From f749a673148c6aec202cd99311782db6b787c557 Mon Sep 17 00:00:00 2001
From: Michael Chaban <arsunt@gmail.com>
Date: Sat, 1 Aug 2020 23:05:34 +0300
Subject: [PATCH] Fixed a bug where pickup sprites were cropped by the floor if
 Z-Buffer is enabled.

---
 3dsystem/scalespr.cpp | 16 ++++++++++++++++
 CHANGELOG.md          |  1 +
 game/draw.cpp         |  3 ++-
 global/types.h        |  1 +
 specific/registry.h   |  1 +
 specific/smain.cpp    |  2 ++
 6 files changed, 23 insertions(+), 1 deletion(-)

diff --git a/3dsystem/scalespr.cpp b/3dsystem/scalespr.cpp
index d03e594..c0a26eb 100644
--- a/3dsystem/scalespr.cpp
+++ b/3dsystem/scalespr.cpp
@@ -28,6 +28,10 @@
 extern int CalculateFogShade(int depth);
 #endif // FEATURE_VIEW_IMPROVED
 
+#ifdef FEATURE_VIDEOFX_IMPROVED
+DWORD PickupItemMode = 1;
+#endif // FEATURE_VIDEOFX_IMPROVED
+
 void __cdecl S_DrawSprite(DWORD flags, int x, int y, int z, __int16 spriteIdx, __int16 shade, __int16 scale) {
 	int xv, yv, zv, zp, depth;
 	int x1, y1, x2, y2;
@@ -70,6 +74,18 @@ void __cdecl S_DrawSprite(DWORD flags, int x, int y, int z, __int16 spriteIdx, _
 	x2 = PhdSpriteInfo[spriteIdx].x2;
 	y2 = PhdSpriteInfo[spriteIdx].y2;
 
+#ifdef FEATURE_VIDEOFX_IMPROVED
+	if( PickupItemMode == 1 && CHK_ALL(flags, SPR_ITEM|SPR_ABS) ) {
+		if( y1 < y2 ) {
+			y1 -= y2;
+			y2 = 0;
+		} else {
+			y2 -= y1;
+			y1 = 0;
+		}
+	}
+#endif // FEATURE_VIDEOFX_IMPROVED
+
 	if( CHK_ANY(flags, SPR_SCALE) ) { // scaling required
 		x1 = (x1 * scale) << (W2V_SHIFT - 8);
 		y1 = (y1 * scale) << (W2V_SHIFT - 8);
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 93af0a5..e6c9b20 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -64,6 +64,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Fixed a rare game crash occurring when you explode an enemy with a grenade launcher.
 - Fixed incorrect sorting of 3D polygons if Z-Buffer is turned off or the software renderer is used.
 - Fixed a bug due to which the skybox was not drawn in some rooms.
+- Fixed a bug where pickup sprites were cropped by the floor if Z-Buffer is enabled. Some pickup items are slightly raised (optional fix).
 
 ### TR2Main bugfixes
 - Background capture is optimized even more, now it is 3-4 times faster than v0.8.2. No lags anymore (broken since v0.8.0).
diff --git a/game/draw.cpp b/game/draw.cpp
index b92f164..4679dbb 100644
--- a/game/draw.cpp
+++ b/game/draw.cpp
@@ -498,7 +498,8 @@ void __cdecl DrawSpriteItem(ITEM_INFO *item) {
 
 	obj = &Objects[item->objectID];
 
-	S_DrawSprite(SPR_ABS | SPR_SHADE | (obj->semi_transparent ? SPR_SEMITRANS : 0),
+	// NOTE: SPR_ITEM is not presented in the original game
+	S_DrawSprite(SPR_ITEM | SPR_ABS | SPR_SHADE | (obj->semi_transparent ? SPR_SEMITRANS : 0),
 				 item->pos.x, item->pos.y, item->pos.z,
 				 obj->meshIndex - item->frameNumber,
 				 LsAdder + 0x1000, 0);
diff --git a/global/types.h b/global/types.h
index 3b076b6..27f0bbd 100644
--- a/global/types.h
+++ b/global/types.h
@@ -223,6 +223,7 @@ typedef struct {
 #define SPR_BLEND_SUB	(0x40000000)
 #define SPR_BLEND_QRT	(SPR_BLEND_ADD|SPR_BLEND_SUB)
 #define SPR_BLEND		(SPR_BLEND_QRT)
+#define SPR_ITEM		(0x80000000)
 
 // Item flags
 #define IFL_INVISIBLE	(0x0100)
diff --git a/specific/registry.h b/specific/registry.h
index 6e2b7a6..2ca98cf 100644
--- a/specific/registry.h
+++ b/specific/registry.h
@@ -60,6 +60,7 @@
 #define REG_ALPHABLEND_MODE		"AlphaBlendMode"
 #define REG_INVTEXTBOX_MODE		"InvTextBoxMode"
 #define REG_HEALTHBAR_MODE		"HealthBarMode"
+#define REG_PICKUPITEM_MODE		"PickupItemMode"
 #define REG_SCREENSHOT_FORMAT	"ScreenshotFormat"
 
 // BOOL value names
diff --git a/specific/smain.cpp b/specific/smain.cpp
index a7a97f5..c369be4 100644
--- a/specific/smain.cpp
+++ b/specific/smain.cpp
@@ -68,6 +68,7 @@ extern DWORD ShadowMode;
 extern DWORD AlphaBlendMode;
 extern DWORD ReflectionMode;
 extern DWORD ReflectionBlur;
+extern DWORD PickupItemMode;
 extern bool CustomWaterColorEnabled;
 #endif // FEATURE_VIDEOFX_IMPROVED
 
@@ -551,6 +552,7 @@ void __cdecl S_LoadSettings() {
 	GetRegistryDwordValue(REG_ALPHABLEND_MODE, &AlphaBlendMode, 0);
 	GetRegistryDwordValue(REG_REFLECTION_MODE, &ReflectionMode, 0);
 	GetRegistryDwordValue(REG_REFLECTION_BLUR, &ReflectionBlur, 2);
+	GetRegistryDwordValue(REG_PICKUPITEM_MODE, &PickupItemMode, 1);
 	GetRegistryBoolValue(REG_CUSTOM_WATER_COLOR, &CustomWaterColorEnabled, false);
 	CLAMPG(AlphaBlendMode, 2);
 	CLAMPG(ReflectionMode, 2);