src/displayer.c (aa3270a) - libflexipix · BlinkenArea

displayer.c

/*
 * FlexiPix library
 *
 * Copyright 2010-2011 Stefan Schuermans <stefan schuermans info>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, version 3 of the License.
 *
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 */

#include <sys/time.h>
#include <stdlib.h>

#include <flexipix/display.h>
#include <flexipix/displayer.h>
#include <flexipix/msg.h>
#include <flexipix/types.h>
#include <intern/displayer.h>
#include <intern/thread.h>
#include <intern/types.h>

/**
 * \brief create a new FlexiPix displayer
 *
 * A displayer manages a display and ensures that a the current
 * image data is sent often enough to the distributors so
 * that the pixels do detect a timeout and turn off automatically.
 * The displayer uses a thread to do this.
 * Initially, the new displayer is inactive and has to be activated
 * using flp_displayer_activate().
 *
 * \param[in] sz_config_file name of config file to read
 * \param[in] p_msg_func message callback function or NULL
 * \param[in] p_msg_ctx user context for message callback
 * \return pointer to new FlexiPix displayer on success
 *         or NULL on error
 */
flp_displayer_t *flp_displayer_create(const char *sz_config_file,
                                      flp_msg_func_p_t p_msg_func,
                                      void *p_msg_ctx)
{
  flp_displayer_t *p_displayer;

/* set up basic structure and display */

/* create displayer structure */
  p_displayer = (flp_displayer_t *)calloc(1, sizeof (flp_displayer_t));
  if (!p_displayer) {
    if (p_msg_func)
      p_msg_func(p_msg_ctx, flp_msg_type_err,
                 "out of memory\n");
    return NULL;
  }

/* set up flags */
  p_displayer->active = 0; /* not sending data to distributors */
  p_displayer->send   = 1; /* send first data as soon as active */
  p_displayer->end    = 0; /* do not end yet */

/* set up managed display */
  p_displayer->p_display = flp_display_create(sz_config_file,
                                              p_msg_func, p_msg_ctx);
  if (!p_displayer->p_display) {
    free(p_displayer);
    if (p_msg_func)
      p_msg_func(p_msg_ctx, flp_msg_type_err,
                 "could not create display\n");
    return NULL;
  }

/* set up output thread */

/* initialize mutex */
  if (!flp_thread_mutex_init(&p_displayer->mtx)) {
    flp_display_free(p_displayer->p_display);
    free(p_displayer);
    if (p_msg_func)
      p_msg_func(p_msg_ctx, flp_msg_type_err,
                 "could not initialize mutex\n");
    return NULL;
  }

/* initialize condition */
  if (!flp_thread_cond_init(&p_displayer->cond)) {
    flp_thread_mutex_destroy(&p_displayer->mtx);
    flp_display_free(p_displayer->p_display);
    free(p_displayer);
    if (p_msg_func)
      p_msg_func(p_msg_ctx, flp_msg_type_err,
                 "could not initialize condition\n");
    return NULL;
  }

/* create thread */
  if (!flp_thread_create(&p_displayer->tid, flp_displayer_thread,
                        (void *)p_displayer)) {
    flp_thread_cond_destroy(&p_displayer->cond);
    flp_thread_mutex_destroy(&p_displayer->mtx);
    flp_display_free(p_displayer->p_display);
    free(p_displayer);
    if (p_msg_func)
      p_msg_func(p_msg_ctx, flp_msg_type_err,
                 "could not create thread\n");
    return NULL;
  }

return p_displayer;
}

/**
 * \brief free a FlexiPix displayer
 *
 * \param[in] p_displayer pointer to FlexiPix displayer
 */
void flp_displayer_free(flp_displayer_t *p_displayer)
{
  /* tear down thread */
  p_displayer->end = 1;
  flp_thread_cond_signal(&p_displayer->cond);
  flp_thread_join(p_displayer->tid);
  flp_thread_cond_destroy(&p_displayer->cond);
  flp_thread_mutex_destroy(&p_displayer->mtx);

/* free managed display */
  flp_display_free(p_displayer->p_display);

/* free basic structure */
  free(p_displayer);
}

/**
 * \brief get size of display managed by displayer
 *
 * \param[in] p_displayer pointer to FlexiPix displayer
 * \param[out] p_width width of display
 * \param[out] p_height height of display
 */
void flp_displayer_get_size(flp_displayer_t *p_displayer,
                            unsigned int *p_width, unsigned int *p_height)
{
  flp_thread_mutex_lock(&p_displayer->mtx);
  flp_display_get_size(p_displayer->p_display, p_width, p_height);
  flp_thread_mutex_unlock(&p_displayer->mtx);
}

/**
 * \brief activate the displayer
 *
 * set the displayer to active, i.e. make it send image data
 * to the distributors automatically,
 * this function might trigger sending of data if the last
 * sending time was too long ago
 *
 * \param[in] p_displayer pointer to FlexiPix displayer
 */
void flp_displayer_activate(flp_displayer_t *p_displayer)
{
  p_displayer->active = 1;
  flp_thread_cond_signal(&p_displayer->cond);
}

/**
 * \brief deactivate the displayer
 *
 * set the displayer to deactive, i.e. prevent it from sening image
 * data to the distributors automatically,
 *
 * \param[in] p_displayer pointer to FlexiPix displayer
 */
void flp_displayer_deactivate(flp_displayer_t *p_displayer)
{
  p_displayer->active = 0;
  /* no need to signal condition: thread does not need to do something yet */
}

/**
 * \brief clear image data to output on FlexiPix displayer
 *
 * clears the stored image data
 *
 * \param[in] p_displayer pointer to FlexiPix displayer
 */
void flp_displayer_data_clear(flp_displayer_t *p_displayer)
{
  flp_thread_mutex_lock(&p_displayer->mtx);
  flp_display_data_clear(p_displayer->p_display);
  flp_thread_mutex_unlock(&p_displayer->mtx);
}

/**
 * \brief set image data to output on FlexiPix display
 *
 * updates (part of) the stored image data
 *
 * \param[in] p_displayer pointer to FlexiPix displayer
 * \param[in] p_data pointer to rectangular section of image data,
 *                   pixels need to be in R8G8B8 format
 * \param[in] stride_x stride between two pixels in X direction
 * \param[in] stride_y stride between two pixels in Y direction
 * \param[in] x X coordinate of left side of rectangular area
 * \param[in] y Y coordinate of top side of rectangular area
 * \param[in] width with of rectangular area
 * \param[in] height height of rectangular area
 */
void flp_displayer_data(flp_displayer_t *p_displayer, flp_u8_t *p_data,
                        int stride_x, int stride_y,
                        unsigned int x, unsigned int y,
                        unsigned int width, unsigned int height)
{
  flp_thread_mutex_lock(&p_displayer->mtx);
  flp_display_data(p_displayer->p_display, p_data, stride_x, stride_y,
                   x, y, width, height);
  flp_thread_mutex_unlock(&p_displayer->mtx);
}

/**
 * \brief trigger immediate sending of new image data to distributors
 *
 * this only works if the displayer is active
 *
 * \param[in] p_displayer pointer to FlexiPix displayer
 */
void flp_displayer_send(flp_displayer_t *p_displayer)
{
  p_displayer->send = 1;
  flp_thread_cond_signal(&p_displayer->cond);
}

/**
 * \brief output thread of displayer object
 *
 * \param[in] vp_displayer pointer to displayer object
 * \return unused, always NULL
 */
FLP_THREAD_FUNC(flp_displayer_thread)
{
  flp_displayer_t *p_displayer = (flp_displayer_t *)vp_displayer;
  struct timeval last, now, delta;
  int timed_send;
  int interval_ms = FLP_MCUF_MAX_FRAME_INTERVAL_MS;

flp_thread_mutex_lock(&p_displayer->mtx);

gettimeofday(&last, NULL); /* initialize last to some valid time */

/* while thread shall not end */
  while (!p_displayer->end) {

/* active */
    if (p_displayer->active) {

/* get current time */
      gettimeofday(&now, NULL);
      /* get time since sending last frame */
      delta.tv_sec = now.tv_sec - last.tv_sec;
      delta.tv_usec = now.tv_usec - last.tv_usec;
      if (delta.tv_usec < 0) {
        delta.tv_usec += 1000000;
        ++delta.tv_sec;
      }
      /* check if late enough for timed send */
      timed_send = delta.tv_sec > interval_ms / 1000
                 || (delta.tv_sec == interval_ms / 1000
                     && delta.tv_usec >= (interval_ms % 1000) * 1000);

/* send if send requested or late enough */
      if (p_displayer->send || timed_send) {
        flp_display_send(p_displayer->p_display); /* send */
        last = now;                               /* remember last send time */
        p_displayer->send = 0;                    /* clear send request */
      }

/* sleep until next frame has to be sent */
      flp_thread_cond_timedwait(&p_displayer->cond, &p_displayer->mtx,
                                &last, interval_ms);

} /* if (p_displayer->active) */

/* inactive */
    else {

/* sleep */
      flp_thread_cond_wait(&p_displayer->cond, &p_displayer->mtx);

} /* if (p_displayer->active) ... else */

} /* while(!p_displayer->end) */

flp_thread_mutex_unlock(&p_displayer->mtx);

FLP_THREAD_RETURN(NULL);
}

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