test/testgesture.c - third_party/sdl - Git at Google

 /*
   Copyright (C) 1997-2020 Sam Lantinga <slouken@libsdl.org>

   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 SDLTest_CommonState *state;
 static SDL_Event events[EVENT_BUF_SIZE];
 static int eventWrite;
 static int colors[7] = {0xFF,0xFF00,0xFF0000,0xFFFF00,0x00FFFF,0xFF00FF,0xFFFFFF};
 static int quitting = 0;

 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;
     }

     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 = (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);

     *pixmem32 = colour;
 }

 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;
     }

     SDL_FillRect(screen, NULL, SDL_MapRGB(screen->format, 75, 75, 75));

     /* 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);
     }

     SDL_UpdateWindowSurface(window);
 }

 static void
 loop(void)
 {
     SDL_Event event;
     SDL_RWops *stream;
     int i;

     while (SDL_PollEvent(&event)) {
         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;

 #if VERBOSE
             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;
 #endif

             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;
         }
     }

     for (i = 0; i < state->num_windows; ++i) {
         if (state->windows[i]) {
             DrawScreen(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
     while (!quitting) {
         loop();
     }
 #endif

     SDLTest_CommonQuit(state);
     return 0;
 }
	/*
	Copyright (C) 1997-2020 Sam Lantinga <slouken@libsdl.org>

	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 SDLTest_CommonState *state;
	static SDL_Event events[EVENT_BUF_SIZE];
	static int eventWrite;
	static int colors[7] = {0xFF,0xFF00,0xFF0000,0xFFFF00,0x00FFFF,0xFF00FF,0xFFFFFF};
	static int quitting = 0;

	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;
	}

	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 = (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);

	*pixmem32 = colour;
	}

	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;
	}

	SDL_FillRect(screen, NULL, SDL_MapRGB(screen->format, 75, 75, 75));

	/* 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);
	}

	SDL_UpdateWindowSurface(window);
	}

	static void
	loop(void)
	{
	SDL_Event event;
	SDL_RWops *stream;
	int i;

	while (SDL_PollEvent(&event)) {
	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;

	#if VERBOSE
	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;
	#endif

	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;
	}
	}

	for (i = 0; i < state->num_windows; ++i) {
	if (state->windows[i]) {
	DrawScreen(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
	while (!quitting) {
	loop();
	}
	#endif

	SDLTest_CommonQuit(state);
	return 0;
	}