feat(launcher): Improve error output when missing vcredist deps

Apply a simple heuristic to provide the user with more
specific information regarding which vcredist package
might not have been found on their system.

This is a common problem as different games require
different versions and different versions of windows
and installations might already come with some versions
already pre-installed.

Also improve the readme regarding that and provide links
to all versions that are required by one game or another
today.

README.md

@@ -148,22 +148,37 @@ helpful or important to know and should be added.
 
 ### Setup and dependencies
 
-Most (older generation) games were developed for Windows XP Embedded but should run fine on any
-consumer version of Windows XP. Newer versions of Windows, e.g. Windows 7, 8 and 10, should be fine
-as well. Some hooks also include fixes required to run the games on a more recent version.
+The games bemanitools support span several generations of (embedded) Windows versions: XP, 7 and 10
+(IoT). With these come different generations of dependencies as requirements.
 
-Depending on the game, you also need the following dependencies installed:
+Simplified, this boils down to the following list of C++ Redistributable (vcredist) packages that
+are recommended to be installed without going into detail which game needs exactly which version.
+Keep in mind the "bitness" (32-bit vs. 64-bit) of each specific game and download the right ones
+accordingly.
 
-- The 32-bit (x86) version of
-  [Microsoft Visual C++ 2010 Service Pack 1 Redistributable Package MFC Security Update](https://www.microsoft.com/en-sg/download/details.aspx?id=26999)
-- The 32-bit (x86) and 64-bit (x64) versions of
-  [Microsoft Visual C++ Redistributable Packages for Visual Studio 2013](https://www.microsoft.com/en-sg/download/details.aspx?id=40784)
-- The
+You can use a tool like [dependencywalker](https://www.dependencywalker.com/) to figure that out if
+it is relevant to you.
+
+Links/files are also provided by
+[bemanitools-supplement](https://github.com/djhackersdev/bemanitools-supplement/tree/master/misc/win-runtime#windows-runtimes-and-libraries)
+
+#### Visual C++ Redistributable Packages
+
+- 2010
+  - [32-bit (x86)](http://download.microsoft.com/download/5/B/C/5BC5DBB3-652D-4DCE-B14A-475AB85EEF6E/vcredist_x86.exe)
+  - [64-bit (x64)](http://download.microsoft.com/download/d/2/4/d242c3fb-da5a-4542-ad66-f9661d0a8d19/vcredist_x64.exe)
+- 2013
+  - [32-bit (x86)](http://download.microsoft.com/download/2/E/6/2E61CFA4-993B-4DD4-91DA-3737CD5CD6E3/vcredist_x86.exe)
+  - [64-bit (x64)](http://download.microsoft.com/download/2/E/6/2E61CFA4-993B-4DD4-91DA-3737CD5CD6E3/vcredist_x64.exe)
+- 2015
+  - [32-bit (x86)](https://download.microsoft.com/download/9/3/F/93FCF1E7-E6A4-478B-96E7-D4B285925B00/vc_redist.x86.exe)
+  - [64-bit (x64)](https://download.microsoft.com/download/9/3/F/93FCF1E7-E6A4-478B-96E7-D4B285925B00/vc_redist.x64.exe)
+
+#### DirectX 9
+
+Most/nearly all games support to this day use the DirectX 9(ex) API. Make sure to install the
 [DirectX 9 End-User Runtimes (June 2010)](https://www.microsoft.com/en-us/download/details.aspx?id=8109)
 
-See also [bemanitools-supplement](https://www.github.com/djhackersdev/bemanitools-supplement/) for
-files.
-
 ## Development
 
 ### Building

src/main/launcher/module.c

@@ -16,6 +16,20 @@
 
 #define MM_ALLOCATION_GRANULARITY 0x10000
 
+static bool _module_dependency_available(const char *lib)
+{
+    HMODULE module;
+
+    module = LoadLibraryA(lib);
+
+    if (module == NULL) {
+        return false;
+    } else {
+        FreeLibrary(module);
+        return true;
+    }
+}
+
 static bool
 module_replace_dll_iat(HMODULE hModule, const struct array *iat_hook_dlls)
 {
@@ -141,7 +155,7 @@ void module_init(struct module_context *module, const char *path)
 
     log_info("init: %s", path);
 
-    module->dll = LoadLibrary(path);
+    module->dll = LoadLibraryA(path);
 
     if (module->dll == NULL) {
         LPSTR buffer;
@@ -160,6 +174,28 @@ void module_init(struct module_context *module, const char *path)
         if (err == ERROR_MOD_NOT_FOUND) {
             log_warning("%s is likely missing dependencies", path);
             log_warning("Do you have vcredist/directx runtimes installed?");
+            log_warning(
+                "Ensure the installed dependencies match the architecture, "
+                "32-bit/64-bit, of the game");
+            log_warning(
+                "Running heuristic for commonly used libraries (actual "
+                "requirements depend on game)...");
+
+            if (_module_dependency_available("d3d9.dll")) {
+                log_warning("Could not find directx9 runtime");
+            }
+
+            if (_module_dependency_available("msvcr100.dll")) {
+                log_warning("Could not find vcredist 2010 runtime");
+            }
+
+            if (_module_dependency_available("msvcr120.dll")) {
+                log_warning("Could not find vcredist 2013 runtime");
+            }
+
+            if (_module_dependency_available("msvcp140.dll")) {
+                log_warning("Could not find vcredist 2015 runtime");
+            }
         }
 
         log_fatal("%s: Failed to load game DLL: %s", path, buffer);