put scrolling into separate thread; activate minutely updates; cleanup

3 files changed, 128 insertions, 60 deletions

diff --git a/anzeige.c b/anzeige.c
index ed79b1c..7bc8980 100644
--- a/anzeige.c
+++ b/anzeige.c
@@ -9,6 +9,7 @@
 #include <string.h>
 #include <pthread.h>
 #include <signal.h>
+#include <time.h>
 
 #include "fonts.h"
 #include "input_gadgets.h"
@@ -17,16 +18,14 @@
 void drop_privileges();
 void handle_signals(int signo);
 
-t_display_data display_data;
+t_scroll_data scroll_data;
 
 int main(int argc, char **argv)
 {
-  pthread_t thread_id;
   int ret_val;
-  #define TEXT_BUFFER_LENGTH 256
+  #define TEXT_BUFFER_LENGTH    SCROLL_BUF_LEN / 5
   char *text_buffer;
   char *text_buffer_end;
-  t_scroll_buffer scroll_buffers[2];
 
   // Set up gpi pointer for direct register access
   ret_val = multiplexer_setup_root();
@@ -49,7 +48,7 @@ int main(int argc, char **argv)
     sigaction (SIGHUP, &new_action, NULL);
   sigaction (SIGTERM, NULL, &old_action);
   if (old_action.sa_handler != SIG_IGN)
-    sigaction (SIGTERM, &new_action, NULL);struct sigaction action;
+    sigaction (SIGTERM, &new_action, NULL);
 
  /************************************************************************\
   * You are about to change the GPIO settings of your computer.          *
@@ -59,62 +58,67 @@ int main(int argc, char **argv)
  \************************************************************************/
 
   // configure the gpio pins and start the multiplexer thread
-  thread_id = multiplexer_setup_non_root(&display_data);
-
-  int i,j;
+  multiplexer_setup_scroll(&scroll_data);
 
   text_buffer = malloc(TEXT_BUFFER_LENGTH);
   if (text_buffer == NULL) {
-    fprintf(stderr, "malloc failed to allocate 24 bytes\n");
+    fprintf(stderr, "malloc failed to allocate %d bytes\n", TEXT_BUFFER_LENGTH);
     exit(EXIT_FAILURE);
   }
-  memset(text_buffer, 0, TEXT_BUFFER_LENGTH);
-
-  text_buffer_end = text_buffer;
 
-  text_buffer_end = gadgets_retrieve_weather_warnings(text_buffer_end,text_buffer + TEXT_BUFFER_LENGTH - text_buffer_end);
-  if (text_buffer_end == NULL) {
-    fprintf(stderr, "gadgets_retrieve_weather_warnings failed\n");
-    free(text_buffer);
-    return EXIT_FAILURE;
-  }
-  if (text_buffer + TEXT_BUFFER_LENGTH - text_buffer_end > 0)
-    text_buffer_end += snprintf(text_buffer_end, text_buffer + TEXT_BUFFER_LENGTH - text_buffer_end, "; ");
-  text_buffer_end = gadgets_retrieve_current_temperature(text_buffer_end,text_buffer + TEXT_BUFFER_LENGTH - text_buffer_end);
-  if (text_buffer_end == NULL) {
-    fprintf(stderr, "gadgets_retrieve_current_temperature failed\n");
-    free(text_buffer);
-    return EXIT_FAILURE;
-  }
-  if (text_buffer + TEXT_BUFFER_LENGTH - text_buffer_end > 0)
-    text_buffer_end += snprintf(text_buffer_end, text_buffer + TEXT_BUFFER_LENGTH - text_buffer_end, "; ");
-  text_buffer_end = gadgets_retrieve_weather_forecast(text_buffer_end,text_buffer + TEXT_BUFFER_LENGTH - text_buffer_end);
-  if (text_buffer_end == NULL) {
-    fprintf(stderr, "gadgets_retrieve_weather_forecast failed\n");
-    free(text_buffer);
-    return EXIT_FAILURE;
-  }
-  if (text_buffer + TEXT_BUFFER_LENGTH - text_buffer_end > 0)
-    text_buffer_end += snprintf(text_buffer_end, text_buffer + TEXT_BUFFER_LENGTH - text_buffer_end, "; ");
-
-  scroll_buffers[0].scroll_len = render(text_buffer, TEXT_BUFFER_LENGTH, scroll_buffers[0].buf, sizeof(scroll_buffers[0].buf), 1);
-
-  i=-40;
-  while (display_data.keep_running) {
-    usleep(100000);
-    for (j=0; j<40; j++)
-      if (i+j<0)
-        display_data.buf[(display_data.should_buf+1)%3][j] = 0;
-      else
-        display_data.buf[(display_data.should_buf+1)%3][j] = scroll_buffers[0].buf[(i+j) % scroll_buffers[0].scroll_len];
-    display_data.should_buf = (display_data.should_buf+1)%3;
-    i++;
-    i = i % scroll_buffers[0].scroll_len;
+  time_t next_update = 0;
+
+  int i=0;
+
+  while (scroll_data . keep_running) {
+    if ((time(NULL) >= next_update) && (scroll_data . update == 0)) {
+      next_update = time(NULL) + 60; // one minute ahead
+
+      memset(text_buffer, 0, TEXT_BUFFER_LENGTH);
+
+      text_buffer_end = text_buffer;
+
+      text_buffer_end = gadgets_retrieve_weather_warnings(text_buffer_end,text_buffer + TEXT_BUFFER_LENGTH - text_buffer_end);
+      if (text_buffer_end == NULL) {
+        fprintf(stderr, "gadgets_retrieve_weather_warnings failed\n");
+        free(text_buffer);
+        return EXIT_FAILURE;
+      }
+      if (text_buffer + TEXT_BUFFER_LENGTH - text_buffer_end > 0)
+        text_buffer_end += snprintf(text_buffer_end, text_buffer + TEXT_BUFFER_LENGTH - text_buffer_end, "; ");
+      text_buffer_end = gadgets_retrieve_current_temperature(text_buffer_end,text_buffer + TEXT_BUFFER_LENGTH - text_buffer_end);
+      if (text_buffer_end == NULL) {
+        fprintf(stderr, "gadgets_retrieve_current_temperature failed\n");
+        free(text_buffer);
+        return EXIT_FAILURE;
+      }
+      if (text_buffer + TEXT_BUFFER_LENGTH - text_buffer_end > 0)
+        text_buffer_end += snprintf(text_buffer_end, text_buffer + TEXT_BUFFER_LENGTH - text_buffer_end, "; ");
+      text_buffer_end = gadgets_retrieve_weather_forecast(text_buffer_end,text_buffer + TEXT_BUFFER_LENGTH - text_buffer_end);
+      if (text_buffer_end == NULL) {
+        fprintf(stderr, "gadgets_retrieve_weather_forecast failed\n");
+        free(text_buffer);
+        return EXIT_FAILURE;
+      }
+      if (text_buffer + TEXT_BUFFER_LENGTH - text_buffer_end > 0)
+        text_buffer_end += snprintf(text_buffer_end, text_buffer + TEXT_BUFFER_LENGTH - text_buffer_end, "; ");
+
+      scroll_data . input_len =
+        render(
+          text_buffer,
+          text_buffer_end - text_buffer,
+          scroll_data . input,
+          sizeof(scroll_data . input),
+          1
+        );
+      scroll_data . update = 1;
+    }
+
+    sleep(1);
   }
 
   free(text_buffer);
-  display_data.keep_running = 0;
-  pthread_join(thread_id, NULL);
+  pthread_join(scroll_data . thread_id, NULL);
 
   return 0;
 
@@ -145,6 +149,6 @@ void handle_signals(int signo)
 {
   if ((signo == SIGINT) || (signo == SIGHUP) || (signo == SIGTERM)) {
     fprintf(stderr, "stopping\n");
-    display_data.keep_running = 0;
+    scroll_data . keep_running = 0;
   }
 }
diff --git a/multiplexer.c b/multiplexer.c
index c81864b..52c7af1 100644
--- a/multiplexer.c
+++ b/multiplexer.c
@@ -7,6 +7,7 @@
 #include <unistd.h>
 #include <string.h>
 #include <pthread.h>
+#include <assert.h>
 
 #include "multiplexer.h"
 
@@ -108,10 +109,54 @@ void *put_on_display(void *param)
   return NULL;
 } // put_on_display
 
-pthread_t multiplexer_setup_non_root(t_display_data *display_data)
+// scroll the text over the display
+void *scroll_it(void *param)
 {
-  pthread_t thread_id;
+  t_scroll_data *scroll_data = (t_scroll_data *) param;
+  t_scroll_buffer buf[3];
+  for (int i=0; i<3; i++)
+    memset(&buf[i], 0, sizeof(buf[i]));
+  t_display_data display_data;
+  multiplexer_setup_non_root(&display_data);
+  int is_buf = 0;
+  int column = 0;
+  while (scroll_data -> keep_running) {
+    if (scroll_data -> update) {
+      if ((buf[is_buf] . len != scroll_data -> input_len) || (memcmp(&buf[is_buf] . buf[buf[is_buf] . start], scroll_data -> input, scroll_data -> input_len) != 0)) {
+        is_buf = (is_buf + 1) % 2;
+        // copy the currently visible, old content
+        memcpy(buf[is_buf] . buf, &buf[(is_buf + 1) % 2] . buf[column + 1], 39);
+        buf[is_buf] . start = 39;
+        // set the length of the new content
+        buf[is_buf] . len = scroll_data -> input_len;
+        // copy the new content from input
+        for (int i=0; i<2; i++)
+          memcpy(
+            &buf[is_buf] . buf[39 + i * buf[is_buf] . len],
+            scroll_data -> input,
+            buf[is_buf] . len
+          );
+        column = 0;
+      }
+      // clear update flag
+      scroll_data -> update = 0;
+    }
+    for (int i=0; i<40; i++)
+      display_data . buf[(display_data . should_buf + 1) % 3][i] =
+        buf[is_buf] . buf[column + i];
+    display_data . should_buf = (display_data . should_buf + 1) % 3;
+    column++;
+    if (buf[is_buf] . len > 0)
+      while (column >= buf[is_buf] . start + buf[is_buf] . len)
+        column -= buf[is_buf] . len;
+    usleep(100000);
+  }
+  display_data . keep_running = 0;
+  pthread_join(display_data . thread_id, NULL);
+} // scroll_it
 
+void multiplexer_setup_non_root(t_display_data *display_data)
+{
 #ifndef SKIP_GPIO
   // must use INP_GPIO before we can use OUT_GPIO
   INP_GPIO(SER_DAT_PIN);
@@ -130,6 +175,14 @@ pthread_t multiplexer_setup_non_root(t_display_data *display_data)
   display_data -> is_buf = 0;
   display_data -> should_buf = 0;
   display_data -> keep_running = 1;
-  pthread_create(&thread_id, NULL, put_on_display, display_data);
-  return thread_id;
+  pthread_create(&display_data -> thread_id, NULL, put_on_display, display_data);
+  return;
 } // multiplexer_setup_non_root
+
+void multiplexer_setup_scroll(t_scroll_data *scroll_data)
+{
+  scroll_data -> update = 0;
+  scroll_data -> keep_running = 1;
+  pthread_create(&scroll_data -> thread_id, NULL, scroll_it, scroll_data);
+  return;
+} // multiplexer_setup_scroll
diff --git a/multiplexer.h b/multiplexer.h
index 9c73632..d7f7aee 100644
--- a/multiplexer.h
+++ b/multiplexer.h
@@ -23,19 +23,29 @@
 #define PAR_CLK_PIN    6
 #define SENSE_PIN      5
 
+#define SCROLL_BUF_LEN 4096
+
 int  mem_fd;
 void *gpio_map;
 
 typedef struct {
   char buf[3][40];
   int should_buf, is_buf, keep_running;
+  pthread_t thread_id;
 } t_display_data;
 
 typedef struct {
-  char buf[2048];
-  int scroll_len;
+  char buf[SCROLL_BUF_LEN];
+  int start, len;
 } t_scroll_buffer;
 
+typedef struct {
+  int update;
+  char input[(SCROLL_BUF_LEN - 39) / 2];
+  int input_len, keep_running;
+  pthread_t thread_id;
+} t_scroll_data;
+
 // I/O access
 volatile unsigned *gpio;
 
@@ -54,4 +64,5 @@ volatile unsigned *gpio;
 #define GPIO_PULLCLK0 *(gpio+38) // Pull up/pull down clock
 
 int multiplexer_setup_root();
-pthread_t multiplexer_setup_non_root(t_display_data *display_data);
+void multiplexer_setup_non_root(t_display_data *display_data);
+void multiplexer_setup_scroll(t_scroll_data *scroll_data);