From 5558fb073ac92ebd1e3c3dc2a632a20542d6f580 Mon Sep 17 00:00:00 2001
From: Sryder <sryder13@gmail.com>
Date: Sun, 18 Oct 2020 19:10:19 +0100
Subject: [PATCH] Basic additive transmap/blend support Can currently be used
 on sprites only added to flames by default because it makes sense

---
 src/dehacked.c         |  4 ++++
 src/hardware/hw_main.c |  1 +
 src/info.c             | 14 +++++++-------
 src/p_mobj.h           |  1 +
 src/p_pspr.h           |  2 ++
 src/r_draw.c           |  3 ++-
 6 files changed, 17 insertions(+), 8 deletions(-)

diff --git a/src/dehacked.c b/src/dehacked.c
index 2d7b58ac9..b57d52c7f 100644
--- a/src/dehacked.c
+++ b/src/dehacked.c
@@ -11123,6 +11123,7 @@ struct {
 	{"FF_TRANS70",FF_TRANS70},
 	{"FF_TRANS80",FF_TRANS80},
 	{"FF_TRANS90",FF_TRANS90},
+	{"FF_TRANSADD",FF_TRANSADD},
 	// compatibility
 	// Transparency for SOCs is pre-shifted
 	{"TR_TRANS10",tr_trans10<<FF_TRANSSHIFT},
@@ -11134,6 +11135,7 @@ struct {
 	{"TR_TRANS70",tr_trans70<<FF_TRANSSHIFT},
 	{"TR_TRANS80",tr_trans80<<FF_TRANSSHIFT},
 	{"TR_TRANS90",tr_trans90<<FF_TRANSSHIFT},
+	{"TR_TRANSADD",tr_transadd<<FF_TRANSSHIFT},
 	// Transparency for Lua is not, unless capitalized as above.
 	{"tr_trans10",tr_trans10},
 	{"tr_trans20",tr_trans20},
@@ -11144,6 +11146,7 @@ struct {
 	{"tr_trans70",tr_trans70},
 	{"tr_trans80",tr_trans80},
 	{"tr_trans90",tr_trans90},
+	{"tr_transadd",tr_transadd},
 	{"NUMTRANSMAPS",NUMTRANSMAPS},
 
 	// Type of levels
@@ -11621,6 +11624,7 @@ struct {
 	{"MFD_TRANS70",MFD_TRANS70},
 	{"MFD_TRANS80",MFD_TRANS80},
 	{"MFD_TRANS90",MFD_TRANS90},
+	{"MFD_TRANSADD",MFD_TRANSADD},
 	{"MFD_TRANSMASK",MFD_TRANSMASK},
 	{"MFD_FULLBRIGHT",MFD_FULLBRIGHT},
 	{"MFD_SEMIBRIGHT",MFD_SEMIBRIGHT},
diff --git a/src/hardware/hw_main.c b/src/hardware/hw_main.c
index 3d9928dd6..135b129f5 100644
--- a/src/hardware/hw_main.c
+++ b/src/hardware/hw_main.c
@@ -781,6 +781,7 @@ FBITFIELD HWR_TranstableToAlpha(INT32 transtablenum, FSurfaceInfo *pSurf)
 		case tr_trans70 : pSurf->PolyColor.s.alpha = 0x4c;return  PF_Translucent;
 		case tr_trans80 : pSurf->PolyColor.s.alpha = 0x33;return  PF_Translucent;
 		case tr_trans90 : pSurf->PolyColor.s.alpha = 0x19;return  PF_Translucent;
+		case tr_transadd : pSurf->PolyColor.s.alpha = 0xFF;return PF_Additive;
 	}
 	return PF_Translucent;
 }
diff --git a/src/info.c b/src/info.c
index 6d5bac1ea..cfa51f9cd 100644
--- a/src/info.c
+++ b/src/info.c
@@ -2231,9 +2231,9 @@ state_t states[NUMSTATES] =
 	{SPR_CHAN, 0, -1, {NULL}, 0, 0, S_NULL}, // S_CEZCHAIN
 
 	// Flame
-	{SPR_FLAM, FF_FULLBRIGHT|FF_ANIMATE,       3*8, {A_FlameParticle}, 7, 3, S_FLAME}, // S_FLAME
-	{SPR_FLAM, FF_FULLBRIGHT|FF_ANIMATE|8, TICRATE,            {NULL}, 3, 3, S_NULL},  // S_FLAMEPARTICLE
-	{SPR_FLAM, FF_FULLBRIGHT|FF_ANIMATE,        -1,            {NULL}, 7, 3, S_NULL},  // S_FLAMEREST
+	{SPR_FLAM, FF_FULLBRIGHT|FF_ANIMATE|FF_TRANSADD,       3*8, {A_FlameParticle}, 7, 3, S_FLAME}, // S_FLAME
+	{SPR_FLAM, FF_FULLBRIGHT|FF_ANIMATE|FF_TRANSADD|8, TICRATE,            {NULL}, 3, 3, S_NULL},  // S_FLAMEPARTICLE
+	{SPR_FLAM, FF_FULLBRIGHT|FF_ANIMATE|FF_TRANSADD,        -1,            {NULL}, 7, 3, S_NULL},  // S_FLAMEREST
 
 	// Eggman statue
 	{SPR_ESTA, 0, -1, {NULL}, 0, 0, S_NULL}, // S_EGGSTATUE1
@@ -4383,10 +4383,10 @@ state_t states[NUMSTATES] =
 
 	{SPR_AUDI, 4|FF_ANIMATE,  -1, {NULL},       1, 17, S_NULL}, // S_AUDIENCE_CHAO_LOSE
 
-	{SPR_FLAM,  0,  3, {NULL}, 0, 0, S_FLAYM2}, // S_FLAYM1,
-	{SPR_FLAM,  1,  3, {NULL}, 0, 0, S_FLAYM3}, // S_FLAYM2,
-	{SPR_FLAM,  2,  3, {NULL}, 0, 0, S_FLAYM4}, // S_FLAYM3,
-	{SPR_FLAM,  3,  3, {NULL}, 0, 0, S_FLAYM1}, // S_FLAYM4,
+	{SPR_FLAM,  FF_FULLBRIGHT|FF_TRANSADD|0,  3, {NULL}, 0, 0, S_FLAYM2}, // S_FLAYM1,
+	{SPR_FLAM,  FF_FULLBRIGHT|FF_TRANSADD|1,  3, {NULL}, 0, 0, S_FLAYM3}, // S_FLAYM2,
+	{SPR_FLAM,  FF_FULLBRIGHT|FF_TRANSADD|2,  3, {NULL}, 0, 0, S_FLAYM4}, // S_FLAYM3,
+	{SPR_FLAM,  FF_FULLBRIGHT|FF_TRANSADD|3,  3, {NULL}, 0, 0, S_FLAYM1}, // S_FLAYM4,
 
 	{SPR_DECO, 0, -1, {NULL}, 0, 0, S_NULL}, // S_DEVIL,
 	{SPR_DECO, 1, -1, {NULL}, 0, 0, S_NULL}, // S_ANGEL,
diff --git a/src/p_mobj.h b/src/p_mobj.h
index cd0cc3bc7..04a75c85e 100644
--- a/src/p_mobj.h
+++ b/src/p_mobj.h
@@ -268,6 +268,7 @@ typedef enum
 	MFD_TRANS70				= 0x0070,
 	MFD_TRANS80				= 0x0080,
 	MFD_TRANS90				= 0x0090,
+	MFD_TRANSADD			= 0x00A0,
 	MFD_TRANSMASK			= 0x00F0,
 	// Brightness override flags
 	MFD_FULLBRIGHT			= 0x0100,
diff --git a/src/p_pspr.h b/src/p_pspr.h
index 6eaf33279..eaa469cd7 100644
--- a/src/p_pspr.h
+++ b/src/p_pspr.h
@@ -59,6 +59,7 @@
 #define FF_TRANS70 (tr_trans70<<FF_TRANSSHIFT)
 #define FF_TRANS80 (tr_trans80<<FF_TRANSSHIFT)
 #define FF_TRANS90 (tr_trans90<<FF_TRANSSHIFT)
+#define FF_TRANSADD (tr_transadd<<FF_TRANSSHIFT)
 
 /// \brief Frame flags: frame always appears full bright (mutually exclusive with below, currently takes priority)
 #define FF_FULLBRIGHT 0x00100000
@@ -99,6 +100,7 @@ typedef enum
 	tr_trans70,
 	tr_trans80,
 	tr_trans90,
+	tr_transadd,
 	NUMTRANSMAPS
 } transnum_t;
 
diff --git a/src/r_draw.c b/src/r_draw.c
index 57c4fe4e4..703462662 100644
--- a/src/r_draw.c
+++ b/src/r_draw.c
@@ -81,7 +81,7 @@ UINT8 *dc_source;
 // -----------------------
 // translucency stuff here
 // -----------------------
-#define NUMTRANSTABLES 9 // how many translucency tables are used
+#define NUMTRANSTABLES 10 // how many translucency tables are used
 
 UINT8 *transtables; // translucency tables
 
@@ -172,6 +172,7 @@ void R_InitTranslationTables(void)
 	W_ReadLump(W_GetNumForName("TRANS70"), transtables+0x60000);
 	W_ReadLump(W_GetNumForName("TRANS80"), transtables+0x70000);
 	W_ReadLump(W_GetNumForName("TRANS90"), transtables+0x80000);
+	W_ReadLump(W_GetNumForName("TRANSADD"),transtables+0x90000);
 }
 
 /**	\brief	Retrieves a translation colormap from the cache.