Better solution for p3dWrapper on windows

direct/src/p3d/p3dWrapper.c

@@ -13,97 +13,46 @@
  * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 
 /* p3dWrapper is a small wrapper executable that locates a .p3d file
-   on the PATH that has the same basename as the executable, and runs
-   it with panda3d(.exe) that is also located on the PATH.  */
+   in the same directory as this executable file, with the same name
+   (except .p3d instead of .exe of course). It is only meant to be
+   used on Windows system, it is not needed on Unix-like systems. */
 
 #include <stdlib.h>
 #include <string.h>
 #include <stdio.h>
-#include <unistd.h>
+#include <windows.h>
+#include <process.h>
+#include <assert.h>
 
-#ifdef _WIN32
-const char delims[] = ";";
-#else
-const char delims[] = ":";
-#endif
+#define BUFFER_SIZE 1024
 
 int main (int argc, char* argv[]) {
-  char havep3dfile = 0;
-  char havepanda3d = 0;
-  char* p3dname = strdup (argv [0]);
-  strcat (p3dname, ".p3d");
-  if (access (p3dname, R_OK) == 0) {
-    havep3dfile = 1;
-  } else {
-    // Make sure that p3dname contains a basename only.
-    int c;
-    for (c = strlen(p3dname) - 1; c >= 0; --c) {
-      if (p3dname[c] == '/' || p3dname[c] == '\\') {
-        p3dname += c + 1;
-        break;
-      }
-    }
-  }
-  
-  char* p3dfile = NULL;
-  char* panda3d = NULL;
-  char* path = getenv ("PATH");
-  if (path) {
-    // Locate the .p3d file and panda3d(.exe) on PATH.
-    char* pathtok = NULL;
-    pathtok = strtok (path, delims);
-    while (pathtok != NULL) {
-      // Check if the p3d file is in this directory.
-      if (!havep3dfile) {
-        p3dfile = strdup (pathtok);
-#ifdef _WIN32
-        strcat (p3dfile, "\\");
-#else
-        strcat (p3dfile, "/");
-#endif
-        strcat (p3dfile, p3dname);
-        if (access (p3dfile, R_OK) == 0) {
-          havep3dfile = 1;
-        }
-      }
-      // Check if panda3d(.exe) is in this directory.
-      if (!havepanda3d) {
-        panda3d = strdup (pathtok);
-#ifdef _WIN32
-        strcat (panda3d, "\\panda3d.exe");
-#else
-        strcat (panda3d, "/panda3d");
-#endif
-        if (access (panda3d, X_OK) == 0) {
-          havepanda3d = 1;
-        }
-      }
-      if (havep3dfile && havepanda3d) {
-        break;
-      }
-      pathtok = strtok(NULL, delims);
-    }
-  }
-  if (havep3dfile == 0 || p3dfile == NULL) {
-    p3dfile = p3dname;
-  }
-  if (havepanda3d == 0 || panda3d == NULL) {
-#ifdef _WIN32
-    panda3d = (char*) "panda3d.exe";
-#else
-    panda3d = (char*) "panda3d";
-#endif
-  }
-  
-  // Fill in a new argv object to pass to panda3d(.exe).
-  char** newargv = (char**) malloc(sizeof(char*) * (argc + 2));
-  newargv [0] = argv [0];
-  newargv [1] = p3dfile;
   int i;
+  char buffer [BUFFER_SIZE];
+  char* p3dfile;
+  char** newargv;
+  DWORD size;
+  size = GetModuleFileName (NULL, buffer, BUFFER_SIZE);
+  assert (size > 0);
+
+  /* Chop off the .exe and replace it by .p3d. */
+  p3dfile = (char*) malloc (size + 1);
+  memcpy (p3dfile, buffer, size);
+  p3dfile [size] = 0;
+  memcpy (p3dfile + size - 3, "p3d", 3);
+
+  /* Fill in a new argv object to pass to panda3d(.exe). */
+  newargv = (char**) malloc (sizeof (char*) * (argc + 2));
+  newargv [0] = "panda3d.exe";
+  newargv [1] = p3dfile;
   for (i = 1; i < argc; ++i) {
-    newargv [i + 1] = argv [i];
+    newargv [i + 1] = _strdup (argv [i]);
   }
-  newargv [argc + 2] = 0;
-  return execvp (panda3d, newargv);
+  newargv [argc + 1] = NULL;
+  if (_execvp ("panda3d.exe", newargv) == -1) {
+    fprintf (stderr, "panda3d.exe: %s", _strerror (NULL));
+    return 1;
+  }
+  return 0;
 }