Camera: Fix shooting line offsets (#9681)

Removes duplicated offset calculations from Game and use whatever the Camera class returns.
This keeps the eye position nicely in sync, and gets rid of duplicated code.

Author: SmallJoker

src/client/camera.cpp

@@ -333,17 +333,21 @@ void Camera::update(LocalPlayer* player, f32 frametime, f32 busytime, f32 tool_r
 		fall_bobbing *= m_cache_fall_bobbing_amount;
 	}
 
-	// Calculate players eye offset for different camera modes
-	v3f PlayerEyeOffset = player->getEyeOffset();
-	if (m_camera_mode == CAMERA_MODE_FIRST)
-		PlayerEyeOffset += player->eye_offset_first;
-	else
-		PlayerEyeOffset += player->eye_offset_third;
-
-	// Set head node transformation
-	m_headnode->setPosition(PlayerEyeOffset+v3f(0,cameratilt*-player->hurt_tilt_strength+fall_bobbing,0));
-	m_headnode->setRotation(v3f(player->getPitch(), 0, cameratilt*player->hurt_tilt_strength));
-	m_headnode->updateAbsolutePosition();
+	// Calculate and translate the head SceneNode offsets
+	{
+		v3f eye_offset = player->getEyeOffset();
+		if (m_camera_mode == CAMERA_MODE_FIRST)
+			eye_offset += player->eye_offset_first;
+		else
+			eye_offset += player->eye_offset_third;
+
+		// Set head node transformation
+		eye_offset.Y += cameratilt * -player->hurt_tilt_strength + fall_bobbing;
+		m_headnode->setPosition(eye_offset);
+		m_headnode->setRotation(v3f(player->getPitch(), 0,
+			cameratilt * player->hurt_tilt_strength));
+		m_headnode->updateAbsolutePosition();
+	}
 
 	// Compute relative camera position and target
 	v3f rel_cam_pos = v3f(0,0,0);

src/client/camera.h

@@ -75,6 +75,12 @@ class Camera
 		return m_camera_position;
 	}
 
+	// Returns the absolute position of the head SceneNode in the world
+	inline v3f getHeadPosition() const
+	{
+		return m_headnode->getAbsolutePosition();
+	}
+
 	// Get the camera direction (in absolute camera coordinates).
 	// This has view bobbing applied.
 	inline v3f getDirection() const

src/client/game.cpp

@@ -3029,16 +3029,9 @@ void Game::processPlayerInteraction(f32 dtime, bool show_hud, bool show_debug)
 {
 	LocalPlayer *player = client->getEnv().getLocalPlayer();
 
-	v3f player_position  = player->getPosition();
-	v3f player_eye_position = player->getEyePosition();
-	v3f camera_position  = camera->getPosition();
-	v3f camera_direction = camera->getDirection();
-	v3s16 camera_offset  = camera->getOffset();
-
-	if (camera->getCameraMode() == CAMERA_MODE_FIRST)
-		player_eye_position += player->eye_offset_first;
-	else
-		player_eye_position += player->eye_offset_third;
+	const v3f head_position = camera->getHeadPosition();
+	const v3f camera_direction = camera->getDirection();
+	const v3s16 camera_offset  = camera->getOffset();
 
 	/*
 		Calculate what block is the crosshair pointing to
@@ -3053,11 +3046,11 @@ void Game::processPlayerInteraction(f32 dtime, bool show_hud, bool show_debug)
 	core::line3d<f32> shootline;
 
 	if (camera->getCameraMode() != CAMERA_MODE_THIRD_FRONT) {
-		shootline = core::line3d<f32>(player_eye_position,
-			player_eye_position + camera_direction * BS * d);
+		shootline = core::line3d<f32>(head_position,
+			head_position + camera_direction * BS * d);
 	} else {
 		// prevent player pointing anything in front-view
-		shootline = core::line3d<f32>(camera_position, camera_position);
+		shootline = core::line3d<f32>(head_position, head_position);
 	}
 
 #ifdef HAVE_TOUCHSCREENGUI
@@ -3145,6 +3138,7 @@ void Game::processPlayerInteraction(f32 dtime, bool show_hud, bool show_debug)
 	} else if (pointed.type == POINTEDTHING_NODE) {
 		handlePointingAtNode(pointed, selected_item, hand_item, dtime);
 	} else if (pointed.type == POINTEDTHING_OBJECT) {
+		v3f player_position  = player->getPosition();
 		handlePointingAtObject(pointed, tool_item, player_position, show_debug);
 	} else if (input->getLeftState()) {
 		// When button is held down in air, show continuous animation

src/client/localplayer.h

@@ -135,6 +135,9 @@ class LocalPlayer : public Player
 	}
 
 	v3f getPosition() const { return m_position; }
+
+	// Non-transformed eye offset getters
+	// For accurate positions, use the Camera functions
 	v3f getEyePosition() const { return m_position + getEyeOffset(); }
 	v3f getEyeOffset() const;
 	void setEyeHeight(float eye_height) { m_eye_height = eye_height; }