From 3320faec8cebecb124882d38c7ec0ad37b79340a Mon Sep 17 00:00:00 2001
From: James R <justsomejames2@gmail.com>
Date: Mon, 14 Aug 2023 01:00:11 -0700
Subject: [PATCH] Interpolate view, even when paused

Fixes slideshow movement with demo freecam while paused.
Does not appear to jitter like texture scrollers do.
---
 src/d_main.c | 3 +++
 src/r_main.c | 3 ++-
 src/r_main.h | 2 ++
 3 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/d_main.c b/src/d_main.c
index cade52936..bc042c57c 100644
--- a/src/d_main.c
+++ b/src/d_main.c
@@ -886,11 +886,14 @@ void D_SRB2Loop(void)
 			{
 				rendertimefrac = FRACUNIT;
 			}
+
+			rendertimefrac_unpaused = g_time.timefrac;
 		}
 		else
 		{
 			renderdeltatics = realtics * FRACUNIT;
 			rendertimefrac = FRACUNIT;
+			rendertimefrac_unpaused = FRACUNIT;
 		}
 
 		if (interp || doDisplay)
diff --git a/src/r_main.c b/src/r_main.c
index 107e6684b..6cf539574 100644
--- a/src/r_main.c
+++ b/src/r_main.c
@@ -81,6 +81,7 @@ mobj_t *r_viewmobj;
 int r_splitscreen;
 
 fixed_t rendertimefrac;
+fixed_t rendertimefrac_unpaused;
 fixed_t renderdeltatics;
 boolean renderisnewtic;
 
@@ -1227,7 +1228,7 @@ R_SetupCommonFrame
 	else
 		newview->sector = R_PointInSubsector(newview->x, newview->y)->sector;
 
-	R_InterpolateView(rendertimefrac);
+	R_InterpolateView(rendertimefrac_unpaused);
 }
 
 static void R_SetupAimingFrame(int s)
diff --git a/src/r_main.h b/src/r_main.h
index dcd496cfb..0f5560308 100644
--- a/src/r_main.h
+++ b/src/r_main.h
@@ -39,6 +39,8 @@ extern size_t validcount, linecount, loopcount, framecount;
 
 // The fraction of a tic being drawn (for interpolation between two tics)
 extern fixed_t rendertimefrac;
+// Same as rendertimefrac but not suspended when the game is paused
+extern fixed_t rendertimefrac_unpaused;
 // Evaluated delta tics for this frame (how many tics since the last frame)
 extern fixed_t renderdeltatics;
 // The current render is a new logical tic