From 0f326d1c44e6ad29db4b2ba56cd47cce91f16848 Mon Sep 17 00:00:00 2001
From: Jerry <isjerryxiao@outlook.com>
Date: Wed, 26 Apr 2023 17:07:19 +0800
Subject: [PATCH] u

---
 server.c | 46 ++++++++++++++++++++++++----------------------
 1 file changed, 24 insertions(+), 22 deletions(-)

diff --git a/server.c b/server.c
index 6c47232..02e33f8 100644
--- a/server.c
+++ b/server.c
@@ -15,8 +15,7 @@
 
 
 #define ARRAY_SIZE(x) (sizeof(x) / sizeof(x[0]))
-/* 10 frames per second (if we can) */
-#define PICTURE_TIMEOUT (1.0/10.0)
+#define FPS 10
 #define UINPUT_ABS_MAX INT16_MAX
 #define UINPUT_MAX_KEY 256
 
@@ -26,22 +25,27 @@ struct Vec2d {
 };
 struct Vec2d resolution;
 
-/*
- * throttle camera updates
-*/
-static int TimeToTakePicture() {
-    static struct timeval now={0,0}, then={0,0};
-    double elapsed, dnow, dthen;
+#define SLEEPNS (1000000000 / FPS)
+static void between_frames() {
+    static struct timespec now={0,0}, then={0,0}, tmp={0,0};
 
-    gettimeofday(&now,NULL);
-
-    dnow  = now.tv_sec  + (now.tv_usec /1000000.0);
-    dthen = then.tv_sec + (then.tv_usec/1000000.0);
-    elapsed = dnow - dthen;
-
-    if (elapsed > PICTURE_TIMEOUT)
-        memcpy((char *)&then, (char *)&now, sizeof(struct timeval));
-    return elapsed > PICTURE_TIMEOUT;
+    clock_gettime(CLOCK_MONOTONIC, &now);
+    memcpy((char*)&then, (char*)&tmp, sizeof(struct timespec));
+    tmp.tv_nsec += SLEEPNS;
+    if (tmp.tv_nsec >= 1000000000) {
+        tmp.tv_sec ++;
+        tmp.tv_nsec %= 1000000000;
+    }
+    if (now.tv_sec < tmp.tv_sec || (now.tv_sec == tmp.tv_sec && now.tv_nsec < tmp.tv_nsec)) {
+        then.tv_sec = tmp.tv_sec - now.tv_sec;
+        then.tv_nsec = tmp.tv_nsec - now.tv_nsec;
+        if (then.tv_nsec < 0) {
+            then.tv_sec --;
+            then.tv_nsec += 1000000000;
+        }
+        nanosleep(&then, &then);
+    }
+    memcpy((char*)&now, (char*)&then, sizeof(struct timespec));
 }
 
 static void convert_bgrx_to_rgb(const char* in, int width, int height, char* buff) {
@@ -477,9 +481,7 @@ int main(int argc, const char **argv)
 
     size_t buflen = fb->width * fb->height * 32 / 8;
     char *buf = malloc(buflen);
-    char *buf2 = malloc(buflen);
     memset(buf, 0, buflen);
-    memset(buf2, 0, buflen);
 
     resolution.x = fb->width;
     resolution.y = fb->height;
@@ -498,11 +500,11 @@ int main(int argc, const char **argv)
     rfbInitServer(server);
     rfbRunEventLoop(server,-1,TRUE);
     while (rfbIsActive(server)) {
-        if (server->clientHead && TimeToTakePicture()) {
+        between_frames();
+        if (server->clientHead) {
             funcs.sync_start(primefd);
-            memcpy(buf2, mapped, buflen);
+            funcs.convert(mapped, fb->width, fb->height, buf);
             funcs.sync_end(primefd);
-            funcs.convert(buf2, fb->width, fb->height, buf);
             rfbMarkRectAsModified(server, 0, 0, fb->width, fb->height);
         }
     }