output: fixup trigger marker position in ascii/bits/hex output modules

[libsigrok.git] / src / output / bits.c

diff --git a/src/output/bits.c b/src/output/bits.c
index 768a985ed84efe134cfedd091cd2810f3fb633a7..379f019be4ed038db70e514afecc8890d379ae3b 100644 (file)
--- a/src/output/bits.c
+++ b/src/output/bits.c
@@ -168,7 +168,14 @@ static int receive(const struct sr_output *o, const struct sr_datafeed_packet *p
                                        g_string_append_len(*out, ctx->lines[j]->str, ctx->lines[j]->len);
                                        g_string_append_c(*out, '\n');
                                        if (j == ctx->num_enabled_channels - 1 && ctx->trigger > -1) {
-                                               offset = ctx->trigger + ctx->trigger / 8;
+                                               /*
+                                                * Each group of 8 bits occupies 8 bit positions
+                                                * plus 1 separator. Calculate the position of the
+                                                * byte which contains the trigger, then adjust for
+                                                * the trigger's bit position within that byte.
+                                                */
+                                               offset = ctx->trigger / 8 * (8 + 1);
+                                               offset += ctx->trigger % 8;
                                                g_string_append_printf(*out, "T:%*s^ %d\n", offset, "", ctx->trigger);
                                                ctx->trigger = -1;
                                        }