src/transform/invert.c

   1 /*
   2  * This file is part of the libsigrok project.
   3  *
   4  * Copyright (C) 2015 Uwe Hermann <uwe@hermann-uwe.de>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include <config.h>
  21 #include <string.h>
  22 #include <libsigrok/libsigrok.h>
  23 #include "libsigrok-internal.h"
  24
  25 #define LOG_PREFIX "transform/invert"
  26
  27 static int receive(const struct sr_transform *t,
  28                 struct sr_datafeed_packet *packet_in,
  29                 struct sr_datafeed_packet **packet_out)
  30 {
  31         const struct sr_datafeed_logic *logic;
  32         const struct sr_datafeed_analog *analog;
  33         uint8_t *b;
  34         int64_t p;
  35         uint64_t i, j, q;
  36
  37         if (!t || !t->sdi || !packet_in || !packet_out)
  38                 return SR_ERR_ARG;
  39
  40         switch (packet_in->type) {
  41         case SR_DF_LOGIC:
  42                 logic = packet_in->payload;
  43                 for (i = 0; i <= logic->length - logic->unitsize; i += logic->unitsize) {
  44                         for (j = 0; j < logic->unitsize; j++) {
  45                                 /* For now invert every bit in every byte. */
  46                                 b = (uint8_t *)logic->data + i + logic->unitsize - 1 - j;
  47                                 *b = ~(*b);
  48                         }
  49                 }
  50                 break;
  51         case SR_DF_ANALOG:
  52                 analog = packet_in->payload;
  53                 p = analog->encoding->scale.p;
  54                 q = analog->encoding->scale.q;
  55                 if (q > INT64_MAX)
  56                         return SR_ERR;
  57                 analog->encoding->scale.p = (p < 0) ? -q : q;
  58                 analog->encoding->scale.q = (p < 0) ? -p : p;
  59                 break;
  60         default:
  61                 sr_spew("Unsupported packet type %d, ignoring.", packet_in->type);
  62                 break;
  63         }
  64
  65         /* Return the in-place-modified packet. */
  66         *packet_out = packet_in;
  67
  68         return SR_OK;
  69 }
  70
  71 SR_PRIV struct sr_transform_module transform_invert = {
  72         .id = "invert",
  73         .name = "Invert",
  74         .desc = "Invert values",
  75         .options = NULL,
  76         .init = NULL,
  77         .receive = receive,
  78         .cleanup = NULL,
  79 };