#include "SDL.h"
#include <stdlib.h>

Include dependency graph for testgesture.c:

Data Structures
struct	Point
struct	Knob

Macros
#define	WIDTH 640
#define	HEIGHT 480
#define	BPP 4
#define	EVENT_BUF_SIZE 256
#define	VERBOSE 0

Functions
void	setpix (SDL_Surface *screen, float _x, float _y, unsigned int col)
void	drawLine (SDL_Surface *screen, float x0, float y0, float x1, float y1, unsigned int col)
void	drawCircle (SDL_Surface *screen, float x, float y, float r, unsigned int c)
void	drawKnob (SDL_Surface *screen, Knob k)
void	DrawScreen (SDL_Surface screen, SDL_Window window)
SDL_Window *	initWindow (SDL_Window *window, int width, int height)
void	loop ()
int	main (int argc, char *argv[])

Variables
static SDL_Event	events [EVENT_BUF_SIZE]
static int	eventWrite
static int	colors [7] = {0xFF,0xFF00,0xFF0000,0xFFFF00,0x00FFFF,0xFF00FF,0xFFFFFF}
SDL_Surface *	screen
SDL_Window *	window
SDL_bool	quitting = SDL_FALSE
static Knob	knob

Macro Definition Documentation

#define BPP 4

Definition at line 27 of file testgesture.c.

Referenced by setpix().

#define EVENT_BUF_SIZE 256

Definition at line 30 of file testgesture.c.

Referenced by DrawScreen(), and loop().

#define HEIGHT 480

Definition at line 26 of file testgesture.c.

Referenced by main().

#define VERBOSE 0

Definition at line 33 of file testgesture.c.

#define WIDTH 640

Definition at line 25 of file testgesture.c.

Referenced by main().

Function Documentation

void drawCircle	(	SDL_Surface *	screen,
		float	x,
		float	y,
		float	r,
		unsigned int	c
	)

Definition at line 92 of file testgesture.c.

References SDL_fabs, SDL_sqrt, and setpix().

Referenced by drawKnob(), and DrawScreen().

{
  float tx,ty;
  float xr;
  for(ty = (float)-SDL_fabs(r);ty <= (float)SDL_fabs((int)r);ty++) {
    xr = (float)SDL_sqrt(r*r - ty*ty);
    if(r > 0) { /* r > 0 ==> filled circle */
      for(tx=-xr+.5f;tx<=xr-.5;tx++) {
    setpix(screen,x+tx,y+ty,c);
      }
    }
    else {
      setpix(screen,x-xr+.5f,y+ty,c);
      setpix(screen,x+xr-.5f,y+ty,c);
    }
  }
}

void drawKnob	(	SDL_Surface *	screen,
		Knob	k
	)

Definition at line 110 of file testgesture.c.

References Knob::ang, drawCircle(), SDL_Surface::h, Knob::p, Knob::r, SDL_cosf, SDL_sinf, SDL_Surface::w, Point::x, and Point::y.

Referenced by DrawScreen().

                                          {
  drawCircle(screen,k.p.x*screen->w,k.p.y*screen->h,k.r*screen->w,0xFFFFFF);
  drawCircle(screen,(k.p.x+k.r/2*SDL_cosf(k.ang))*screen->w,
                (k.p.y+k.r/2*SDL_sinf(k.ang))*screen->h,k.r/4*screen->w,0);
}

void drawLine	(	SDL_Surface *	screen,
		float	x0,
		float	y0,
		float	x1,
		float	y1,
		unsigned int	col
	)

Definition at line 86 of file testgesture.c.

References SDL_fabs, SDL_max, and setpix().

                                                                                        {
  float t;
  for(t=0;t<1;t+=(float)(1.f/SDL_max(SDL_fabs(x0-x1),SDL_fabs(y0-y1))))
    setpix(screen,x1+t*(x0-x1),y1+t*(y0-y1),col);
}

void DrawScreen	(	SDL_Surface *	screen,
		SDL_Window *	window
	)

Definition at line 116 of file testgesture.c.

References colors, drawCircle(), drawKnob(), EVENT_BUF_SIZE, eventWrite, SDL_Surface::h, i, NULL, Knob::p, SDL_FillRect, SDL_FINGERDOWN, SDL_FINGERMOTION, SDL_FINGERUP, SDL_UpdateWindowSurface, setpix(), SDL_Surface::w, and Point::x.

Referenced by loop().

{
  int i;
#if 1
  SDL_FillRect(screen, NULL, 0);
#else
  int x, y;
  for(y = 0;y < screen->h;y++)
    for(x = 0;x < screen->w;x++)
    setpix(screen,(float)x,(float)y,((x%255)<<16) + ((y%255)<<8) + (x+y)%255);
#endif
  /* draw Touch History */
  for(i = eventWrite; i < eventWrite+EVENT_BUF_SIZE; ++i) {
    const SDL_Event *event = &events[i&(EVENT_BUF_SIZE-1)];
    float age = (float)(i - eventWrite) / EVENT_BUF_SIZE;
    float x, y;
    unsigned int c, col;
    if(event->type == SDL_FINGERMOTION ||
       event->type == SDL_FINGERDOWN ||
       event->type == SDL_FINGERUP) {
      x = event->tfinger.x;
      y = event->tfinger.y;
      /* draw the touch: */
      c = colors[event->tfinger.fingerId%7];
      col = ((unsigned int)(c*(.1+.85))) | (unsigned int)(0xFF*age)<<24;
      if(event->type == SDL_FINGERMOTION)
    drawCircle(screen,x*screen->w,y*screen->h,5,col);
      else if(event->type == SDL_FINGERDOWN)
    drawCircle(screen,x*screen->w,y*screen->h,-10,col);
    }
  }
  if(knob.p.x > 0)
    drawKnob(screen,knob);
  SDL_UpdateWindowSurface(window);
}

SDL_Window* initWindow	(	SDL_Window *	window,
		int	width,
		int	height
	)

Definition at line 159 of file testgesture.c.

References SDL_CreateWindow, SDL_WINDOW_RESIZABLE, and SDL_WINDOWPOS_CENTERED.

Referenced by loop(), and main().

{
  if (!window) {
    window = SDL_CreateWindow("Gesture Test",
                              SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED,
                              width, height, SDL_WINDOW_RESIZABLE);
  }
  return window;
}

void loop ( )

Definition at line 169 of file testgesture.c.

References Knob::ang, SDL_WindowEvent::data1, SDL_WindowEvent::data2, SDL_MultiGestureEvent::dDist, SDL_Event::dgesture, DrawScreen(), SDL_MultiGestureEvent::dTheta, SDL_DollarGestureEvent::error, SDL_WindowEvent::event, EVENT_BUF_SIZE, eventWrite, SDL_TouchFingerEvent::fingerId, SDL_DollarGestureEvent::gestureId, i, initWindow(), SDL_Event::key, SDL_KeyboardEvent::keysym, SDL_Event::mgesture, SDL_MultiGestureEvent::numFingers, Knob::p, quitting, Knob::r, SDL_DOLLARGESTURE, SDL_DOLLARRECORD, SDL_FINGERDOWN, SDL_FINGERMOTION, SDL_FINGERUP, SDL_GetNumTouchDevices, SDL_GetNumTouchFingers, SDL_GetTouchDevice, SDL_GetWindowSurface, SDL_KEYDOWN, SDL_LoadDollarTemplates, SDL_Log, SDL_MULTIGESTURE, SDL_PollEvent, SDL_PRIs64, SDL_Quit, SDL_QUIT, SDL_RecordGesture, SDL_RWclose, SDL_RWFromFile, SDL_SaveAllDollarTemplates, SDL_TRUE, SDL_WINDOWEVENT, SDL_WINDOWEVENT_RESIZED, SDLK_ESCAPE, SDLK_i, SDLK_l, SDLK_s, SDLK_SPACE, SDL_Keysym::sym, SDL_Event::tfinger, SDL_Event::type, SDL_Event::window, Point::x, SDL_TouchFingerEvent::x, SDL_MultiGestureEvent::x, Point::y, SDL_TouchFingerEvent::y, and SDL_MultiGestureEvent::y.

{
    SDL_Event event;
    SDL_RWops *stream;
    while(SDL_PollEvent(&event))
    {
    /* Record _all_ events */
    events[eventWrite & (EVENT_BUF_SIZE-1)] = event;
    eventWrite++;
    switch (event.type)
      {
      case SDL_QUIT:
        quitting = SDL_TRUE;
        break;
      case SDL_KEYDOWN:
        switch (event.key.keysym.sym)
          {
              case SDLK_i:
              {
                  int i;
                  for (i = 0; i < SDL_GetNumTouchDevices(); ++i) {
                      SDL_TouchID id = SDL_GetTouchDevice(i);
                      SDL_Log("Fingers Down on device %"SDL_PRIs64": %d", id, SDL_GetNumTouchFingers(id));
                  }
                  break;
              }
          case SDLK_SPACE:
        SDL_RecordGesture(-1);
        break;
          case SDLK_s:
        stream = SDL_RWFromFile("gestureSave", "w");
        SDL_Log("Wrote %i templates", SDL_SaveAllDollarTemplates(stream));
        SDL_RWclose(stream);
        break;
          case SDLK_l:
        stream = SDL_RWFromFile("gestureSave", "r");
        SDL_Log("Loaded: %i", SDL_LoadDollarTemplates(-1, stream));
        SDL_RWclose(stream);
        break;
          case SDLK_ESCAPE:
        quitting = SDL_TRUE;
        break;
        }
        break;
      case SDL_WINDOWEVENT:
            if (event.window.event == SDL_WINDOWEVENT_RESIZED) {
          if (!(window = initWindow(window, event.window.data1, event.window.data2)) ||
              !(screen = SDL_GetWindowSurface(window)))
          {
        SDL_Quit();
        exit(1);
          }
            }
        break;
      case SDL_FINGERMOTION:
#if VERBOSE
        SDL_Log("Finger: %"SDL_PRIs64",x: %f, y: %f",event.tfinger.fingerId,
               event.tfinger.x,event.tfinger.y);
#endif
        break;
      case SDL_FINGERDOWN:
#if VERBOSE
        SDL_Log("Finger: %"SDL_PRIs64" down - x: %f, y: %f",
           event.tfinger.fingerId,event.tfinger.x,event.tfinger.y);
#endif
        break;
      case SDL_FINGERUP:
#if VERBOSE
        SDL_Log("Finger: %"SDL_PRIs64" up - x: %f, y: %f",
               event.tfinger.fingerId,event.tfinger.x,event.tfinger.y);
#endif
        break;
      case SDL_MULTIGESTURE:
#if VERBOSE
        SDL_Log("Multi Gesture: x = %f, y = %f, dAng = %f, dR = %f",
           event.mgesture.x,
           event.mgesture.y,
           event.mgesture.dTheta,
           event.mgesture.dDist);
        SDL_Log("MG: numDownTouch = %i",event.mgesture.numFingers);
#endif
        knob.p.x = event.mgesture.x;
        knob.p.y = event.mgesture.y;
        knob.ang += event.mgesture.dTheta;
        knob.r += event.mgesture.dDist;
        break;
      case SDL_DOLLARGESTURE:
        SDL_Log("Gesture %"SDL_PRIs64" performed, error: %f",
           event.dgesture.gestureId,
           event.dgesture.error);
        break;
      case SDL_DOLLARRECORD:
        SDL_Log("Recorded gesture: %"SDL_PRIs64"",event.dgesture.gestureId);
        break;
      }
    }
    DrawScreen(screen, window);
#ifdef __EMSCRIPTEN__
    if (quitting) {
        emscripten_cancel_main_loop();
    }
#endif
}

int main	(	int	argc,
		char *	argv[]
	)

Definition at line 276 of file testgesture.c.

References Knob::ang, HEIGHT, initWindow(), loop(), NULL, quitting, Knob::r, SDL_FALSE, SDL_GetWindowSurface, SDL_Init, SDL_INIT_VIDEO, SDL_LOG_CATEGORY_APPLICATION, SDL_LOG_PRIORITY_INFO, SDL_LogSetPriority, SDL_Quit, and WIDTH.

{
  window = NULL;
  screen = NULL;
  quitting = SDL_FALSE;
  /* Enable standard application logging */
  SDL_LogSetPriority(SDL_LOG_CATEGORY_APPLICATION, SDL_LOG_PRIORITY_INFO);
  /* gesture variables */
  knob.r = .1f;
  knob.ang = 0;
  if (SDL_Init(SDL_INIT_VIDEO) < 0 ) return 1;
  if (!(window = initWindow(window, WIDTH, HEIGHT)) ||
      !(screen = SDL_GetWindowSurface(window)))
  {
      SDL_Quit();
      return 1;
  }
#ifdef __EMSCRIPTEN__
    emscripten_set_main_loop(loop, 0, 1);
#else
    while(!quitting) {
        loop();
    }
#endif
  SDL_Quit();
  return 0;
}

void setpix	(	SDL_Surface *	screen,
		float	_x,
		float	_y,
		unsigned int	col
	)

Definition at line 56 of file testgesture.c.

References BPP, SDL_PixelFormat::BytesPerPixel, SDL_Surface::format, SDL_Surface::h, SDL_Surface::pitch, SDL_Surface::pixels, SDL_GetRGB, SDL_MapRGB, SDL_memcpy, and SDL_Surface::w.

Referenced by drawCircle(), drawLine(), and DrawScreen().

{
  Uint32 *pixmem32;
  Uint32 colour;
  Uint8 r,g,b;
  int x = (int)_x;
  int y = (int)_y;
  float a;
  if(x < 0 || x >= screen->w) return;
  if(y < 0 || y >= screen->h) return;
  pixmem32 = (Uint32*) screen->pixels  + y*screen->pitch/BPP + x;
  SDL_memcpy(&colour,pixmem32,screen->format->BytesPerPixel);
  SDL_GetRGB(colour,screen->format,&r,&g,&b);
  /* r = 0;g = 0; b = 0; */
  a = (float)((col>>24)&0xFF);
  if(a == 0) a = 0xFF; /* Hack, to make things easier. */
  a /= 0xFF;
  r = (Uint8)(r*(1-a) + ((col>>16)&0xFF)*(a));
  g = (Uint8)(g*(1-a) + ((col>> 8)&0xFF)*(a));
  b = (Uint8)(b*(1-a) + ((col>> 0)&0xFF)*(a));
  colour = SDL_MapRGB( screen->format,r, g, b);
  *pixmem32 = colour;
}