Merge pull request #1333 from TomHarte/DeferredSwitches

Apple II: Apply deferred video actions before getting vapour value.

ClockReceiver/DeferredQueue.hpp

@@ -73,6 +73,11 @@ template <typename TimeUnit> class DeferredQueue {
 			}
 		}
 
+		/// @returns @c true if no actions are enqueued; @c false otherwise.
+		bool empty() const {
+			return pending_actions_.empty();
+		}
+
 	private:
 		// The list of deferred actions.
 		struct DeferredAction {

Machines/Apple/ADB/ReactiveDevice.cpp

@@ -13,7 +13,7 @@
 using namespace Apple::ADB;
 
 namespace {
-Log::Logger<Log::Source::ADBDevice> logger;
+[[maybe_unused]] Log::Logger<Log::Source::ADBDevice> logger;
 }
 
 ReactiveDevice::ReactiveDevice(Apple::ADB::Bus &bus, uint8_t adb_device_id) :

Machines/Apple/AppleII/AppleII.cpp

@@ -742,6 +742,11 @@ template <Analyser::Static::AppleII::Target::Model model, bool has_mockingboard>
 				// actor, but this will actually be the result most of the time so it's not
 				// too terrible.
 				if(isReadOperation(operation) && address != 0xc000) {
+					// Ensure any enqueued video changes are applied before grabbing the
+					// vapour value.
+					if(video_.has_deferred_actions()) {
+						update_video();
+					}
 					*value = video_.get_last_read_value(cycles_since_video_update_);
 				}
 
@@ -826,19 +831,19 @@ template <Analyser::Static::AppleII::Target::Model model, bool has_mockingboard>
 									case 0xc000:
 									case 0xc001:
 										update_video();
-										video_.set_80_store(!!(address&1));
+										video_.set_80_store(address&1);
 									break;
 
 									case 0xc00c:
 									case 0xc00d:
 										update_video();
-										video_.set_80_columns(!!(address&1));
+										video_.set_80_columns(address&1);
 									break;
 
 									case 0xc00e:
 									case 0xc00f:
 										update_video();
-										video_.set_alternative_character_set(!!(address&1));
+										video_.set_alternative_character_set(address&1);
 									break;
 								}
 							}
@@ -851,7 +856,7 @@ template <Analyser::Static::AppleII::Target::Model model, bool has_mockingboard>
 					case 0xc050:
 					case 0xc051:
 						update_video();
-						video_.set_text(!!(address&1));
+						video_.set_text(address&1);
 					break;
 					case 0xc052:	update_video();		video_.set_mixed(false);		break;
 					case 0xc053:	update_video();		video_.set_mixed(true);			break;

Machines/Apple/AppleII/Video.hpp

@@ -10,7 +10,6 @@
 
 #include "../../../Outputs/CRT/CRT.hpp"
 #include "../../../ClockReceiver/ClockReceiver.hpp"
-#include "../../../ClockReceiver/DeferredQueue.hpp"
 
 #include "VideoSwitches.hpp"
 
@@ -124,7 +123,8 @@ template <class BusHandler, bool is_iie> class Video: public VideoBase {
 			bus_handler_(bus_handler) {}
 
 		/*!
-			Obtains the last value the video read prior to time now+offset.
+			Obtains the last value the video read prior to time now+offset, according to the *current*
+			video mode, i.e. not allowing for any changes still enqueued.
 		*/
 		uint8_t get_last_read_value(Cycles offset) {
 			// Rules of generation:

Machines/Apple/AppleII/VideoSwitches.hpp

@@ -247,6 +247,10 @@ template <typename TimeUnit> class VideoSwitches {
 			}
 		}
 
+		bool has_deferred_actions() const {
+			return !deferrer_.empty();
+		}
+
 	protected:
 		GraphicsMode graphics_mode(int row) const {
 			if(