some refactoring

src/display.c

@@ -46,9 +46,9 @@ static void print_current_image(const struct message* msg, int start, int end) {
 void callback(const struct message *msg, const struct prog_info *pinfo) {
 	printf("in callback, tst=%d\n", msg->timestamp);
 	
-	int start;
-	
-	
+	// calculate the actual offset to use
+	int start = msg->timestamp % msg->width  +  pinfo->client_offset;
+
 	print_current_image(msg, start, start+80);
 	
 }

src/main.c

@@ -13,19 +13,19 @@
 
 int parseArgs(struct prog_info *pinfo, int argc, char **argv) {
 	pinfo->mode = MODE_SERVER;
-	pinfo->client_num = 1;
+	pinfo->client_offset = 1;
 	pinfo->port = 4711;
 	pinfo->fps = 10;
 
 	if (argc <= 1) {
 		printf("usage: %s [-s|-c <off>] [-p <port>] [-t <fps>]\n", argv[0]);
 		printf("where:\n -s         run in server mode\n");
-		printf(        " -c <num>   run in client mode\n");
-		printf(        "            num is the column offset to use.\n");
+		printf(        " -c <off>   run in client mode\n");
+		printf(        "            off is the column offset to use.\n");
 		printf(        " -p <port>  use the specified port\n");
 		printf(        " -t <fps>   when in server mode: update <fps> times\n"); 
 		printf(        "            per second. Valid range: 2 - 99\n");
-		printf(        "            no use in client mode\n");
+		printf(        "            ignored in client mode\n");
 		printf(        " -v          \n");
 		printf("\n\n");
 		return -1;
@@ -42,8 +42,8 @@ int parseArgs(struct prog_info *pinfo, int argc, char **argv) {
 				printf("client number not specified\n");
 				return -2;
 			}
-			pinfo->client_num = (int)strtol(argv[++i], NULL, 10);
-			if (pinfo->client_num <= 0) {
+			pinfo->client_offset = (int)strtol(argv[++i], NULL, 10);
+			if (pinfo->client_offset <= 0) {
 				printf("invalid client number!\n");
 				return -3;
 			}
@@ -89,10 +89,10 @@ int main(int argc, char **argv) {
 			
 		printf("port: %d\n", prog_info.port);
 		if (prog_info.mode == MODE_SERVER) {
-			printf("runnin in SERVER mode @%d FPS\n", prog_info.fps);
+			printf("running in SERVER mode @%d FPS\n", prog_info.fps);
 			ret = run_server(&prog_info);
 		} else {
-			printf("running in CLIENT mode, using client number %d\n", prog_info.client_num);
+			printf("running in CLIENT mode, using client number %d\n", prog_info.client_offset);
 			ret = run_client(&prog_info, callback);
 		}
 

src/main.h

@@ -1,5 +1,5 @@
 // nüscht ...
-// 
+//
 //
 //
 //

src/misc.h

@@ -1,11 +1,12 @@
 #ifndef __MISC
-#  define __MISC
+#define __MISC
 
 struct prog_info {
 	int mode;
-	int client_num;
+	int client_offset;
 	int port;
 	int fps;
 } prog_info;
 
 #endif
+

src/msg.c

@@ -13,7 +13,7 @@ void serialize (char *buf, struct message *msg) {
 	memcpy(&buf[0], &msg->timestamp, 4);
 	memcpy(&buf[4], &msg->width, 4);
 	memcpy(&buf[8], &msg->height, 4);
-	if (msg->width * msg->height) 
+	if (msg->width * msg->height)
 		memcpy(&buf[12], msg->image, msg->width * msg->height);
 }
 
@@ -90,4 +90,3 @@ int main() {
 }
 */
 
-

src/msg.h

@@ -1,5 +1,5 @@
 #ifndef __MSG
-#  define __MSG
+#define __MSG
 
 #include <stdint.h>
 
@@ -34,3 +34,4 @@ void serialize_message(struct message *msg,Buffer *b);
 */
 
 #endif
+

src/net.c

@@ -22,11 +22,11 @@
 //
 void *get_in_addr(struct sockaddr *sa)
 {
-    if (sa->sa_family == AF_INET) {
-        return &(((struct sockaddr_in*)sa)->sin_addr);
-    }
+	if (sa->sa_family == AF_INET) {
+		return &(((struct sockaddr_in*)sa)->sin_addr);
+	}
 
-    return &(((struct sockaddr_in6*)sa)->sin6_addr);
+	return &(((struct sockaddr_in6*)sa)->sin6_addr);
 }
 
 
@@ -46,14 +46,14 @@ int run_server(const struct prog_info *pinfo) {
 	sprintf(portbuf, "%d", pinfo->port);
 	if ((ret=getaddrinfo("255.255.255.255", portbuf, &hints, &servinfo)) != 0) {
 		fprintf(stderr, "getaddrinfo: %s\n", gai_strerror(ret));
-	        return 1;
+			return 1;
 	}
 
 	for(p = servinfo; p != NULL; p = p->ai_next) {
 	 	if ((sockfd = socket(p->ai_family, p->ai_socktype, p->ai_protocol)) == -1) {
-	    	perror("talker: socket");
-    	    continue;
-        }
+			perror("talker: socket");
+			continue;
+		}
 		break;
 	}
 
@@ -68,7 +68,7 @@ int run_server(const struct prog_info *pinfo) {
 
 	// Einem Socket muss das Broadcasting explizit erlaubt werden:
  	int broadcastPermission = 1;
-    if (setsockopt(sockfd, SOL_SOCKET, SO_BROADCAST, (void *) &broadcastPermission,sizeof(broadcastPermission)) < 0){
+	if (setsockopt(sockfd, SOL_SOCKET, SO_BROADCAST, (void *) &broadcastPermission,sizeof(broadcastPermission)) < 0){
 		fprintf(stderr, "setsockopt error");
 		exit(1);
 	}
@@ -115,8 +115,8 @@ int run_client(const struct prog_info *pinfo, void (*framecallback)(const struct
 	char portbuf[6];
 
 	memset(&hints, 0, sizeof(hints));
-	hints.ai_family = AF_INET;      // IPv4
-	hints.ai_socktype = SOCK_DGRAM; // UDP
+	hints.ai_family = AF_INET;			// IPv4
+	hints.ai_socktype = SOCK_DGRAM;		// UDP
 	hints.ai_flags = AI_PASSIVE;
 
 	sprintf(portbuf, "%d", pinfo->port);
@@ -159,8 +159,8 @@ int run_client(const struct prog_info *pinfo, void (*framecallback)(const struct
 	char buf[10000];
 	do {
 		if ((numbytes = recvfrom(sockfd, buf, 9999 , 0, (struct sockaddr *)&their_addr, &addr_len)) == -1) {
-	    	perror("recvfrom");
-		    exit(1);
+			perror("recvfrom");
+			exit(1);
 		}
 		
 		//printf("listener: got packet from %s\n", inet_ntop(their_addr.ss_family, get_in_addr((struct sockaddr *)&their_addr), s, sizeof s));

src/net.h

@@ -1,13 +1,14 @@
 #ifndef __NET
-#  define __NET
+#define __NET
 
-#include <sys/socket.h> // struct sockaddr
-#include "misc.h"     // prog_info
-#include "msg.h"      // message serialization
-#include "display.h"  // callback 
+#include <sys/socket.h>	// struct sockaddr
+#include "misc.h"		// prog_info
+#include "msg.h"		// message serialization
+#include "display.h"	// callback 
 
 void *get_in_addr(struct sockaddr *sa);
 int run_server(const struct prog_info *pinfo);
 int run_client(const struct prog_info *pinfo,void(*framecallback)(const struct message *, const struct prog_info *));
 
 #endif
+