examples/src/event.c (e2a21a2) - libflexipix · BlinkenArea

event.c

#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>

#include <flexipix/flexipix.h>

#ifdef WINDOWS
#include <winsock.h>
#endif

/* just an example for some data */
typedef struct userdata_s {
  int i;
  float f;
  char c;
} userdata_t;

/* callback function called during display creation,
   the p_ctx parameter is the userdata supplied in the call
   to flp_display_create() */
void msg(void *p_ctx, flp_msg_type_t type, const char *fmt, ...)
{
  userdata_t *p_userdata = (userdata_t *)p_ctx;
  va_list va;

printf("msg (%d %f %c): ",
         p_userdata->i, p_userdata->f,
         p_userdata->c); /* make use of the userdata */

/* type tells if the message is an error, a warning or an information */
  switch (type) {
    case flp_msg_type_err:
      printf("ERROR: ");
      break;
    case flp_msg_type_warn:
      printf("WARNING: ");
      break;
    case flp_msg_type_info:
      printf("INFORMATION: ");
      break;
  }

/* fmt is a printf-style format string,
     the arguments are passed exactly as for printf */
  va_start(va, fmt);
  vprintf(fmt, va);
  va_end(va);
}

int main(int argc, char *argv[])
{
  const char *config;
  userdata_t userdata = { 42, 42.0, '!' }; /* just an example */
  flp_displayer_t *p_displayer;
  unsigned int width, height, i, j, c, x, y;
  flp_u8_t *p_image;
  char line[64];

if (argc < 2) {
    printf("usage: %s <config.flp>\n", argv[0]);
    return -1;
  }
  config = argv[1];

#ifdef WINDOWS
  {
    WSADATA data;
    WSAStartup(MAKEWORD(1,1), &data);
  }
#endif

/* create a displayer that manages a display in the background
     and takes care that data is sent periodically to the distributors
     to prevent that the pixels turn off after a timeout,
     take the configuration from a file,
     deliver messages to the callback function msg(),
     the last parameter is passed as first parameter to msg()
     and can be used to supply some user defined data */
  p_displayer = flp_displayer_create(config, msg, (void *)&userdata);
  if (!p_displayer) {
    printf("could not create displayer\n");
    return -1;
  }

flp_displayer_get_size(p_displayer, &width, &height);
  printf("width:  %5u\nheight: %5u\n", width, height);

/* create a buffer for the image */
  p_image = (flp_u8_t *)malloc(height * width * 3);
  if (!p_image) {
    flp_displayer_free(p_displayer);
    printf("out of memory\n");
    return -1;
  }

/* make displayer start sending data to distributors */
  flp_displayer_activate(p_displayer);

/* The following loop will spent most waiting for user input.
     While it is waiting, the displayer will periodically sent
     data to the distributors. */

printf("enter something, \".\" for end\n");
  while (1) {

/* wait for user input */
    printf("> ");
    scanf("%50s", line);
    if (line[0] == 0 || (line[0] == '.' && line[1] == 0))
      break;

/* create some image from entered text
       (this is just creating some image out of the entered data,
        it does not do any useful processing) */
    i = 0;
    j = 0;
    for (y = 0; y < height; ++y) {
      for (x = 0; x < width; ++x) {
        for (c = 0; c < 3; ++c) {
          p_image[i++] = (line[j++] & 0xF) * 0x11;
          if (line[j] == 0)
            j = 0;
        }
      }
    }

/* set new image */
    flp_displayer_data(p_displayer, p_image,
                       3, /* consecutive pixels are 3 bytes apart */
                       width*3, /* consecutive lines are width*3 bytes apart */
                       0, 0, width, height);
    /* force sending data to distris immediately */
    flp_displayer_send(p_displayer);

} /* while (1) */

free(p_image);
  flp_displayer_free(p_displayer);

#ifdef WINDOWS
  WSACleanup();
#endif

return 0;
}

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