Allow seeking client demo to file position percentage.

doc/client.md

@@ -1692,11 +1692,12 @@ root of quake file system. Can be used to launch MVD playback as well, if
 MVD file type is detected, it will be automatically passed to the server
 subsystem. To stop demo playback, type `disconnect`.
 
-#### `seek [+-]<timespec>`
+#### `seek [+-]<timespec|percent>[%]`
 Seeks the given amount of time during demo playback.  Prepend with `+` to
 seek forward relative to current position, prepend with `-` to seek
 backward relative to current position. Without prefix, seeks to an absolute
-position within the demo file. See below for _timespec_ syntax description.
+frame position within the demo file.  See below for _timespec_ syntax
+description.  With `%` suffix, seeks to specified file position percentage.
 Initial forward seek may be slow, so be patient.
 
 *NOTE*: The `seek` command actually operates on demo frame numbers, not pure

src/client/demo.c

@@ -851,7 +851,7 @@ void CL_EmitDemoSnapshot(void)
     cls.demo.last_snapshot = cls.demo.frames_read;
 }
 
-static demosnap_t *find_snapshot(int framenum)
+static demosnap_t *find_snapshot(int64_t dest, bool byte_seek)
 {
     int l = 0;
     int r = cls.demo.numsnapshots - 1;
@@ -862,9 +862,10 @@ static demosnap_t *find_snapshot(int framenum)
     do {
         int m = (l + r) / 2;
         demosnap_t *snap = cls.demo.snapshots[m];
-        if (snap->framenum < framenum)
+        int64_t pos = byte_seek ? snap->filepos : snap->framenum;
+        if (pos < dest)
             l = m + 1;
-        else if (snap->framenum > framenum)
+        else if (pos > dest)
             r = m - 1;
         else
             return snap;
@@ -913,14 +914,21 @@ void CL_FirstDemoFrame(void)
     cls.demo.last_snapshot = INT_MIN;
 }
 
+/*
+====================
+CL_Seek_f
+====================
+*/
 static void CL_Seek_f(void)
 {
     demosnap_t *snap;
-    int i, j, ret, index, frames, dest, prev;
+    int i, j, ret, index, frames, prev;
+    int64_t dest;
+    bool byte_seek, back_seek;
     char *from, *to;
 
     if (Cmd_Argc() < 2) {
-        Com_Printf("Usage: %s [+-]<timespec>\n", Cmd_Argv(0));
+        Com_Printf("Usage: %s [+-]<timespec|percent>[%%]\n", Cmd_Argv(0));
         return;
     }
 
@@ -938,31 +946,53 @@ static void CL_Seek_f(void)
 
     to = Cmd_Argv(1);
 
-    if (*to == '-' || *to == '+') {
-        // relative to current frame
-        if (!Com_ParseTimespec(to + 1, &frames)) {
-            Com_Printf("Invalid relative timespec.\n");
+    if (strchr(to, '%')) {
+        char *suf;
+        float percent = strtof(to, &suf);
+        if (strcmp(suf, "%") || !isfinite(percent)) {
+            Com_Printf("Invalid percentage.\n");
             return;
         }
-        if (*to == '-')
-            frames = -frames;
-        dest = cls.demo.frames_read + frames;
-    } else {
-        // relative to first frame
-        if (!Com_ParseTimespec(to, &dest)) {
-            Com_Printf("Invalid absolute timespec.\n");
+
+        if (!cls.demo.file_size) {
+            Com_Printf("Unknown file size, can't seek.\n");
             return;
         }
-        frames = dest - cls.demo.frames_read;
-    }
 
-    if (!frames)
-        // already there
-        return;
+        clamp(percent, 0, 100);
+        dest = cls.demo.file_offset + cls.demo.file_size * percent / 100;
 
-    if (frames > 0 && cls.demo.eof && cl_demowait->integer)
-        // already at end
-        return;
+        byte_seek = true;
+        back_seek = dest < FS_Tell(cls.demo.playback);
+    } else {
+        if (*to == '-' || *to == '+') {
+            // relative to current frame
+            if (!Com_ParseTimespec(to + 1, &frames)) {
+                Com_Printf("Invalid relative timespec.\n");
+                return;
+            }
+            if (*to == '-')
+                frames = -frames;
+            dest = cls.demo.frames_read + frames;
+        } else {
+            // relative to first frame
+            if (!Com_ParseTimespec(to, &i)) {
+                Com_Printf("Invalid absolute timespec.\n");
+                return;
+            }
+            dest = i;
+            frames = i - cls.demo.frames_read;
+        }
+
+        if (!frames)
+            return; // already there
+
+        byte_seek = false;
+        back_seek = frames < 0;
+    }
+
+    if (!back_seek && cls.demo.eof && cl_demowait->integer)
+        return; // already at end
 
     // disable effects processing
     cls.demo.seeking = true;
@@ -976,11 +1006,11 @@ static void CL_Seek_f(void)
     // save previous server frame number
     prev = cl.frame.number;
 
-    Com_DPrintf("[%d] seeking to %d\n", cls.demo.frames_read, dest);
+    Com_DPrintf("[%d] seeking to %"PRId64"\n", cls.demo.frames_read, dest);
 
     // seek to the previous most recent snapshot
-    if (frames < 0 || cls.demo.last_snapshot > cls.demo.frames_read) {
-        snap = find_snapshot(dest);
+    if (back_seek || cls.demo.last_snapshot > cls.demo.frames_read) {
+        snap = find_snapshot(dest, byte_seek);
 
         if (snap) {
             Com_DPrintf("found snap at %d\n", snap->framenum);
@@ -1011,14 +1041,18 @@ static void CL_Seek_f(void)
             CL_SeekDemoMessage();
             cls.demo.frames_read = snap->framenum;
             Com_DPrintf("[%d] after snap parse %d\n", cls.demo.frames_read, cl.frame.number);
-        } else if (frames < 0) {
+        } else if (back_seek) {
             Com_Printf("Couldn't seek backwards without snapshots!\n");
             goto done;
         }
     }
 
-    // skip forward to destination frame
-    while (cls.demo.frames_read < dest) {
+    // skip forward to destination frame/position
+    while (1) {
+        int64_t pos = byte_seek ? FS_Tell(cls.demo.playback) : cls.demo.frames_read;
+        if (pos >= dest)
+            break;
+
         ret = read_next_message(cls.demo.playback);
         if (ret == 0 && cl_demowait->integer) {
             cls.demo.eof = true;