {
228    /* Record _all_ events */
229    events[eventWrite & (EVENT_BUF_SIZE-1)] = event;
230    eventWrite++;
231
232    switch (event.type)
233      {
234      case SDL_QUIT:
235        quitting = SDL_TRUE;
236        break;
237      case SDL_KEYDOWN:
238        switch (event.key.keysym.sym)
239          {
240          case SDLK_SPACE:
241        SDL_RecordGesture(-1);
242        break;
243          case SDLK_s:
244        stream = SDL_RWFromFile("gestureSave", "w");
245        SDL_Log("Wrote %i templates", SDL_SaveAllDollarTemplates(stream));
246        SDL_RWclose(stream);
247        break;
248          case SDLK_l:
249        stream = SDL_RWFromFile("gestureSave", "r");
250        SDL_Log("Loaded: %i", SDL_LoadDollarTemplates(-1, stream));
251        SDL_RWclose(stream);
252        break;
253          case SDLK_ESCAPE:
254        quitting = SDL_TRUE;
255        break;
256        }
257        break;
258      case SDL_WINDOWEVENT:
259            if (event.window.event == SDL_WINDOWEVENT_RESIZED) {
260          if (!(screen = initScreen(event.window.data1, event.window.data2)))
261          {
262        SDL_Quit();
263        return 1;
264          }
265            }
266        break;
267      case SDL_FINGERMOTION:
268#if VERBOSE
269        SDL_Log("Finger: %i,x: %i, y: %i",event.tfinger.fingerId,
270               event.tfinger.x,event.tfinger.y);
271#endif
272        break;
273      case SDL_FINGERDOWN:
274#if VERBOSE
275        SDL_Log("Finger: %"PRIs64" down - x: %i, y: %i",
276           event.tfinger.fingerId,event.tfinger.x,event.tfinger.y);
277#endif
278        break;
279      case SDL_FINGERUP:
280#if VERBOSE
281        SDL_Log("Finger: %"PRIs64" up - x: %i, y: %i",
282               event.tfinger.fingerId,event.tfinger.x,event.tfinger.y);
283#endif
284        break;
285      case SDL_MULTIGESTURE:
286#if VERBOSE
287        SDL_Log("Multi Gesture: x = %f, y = %f, dAng = %f, dR = %f",
288           event.mgesture.x,
289           event.mgesture.y,
290           event.mgesture.dTheta,
291           event.mgesture.dDist);
292        SDL_Log("MG: numDownTouch = %i",event.mgesture.numFingers);
293#endif
294        knob.p.x = event.mgesture.x;
295        knob.p.y = event.mgesture.y;
296        knob.ang += event.mgesture.dTheta;
297        knob.r += event.mgesture.dDist;
298        break;
299      case SDL_DOLLARGESTURE:
300        SDL_Log("Gesture %"PRIs64" performed, error: %f",
301           event.dgesture.gestureId,
302           event.dgesture.error);
303        break;
304      case SDL_DOLLARRECORD:
305        SDL_Log("Recorded gesture: %"PRIs64"",event.dgesture.gestureId);
306        break;
307      }
308      }
309    DrawScreen(screen);
310  }
311  SDL_Quit();
312  return 0;
313}
314
315