From 7aa8728b395a3549a6842f01e7bebbb9cf0a5aac Mon Sep 17 00:00:00 2001
From: Thomas Harte <thomas.harte@gmail.com>
Date: Sat, 18 Feb 2023 21:50:12 -0500
Subject: [PATCH] Reimagine G3 for sprite mode 2.

---
 Components/9918/Implementation/Fetch.hpp   | 10 ++++++++--
 Components/9918/Implementation/Storage.hpp |  3 ++-
 2 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/Components/9918/Implementation/Fetch.hpp b/Components/9918/Implementation/Fetch.hpp
index aed89ab7b..d476c98df 100644
--- a/Components/9918/Implementation/Fetch.hpp
+++ b/Components/9918/Implementation/Fetch.hpp
@@ -522,7 +522,6 @@ template<ScreenMode mode> void Base<personality>::fetch_yamaha(LineBuffer &line_
 					case ScreenMode::Graphics:
 					case ScreenMode::MultiColour:
 					case ScreenMode::ColouredText:
-					case ScreenMode::YamahaGraphics3:
 						character_fetcher.fetch_tile_name(Storage<personality>::next_event_->id);
 					break;
 
@@ -541,7 +540,6 @@ template<ScreenMode mode> void Base<personality>::fetch_yamaha(LineBuffer &line_
 					case ScreenMode::Graphics:
 					case ScreenMode::MultiColour:
 					case ScreenMode::ColouredText:
-					case ScreenMode::YamahaGraphics3:
 						character_fetcher.fetch_tile_colour(Storage<personality>::next_event_->id);
 					break;
 
@@ -571,7 +569,15 @@ template<ScreenMode mode> void Base<personality>::fetch_yamaha(LineBuffer &line_
 					case ScreenMode::Graphics:
 					case ScreenMode::MultiColour:
 					case ScreenMode::ColouredText:
+						character_fetcher.fetch_tile_pattern(Storage<personality>::next_event_->id);
+					break;
+
 					case ScreenMode::YamahaGraphics3:
+						// As per comment elsewhere; my _guess_ is that G3 is slotted as if it were
+						// a bitmap mode, with the three bytes that describe each column fitting into
+						// the relevant windows.
+						character_fetcher.fetch_tile_name(Storage<personality>::next_event_->id);
+						character_fetcher.fetch_tile_colour(Storage<personality>::next_event_->id);
 						character_fetcher.fetch_tile_pattern(Storage<personality>::next_event_->id);
 					break;
 
diff --git a/Components/9918/Implementation/Storage.hpp b/Components/9918/Implementation/Storage.hpp
index 7e9278180..bb27678ba 100644
--- a/Components/9918/Implementation/Storage.hpp
+++ b/Components/9918/Implementation/Storage.hpp
@@ -110,10 +110,11 @@ template <Personality personality> struct Storage<personality, std::enable_if_t<
 			case ScreenMode::MultiColour:
 			case ScreenMode::YamahaGraphics1:
 			case ScreenMode::YamahaGraphics2:
-			case ScreenMode::YamahaGraphics3:				// TODO: possibly? Does this give enough bandwidth for sprites?
 				next_event_ = character_events.data();
 			break;
 
+			case ScreenMode::YamahaGraphics3:				// TODO: verify; my guess is that G3 is timed like a bitmap mode
+															// in order to fit the pattern for sprite mode 2. Just a guess.
 			default:
 				next_event_ = sprites_enabled_ ? sprites_events.data() : no_sprites_events.data();
 			break;