From 03049db837c91a0439e5cc7c1ca22ee7a4a0fee1 Mon Sep 17 00:00:00 2001
From: toaster <rollerorbital@gmail.com>
Date: Fri, 7 Apr 2023 21:01:36 +0100
Subject: [PATCH] UFO Catchet glass ball

Preliminary offset, no effects, but closer to complete visually.
---
 src/deh_tables.c  |  2 ++
 src/info.c        |  4 ++++
 src/info.h        |  4 ++++
 src/objects/ufo.c | 48 ++++++++++++++++++++++++++++++++++++++++++++++-
 4 files changed, 57 insertions(+), 1 deletion(-)

diff --git a/src/deh_tables.c b/src/deh_tables.c
index 764bf9742..bdb74b55b 100644
--- a/src/deh_tables.c
+++ b/src/deh_tables.c
@@ -4562,6 +4562,8 @@ const char *const STATE_LIST[] = { // array length left dynamic for sanity testi
 
 	"S_SPECIAL_UFO_POD",
 	"S_SPECIAL_UFO_OVERLAY",
+	"S_SPECIAL_UFO_GLASS",
+	"S_SPECIAL_UFO_GLASS_UNDER",
 	"S_SPECIAL_UFO_ARM",
 	"S_SPECIAL_UFO_STEM",
 
diff --git a/src/info.c b/src/info.c
index e2c00bd88..253baa581 100644
--- a/src/info.c
+++ b/src/info.c
@@ -795,6 +795,8 @@ char sprnames[NUMSPRITES + 1][5] =
 	"UFOB",
 	"UFOA",
 	"UFOS",
+	"SSCA",
+	"SSCB",
 
 	"UQMK",
 
@@ -5190,6 +5192,8 @@ state_t states[NUMSTATES] =
 
 	{SPR_UFOB, 0, -1, {NULL}, 0, 0, S_NULL}, // S_SPECIAL_UFO_POD
 	{SPR_UFOB, 1|FF_FULLBRIGHT|FF_ANIMATE, -1, {NULL}, 1, 1, S_NULL}, // S_SPECIAL_UFO_OVERLAY
+	{SPR_SSCA, 0,           -1, {NULL}, 0, 0, S_NULL}, // S_SPECIAL_UFO_GLASS
+	{SPR_SSCB, FF_SUBTRACT, -1, {NULL}, 0, 0, S_NULL}, // S_SPECIAL_UFO_GLASS_UNDER
 	{SPR_UFOA, FF_PAPERSPRITE, -1, {NULL}, 0, 0, S_NULL}, // S_SPECIAL_UFO_ARM
 	{SPR_UFOS, 0, -1, {NULL}, 0, 0, S_NULL}, // S_SPECIAL_UFO_STEM
 
diff --git a/src/info.h b/src/info.h
index 47ce02a7e..6c9d7c773 100644
--- a/src/info.h
+++ b/src/info.h
@@ -1346,6 +1346,8 @@ typedef enum sprite
 	SPR_UFOB,
 	SPR_UFOA,
 	SPR_UFOS,
+	SPR_SSCA,
+	SPR_SSCB,
 
 	SPR_UQMK,
 
@@ -5616,6 +5618,8 @@ typedef enum state
 
 	S_SPECIAL_UFO_POD,
 	S_SPECIAL_UFO_OVERLAY,
+	S_SPECIAL_UFO_GLASS,
+	S_SPECIAL_UFO_GLASS_UNDER,
 	S_SPECIAL_UFO_ARM,
 	S_SPECIAL_UFO_STEM,
 
diff --git a/src/objects/ufo.c b/src/objects/ufo.c
index 4aa9b949f..ef71da4c0 100644
--- a/src/objects/ufo.c
+++ b/src/objects/ufo.c
@@ -54,6 +54,8 @@
 enum
 {
 	UFO_PIECE_TYPE_POD,
+	UFO_PIECE_TYPE_GLASS,
+	UFO_PIECE_TYPE_GLASS_UNDER,
 	UFO_PIECE_TYPE_ARM,
 	UFO_PIECE_TYPE_STEM,
 };
@@ -544,6 +546,8 @@ static void UFOKillPiece(mobj_t *piece)
 
 	switch (ufo_piece_type(piece))
 	{
+		case UFO_PIECE_TYPE_GLASS:
+		case UFO_PIECE_TYPE_GLASS_UNDER:
 		case UFO_PIECE_TYPE_STEM:
 		{
 			piece->tics = 1;
@@ -794,18 +798,25 @@ void Obj_UFOPieceThink(mobj_t *piece)
 		return;
 	}
 
-	piece->destscale = 3 * ufo->destscale / 2;
 	piece->scalespeed = ufo->scalespeed;
 
 	switch (ufo_piece_type(piece))
 	{
 		case UFO_PIECE_TYPE_POD:
 		{
+			piece->destscale = 3 * ufo->destscale / 2;
 			UFOMoveTo(piece, ufo->x, ufo->y, ufo->z + (132 * piece->scale));
 			if (S_SoundPlaying(ufo, sfx_clawzm) && ufo_speed(ufo) > 70*FRACUNIT)
 				SpawnUFOSpeedLines(piece);
 			break;
 		}
+		case UFO_PIECE_TYPE_GLASS:
+		case UFO_PIECE_TYPE_GLASS_UNDER:
+		{
+			piece->destscale = ufo->destscale;
+			UFOMoveTo(piece, ufo->x, ufo->y, ufo->z);
+			break;
+		}
 		case UFO_PIECE_TYPE_ARM:
 		{
 			fixed_t dis = (88 * piece->scale);
@@ -813,6 +824,7 @@ void Obj_UFOPieceThink(mobj_t *piece)
 			fixed_t x = ufo->x - FixedMul(dis, FINECOSINE(piece->angle >> ANGLETOFINESHIFT));
 			fixed_t y = ufo->y - FixedMul(dis, FINESINE(piece->angle >> ANGLETOFINESHIFT));
 
+			piece->destscale = 3 * ufo->destscale / 2;
 			UFOMoveTo(piece, x, y, ufo->z + (24 * piece->scale));
 
 			piece->angle -= FixedMul(ANG2, FixedDiv(ufo_speed(ufo), UFO_BASE_SPEED));
@@ -823,6 +835,7 @@ void Obj_UFOPieceThink(mobj_t *piece)
 			fixed_t stemZ = ufo->z + (294 * piece->scale);
 			fixed_t sc = FixedDiv(FixedDiv(ufo->ceilingz - stemZ, piece->scale), 15 * FRACUNIT);
 
+			piece->destscale = 3 * ufo->destscale / 2;
 			UFOMoveTo(piece, ufo->x, ufo->y, stemZ);
 			if (sc > 0)
 			{
@@ -961,6 +974,39 @@ static mobj_t *InitSpecialUFO(waypoint_t *start)
 	P_SetTarget(&ufo_pieces(ufo), piece);
 	prevPiece = piece;
 
+	// Next, the glass ball.
+	{
+		piece = P_SpawnMobjFromMobj(ufo, 0, 0, 0, MT_SPECIAL_UFO_PIECE);
+		P_SetTarget(&ufo_piece_owner(piece), ufo);
+
+		P_SetMobjState(piece, S_SPECIAL_UFO_GLASS);
+		ufo_piece_type(piece) = UFO_PIECE_TYPE_GLASS;
+
+		/*overlay = P_SpawnMobjFromMobj(piece, 0, 0, 0, MT_OVERLAY);
+		P_SetTarget(&overlay->target, piece);
+		P_SetMobjState(overlay, S_SPECIAL_UFO_GLASS_UNDER);
+		overlay->dispoffset = -20;*/
+
+		P_SetTarget(&ufo_piece_next(prevPiece), piece);
+		P_SetTarget(&ufo_piece_prev(piece), prevPiece);
+		prevPiece = piece;
+	}
+
+	// This SHOULD have been an MT_OVERLAY... but it simply doesn't
+	// draw-order stack with the Emerald correctly any other way.
+	{
+		piece = P_SpawnMobjFromMobj(ufo, 0, 0, 0, MT_SPECIAL_UFO_PIECE);
+		P_SetTarget(&ufo_piece_owner(piece), ufo);
+
+		P_SetMobjState(piece, S_SPECIAL_UFO_GLASS_UNDER);
+		ufo_piece_type(piece) = UFO_PIECE_TYPE_GLASS_UNDER;
+		piece->dispoffset = -2;
+
+		P_SetTarget(&ufo_piece_next(prevPiece), piece);
+		P_SetTarget(&ufo_piece_prev(piece), prevPiece);
+		prevPiece = piece;
+	}
+
 	// Add the catcher arms.
 	for (i = 0; i < UFO_NUMARMS; i++)
 	{