gnuplot: fix for big-endian architectures.

[libsigrok.git] / output / gnuplot.c

diff --git a/output/gnuplot.c b/output/gnuplot.c
index 361ac25d79aa15b1f0c46952e343b46c871e5197..e2655ff1b73b4ae10f83744936210c62435d1c0f 100644 (file)
--- a/output/gnuplot.c
+++ b/output/gnuplot.c
@@ -39,6 +39,7 @@ struct context {
        unsigned int unitsize;
        char *probelist[SR_MAX_NUM_PROBES + 1];
        char *header;
+       uint8_t *old_sample;
 };
 
 #define MAX_HEADER_LEN \
@@ -154,6 +155,13 @@ static int init(struct sr_output *o)
                return SR_ERR;
        }
 
+       if (!(ctx->old_sample = g_try_malloc0(ctx->unitsize))) {
+               sr_err("%s: ctx->old_sample malloc failed", __func__);
+               g_free(ctx->header);
+               g_free(ctx);
+               return SR_ERR_MALLOC;
+       }
+
        return 0;
 }
 
@@ -199,8 +207,8 @@ static int data(struct sr_output *o, const uint8_t *data_in,
 {
        struct context *ctx;
        unsigned int max_linelen, outsize, p, curbit, i;
-       uint64_t sample;
-       static uint64_t samplecount = 0, old_sample = 0;
+       const uint8_t *sample;
+       static uint64_t samplecount = 0;
        uint8_t *outbuf, *c;
 
        if (!o) {
@@ -249,17 +257,18 @@ static int data(struct sr_output *o, const uint8_t *data_in,
 
        for (i = 0; i <= length_in - ctx->unitsize; i += ctx->unitsize) {
 
-               memcpy(&sample, data_in + i, ctx->unitsize);
+               sample = data_in + i;
 
                /*
                 * Don't output the same samples multiple times. However, make
                 * sure to output at least the first and last sample.
                 */
-               if (samplecount++ != 0 && sample == old_sample) {
+               if (samplecount++ != 0 &&
+                               !memcmp(sample, ctx->old_sample, ctx->unitsize)) {
                        if (i != (length_in - ctx->unitsize))
                                continue;
                }
-               old_sample = sample;
+               memcpy(ctx->old_sample, sample, ctx->unitsize);
 
                /* The first column is a counter (needed for gnuplot). */
                c = outbuf + strlen((const char *)outbuf);
@@ -267,7 +276,7 @@ static int data(struct sr_output *o, const uint8_t *data_in,
 
                /* The next columns are the values of all channels. */
                for (p = 0; p < ctx->num_enabled_probes; p++) {
-                       curbit = (sample & ((uint64_t) (1 << p))) >> p;
+                       curbit = (sample[p / 8] & ((uint8_t) (1 << (p % 8)))) >> (p % 8);
                        c = outbuf + strlen((const char *)outbuf);
                        sprintf((char *)c, "%d ", curbit);
                }