From cee18a572e3cb39b2ee34eb3328266401ec707bb Mon Sep 17 00:00:00 2001
From: kichikuou <KichikuouChrome@gmail.com>
Date: Sun, 31 Jul 2022 12:44:30 +0900
Subject: [PATCH] Implement palette shift effect (CD 1001)

Used in Toushin Toshi 2.
---
 src/ags.c    | 14 ++++++++++++++
 src/ags.h    |  1 +
 src/ecopy.c  | 15 +++++++--------
 src/effect.h |  3 ++-
 4 files changed, 24 insertions(+), 9 deletions(-)

diff --git a/src/ags.c b/src/ags.c
index d071cc7..4220c55 100644
--- a/src/ags.c
+++ b/src/ags.c
@@ -301,6 +301,20 @@ void ags_getPixel(int x, int y, Palette *cell) {
 	sdl_getPixel(x, y, cell);
 }
 
+void ags_copyPaletteShift(int sx, int sy, int w, int h, int dx, int dy, BYTE sprite) {
+	if (!ags_check_param(&sx, &sy, &w, &h)) return;
+	if (!ags_check_param(&dx, &dy, &w, &h)) return;
+
+	for (int y = 0; y < h; y++) {
+		BYTE *src = GETOFFSET_PIXEL(nact->ags.dib, sx, sy + y);
+		BYTE *dst = GETOFFSET_PIXEL(nact->ags.dib, dx, dy + y);
+		for (int x = 0; x < w; x++, src++, dst++) {
+			if (*src != sprite)
+				*dst = (*src & 0xf0) | (*dst & 0x0f);
+		}
+	}
+}
+
 void ags_changeColorArea(int sx, int sy, int w, int h, int dst, int src, int cnt) {
 	if (nact->ags.world_depth != 8) return;
 	
diff --git a/src/ags.h b/src/ags.h
index 8b06f73..e777d53 100644
--- a/src/ags.h
+++ b/src/ags.h
@@ -161,6 +161,7 @@ extern void ags_copyArea_shadow_withrate(int sx, int sy, int w, int h, int dx, i
 
 extern void ags_wrapColor(int x, int y, int w, int h, int p1, int p2);
 extern void ags_getPixel(int x, int y, Palette *cell);
+extern void ags_copyPaletteShift(int sx, int sy, int w, int h, int dx, int dy, BYTE sprite);
 extern void ags_changeColorArea(int x, int y, int w, int h, int dst, int src, int cnt);
 
 extern void* ags_saveRegion(int x, int y, int w, int h);
diff --git a/src/ecopy.c b/src/ecopy.c
index aa239f1..9b859b1 100644
--- a/src/ecopy.c
+++ b/src/ecopy.c
@@ -284,11 +284,6 @@ static int eCopyArea1000(int sx, int sy, int w, int h, int dx, int dy, int opt,
 	return sys_getInputInfo();
 }
 
-static int eCopyArea1001(int sx, int sy, int w, int h, int dx, int dy, int opt, int spCol) {
-	/* パレットシフト */
-	return sys_getInputInfo();
-}
-
 static int eCopyArea2000(int sx, int sy, int w, int h, int dx, int dy, int opt) {
 	sdl_fillRectangleRGB(dx, dy, w, h, 0, 0, 0);
 	ags_copyArea_alphaLevel(sx, sy, w, h, dx, dy, opt);
@@ -401,6 +396,8 @@ static int duration(enum nact_effect effect, int opt, SDL_Rect *rect) {
 		 return opt ? opt : 1000;
 	case NACT_EFFECT_LINEAR_BLUR:
 		return opt ? opt : 1700;
+	case NACT_EFFECT_PALETTE_SHIFT:
+		return 0;
 	}
 	return 1000;
 }
@@ -522,9 +519,11 @@ void ags_eCopyArea(int sx, int sy, int w, int h, int dx, int dy, int sw, int opt
 		if (nact->ags.world_depth != 8) return;
 		ret = eCopyArea1000(sx, sy, w, h, dx, dy, opt, spCol);
 		break;
-	case 1001:
-		if (nact->ags.world_depth != 8) return;
-		ret = eCopyArea1001(sx, sy, w, h, dx, dy, opt, spCol);
+	case NACT_EFFECT_PALETTE_SHIFT:
+		if (nact->ags.world_depth != 8 || spCol == -1) return;
+		ags_copyPaletteShift(sx, sy, w, h, dx, dy, spCol);
+		ags_updateArea(dx, dy, w, h);
+		ret = sys_getInputInfo();
 		break;
 	case 2000:
 		if (nact->ags.world_depth == 8) return;
diff --git a/src/effect.h b/src/effect.h
index dc65546..7a21566 100644
--- a/src/effect.h
+++ b/src/effect.h
@@ -20,7 +20,7 @@
 #ifndef __EFFECT_H__
 #define __EFFECT_H__
 
-// Effect types of the CE command.
+// Effect types of the CE/CD command.
 enum nact_effect {
 	NACT_EFFECT_WIPE_IN           = 7,
 	NACT_EFFECT_WIPE_OUT          = 8,
@@ -64,6 +64,7 @@ enum nact_effect {
 	NACT_EFFECT_WINDMILL_180      = 51,
 	NACT_EFFECT_WINDMILL_360      = 52,
 	NACT_EFFECT_LINEAR_BLUR       = 53,
+	NACT_EFFECT_PALETTE_SHIFT     = 1001,  // CD command only
 };
 
 // Effect types of SCAT.DrawEffect and Gpx.EffectCopy.