Unified digital steering for smoother control

core/src/com/agateau/pixelwheels/gameinput/DigitalSteering.java

@@ -0,0 +1,65 @@
+/*
+ * Copyright 2024 Compl Yue
+ *
+ * This file is part of Pixel Wheels.
+ *
+ * Pixel Wheels is free software: you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License as published by the Free
+ * Software Foundation, either version 3 of the License, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package com.agateau.pixelwheels.gameinput;
+
+import com.agateau.pixelwheels.GamePlay;
+import com.badlogic.gdx.math.MathUtils;
+
+public class DigitalSteering {
+
+    private float mRawDirection = 0;
+
+    public float direction() {
+        // use parabolic curve to smooth the ctrl
+        return mRawDirection * mRawDirection * Math.signum(mRawDirection);
+    }
+
+    public float steer(boolean left, boolean right) {
+        if (left && right) {
+            // both left and right, full steer in original direction.
+            // currently there are 2 folds to do it this way:
+            //
+            // * with two-sides button control, I seldom purposfully do a
+            // straight braking/slow-down, almost always meant to reverse at
+            // a direction, then I always press the other button too quickly
+            // after pressed the 1st button, making it reverse almost
+            // straightly, the treatment here meant to make that op easy.
+            // also there are times I'd mean slow-down & turn-hard, this case
+            // works pretty well like a trick - just release the other button
+            // after the speed is sufficiently slowed down, and keep holding
+            // the 1st button to keep hard turning toward the original direction
+            // using full steering during the whole course.
+            //
+            // * for kbd control (maybe also pie-touch), this happens to enable
+            // a hard-turning trick - the player first press the button for the
+            // target direction, immediately followed by a press on the other
+            // button, it'll skip the gradually increasing steering output, and
+            // do an instant, full steering.
+            mRawDirection = Math.signum(mRawDirection);
+        } else if (left) {
+            mRawDirection += GamePlay.instance.steeringStep;
+        } else if (right) {
+            mRawDirection -= GamePlay.instance.steeringStep;
+        } else {
+            mRawDirection *= 0.4;
+        }
+        mRawDirection = MathUtils.clamp(mRawDirection, -1, 1);
+        return this.direction();
+    }
+}

core/src/com/agateau/pixelwheels/gameinput/InputMapperInputHandler.java

@@ -19,18 +19,17 @@
 package com.agateau.pixelwheels.gameinput;
 
 import com.agateau.pixelwheels.Assets;
-import com.agateau.pixelwheels.GamePlay;
 import com.agateau.pixelwheels.bonus.Bonus;
 import com.agateau.pixelwheels.racescreen.Hud;
 import com.agateau.ui.InputMapper;
 import com.agateau.ui.VirtualKey;
 import com.badlogic.gdx.Preferences;
-import com.badlogic.gdx.math.MathUtils;
 
 /** Base class for InputMapper-based GameInputHandlers */
 public abstract class InputMapperInputHandler implements GameInputHandler {
     private final InputMapper mInputMapper;
     private final GameInput mInput = new GameInput();
+    private final DigitalSteering mSteer = new DigitalSteering();
 
     InputMapperInputHandler(InputMapper inputMapper) {
         mInputMapper = inputMapper;
@@ -42,14 +41,10 @@ public GameInput getGameInput() {
                 mInputMapper.isKeyPressed(VirtualKey.DOWN)
                         || mInputMapper.isKeyPressed(VirtualKey.BACK);
         mInput.accelerating = !mInput.braking;
-        if (mInputMapper.isKeyPressed(VirtualKey.LEFT)) {
-            mInput.direction += GamePlay.instance.steeringStep;
-        } else if (mInputMapper.isKeyPressed(VirtualKey.RIGHT)) {
-            mInput.direction -= GamePlay.instance.steeringStep;
-        } else {
-            mInput.direction *= 0.4;
-        }
-        mInput.direction = MathUtils.clamp(mInput.direction, -1, 1);
+        mInput.direction =
+                mSteer.steer(
+                        mInputMapper.isKeyPressed(VirtualKey.LEFT),
+                        mInputMapper.isKeyPressed(VirtualKey.RIGHT));
         mInput.triggeringBonus = mInputMapper.isKeyPressed(VirtualKey.TRIGGER);
 
         return mInput;

core/src/com/agateau/pixelwheels/gameinput/PieTouchInputHandler.java

@@ -32,6 +32,7 @@
 /** Handle input using pie buttons in the bottom left and right corners */
 public class PieTouchInputHandler implements GameInputHandler {
     private final GameInput mInput = new GameInput();
+    private final DigitalSteering mSteer = new DigitalSteering();
     private PieButton mLeftButton, mRightButton, mBrakeButton, mBonusButton;
 
     public static class Factory implements GameInputHandlerFactory {
@@ -61,8 +62,7 @@ public Array<GameInputHandler> getAllHandlers() {
     public GameInput getGameInput() {
         mInput.braking = mBrakeButton.isPressed();
         mInput.accelerating = !mInput.braking;
-        mInput.direction =
-                TouchInputUtils.applyDirectionInput(mLeftButton, mRightButton, mInput.direction);
+        mInput.direction = mSteer.steer(mLeftButton.isPressed(), mRightButton.isPressed());
         mInput.triggeringBonus = mBonusButton.isPressed();
         return mInput;
     }

core/src/com/agateau/pixelwheels/gameinput/SidesTouchInputHandler.java

@@ -32,6 +32,7 @@
 /** Handle input using buttons on the sides */
 public class SidesTouchInputHandler implements GameInputHandler {
     private final GameInput mInput = new GameInput();
+    private final DigitalSteering mSteer = new DigitalSteering();
     private HudButton mLeftButton, mRightButton, mBonusButton;
 
     public static class Factory implements GameInputHandlerFactory {
@@ -61,11 +62,7 @@ public Array<GameInputHandler> getAllHandlers() {
     public GameInput getGameInput() {
         mInput.braking = isBraking();
         mInput.accelerating = !mInput.braking;
-        if (!mInput.braking) {
-            mInput.direction =
-                    TouchInputUtils.applyDirectionInput(
-                            mLeftButton, mRightButton, mInput.direction);
-        }
+        mInput.direction = mSteer.steer(mLeftButton.isPressed(), mRightButton.isPressed());
         mInput.triggeringBonus = mBonusButton.isPressed();
         return mInput;
     }