Add files via upload

diablo2-fend-fix.c

@@ -0,0 +1,96 @@
+/* Fixes the Fend bug in Diablo II LoD 1.14d by disabling Dodge and Avoid
+ * animations. The skills themselves still work, and the player will hear the
+ * Amazon's "hyah" sound when they trigger. Many thanks to EnPhreg and other
+ * forum users in this thread for sharing their finds:
+ * https://d2mods.info/forum/viewtopic.php?p=501489#p501489
+ *
+ * The file "Game.exe" will be changed. Make a backup beforehand in case you
+ * ever want to go back. In general, please do not try to connect to Battle.net
+ * with modified game files (you might face a ban).
+ * Game versions other than 1.14d are currently not supported.
+ *
+ * https://github.com/hippie68/diablo2-fend-fix */
+
+#include <stdio.h>
+#include <stdlib.h>
+
+struct patch_data{
+  size_t offset;
+  const int old;
+  const int new;
+  char name[8];
+};
+
+struct patch_data patches[] = {
+  {0x17ecfd, 0x80, 0x00, "Dodge 1"},
+  {0x17ecfe, 0x00, 0x02, "Dodge 2"},
+  {0x17ecf4, 0x01, 0x02, "Avoid 1"},
+  {0x1ad84b, 0x01, 0x02, "Avoid 2"},
+};
+int patch_count = (int) sizeof(patches) / sizeof(struct patch_data);
+
+// Patches a Game.exe file with given patch data
+void patch(FILE *file, struct patch_data pdata) {
+  int byte;
+
+  fseek(file, pdata.offset, SEEK_SET);
+  byte = getc(file);
+
+  // Quit program on read error
+  if (byte == EOF) {
+    printf("Could not read from file, aborting.\n");
+    exit(1);
+  }
+
+  // Patch
+  if (byte == pdata.old) {
+    fseek(file, -1, SEEK_CUR);
+    // Quit program on write error
+    if (putc(pdata.new, file) == EOF) {
+      fprintf(stderr, "Could not write to file, aborting.\n");
+      exit(1);
+    }
+  // Skip if already patched
+  } else if (byte == pdata.new) {
+    printf("Already patched: \"%s\" (offset: 0x%lx, current value: 0x%02x)\n",
+      pdata.name, pdata.offset, byte);
+  // Quit program if unknown value found
+  } else {
+    fprintf(stderr, "Unexpected value found: \"%s\" (offset 0x%lx, "
+      "current value: 0x%02x).\nExpected value: 0x%02x, aborting.\n",
+      pdata.name, pdata.offset, byte, pdata.old);
+    exit(1);
+  }
+}
+
+int main(int argc, char *argv[]) {
+  // Print usage if no arguments provided
+  if (argc == 1) {
+    printf("Please provide the full path to Diablo II's \"Game.exe\" "
+      "as argument.\n");
+    return 1;
+  }
+
+  // Open Game.exe
+  FILE *file;
+  file = fopen(argv[1], "r+b");
+  if (file == NULL) {
+    fprintf(stderr, "Could not open file \"%s\"\n", argv[1]);
+    return 1;
+  }
+
+  // Patch Game.exe
+  for (int i = 0; i < patch_count; i++) {
+    patch(file, patches[i]);
+  }
+
+  // Close Game.exe
+  if (fclose(file) == EOF) {
+    fprintf(stderr, "Could not close file \"%s\"\n", argv[1]);
+    return 1;
+  } else {
+    printf("Done.\n");
+  }
+
+  return 0;
+}