Client-side autojump. Remove Android-only stepheight autojump (#7228)

Works by detecting a collision while moving forward and then
simulating a jump. If the simulated jump is more successful,
an artificial jump key press is injected in the client.

Includes setting and key change GUI element for enabling and
disabling this feature.

10 files changed, 141 insertions, 18 deletions

diff --git a/src/collision.cpp b/src/collision.cpp
index 48a681dca..9626221a0 100644
--- a/src/collision.cpp
+++ b/src/collision.cpp
@@ -515,6 +515,7 @@ collisionMoveResult collisionMoveSimple(Environment *env, IGameDef *gamedef,
 
 			info.node_p = nearest_info.position;
 			info.old_speed = *speed_f;
+			info.plane = nearest_collided;
 
 			// Set the speed component that caused the collision to zero
 			if (step_up) {
diff --git a/src/collision.h b/src/collision.h
index 4d47171ea..4c5594528 100644
--- a/src/collision.h
+++ b/src/collision.h
@@ -41,6 +41,7 @@ struct CollisionInfo
 	v3s16 node_p = v3s16(-32768,-32768,-32768); // COLLISION_NODE
 	v3f old_speed;
 	v3f new_speed;
+	int plane = -1;
 };
 
 struct collisionMoveResult
diff --git a/src/defaultsettings.cpp b/src/defaultsettings.cpp
index 6a0474e74..2408bffeb 100644
--- a/src/defaultsettings.cpp
+++ b/src/defaultsettings.cpp
@@ -247,6 +247,11 @@ void set_default_settings(Settings *settings)
 	settings->setDefault("aux1_descends", "false");
 	settings->setDefault("doubletap_jump", "false");
 	settings->setDefault("always_fly_fast", "true");
+#ifdef __ANDROID__
+	settings->setDefault("autojump", "true");
+#else
+	settings->setDefault("autojump", "false");
+#endif
 	settings->setDefault("continuous_forward", "false");
 	settings->setDefault("enable_joysticks", "false");
 	settings->setDefault("joystick_id", "0");
diff --git a/src/game.cpp b/src/game.cpp
index 227b21db5..1cb9a1650 100644
--- a/src/game.cpp
+++ b/src/game.cpp
@@ -2449,8 +2449,15 @@ void Game::updatePlayerControl(const CameraOrientation &cam)
 	}
 #endif
 
-	client->setPlayerControl(control);
 	LocalPlayer *player = client->getEnv().getLocalPlayer();
+
+	// autojump if set: simulate "jump" key
+	if (player->getAutojump()) {
+		control.jump = true;
+		keypress_bits |= 1U << 4;
+	}
+
+	client->setPlayerControl(control);
 	player->keyPressed = keypress_bits;
 
 	//tt.stop();
diff --git a/src/gui/guiKeyChangeMenu.cpp b/src/gui/guiKeyChangeMenu.cpp
index ca97e0b9e..f3d8e8eef 100644
--- a/src/gui/guiKeyChangeMenu.cpp
+++ b/src/gui/guiKeyChangeMenu.cpp
@@ -77,6 +77,7 @@ enum
 	// other
 	GUI_ID_CB_AUX1_DESCENDS,
 	GUI_ID_CB_DOUBLETAP_JUMP,
+	GUI_ID_CB_AUTOJUMP,
 };
 
 GUIKeyChangeMenu::GUIKeyChangeMenu(gui::IGUIEnvironment* env,
@@ -196,6 +197,21 @@ void GUIKeyChangeMenu::regenerateGui(v2u32 screensize)
 	}
 
 	{
+		s32 option_x = offset.X;
+		s32 option_y = offset.Y + 5;
+		u32 option_w = 280;
+		{
+			core::rect<s32> rect(0, 0, option_w, 30);
+			rect += topleft + v2s32(option_x, option_y);
+			const wchar_t *text = wgettext("Automatic jumping");
+			Environment->addCheckBox(g_settings->getBool("autojump"), rect, this,
+					GUI_ID_CB_AUTOJUMP, text);
+			delete[] text;
+		}
+		offset += v2s32(0, 25);
+	}
+
+	{
 		core::rect < s32 > rect(0, 0, 100, 30);
 		rect += topleft + v2s32(size.X / 2 - 105, size.Y - 40);
 		const wchar_t *text =  wgettext("Save");
@@ -239,14 +255,19 @@ bool GUIKeyChangeMenu::acceptInput()
 
 	{
 		gui::IGUIElement *e = getElementFromId(GUI_ID_CB_AUX1_DESCENDS);
-		if(e != NULL && e->getType() == gui::EGUIET_CHECK_BOX)
+		if(e && e->getType() == gui::EGUIET_CHECK_BOX)
 			g_settings->setBool("aux1_descends", ((gui::IGUICheckBox*)e)->isChecked());
 	}
 	{
 		gui::IGUIElement *e = getElementFromId(GUI_ID_CB_DOUBLETAP_JUMP);
-		if(e != NULL && e->getType() == gui::EGUIET_CHECK_BOX)
+		if(e && e->getType() == gui::EGUIET_CHECK_BOX)
 			g_settings->setBool("doubletap_jump", ((gui::IGUICheckBox*)e)->isChecked());
 	}
+	{
+		gui::IGUIElement *e = getElementFromId(GUI_ID_CB_AUTOJUMP);
+		if(e && e->getType() == gui::EGUIET_CHECK_BOX)
+			g_settings->setBool("autojump", ((gui::IGUICheckBox*)e)->isChecked());
+	}
 
 	clearKeyCache();
 
diff --git a/src/localplayer.cpp b/src/localplayer.cpp
index 4bf689428..1c65d3b4d 100644
--- a/src/localplayer.cpp
+++ b/src/localplayer.cpp
@@ -287,16 +287,9 @@ void LocalPlayer::move(f32 dtime, Environment *env, f32 pos_max_d,
 	float player_stepheight = (m_cao == nullptr) ? 0.0f :
 		(touching_ground ? m_cao->getStepHeight() : (0.2f * BS));
 
-	// TODO this is a problematic hack.
-	// Use a better implementation for autojump, or apply a custom stepheight
-	// to all players, as this currently creates unintended special movement
-	// abilities and advantages for Android players on a server.
-#ifdef __ANDROID__
-	if (touching_ground)
-		player_stepheight += (0.6f * BS);
-#endif
-
 	v3f accel_f = v3f(0,0,0);
+	const v3f initial_position = position;
+	const v3f initial_speed = m_speed;
 
 	collisionMoveResult result = collisionMoveSimple(env, m_client,
 		pos_max_d, m_collisionbox, player_stepheight, dtime,
@@ -461,6 +454,9 @@ void LocalPlayer::move(f32 dtime, Environment *env, f32 pos_max_d,
 		setSpeed(m_speed);
 		m_can_jump = false;
 	}
+
+	// Autojump
+	handleAutojump(dtime, env, result, initial_position, initial_speed, pos_max_d);
 }
 
 void LocalPlayer::move(f32 dtime, Environment *env, f32 pos_max_d)
@@ -891,11 +887,9 @@ void LocalPlayer::old_move(f32 dtime, Environment *env, f32 pos_max_d,
 	// this shouldn't be hardcoded but transmitted from server
 	float player_stepheight = touching_ground ? (BS * 0.6) : (BS * 0.2);
 
-#ifdef __ANDROID__
-	player_stepheight += (0.6 * BS);
-#endif
-
 	v3f accel_f = v3f(0, 0, 0);
+	const v3f initial_position = position;
+	const v3f initial_speed = m_speed;
 
 	collisionMoveResult result = collisionMoveSimple(env, m_client,
 		pos_max_d, m_collisionbox, player_stepheight, dtime,
@@ -1059,6 +1053,9 @@ void LocalPlayer::old_move(f32 dtime, Environment *env, f32 pos_max_d,
 		setSpeed(m_speed);
 		m_can_jump = false;
 	}
+
+	// Autojump
+	handleAutojump(dtime, env, result, initial_position, initial_speed, pos_max_d);
 }
 
 float LocalPlayer::getSlipFactor(Environment *env, const v3f &speedH)
@@ -1080,3 +1077,82 @@ float LocalPlayer::getSlipFactor(Environment *env, const v3f &speedH)
 	}
 	return 1.0f;
 }
+
+void LocalPlayer::handleAutojump(f32 dtime, Environment *env,
+		const collisionMoveResult &result, const v3f &initial_position,
+		const v3f &initial_speed, f32 pos_max_d)
+{
+	PlayerSettings &player_settings = getPlayerSettings();
+	if (!player_settings.autojump)
+		return;
+
+	if (m_autojump) {
+		// release autojump after a given time
+		m_autojump_time -= dtime;
+		if (m_autojump_time <= 0.0f)
+			m_autojump = false;
+		return;
+	}
+
+	bool control_forward = control.up ||
+			       (!control.up && !control.down &&
+					       control.forw_move_joystick_axis < -0.05);
+	bool could_autojump =
+			m_can_jump && !control.jump && !control.sneak && control_forward;
+	if (!could_autojump)
+		return;
+
+	bool horizontal_collision = false;
+	for (const auto &colinfo : result.collisions) {
+		if (colinfo.type == COLLISION_NODE && colinfo.plane != 1) {
+			horizontal_collision = true;
+			break; // one is enough
+		}
+	}
+
+	// must be running against something to trigger autojumping
+	if (!horizontal_collision)
+		return;
+
+	// check for nodes above
+	v3f headpos_min = m_position + m_collisionbox.MinEdge * 0.99f;
+	v3f headpos_max = m_position + m_collisionbox.MaxEdge * 0.99f;
+	headpos_min.Y = headpos_max.Y; // top face of collision box
+	v3s16 ceilpos_min = floatToInt(headpos_min, BS) + v3s16(0, 1, 0);
+	v3s16 ceilpos_max = floatToInt(headpos_max, BS) + v3s16(0, 1, 0);
+	const NodeDefManager *ndef = env->getGameDef()->ndef();
+	bool is_position_valid;
+	for (s16 z = ceilpos_min.Z; z <= ceilpos_max.Z; z++) {
+		for (s16 x = ceilpos_min.X; x <= ceilpos_max.X; x++) {
+			MapNode n = env->getMap().getNodeNoEx(v3s16(x, ceilpos_max.Y, z), &is_position_valid);
+
+			if (!is_position_valid)
+				break;  // won't collide with the void outside
+			if (n.getContent() == CONTENT_IGNORE)
+				return; // players collide with ignore blocks -> same as walkable
+			const ContentFeatures &f = ndef->get(n);
+			if (f.walkable)
+				return; // would bump head, don't jump
+		}
+	}
+
+	float jump_height = 1.1f; // TODO: better than a magic number
+	v3f jump_pos = initial_position + v3f(0.0f, jump_height * BS, 0.0f);
+	v3f jump_speed = initial_speed;
+
+	// try at peak of jump, zero step height
+	collisionMoveResult jump_result = collisionMoveSimple(env, m_client, pos_max_d,
+			m_collisionbox, 0.0f, dtime, &jump_pos, &jump_speed,
+			v3f(0, 0, 0));
+
+	// see if we can get a little bit farther horizontally if we had
+	// jumped
+	v3f run_delta = m_position - initial_position;
+	run_delta.Y = 0.0f;
+	v3f jump_delta = jump_pos - initial_position;
+	jump_delta.Y = 0.0f;
+	if (jump_delta.getLengthSQ() > run_delta.getLengthSQ() * 1.01f) {
+		m_autojump = true;
+		m_autojump_time = 0.1f;
+	}
+}
diff --git a/src/localplayer.h b/src/localplayer.h
index dc59c4179..7148bc4de 100644
--- a/src/localplayer.h
+++ b/src/localplayer.h
@@ -31,6 +31,7 @@ class GenericCAO;
 class ClientActiveObject;
 class ClientEnvironment;
 class IGameDef;
+struct collisionMoveResult;
 
 enum LocalPlayerAnimations
 {
@@ -145,11 +146,17 @@ public:
 	float getZoomFOV() const { return m_zoom_fov; }
 	void setZoomFOV(float zoom_fov) { m_zoom_fov = zoom_fov; }
 
+	bool getAutojump() const { return m_autojump; }
+
 private:
 	void accelerateHorizontal(const v3f &target_speed, const f32 max_increase);
 	void accelerateVertical(const v3f &target_speed, const f32 max_increase);
 	bool updateSneakNode(Map *map, const v3f &position, const v3f &sneak_max);
 	float getSlipFactor(Environment *env, const v3f &speedH);
+	void handleAutojump(f32 dtime, Environment *env,
+			const collisionMoveResult &result,
+			const v3f &position_before_move, const v3f &speed_before_move,
+			f32 pos_max_d);
 
 	v3f m_position;
 	v3s16 m_standing_node;
@@ -183,6 +190,8 @@ private:
 			BS * 1.75f, BS * 0.30f);
 	float m_eye_height = 1.625f;
 	float m_zoom_fov = 0.0f;
+	bool m_autojump = false;
+	float m_autojump_time = 0.0f;
 
 	GenericCAO *m_cao = nullptr;
 	Client *m_client;
diff --git a/src/player.cpp b/src/player.cpp
index ccc753834..4b104a71b 100644
--- a/src/player.cpp
+++ b/src/player.cpp
@@ -144,6 +144,7 @@ void PlayerSettings::readGlobalSettings()
 	always_fly_fast = g_settings->getBool("always_fly_fast");
 	aux1_descends = g_settings->getBool("aux1_descends");
 	noclip = g_settings->getBool("noclip");
+	autojump = g_settings->getBool("autojump");
 }
 
 void Player::settingsChangedCallback(const std::string &name, void *data)
diff --git a/src/player.h b/src/player.h
index 66cd0f5cf..674491546 100644
--- a/src/player.h
+++ b/src/player.h
@@ -92,10 +92,11 @@ struct PlayerSettings
 	bool always_fly_fast = false;
 	bool aux1_descends = false;
 	bool noclip = false;
+	bool autojump = false;
 
-	const std::string setting_names[6] = {
+	const std::string setting_names[7] = {
 		"free_move", "fast_move", "continuous_forward", "always_fly_fast",
-		"aux1_descends", "noclip"
+		"aux1_descends", "noclip", "autojump"
 	};
 	void readGlobalSettings();
 };
diff --git a/src/settings_translation_file.cpp b/src/settings_translation_file.cpp
index c2390c189..2b56115df 100644
--- a/src/settings_translation_file.cpp
+++ b/src/settings_translation_file.cpp
@@ -27,6 +27,7 @@ fake_function() {
 	gettext("Double tap jump for fly");
 	gettext("Double-tapping the jump key toggles fly mode.");
 	gettext("Always fly and fast");
+	gettext("Automatic jumping");
 	gettext("If disabled, \"special\" key is used to fly fast if both fly and fast mode are enabled.");
 	gettext("Rightclick repetition interval");
 	gettext("The time in seconds it takes between repeated right clicks when holding the right mouse button.");