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Merged
theEvilReaper merged 1 commit into from
Aug 17, 2026
Merged

fix(player): switch to a virtual border #185

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43 changes: 27 additions & 16 deletions game/src/main/java/net/onelitefeather/cygnus/player/CygnusPlayer.java
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Original file line number Diff line number Diff line change
Expand Up @@ -6,7 +6,7 @@
import net.minestom.server.entity.attribute.AttributeModifier;
import net.minestom.server.entity.attribute.AttributeOperation;
import net.minestom.server.network.packet.server.play.EntityAttributesPacket;
import net.minestom.server.network.packet.server.play.WorldBorderWarningReachPacket;
import net.minestom.server.network.packet.server.play.InitializeWorldBorderPacket;
import net.minestom.server.network.player.GameProfile;
import net.minestom.server.network.player.PlayerConnection;
import net.minestom.server.sound.SoundEvent;
Expand All @@ -17,11 +17,21 @@
@SuppressWarnings("java:S3252")
public final class CygnusPlayer extends InstanceSwitchChunkPlayer {

static final int PORTAL_TELEPORT_BOUNDARY = 29_999_984;

/**
* Radius (in blocks) of the virtual, per-player world border used to fake the heartbeat
* vignette. It is recentered on the player every tick, so the real client-side distance to
* its edge is always exactly this value, independent of the instance's actual world border.
*/
static final double FAKE_BORDER_RADIUS = 50.0;
static final double FAKE_BORDER_DIAMETER = FAKE_BORDER_RADIUS * 2.0;

static final AttributeModifier SPEED_MODIFIER_SPRINTING =
new AttributeModifier(Key.key("cygnus:sprinting"), 0.25, AttributeOperation.ADD_MULTIPLIED_TOTAL);
new AttributeModifier(Key.key("cygnus","sprinting"), 0.25, AttributeOperation.ADD_MULTIPLIED_TOTAL);

static final AttributeModifier DISABLED_SPRINT_MODIFIER =
new AttributeModifier(Key.key("cygnus:sprinting"), 0.0, AttributeOperation.ADD_MULTIPLIED_TOTAL);
new AttributeModifier(Key.key("cygnus", "sprinting"), 0.0, AttributeOperation.ADD_MULTIPLIED_TOTAL);

private static final float HEALTH_THRESHOLD = 6.0f; // 3 hearts
private static final int MAX_INTERVAL_TICKS = 36; // Every 1.8s (slow, subtle pulse at start)
Expand Down Expand Up @@ -107,21 +117,17 @@ public void tickHeartbeat() {

float intensity = Math.clamp(1.0f - (health / HEALTH_THRESHOLD), 0.0f, 1.0f);

double distanceToBorder = 29_999_984.0;
var instance = getInstance();
if (instance != null && instance.getWorldBorder() != null) {
var border = instance.getWorldBorder();
double radius = border.diameter() / 2.0;
double dx = Math.abs(getPosition().x() - border.centerX());
double dz = Math.abs(getPosition().z() - border.centerZ());
distanceToBorder = Math.max(1.0, radius - Math.max(dx, dz));
}

// Non-linear visual curve makes the red border vignette stronger earlier and very intense at low HP
float visualIntensity = (float) Math.pow(intensity, 0.6);
float clampedIntensity = Math.min(visualIntensity, 0.995f);
int warningBlocks = (int) (distanceToBorder / (1.0f - clampedIntensity));
sendPacket(new WorldBorderWarningReachPacket(warningBlocks));
int warningBlocks = (int) (FAKE_BORDER_RADIUS / (1.0f - clampedIntensity));

var position = getPosition();
sendPacket(new InitializeWorldBorderPacket(
position.x(), position.z(),
FAKE_BORDER_DIAMETER, FAKE_BORDER_DIAMETER, 0L,
PORTAL_TELEPORT_BOUNDARY, 0, warningBlocks
));

float intervalFactor = (float) Math.pow(intensity, 0.85);
int targetInterval = (int) (MAX_INTERVAL_TICKS - (intervalFactor * (MAX_INTERVAL_TICKS - MIN_INTERVAL_TICKS)));
Expand Down Expand Up @@ -151,7 +157,9 @@ private void playHeartbeatSound(float intensity) {
private void resetHeartbeat() {
heartbeatActive = false;
heartbeatTicks = 0;
sendPacket(new WorldBorderWarningReachPacket(0));
// Restores the real (instance-wide) world border after the per-tick fake one used for
// the vignette, so the client stops seeing the small virtual border we sent it.
sendPacket(getInstance().createInitializeWorldBorderPacket());
}

/**
Expand All @@ -163,6 +171,9 @@ public boolean isHeartbeatActive() {
return heartbeatActive;
}

/**
* {@inheritDoc}
*/
@Override
public EntityAttributesPacket getPropertiesPacket() {
return super.getPropertiesPacket();
Expand Down
62 changes: 62 additions & 0 deletions game/src/test/java/net/onelitefeather/cygnus/player/CygnusPlayerHeartbeatTest.java
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Original file line number Diff line number Diff line change
@@ -1,7 +1,10 @@
package net.onelitefeather.cygnus.player;

import net.minestom.server.coordinate.Pos;
import net.minestom.server.instance.Instance;
import net.minestom.server.network.packet.server.play.InitializeWorldBorderPacket;
import net.minestom.testing.Env;
import net.minestom.testing.TestConnection;
import net.onelitefeather.cygnus.CygnusPlayerTestBase;
import org.jetbrains.annotations.NotNull;
import org.junit.jupiter.api.Test;
Expand All @@ -23,6 +26,65 @@ void testHeartbeatInactiveAboveThreshold(@NotNull Env env) {
env.destroyInstance(instance, true);
}

@Test
void testHeartbeatSendsVirtualBorderCenteredOnPlayer(@NotNull Env env) {
Instance instance = env.createFlatInstance();
TestConnection connection = env.createConnection();
Pos spawnPos = new Pos(120.5, 40, -75.25);
CygnusPlayer player = (CygnusPlayer) connection.connect(instance, spawnPos);

player.setHealth(4.0f);
var collector = connection.trackIncoming(InitializeWorldBorderPacket.class);
player.tickHeartbeat();

collector.assertSingle(packet -> {
assertEquals(spawnPos.x(), packet.x(), 0.001);
assertEquals(spawnPos.z(), packet.z(), 0.001);
assertEquals(100.0, packet.newDiameter(), 0.001);
});

env.destroyInstance(instance, true);
}

@Test
void testHeartbeatWarningBlocksStayWithinIntRangeNearDeath(@NotNull Env env) {
Instance instance = env.createFlatInstance();
TestConnection connection = env.createConnection();
CygnusPlayer player = (CygnusPlayer) connection.connect(instance, Pos.ZERO);

player.setHealth(0.5f);
var collector = connection.trackIncoming(InitializeWorldBorderPacket.class);
player.tickHeartbeat();

collector.assertSingle(packet -> assertTrue(packet.warningBlocks() <= 10_000,
"warningBlocks should stay in a sane range, was " + packet.warningBlocks()));

env.destroyInstance(instance, true);
}

@Test
void testHeartbeatResetRestoresRealBorder(@NotNull Env env) {
Instance instance = env.createFlatInstance();
TestConnection connection = env.createConnection();
CygnusPlayer player = (CygnusPlayer) connection.connect(instance, Pos.ZERO);

player.setHealth(4.0f);
player.tickHeartbeat();
assertTrue(player.isHeartbeatActive());

player.setHealth(20.0f);
var collector = connection.trackIncoming(InitializeWorldBorderPacket.class);
player.tickHeartbeat();

collector.assertSingle(packet -> {
assertEquals(instance.getWorldBorder().centerX(), packet.x(), 0.001);
assertEquals(instance.getWorldBorder().centerZ(), packet.z(), 0.001);
assertEquals(instance.getWorldBorder().diameter(), packet.newDiameter(), 0.001);
});

env.destroyInstance(instance, true);
}

@Test
void testHeartbeatActiveBelowThreshold(@NotNull Env env) {
Instance instance = env.createFlatInstance();
Expand Down
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