From 19dd2f92bd3416f90cde934ec1712b6ae0dadd85 Mon Sep 17 00:00:00 2001
From: Thomas Harte <thomas.harte@gmail.com>
Date: Sat, 25 Sep 2021 21:52:41 -0400
Subject: [PATCH] Implements test case. Failing at present, naturally.

---
 .../Clock SignalTests/AmigaBlitterTests.mm    | 141 ++++++++++++++++++
 1 file changed, 141 insertions(+)

diff --git a/OSBindings/Mac/Clock SignalTests/AmigaBlitterTests.mm b/OSBindings/Mac/Clock SignalTests/AmigaBlitterTests.mm
index 161853ceb..21eee0eae 100644
--- a/OSBindings/Mac/Clock SignalTests/AmigaBlitterTests.mm	
+++ b/OSBindings/Mac/Clock SignalTests/AmigaBlitterTests.mm	
@@ -10,6 +10,8 @@
 
 #include "Blitter.hpp"
 
+#include <vector>
+
 namespace Amiga {
 /// An empty stub to satisfy Amiga::Blitter's inheritance from Amiga::DMADevice;
 struct Chipset {};
@@ -24,6 +26,145 @@ struct Chipset {};
 	uint16_t ram[512 * 1024]{};
 	Amiga::Chipset nonChipset;
 	Amiga::Blitter blitter(nonChipset, ram, 256 * 1024);
+
+	NSURL *const traceURL = [[NSBundle bundleForClass:[self class]] URLForResource:@"workbench13 boot logo" withExtension:@"json"];
+	NSData *const traceData = [NSData dataWithContentsOfURL:traceURL];
+	NSArray *const trace = [NSJSONSerialization JSONObjectWithData:traceData options:0 error:nil];
+
+	// Step 1 in developing my version of the Blitter is to make sure that I understand
+	// the logic; as a result the first implementation is going to be a magical thing that
+	// completes all Blits in a single cycle.
+	//
+	// Therefore I've had to bodge my way around the trace's record of reads and writes by
+	// accumulating all writes into a blob and checking them en massse at the end of a blit
+	// (as detected by any register work in between memory accesses, since Kickstart 1.3
+	// doesn't do anything off-book).
+	enum class State {
+		AwaitingWrites,
+		LoggingWrites
+	} state = State::AwaitingWrites;
+
+	std::vector<std::pair<uint32_t, uint16_t>> writes;
+
+	for(NSArray *const event in trace) {
+		NSString *const type = event[0];
+		const NSInteger param1 = [event[1] integerValue];
+
+		if([type isEqualToString:@"bltcon0"]) {
+			blitter.set_control(0, param1);
+			state = State::AwaitingWrites;
+			continue;
+		}
+		if([type isEqualToString:@"bltcon1"]) {
+			blitter.set_control(1, param1);
+			state = State::AwaitingWrites;
+			continue;
+		}
+
+		if([type isEqualToString:@"bltsize"]) {
+			blitter.set_size(param1);
+			state = State::AwaitingWrites;
+			continue;
+		}
+
+		if([type isEqualToString:@"bltafwm"]) {
+			blitter.set_first_word_mask(param1);
+			state = State::AwaitingWrites;
+			continue;
+		}
+		if([type isEqualToString:@"bltalwm"]) {
+			blitter.set_last_word_mask(param1);
+			state = State::AwaitingWrites;
+			continue;
+		}
+
+		if([type isEqualToString:@"bltadat"]) {
+			blitter.set_data(0, param1);
+			state = State::AwaitingWrites;
+			continue;
+		}
+		if([type isEqualToString:@"bltbdat"]) {
+			blitter.set_data(1, param1);
+			state = State::AwaitingWrites;
+			continue;
+		}
+		if([type isEqualToString:@"bltcdat"]) {
+			blitter.set_data(2, param1);
+			state = State::AwaitingWrites;
+			continue;
+		}
+
+		if([type isEqualToString:@"bltaptl"]) {
+			blitter.set_pointer<0, 0>(param1);
+			state = State::AwaitingWrites;
+			continue;
+		}
+		if([type isEqualToString:@"bltbptl"]) {
+			blitter.set_pointer<1, 0>(param1);
+			state = State::AwaitingWrites;
+			continue;
+		}
+		if([type isEqualToString:@"bltcptl"]) {
+			blitter.set_pointer<2, 0>(param1);
+			state = State::AwaitingWrites;
+			continue;
+		}
+		if([type isEqualToString:@"bltdptl"]) {
+			blitter.set_pointer<3, 0>(param1);
+			state = State::AwaitingWrites;
+			continue;
+		}
+
+		if([type isEqualToString:@"bltapth"]) {
+			blitter.set_pointer<0, 16>(param1);
+			state = State::AwaitingWrites;
+			continue;
+		}
+		if([type isEqualToString:@"bltbpth"]) {
+			blitter.set_pointer<1, 16>(param1);
+			state = State::AwaitingWrites;
+			continue;
+		}
+		if([type isEqualToString:@"bltcpth"]) {
+			blitter.set_pointer<2, 16>(param1);
+			state = State::AwaitingWrites;
+			continue;
+		}
+		if([type isEqualToString:@"bltdpth"]) {
+			blitter.set_pointer<3, 16>(param1);
+			state = State::AwaitingWrites;
+			continue;
+		}
+
+		// Hackaround for testing my magical all-at-once Blitter is here.
+		if(state == State::AwaitingWrites) {
+			for(const auto &write: writes) {
+				XCTAssertEqual(ram[write.first >> 1], write.second, @"Didn't find %04x at address %08x; found %04x instead", write.second, write.first, ram[write.first >> 1]);
+
+				// For now, indicate only the first failure.
+				if(ram[write.first >> 1] != write.second) {
+					break;
+				}
+			}
+			writes.clear();
+			state = State::LoggingWrites;
+		}
+		// Hack ends here.
+
+		if([type isEqualToString:@"cread"] || [type isEqualToString:@"bread"] || [type isEqualToString:@"aread"]) {
+			ram[param1 >> 1] = [event[2] integerValue];
+			continue;
+		}
+
+		if([type isEqualToString:@"write"]) {
+			writes.push_back(std::make_pair(uint32_t(param1), uint16_t([event[2] integerValue])));
+			continue;
+		}
+
+		NSLog(@"Unhandled type: %@", type);
+		XCTAssert(false);
+		break;
+	}
 }
 
 @end