From c83d1be21ffd31d127b9559570462a742ecb9498 Mon Sep 17 00:00:00 2001
From: Sally Coolatta <tehrealsalt@gmail.com>
Date: Tue, 29 Mar 2022 20:51:58 -0400
Subject: [PATCH] Add interpdebug

---
 src/d_main.c   | 13 ++++---------
 src/r_fps.c    |  2 ++
 src/r_fps.h    |  1 +
 src/r_main.c   |  1 +
 src/st_stuff.c | 22 ++++++++++++++++++++++
 src/st_stuff.h |  2 ++
 6 files changed, 32 insertions(+), 9 deletions(-)

diff --git a/src/d_main.c b/src/d_main.c
index 6912ec988..7a8ae5f0f 100644
--- a/src/d_main.c
+++ b/src/d_main.c
@@ -841,17 +841,12 @@ void D_SRB2Loop(void)
 				tictime = entertime;
 			}
 
+			dbg_entertime = entertime;
+			dbg_prevtime = prevtime;
+			dbg_tictime = tictime;
+
 			if (!(paused || P_AutoPause()))
 			{
-#if 0
-				CONS_Printf("prevtime = %f\n", prevtime);
-				CONS_Printf("entertime = %f\n", entertime);
-				CONS_Printf("tictime = %f\n", tictime);
-				CONS_Printf("entertime - prevtime = %f\n", entertime - prevtime);
-				CONS_Printf("entertime - tictime = %f\n", entertime - tictime);
-				CONS_Printf("========\n");
-#endif
-
 				if (entertime - prevtime >= 1.0f)
 				{
 					// Lagged for more frames than a gametic...
diff --git a/src/r_fps.c b/src/r_fps.c
index 45f301551..6307d83a1 100644
--- a/src/r_fps.c
+++ b/src/r_fps.c
@@ -40,6 +40,8 @@ static CV_PossibleValue_t fpscap_cons_t[] = {
 };
 consvar_t cv_fpscap = CVAR_INIT ("fpscap", "Match refresh rate", CV_SAVE, fpscap_cons_t, NULL);
 
+consvar_t cv_interpdebug = CVAR_INIT ("interpdebug", "Off", 0, CV_OnOff, NULL);
+
 UINT32 R_GetFramerateCap(void)
 {
 	if (rendermode == render_none)
diff --git a/src/r_fps.h b/src/r_fps.h
index 32c9131fe..4a0750c3a 100644
--- a/src/r_fps.h
+++ b/src/r_fps.h
@@ -20,6 +20,7 @@
 #include "r_state.h"
 
 extern consvar_t cv_fpscap;
+extern consvar_t cv_interpdebug;
 
 UINT32 R_GetFramerateCap(void);
 boolean R_UsingFrameInterpolation(void);
diff --git a/src/r_main.c b/src/r_main.c
index 896b6a29b..a3bddf44f 100644
--- a/src/r_main.c
+++ b/src/r_main.c
@@ -1625,4 +1625,5 @@ void R_RegisterEngineStuff(void)
 
 	// Frame interpolation/uncapped
 	CV_RegisterVar(&cv_fpscap);
+	CV_RegisterVar(&cv_interpdebug);
 }
diff --git a/src/st_stuff.c b/src/st_stuff.c
index 6c9a0eeca..535c68ee8 100644
--- a/src/st_stuff.c
+++ b/src/st_stuff.c
@@ -45,6 +45,8 @@
 #include "lua_hud.h"
 #include "lua_hook.h"
 
+#include "r_fps.h"
+
 UINT16 objectsdrawn = 0;
 
 //
@@ -621,6 +623,24 @@ static void ST_drawDebugInfo(void)
 #undef VFLAGS
 }
 
+float dbg_entertime = 0.0f, dbg_prevtime = 0.0f, dbg_tictime = 0.0f;
+static void ST_DrawInterpDebug(void)
+{
+	// TODO: when the devmode situation stops sucking eggs,
+	// remove cv_interpdebug and use DBG_RENDER instead.
+	if (!cv_interpdebug.value || !R_UsingFrameInterpolation())
+	{
+		return;
+	}
+
+	V_DrawRightAlignedString(312, 8, V_MONOSPACE, va("enter - tic: %.3f", dbg_entertime - dbg_tictime));
+	V_DrawRightAlignedString(312, 16, V_MONOSPACE, va("enter - prev: %.3f", dbg_entertime - dbg_prevtime));
+
+	V_DrawRightAlignedString(312, 24, V_MONOSPACE, va("tic: %.3f", dbg_tictime));
+	V_DrawRightAlignedString(312, 32, V_MONOSPACE, va("prev: %.3f", dbg_prevtime));
+	V_DrawRightAlignedString(312, 40, V_MONOSPACE, va("enter: %.3f", dbg_entertime));
+}
+
 static void ST_drawScore(void)
 {
 	if (F_GetPromptHideHud(hudinfo[HUD_SCORE].y))
@@ -2755,6 +2775,8 @@ static void ST_overlayDrawer(void)
 		ST_drawInput();
 
 	ST_drawDebugInfo();
+
+	ST_DrawInterpDebug();
 }
 
 void ST_Drawer(void)
diff --git a/src/st_stuff.h b/src/st_stuff.h
index c59bc2ac6..0956bbb7d 100644
--- a/src/st_stuff.h
+++ b/src/st_stuff.h
@@ -55,6 +55,8 @@ void ST_preDrawTitleCard(void);
 void ST_preLevelTitleCardDrawer(void);
 void ST_drawWipeTitleCard(void);
 
+extern float dbg_entertime, dbg_prevtime, dbg_tictime;
+
 extern tic_t lt_ticker, lt_lasttic;
 extern tic_t lt_exitticker, lt_endtime;