From 8d40ca8be68725c11dcaadbc95cb20084bd93649 Mon Sep 17 00:00:00 2001
From: Quietust <quietust@gmail.com>
Date: Sat, 1 Apr 2023 12:37:36 -0600
Subject: [PATCH] Add "faststart" plugin to make DF start faster

In particular, it makes the game's "Loading..." screen animate
as quickly as possible, shortening it from around 10 seconds to
slightly more than 1 second.

A conditional build setting makes it skip the animation as well,
making it slightly faster yet.

Ideally, this should become part of the Tweak plugin, but we're
not building that right now.
---
 docs/changelog.txt         |  1 +
 docs/plugins/faststart.rst | 18 ++++++++++
 plugins/CMakeLists.txt     |  1 +
 plugins/faststart.cpp      | 69 ++++++++++++++++++++++++++++++++++++++
 4 files changed, 89 insertions(+)
 create mode 100644 docs/plugins/faststart.rst
 create mode 100644 plugins/faststart.cpp

diff --git a/docs/changelog.txt b/docs/changelog.txt
index 4be3e6a64..59c0dc2b1 100644
--- a/docs/changelog.txt
+++ b/docs/changelog.txt
@@ -34,6 +34,7 @@ changelog.txt uses a syntax similar to RST, with a few special sequences:
 # Future
 
 ## New Plugins
+- `faststart`: speeds up the "Loading..." screen so the Main Menu appears sooner
 
 ## Fixes
 - `hotkeys`: hotkey hints on menu popup will no longer get their last character cut off by the scrollbar
diff --git a/docs/plugins/faststart.rst b/docs/plugins/faststart.rst
new file mode 100644
index 000000000..3dc734183
--- /dev/null
+++ b/docs/plugins/faststart.rst
@@ -0,0 +1,18 @@
+faststart
+=========
+
+.. dfhack-tool::
+    :summary: Makes the main menu appear sooner.
+    :tags: interface
+    :no-command:
+
+This plugin accelerates the initial "Loading..." screen that appears when the
+game first starts, so you don't have to wait as long before the Main Menu
+appears and you can start playing.
+
+Usage
+-----
+
+::
+
+    enable faststart
diff --git a/plugins/CMakeLists.txt b/plugins/CMakeLists.txt
index dc7fa9276..53d0296c7 100644
--- a/plugins/CMakeLists.txt
+++ b/plugins/CMakeLists.txt
@@ -112,6 +112,7 @@ dfhack_plugin(dig-now dig-now.cpp LINK_LIBRARIES lua)
 #dfhack_plugin(embark-tools embark-tools.cpp)
 dfhack_plugin(eventful eventful.cpp LINK_LIBRARIES lua)
 dfhack_plugin(fastdwarf fastdwarf.cpp)
+dfhack_plugin(faststart faststart.cpp)
 dfhack_plugin(filltraffic filltraffic.cpp)
 #dfhack_plugin(fix-unit-occupancy fix-unit-occupancy.cpp)
 #dfhack_plugin(fixveins fixveins.cpp)
diff --git a/plugins/faststart.cpp b/plugins/faststart.cpp
new file mode 100644
index 000000000..d885726c0
--- /dev/null
+++ b/plugins/faststart.cpp
@@ -0,0 +1,69 @@
+// Fast Startup tweak
+
+#include "Core.h"
+#include <Console.h>
+#include <Export.h>
+#include <PluginManager.h>
+#include <MiscUtils.h>
+#include <VTableInterpose.h>
+
+#include "df/viewscreen_initial_prepst.h"
+#include <vector>
+
+using namespace DFHack;
+using namespace df::enums;
+using std::vector;
+
+// Uncomment this to make the Loading screen as fast as possible
+// This has the side effect of removing the dwarf face animation
+// (and briefly making the game become unresponsive)
+
+//#define REALLY_FAST 
+
+DFHACK_PLUGIN("faststart");
+DFHACK_PLUGIN_IS_ENABLED(is_enabled);
+
+struct prep_hook : df::viewscreen_initial_prepst
+{
+    typedef df::viewscreen_initial_prepst interpose_base;
+
+    DEFINE_VMETHOD_INTERPOSE(void, logic, ())
+    {
+#ifdef REALLY_FAST
+        while (breakdown_level != interface_breakdown_types::STOPSCREEN)
+        {
+            render_count++;
+            INTERPOSE_NEXT(logic)();
+        }
+#else
+        render_count = 4;
+        INTERPOSE_NEXT(logic)();
+#endif
+    }
+};
+
+IMPLEMENT_VMETHOD_INTERPOSE(prep_hook, logic);
+
+DFhackCExport command_result plugin_enable(color_ostream &out, bool enable)
+{
+    if (enable != is_enabled)
+    {
+        if (!INTERPOSE_HOOK(prep_hook, logic).apply(enable))
+            return CR_FAILURE;
+
+        is_enabled = enable;
+    }
+
+    return CR_OK;
+}
+
+DFhackCExport command_result plugin_init ( color_ostream &out, vector <PluginCommand> &commands)
+{
+    return CR_OK;
+}
+
+DFhackCExport command_result plugin_shutdown ( color_ostream &out )
+{
+    INTERPOSE_HOOK(prep_hook, logic).remove();
+    return CR_OK;
+}