From afacf5506743644e0c44a0200529505266007af2 Mon Sep 17 00:00:00 2001
From: yamamama <anonimus.srb2k@gmail.com>
Date: Tue, 3 Mar 2026 08:08:04 -0500
Subject: [PATCH] FF_AFFINEPAPER and RF2_AFFINEPAPER

He made a BANDAID so TRASH even his TEAM clowned him
---
 src/deh_tables.c |  2 ++
 src/p_pspr.h     |  3 +++
 src/r_defs.h     |  1 +
 src/r_things.cpp | 14 ++++++++++++--
 4 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/src/deh_tables.c b/src/deh_tables.c
index 5f7c4f28f..b8b55e9cb 100644
--- a/src/deh_tables.c
+++ b/src/deh_tables.c
@@ -949,6 +949,7 @@ struct int_const_s const INT_CONST[] = {
 	{"FF_PAPERSPRITE",FF_PAPERSPRITE},
 	{"FF_FLOORSPRITE",FF_FLOORSPRITE},
 	{"FF_NOAFFINE",FF_NOAFFINE},
+	{"FF_AFFINEPAPER",FF_AFFINEPAPER},
 	{"FF_BLENDMASK",FF_BLENDMASK},
 	{"FF_BLENDSHIFT",FF_BLENDSHIFT},
 	{"FF_ADD",FF_ADD},
@@ -1059,6 +1060,7 @@ struct int_const_s const INT_CONST[] = {
 	{"RF_GHOSTLY",RF_GHOSTLY},
 	{"RF_GHOSTLYMASK",RF_GHOSTLYMASK},
 	{"RF2_NOAFFINE",RF2_NOAFFINE},
+	{"RF2_AFFINEPAPER",RF2_AFFINEPAPER},
 
 	// Level flags
 	{"LF_SCRIPTISFILE",LF_SCRIPTISFILE},
diff --git a/src/p_pspr.h b/src/p_pspr.h
index d508f909e..12fbb3b95 100644
--- a/src/p_pspr.h
+++ b/src/p_pspr.h
@@ -93,6 +93,9 @@ extern "C" {
 /// \brief Frame flags: Turns off Mode 7-style scaling and rotation
 #define FF_NOAFFINE 0x04000000
 
+/// \brief Frame flags: Enables "affine papersprites"
+#define FF_AFFINEPAPER 0x08000000
+
 /// \brief Frame flags - Animate: Simple stateless animation
 #define FF_ANIMATE 0x10000000
 /// \brief Frame flags - Animate: Sync animation to global timer (mutually exclusive with below, currently takes priority)
diff --git a/src/r_defs.h b/src/r_defs.h
index d0db384f8..c84bf1bad 100644
--- a/src/r_defs.h
+++ b/src/r_defs.h
@@ -1039,6 +1039,7 @@ typedef enum
 typedef enum
 {
 	RF2_NOAFFINE          = 0x00000001,  // Disables affine drawing for this sprite
+	RF2_AFFINEPAPER       = 0x00000002,  // Enables "affine papersprites"
 } renderflags2_t;
 
 typedef enum
diff --git a/src/r_things.cpp b/src/r_things.cpp
index 9408877df..7ce247153 100644
--- a/src/r_things.cpp
+++ b/src/r_things.cpp
@@ -4296,12 +4296,22 @@ boolean R_ThingVerticallyFlipped(mobj_t *thing)
 
 boolean R_ThingIsPaperSprite(mobj_t *thing)
 {
-	return (thing->frame & FF_PAPERSPRITE || thing->renderflags & RF_PAPERSPRITE);
+	boolean affinepaper = (thing->frame & FF_AFFINEPAPER || thing->renderflags2 & RF2_AFFINEPAPER);
+
+	return (thing->frame & FF_PAPERSPRITE || thing->renderflags & RF_PAPERSPRITE || affinepaper);
 }
 
 boolean R_ThingIsAffineSprite(mobj_t *thing)
 {
-	return (!(thing->frame & FF_NOAFFINE || thing->renderflags2 & RF2_NOAFFINE));
+	boolean affinepaper = (thing->frame & FF_AFFINEPAPER || thing->renderflags2 & RF2_AFFINEPAPER);
+
+	// Affine papersprites are messy in software rendering; let modders enable them at their own discretion.
+	// Yes, I'm lazy; I've been at this for TWO WEEKS.
+	boolean papersprite = (R_ThingIsPaperSprite(thing) && !affinepaper);
+
+	boolean notaffine = ((thing->frame & FF_NOAFFINE || thing->renderflags2 & RF2_NOAFFINE) || papersprite);
+
+	return (!notaffine);
 }
 
 boolean R_ThingIsFloorSprite(mobj_t *thing)