tr2/input: allow holding up/down in menus

This mimics the TR1 behaviour of allowing up/down to be held in menus
such as save/load.

Resolves #1644.

docs/tr2/CHANGELOG.md

@@ -4,6 +4,7 @@
 - added a level skip cheat key (#1640)
 - added the ability to skip end credits with the action and escape keys (#1800)
 - added the ability to skip FMVs with the action key (#1650)
+- added the ability to hold forward/back to move through menus more quickly (#1644)
 - changed the inputs backend from DirectX to SDL (#1695)
     - improved controller support to match TR1X
     - changed the number of custom layouts to 3

docs/tr2/README.md

@@ -40,6 +40,9 @@ decompilation process. We recognize that there is much work to be done.
 - fixed the dragon counting as more than one kill if allowed to revive
 - fixed enemies that are run over by the skidoo not being counted in the statistics
 
+#### Input
+- added the ability to hold forward/back to move through menus more quickly
+
 #### Visuals
 
 - fixed TGA screenshots crashing the game

src/tr2/game/clock.c

@@ -1,5 +1,7 @@
 #include "game/clock.h"
 
+#include <libtrx/game/const.h>
+
 #include <windows.h>
 
 double Clock_GetHighPrecisionCounter(void)
@@ -10,3 +12,8 @@ double Clock_GetHighPrecisionCounter(void)
     QueryPerformanceCounter(&counter);
     return counter.QuadPart * 1000.0 / frequency.QuadPart;
 }
+
+int32_t Clock_GetLogicalFrame(void)
+{
+    return Clock_GetHighPrecisionCounter() * LOGIC_FPS / 1000.0;
+}

src/tr2/game/clock.h

@@ -1,3 +1,6 @@
 #pragma once
 
+#include <stdint.h>
+
 double Clock_GetHighPrecisionCounter(void);
+int32_t Clock_GetLogicalFrame(void);

src/tr2/game/input.c

@@ -1,6 +1,7 @@
 #include "game/input.h"
 
 #include "config.h"
+#include "game/clock.h"
 #include "game/console/common.h"
 #include "game/game_string.h"
 #include "game/shell.h"
@@ -11,6 +12,12 @@
 #include <libtrx/game/input/backends/controller.h>
 #include <libtrx/game/input/backends/keyboard.h>
 
+#define DELAY_FRAMES 12
+#define HOLD_FRAMES 3
+
+static int32_t m_HoldBack = 0;
+static int32_t m_HoldForward = 0;
+
 static INPUT_STATE M_GetDebounced(INPUT_STATE input);
 static void M_UpdateFromBackend(
     INPUT_STATE *s, const INPUT_BACKEND_IMPL *backend, INPUT_LAYOUT layout);
@@ -20,6 +27,28 @@ static INPUT_STATE M_GetDebounced(const INPUT_STATE input)
     INPUT_STATE result;
     result.any = input.any & ~g_OldInputDB.any;
 
+    const int32_t frame = Clock_GetLogicalFrame();
+    if (input.forward || !input.back) {
+        m_HoldBack = 0;
+    } else if (input.back && m_HoldBack == 0) {
+        m_HoldBack = frame;
+    } else if (input.back && frame - m_HoldBack >= DELAY_FRAMES + HOLD_FRAMES) {
+        result.back = 1;
+        result.menu_down = 1;
+        m_HoldBack = frame - DELAY_FRAMES;
+    }
+
+    if (!input.forward || input.back) {
+        m_HoldForward = 0;
+    } else if (input.forward && m_HoldForward == 0) {
+        m_HoldForward = frame;
+    } else if (
+        input.forward && frame - m_HoldForward >= DELAY_FRAMES + HOLD_FRAMES) {
+        result.forward = 1;
+        result.menu_up = 1;
+        m_HoldForward = frame - DELAY_FRAMES;
+    }
+
     g_OldInputDB = input;
     return result;
 }