This software is provided 'as-is', without any express or implied

warranty. In no event will the authors be held liable for any damages

arising from the use of this software.

Permission is granted to anyone to use this software for any purpose,

including commercial applications, and to alter it and redistribute it

freely.

*/

/* Usage:

* Spacebar to begin recording a gesture on all touches.

* s to save all touches into "./gestureSave"

* l to load all touches from "./gestureSave"

*/

#include "SDL.h"

#include <stdlib.h> /* for exit() */

#ifdef __EMSCRIPTEN__

#include <emscripten/emscripten.h>

#endif

#include "SDL_test.h"

#include "SDL_test_common.h"

#define WIDTH 640

#define HEIGHT 480

#define BPP 4

/* MUST BE A POWER OF 2! */

#define EVENT_BUF_SIZE 256

#define VERBOSE 0

static SDL_Event events[EVENT_BUF_SIZE];

static int eventWrite;

static int colors[7] = {0xFF,0xFF00,0xFF0000,0xFFFF00,0x00FFFF,0xFF00FF,0xFFFFFF};

typedef struct

{

float x, y;

} Point;

typedef struct

{

float ang, r;

Point p;

} Knob;

static Knob knob = { 0.0f, 0.1f, { 0.0f, 0.0f } };

static void

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

Uint32 *pixmem32;

Uint32 colour;

Uint8 r, g, b;

const int x = (int)_x;

const int y = (int)_y;

float a;

if ( (x < 0) || (x >= screen->w) || (y < 0) || (y >= screen->h) ) {

return;

}

/* r = 0;g = 0; b = 0; */

a = (float) ((col >> 24) & 0xFF);

if (a == 0) {

a = 0xFF; /* Hack, to make things easier. */

}

a = (a == 0.0f) ? 1 : (a / 255.0f);

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);

}

static void

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

{

float t;

for (t = 0; t < 1; t += (float) (1.0f / SDL_max(SDL_fabs(x0 - x1), SDL_fabs(y0 - y1)))) {

setpix(screen, x1 + t * (x0 - x1), y1 + t * (y0 - y1), col);

}

}

static void

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

float tx,ty, 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 + 0.5f; tx <= xr - 0.5f; tx++) {

setpix(screen, x + tx, y + ty, c);

}

} else {

setpix(screen, x - xr + 0.5f, y + ty, c);

setpix(screen, x + xr - 0.5f, y + ty, c);

}

}

}

static void

drawKnob(SDL_Surface *screen, const Knob *k)

{

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);

}

static void

DrawScreen(SDL_Window *window)

SDL_Surface *screen = SDL_GetWindowSurface(window);

int i;

if (!screen) {

return;

}

/* draw Touch History */

for (i = eventWrite; i < eventWrite + EVENT_BUF_SIZE; ++i) {

const SDL_Event *event = &events[i & (EVENT_BUF_SIZE - 1)];

const 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 * (0.1f + 0.85f))) | (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);

}

}

static void

loop(void)

{

SDL_Event event;

SDL_RWops *stream;

SDLTest_CommonEvent(state, &event, &quitting);

/* Record _all_ events */

events[eventWrite & (EVENT_BUF_SIZE-1)] = event;

eventWrite++;

switch (event.type) {

case SDL_KEYDOWN:

switch (event.key.keysym.sym) {

case SDLK_i: {

for (i = 0; i < SDL_GetNumTouchDevices(); ++i) {

const 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;

}

break;

case SDL_FINGERMOTION:

SDL_Log("Finger: %"SDL_PRIs64",x: %f, y: %f",event.tfinger.fingerId,

event.tfinger.x,event.tfinger.y);

break;

case SDL_FINGERDOWN:

SDL_Log("Finger: %"SDL_PRIs64" down - x: %f, y: %f",

event.tfinger.fingerId,event.tfinger.x,event.tfinger.y);

break;

case SDL_FINGERUP:

SDL_Log("Finger: %"SDL_PRIs64" up - x: %f, y: %f",

event.tfinger.fingerId,event.tfinger.x,event.tfinger.y);

break;

case SDL_MULTIGESTURE:

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);

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;

}

for (i = 0; i < state->num_windows; ++i) {

if (state->windows[i]) {

}

}

#ifdef __EMSCRIPTEN__

if (quitting) {

emscripten_cancel_main_loop();

}

#endif

}

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

{

state = SDLTest_CommonCreateState(argv, SDL_INIT_VIDEO);

if (!state) {

return 1;

}

state->window_title = "Gesture Test";

state->window_w = WIDTH;

state->window_h = HEIGHT;

state->skip_renderer = SDL_TRUE;

if (!SDLTest_CommonDefaultArgs(state, argc, argv) || !SDLTest_CommonInit(state)) {

SDLTest_CommonQuit(state);

return 1;

}

#ifdef __EMSCRIPTEN__

emscripten_set_main_loop(loop, 0, 1);

#else

loop();

}

#endif

SDLTest_CommonQuit(state);

return 0;