From 039cf08f4fdbbf05798cbf22cec38f7ce76fbda9 Mon Sep 17 00:00:00 2001
From: Filippos Karapetis <bluegr@gmail.com>
Date: Mon, 14 Jun 2021 03:55:50 +0300
Subject: [PATCH] TRECISION: Fix drawing frames from disabled animations - bugs
 #12624, #12626

Fixes the chain shown incorrectly when entering the platforms and the
shopkeeper's wife appearing frozen after she's left the storeroom
---
 engines/trecision/video.cpp | 42 +++++++++++++++++++++++++------------
 1 file changed, 29 insertions(+), 13 deletions(-)

diff --git a/engines/trecision/video.cpp b/engines/trecision/video.cpp
index 3b74377486e..1cbaa88c0ee 100644
--- a/engines/trecision/video.cpp
+++ b/engines/trecision/video.cpp
@@ -436,14 +436,16 @@ void AnimManager::refreshSmkAnim(uint16 animation) {
 		handleEndOfVideo(animation, kSmackerAction);
 	}
 
-	for (int32 a = 0; a < MAXCHILD; a++) {
-		if (!(_animTab[animation]._flag & (SMKANIM_OFF1 << a)) && (_animTab[animation]._lim[a].bottom != 0)) {
-			_vm->_graphicsMgr->addDirtyRect(_animTab[animation]._lim[a], true);
+	for (int32 i = 0; i < MAXCHILD; i++) {
+		if (!(_animTab[animation]._flag & (SMKANIM_OFF1 << i)) && _animTab[animation]._lim[i].bottom != 0) {
+			_vm->_graphicsMgr->addDirtyRect(_animTab[animation]._lim[i], true);
 		}
 	}
 }
 
 void AnimManager::handleEndOfVideo(int animation, int slot) {
+	const bool isLoopingOrBackground = (_animTab[animation]._flag & SMKANIM_LOOP) || (_animTab[animation]._flag & SMKANIM_BKG);
+
 	if (_smkAnims[slot] == nullptr) {
 		smkStop(slot);
 		return;
@@ -451,7 +453,7 @@ void AnimManager::handleEndOfVideo(int animation, int slot) {
 	if (!_smkAnims[slot]->endOfFrames())
 		return;
 	
-	if (!(_animTab[animation]._flag & SMKANIM_LOOP) && !(_animTab[animation]._flag & SMKANIM_BKG)) {
+	if (!isLoopingOrBackground) {
 		smkStop(slot);
 		_vm->_flagPaintCharacter = true;
 	} else {
@@ -461,6 +463,10 @@ void AnimManager::handleEndOfVideo(int animation, int slot) {
 	}
 }
 
+static bool rectsIntersect(Common::Rect r1, Common::Rect r2) {
+	return (r1.left <= r2.right) && (r1.right >= r2.left) && (r1.top <= r2.bottom) && (r1.bottom >= r2.top);
+}
+
 void AnimManager::drawSmkBackgroundFrame(int animation) {
 	NightlongSmackerDecoder *smkDecoder = _smkAnims[kSmackerBackground];
 	if (smkDecoder == nullptr)
@@ -473,20 +479,30 @@ void AnimManager::drawSmkBackgroundFrame(int animation) {
 	const byte *palette = smkDecoder->getPalette();
 
 	if (smkDecoder->getCurFrame() == 0 && !_bgAnimRestarted) {
-		_vm->_graphicsMgr->blitToScreenBuffer(frame, 0, TOP, palette, true);
+		bool drawFrame = true;
+
+		for (int32 i = 0; i < MAXCHILD; i++) {
+			if ((_animTab[animation]._flag & (SMKANIM_OFF1 << i))) {
+				drawFrame = false;
+				break;
+			}
+		}
+
+		if (drawFrame)
+			_vm->_graphicsMgr->blitToScreenBuffer(frame, 0, TOP, palette, true);
 	} else {
 		while (lastRect) {
-			bool intersects = false;
-			for (int32 a = 0; a < MAXCHILD; a++) {
-				if (_animTab[animation]._flag & (SMKANIM_OFF1 << a)) {
-					if (_animTab[animation]._lim[a].intersects(*lastRect)) {
-						intersects = true;
-						break;
-					}
+			bool drawDirtyRect = true;
+
+			for (int32 i = 0; i < MAXCHILD; i++) {
+				const bool intersect = rectsIntersect(_animTab[animation]._lim[i], *lastRect);
+				if ((_animTab[animation]._flag & (SMKANIM_OFF1 << i)) && intersect) {
+					drawDirtyRect = false;
+					break;
 				}
 			}
 
-			if (smkDecoder->getCurFrame() > 0 && !intersects) {
+			if (smkDecoder->getCurFrame() > 0 && drawDirtyRect) {
 				Graphics::Surface anim = frame->getSubArea(*lastRect);
 				_vm->_graphicsMgr->blitToScreenBuffer(&anim, lastRect->left, lastRect->top + TOP, palette, true);
 			}