Reset transformation progress on new run identity

Author: emp0ry

src/EIDRunResetFix.m

@@ -0,0 +1,137 @@
+#import "EIDLogger.h"
+#import <Foundation/Foundation.h>
+#import <mach-o/dyld.h>
+#import <mach-o/loader.h>
+#import <mach/mach.h>
+#import <objc/message.h>
+#import <objc/runtime.h>
+
+static const char *kEIDRunResetSupportedUUID = "F4357753-A25F-30EE-BACF-63709F902895";
+static const uintptr_t kEIDRunResetGameGlobalOffset = 0xac3b90;
+
+struct EIDRemotePointerVector {
+    uintptr_t begin;
+    uintptr_t end;
+    uintptr_t capacity;
+};
+
+static BOOL EIDRunResetRead(vm_address_t address, void *destination, vm_size_t size) {
+    if (!address || !destination || !size) return NO;
+    vm_size_t copied = 0;
+    return vm_read_overwrite(mach_task_self(), address, size,
+                             (vm_address_t)destination, &copied) == KERN_SUCCESS && copied == size;
+}
+
+static NSString *EIDRunResetUUIDForHeader(const struct mach_header_64 *header) {
+    if (!header || header->magic != MH_MAGIC_64) return nil;
+    const uint8_t *cursor = (const uint8_t *)(header + 1);
+    const uint8_t *end = cursor + header->sizeofcmds;
+    for (uint32_t index = 0; index < header->ncmds; ++index) {
+        if (cursor + sizeof(struct load_command) > end) break;
+        const struct load_command *command = (const struct load_command *)cursor;
+        if (!command->cmdsize || cursor + command->cmdsize > end) break;
+        if (command->cmd == LC_UUID && command->cmdsize >= sizeof(struct uuid_command)) {
+            const struct uuid_command *uuidCommand = (const struct uuid_command *)cursor;
+            const unsigned char *u = uuidCommand->uuid;
+            return [NSString stringWithFormat:
+                @"%02X%02X%02X%02X-%02X%02X-%02X%02X-%02X%02X-%02X%02X%02X%02X%02X%02X",
+                u[0],u[1],u[2],u[3],u[4],u[5],u[6],u[7],u[8],u[9],u[10],u[11],u[12],u[13],u[14],u[15]];
+        }
+        cursor += command->cmdsize;
+    }
+    return nil;
+}
+
+static const struct mach_header_64 *EIDRunResetIsaacHeader(void) {
+    NSString *wanted = [NSString stringWithUTF8String:kEIDRunResetSupportedUUID];
+    for (uint32_t index = 0; index < _dyld_image_count(); ++index) {
+        const struct mach_header_64 *header = (const struct mach_header_64 *)_dyld_get_image_header(index);
+        NSString *uuid = EIDRunResetUUIDForHeader(header);
+        if (uuid && [uuid caseInsensitiveCompare:wanted] == NSOrderedSame) return header;
+    }
+    return NULL;
+}
+
+static uintptr_t EIDCurrentRunIdentity(id probe) {
+    if (!probe) return 0;
+    NSNumber *offsetNumber = nil;
+    @try { offsetNumber = [probe valueForKey:@"playerVectorOffset"]; }
+    @catch (__unused NSException *exception) { return 0; }
+    if (![offsetNumber isKindOfClass:NSNumber.class]) return 0;
+    NSUInteger playerVectorOffset = offsetNumber.unsignedIntegerValue;
+    if (playerVectorOffset == NSUIntegerMax) return 0;
+
+    const struct mach_header_64 *header = EIDRunResetIsaacHeader();
+    if (!header) return 0;
+    uintptr_t game = 0;
+    if (!EIDRunResetRead((vm_address_t)header + kEIDRunResetGameGlobalOffset,
+                         &game, sizeof(game)) || !game) return 0;
+
+    EIDRemotePointerVector vector = {};
+    if (!EIDRunResetRead(game + playerVectorOffset, &vector, sizeof(vector))) return 0;
+    if (!vector.begin || vector.end <= vector.begin || vector.capacity < vector.end) return 0;
+    if ((vector.end - vector.begin) % sizeof(uintptr_t) != 0) return 0;
+
+    uintptr_t firstPlayer = 0;
+    if (!EIDRunResetRead(vector.begin, &firstPlayer, sizeof(firstPlayer))) return 0;
+    return firstPlayer;
+}
+
+static void EIDResetTransformationTracker(NSString *reason) {
+    Class trackerClass = NSClassFromString(@"EIDTransformationProgress");
+    SEL sharedSEL = NSSelectorFromString(@"shared");
+    SEL resetSEL = NSSelectorFromString(@"resetForNewRun");
+    if (!trackerClass || ![trackerClass respondsToSelector:sharedSEL]) return;
+    id (*sendShared)(id, SEL) = (id (*)(id, SEL))objc_msgSend;
+    id tracker = sendShared(trackerClass, sharedSEL);
+    if (!tracker || ![tracker respondsToSelector:resetSEL]) return;
+    void (*sendReset)(id, SEL) = (void (*)(id, SEL))objc_msgSend;
+    sendReset(tracker, resetSEL);
+    EIDLog(@"transformation progress reset: %@", reason);
+}
+
+@interface NSObject (EIDRunResetFix)
+- (void)eid_runreset_updateMenuModeForGameplay:(BOOL)gameplayActive;
+@end
+
+@implementation NSObject (EIDRunResetFix)
+- (void)eid_runreset_updateMenuModeForGameplay:(BOOL)gameplayActive {
+    static uintptr_t lastRunIdentity = 0;
+    static BOOL sawInactiveSinceRun = YES;
+
+    if (!gameplayActive) {
+        sawInactiveSinceRun = YES;
+    } else {
+        id probe = nil;
+        @try { probe = [self valueForKey:@"probe"]; }
+        @catch (__unused NSException *exception) {}
+        uintptr_t identity = EIDCurrentRunIdentity(probe);
+        if (identity) {
+            BOOL changedIdentity = lastRunIdentity && identity != lastRunIdentity;
+            BOOL restartedAfterInactive = sawInactiveSinceRun && lastRunIdentity != 0;
+            if (changedIdentity || restartedAfterInactive) {
+                EIDResetTransformationTracker(changedIdentity ? @"native run identity changed"
+                                                              : @"gameplay restarted after menu/death");
+            }
+            lastRunIdentity = identity;
+            sawInactiveSinceRun = NO;
+        }
+    }
+
+    [self eid_runreset_updateMenuModeForGameplay:gameplayActive];
+}
+@end
+
+__attribute__((constructor)) static void EIDInstallRunResetFix(void) {
+    dispatch_async(dispatch_get_main_queue(), ^{
+        Class cls = NSClassFromString(@"EIDOverlayController");
+        if (!cls) return;
+        SEL replacementSEL = @selector(eid_runreset_updateMenuModeForGameplay:);
+        Method source = class_getInstanceMethod(NSObject.class, replacementSEL);
+        if (!source) return;
+        class_addMethod(cls, replacementSEL, method_getImplementation(source), method_getTypeEncoding(source));
+        Method original = class_getInstanceMethod(cls, NSSelectorFromString(@"updateMenuModeForGameplay:"));
+        Method replacement = class_getInstanceMethod(cls, replacementSEL);
+        if (original && replacement) method_exchangeImplementations(original, replacement);
+    });
+}