add a sine wave to demo.c

diff --git a/hardware/demo/demo.c b/hardware/demo/demo.c
index c18161f03ce3b23cdeed749e54a7e95f96cceaeb..e117e6a59afa29cf065e6f0afcd4e0975eb68c89 100644 (file)
--- a/hardware/demo/demo.c
+++ b/hardware/demo/demo.c
@@ -19,12 +19,13 @@
  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
  */
 
-//#define DEMO_ANALOG
+#define DEMO_ANALOG
 
 #include <stdlib.h>
 #include <unistd.h>
 #include <string.h>
 #include <sigrok.h>
+#include <math.h>
 #ifdef _WIN32
 #include <io.h>
 #include <fcntl.h>
@@ -49,6 +50,7 @@ enum {
        GENMODE_DEFAULT,
        GENMODE_RANDOM,
        GENMODE_INC,
+       GENMODE_SINE,
 };
 
 GIOChannel *channels[2];
@@ -74,6 +76,7 @@ static int capabilities[] = {
 static const char *patternmodes[] = {
        "random",
        "incremental",
+       "sine",
        NULL,
 };
 
@@ -206,6 +209,9 @@ static int hw_set_configuration(int device_index, int capability, void *value)
                } else if (!strcmp(stropt, "incremental")) {
                        default_genmode = GENMODE_INC;
                        ret = SIGROK_OK;
+               } else if (!strcmp(stropt, "sine")) {
+                       default_genmode = GENMODE_SINE;
+                       ret = SIGROK_OK;
                } else {
                        ret = SIGROK_ERR;
                }
@@ -235,6 +241,13 @@ static void samples_generator(uint8_t *buf, uint64_t size, void *data)
        switch (mydata->sample_generator) {
        default:
        case GENMODE_DEFAULT:
+       case GENMODE_SINE:
+               for (i = 0; i < size * 3; i += 3) {
+                       *(buf + i) = i / 3;
+                       *(uint16_t *) (buf + i + 1) =
+                               (uint16_t) (sin(i / 3) * 256 * 30);
+               }
+               break;
        case GENMODE_RANDOM:
                for (i = 0; i < size * 3; i += 3) {
                        *(buf + i) = (uint8_t)(rand() & 0xff);