From 1184c1d0c44de056f0a4963b7ce526fe76f5077b Mon Sep 17 00:00:00 2001
From: Omer Mor <omer.mor@gmail.com>
Date: Sat, 28 May 2016 23:34:42 +0300
Subject: [PATCH] SCI: Script patch for QfG3 giant tree bounds

At the base of the giant tree, when entering from the top east path,
the hero can get out of bounds and walk freely in the room.
This is caused by an incorrect cutoff used to determine whether the
hero entered from the top or bottom path.
The patch changes this cutoff, and prevents going out of bounds.

Fixes bug #6693
---
 engines/sci/engine/script_patches.cpp | 83 +++++++++++++++++++++++++++
 1 file changed, 83 insertions(+)

diff --git a/engines/sci/engine/script_patches.cpp b/engines/sci/engine/script_patches.cpp
index 116ffdd5a28a..66c4184c9516 100644
--- a/engines/sci/engine/script_patches.cpp
+++ b/engines/sci/engine/script_patches.cpp
@@ -3071,6 +3071,86 @@ static const uint16 qfg3PatchCombatSpeedThrottling2[] = {
 	PATCH_END
 };
 
+// In room #750, when the hero enters from the top east path (room #755), it
+// could go out of the contained-access polygon bounds, and be able to travel
+// freely in the room.
+// The reason is that the cutoff y value (42) that determines whether the hero
+// enters from the top or bottom path is inaccurate: it's possible to enter the
+// top path from as low as y=45.
+// This patch changes the cutoff to be 50 which should be low enough.
+// It also changes the position in which the hero enters from the top east path
+// as the current location is hidden behind the tree.
+//
+// Applies to: English, French, German, Italian, Spanish and the GOG release.
+// Responsible method: enterEast::changeState (script 750)
+// Fixes bug #6693
+static const uint16 qfg3SignatureRoom750Bounds1[] = {
+	// (if (< (ego y?) 42)
+	0x76,                               // push0 ("y")
+	0x76,                               // push0
+	0x81, 0x00,                         // lag global[0] (ego)
+	0x4a, 0x04,                         // send 4
+	SIG_MAGICDWORD,
+	0x36,                               // push
+	0x35,   42,                         // ldi 42 <-- comparing ego.y with 42
+	0x22,                               // lt?
+	SIG_END
+};
+
+static const uint16 qfg3PatchRoom750Bounds1[] = {
+	// (if (< (ego y?) 50)
+	PATCH_ADDTOOFFSET(+8),
+	50,                                 // 42 --> 50
+	PATCH_END
+};
+
+static const uint16 qfg3SignatureRoom750Bounds2[] = {
+	// (ego x: 294 y: 39)
+	0x78,                               // push1 ("x")
+	0x78,                               // push1 
+	0x38, SIG_UINT16(294),              // pushi 294
+	0x76,                               // push0 ("y")
+	0x78,                               // push1
+	SIG_MAGICDWORD,
+	0x39,   29,                         // pushi 29
+	0x81, 0x00,                         // lag global[0] (ego)
+	0x4a, 0x0c,                         // send 12
+	SIG_END
+};
+
+static const uint16 qfg3PatchRoom750Bounds2[] = {
+	// (ego x: 320 y: 39)
+	PATCH_ADDTOOFFSET(+3),
+	PATCH_UINT16(320),                  // 294 --> 320
+	PATCH_ADDTOOFFSET(+3),
+	39,                                 //  29 -->  39
+	PATCH_END
+};
+
+static const uint16 qfg3SignatureRoom750Bounds3[] = {
+	// (ego setMotion: MoveTo 282 29 self)
+	0x38, SIG_SELECTOR16(setMotion),    // pushi "setMotion" 0x133 in QfG3
+	0x39, 0x04,                         // pushi 4
+	0x51, SIG_ADDTOOFFSET(+1),          // class MoveTo
+	0x36,                               // push
+	0x38, SIG_UINT16(282),              // pushi 282
+	SIG_MAGICDWORD,
+	0x39,   29,                         // pushi 29
+	0x7c,                               // pushSelf
+	0x81, 0x00,                         // lag global[0] (ego)
+	0x4a, 0x0c,                         // send 12
+	SIG_END
+};
+
+static const uint16 qfg3PatchRoom750Bounds3[] = {
+	// (ego setMotion: MoveTo 309 35 self)
+	PATCH_ADDTOOFFSET(+9),
+	PATCH_UINT16(309),                  // 282 --> 309
+	PATCH_ADDTOOFFSET(+1),
+	35,                                 //  29 -->  35
+	PATCH_END
+};
+
 //          script, description,                                      signature                    patch
 static const SciScriptPatcherEntry qfg3Signatures[] = {
 	{  true,   944, "import dialog continuous calls",                     1, qfg3SignatureImportDialog,           qfg3PatchImportDialog },
@@ -3084,6 +3164,9 @@ static const SciScriptPatcherEntry qfg3Signatures[] = {
 	{  true,   285, "missing points for telling about initiation script", 1, qfg3SignatureMissingPoints2b,        qfg3PatchMissingPoints2 },
 	{  true,   550, "combat speed throttling script",                     1, qfg3SignatureCombatSpeedThrottling1, qfg3PatchCombatSpeedThrottling1 },
 	{  true,   550, "combat speed throttling heap",                       1, qfg3SignatureCombatSpeedThrottling2, qfg3PatchCombatSpeedThrottling2 },
+	{  true,   750, "hero goes out of bounds in room 750",                2, qfg3SignatureRoom750Bounds1,         qfg3PatchRoom750Bounds1 },
+	{  true,   750, "hero goes out of bounds in room 750",                2, qfg3SignatureRoom750Bounds2,         qfg3PatchRoom750Bounds2 },
+	{  true,   750, "hero goes out of bounds in room 750",                2, qfg3SignatureRoom750Bounds3,         qfg3PatchRoom750Bounds3 },
 	SCI_SIGNATUREENTRY_TERMINATOR
 };