From a473aeff2cd8c29825cd3677c699485a2592ac5d Mon Sep 17 00:00:00 2001
From: Vicki Pfau <vi@endrift.com>
Date: Tue, 14 Feb 2023 23:13:04 -0800
Subject: [PATCH] Qt: Fix a handful of edge cases with graphics viewers (fixes
 #2827)

---
 CHANGES                      |  1 +
 src/platform/qt/MapView.cpp  | 12 +++++++++++-
 src/platform/qt/TileView.cpp |  4 ++--
 3 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/CHANGES b/CHANGES
index 7536739cb..86f75a8e4 100644
--- a/CHANGES
+++ b/CHANGES
@@ -13,6 +13,7 @@ Other fixes:
  - Qt: Properly cap number of attached players by platform (fixes mgba.io/i/2807)
  - Qt: Disable attempted linking betwen incompatible platforms (fixes mgba.io/i/2702)
  - Qt: Fix modifier key names in shortcut editor (fixes mgba.io/i/2817)
+ - Qt: Fix a handful of edge cases with graphics viewers (fixes mgba.io/i/2827)
 Misc:
  - Qt: Include wayland QPA in AppImage (fixes mgba.io/i/2796)
  - Qt: Stop eating boolean action key events (fixes mgba.io/i/2636)
diff --git a/src/platform/qt/MapView.cpp b/src/platform/qt/MapView.cpp
index ba2255ee9..f52c375c4 100644
--- a/src/platform/qt/MapView.cpp
+++ b/src/platform/qt/MapView.cpp
@@ -42,7 +42,7 @@ MapView::MapView(std::shared_ptr<CoreController> controller, QWidget* parent)
 #ifdef M_CORE_GBA
 	case mPLATFORM_GBA:
 		m_boundary = 2048;
-		m_ui.tile->setMaxTile(3096);
+		m_ui.tile->setMaxTile(3072);
 		m_addressBase = BASE_VRAM;
 		m_addressWidth = 8;
 		m_ui.bgInfo->addCustomProperty("priority", tr("Priority"));
@@ -119,6 +119,9 @@ void MapView::selectMap(int map) {
 	}
 	m_map = map;
 	m_mapStatus.fill({});
+	// Different maps can have different max palette counts; set it to
+	// 0 immediately to avoid tile lookups with state palette IDs break
+	m_ui.tile->setPalette(0);
 	updateTiles(true);
 }
 
@@ -184,11 +187,18 @@ void MapView::updateTilesGBA(bool) {
 					frame = GBARegisterDISPCNTGetFrameSelect(io[REG_DISPCNT >> 1]);
 				}
 			}
+			m_boundary = 1024;
+			m_ui.tile->setMaxTile(1536);
 			priority = GBARegisterBGCNTGetPriority(io[(REG_BG0CNT >> 1) + m_map]);
 			if (mode == 0 || (mode == 1 && m_map != 2)) {
 				offset = QString("%1, %2")
 					.arg(io[(REG_BG0HOFS >> 1) + (m_map << 1)])
 					.arg(io[(REG_BG0VOFS >> 1) + (m_map << 1)]);
+
+				if (!GBARegisterBGCNTIs256Color(io[(REG_BG0CNT >> 1) + m_map])) {
+					m_boundary = 2048;
+					m_ui.tile->setMaxTile(3072);
+				}
 			} else if ((mode > 0 && m_map == 2) || (mode == 2 && m_map == 3)) {
 				int32_t refX = io[(REG_BG2X_LO >> 1) + ((m_map - 2) << 2)];
 				refX |= io[(REG_BG2X_HI >> 1) + ((m_map - 2) << 2)] << 16;
diff --git a/src/platform/qt/TileView.cpp b/src/platform/qt/TileView.cpp
index 116935e29..7d8d1a71e 100644
--- a/src/platform/qt/TileView.cpp
+++ b/src/platform/qt/TileView.cpp
@@ -51,7 +51,7 @@ TileView::TileView(std::shared_ptr<CoreController> controller, QWidget* parent)
 #ifdef M_CORE_GBA
 	case mPLATFORM_GBA:
 		m_ui.tile->setBoundary(2048, 0, 2);
-		m_ui.tile->setMaxTile(3096);
+		m_ui.tile->setMaxTile(3072);
 		break;
 #endif
 #ifdef M_CORE_GB
@@ -76,7 +76,7 @@ TileView::TileView(std::shared_ptr<CoreController> controller, QWidget* parent)
 #ifdef M_CORE_GBA
 		case mPLATFORM_GBA:
 			m_ui.tile->setBoundary(2048 >> selected, selected, selected + 2);
-			m_ui.tile->setMaxTile(3096 >> selected);
+			m_ui.tile->setMaxTile(3072 >> selected);
 			break;
 #endif
 #ifdef M_CORE_GB