From baf7da9d4a7fc0566840b159903999d76d99a228 Mon Sep 17 00:00:00 2001
From: Kahrl <kahrl@gmx.net>
Date: Thu, 8 Sep 2011 01:08:47 +0200
Subject: Collected and moved existing camera infrastructure from game.cpp to
 camera.cpp and camera.h. Introduced configuration settings 'fov' which
 chooses the camera's (vertical) field of view and 'view_bobbing' which
 currently does nothing. Other code refactored to not expect the FOV to be a
 build time constant.

---
 src/camera.cpp | 243 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 243 insertions(+)
 create mode 100644 src/camera.cpp

(limited to 'src/camera.cpp')

diff --git a/src/camera.cpp b/src/camera.cpp
new file mode 100644
index 000000000..30df439ed
--- /dev/null
+++ b/src/camera.cpp
@@ -0,0 +1,243 @@
+/*
+Minetest-c55
+Copyright (C) 2010-2011 celeron55, Perttu Ahola <celeron55@gmail.com>
+
+This program 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 2 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, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+
+#include "camera.h"
+#include "debug.h"
+#include "main.h" // for g_settings
+#include "map.h"
+#include "player.h"
+#include "utility.h"
+#include <cmath>
+
+Camera::Camera(scene::ISceneManager* smgr, MapDrawControl& draw_control):
+	m_smgr(smgr),
+	m_playernode(NULL),
+	m_cameranode(NULL),
+	m_draw_control(draw_control),
+	m_viewing_range_min(5.0),
+	m_viewing_range_max(5.0),
+
+	m_camera_position(0,0,0),
+	m_camera_direction(0,0,0),
+
+	m_aspect(1.0),
+	m_fov_x(1.0),
+	m_fov_y(1.0),
+
+	m_wanted_frametime(0.0),
+	m_added_frametime(0),
+	m_added_frames(0),
+	m_range_old(0),
+	m_frametime_old(0),
+	m_frametime_counter(0),
+	m_time_per_range(30. / 50), // a sane default of 30ms per 50 nodes of range
+
+	m_view_bobbing_anim(0),
+	m_view_bobbing_anim_left(0)
+{
+	dstream<<__FUNCTION_NAME<<std::endl;
+
+	m_playernode = smgr->addEmptySceneNode(smgr->getRootSceneNode());
+	m_cameranode = smgr->addCameraSceneNode(m_playernode);
+
+	updateSettings();
+}
+
+Camera::~Camera()
+{
+}
+
+void Camera::step(f32 dtime)
+{
+}
+
+void Camera::update(LocalPlayer* player, f32 frametime, v2u32 screensize)
+{
+	if (m_playernode == NULL || m_cameranode == NULL)
+		return;
+
+	// FOV and and aspect ratio
+	m_aspect = (f32)screensize.X / (f32) screensize.Y;
+	m_fov_x = 2 * atan(0.5 * m_aspect * tan(m_fov_y));
+	m_cameranode->setAspectRatio(m_aspect);
+	m_cameranode->setFOV(m_fov_y);
+
+	// Just so big a value that everything rendered is visible
+	// Some more allowance that m_viewing_range_max * BS because of active objects etc.
+	m_cameranode->setFarValue(m_viewing_range_max * BS * 10);
+
+	m_camera_position = player->getEyePosition();  // TODO bobbing
+	m_cameranode->setPosition(m_camera_position);
+
+	m_camera_direction = v3f(0,0,1);
+	m_camera_direction.rotateYZBy(player->getPitch());
+	m_camera_direction.rotateXZBy(player->getYaw());
+	// *100.0 helps in large map coordinates
+	m_cameranode->setTarget(m_camera_position + m_camera_direction * 100.0);
+
+	// Render distance feedback loop
+	updateViewingRange(frametime);
+
+	// Check if view bobbing is active
+	v3f speed = player->getSpeed();
+	f32 epsilon = BS / 1000.0;
+	if (speed.X * speed.X + speed.Z * speed.Z > epsilon*epsilon &&
+			speed.Y < epsilon &&
+			g_settings.getBool("view_bobbing") == true &&
+			g_settings.getBool("free_move") == false)
+	{
+		// The player seems to be walking on solid ground.
+		// Enable view bobbing.
+		//dstream << "View bobbing active" << std::endl;
+	}
+	else
+	{
+		//dstream << "View bobbing inactive" << std::endl;
+	}
+}
+
+void Camera::updateViewingRange(f32 frametime_in)
+{
+	if (m_draw_control.range_all)
+		return;
+
+	m_added_frametime += frametime_in;
+	m_added_frames += 1;
+
+	// Actually this counter kind of sucks because frametime is busytime
+	m_frametime_counter -= frametime_in;
+	if (m_frametime_counter > 0)
+		return;
+	m_frametime_counter = 0.2;
+
+	dstream<<__FUNCTION_NAME
+			<<": Collected "<<m_added_frames<<" frames, total of "
+			<<m_added_frametime<<"s."<<std::endl;
+
+	dstream<<"m_draw_control.blocks_drawn="
+			<<m_draw_control.blocks_drawn
+			<<", m_draw_control.blocks_would_have_drawn="
+			<<m_draw_control.blocks_would_have_drawn
+			<<std::endl;
+
+	m_draw_control.wanted_min_range = m_viewing_range_min;
+	m_draw_control.wanted_max_blocks = (1.5*m_draw_control.blocks_would_have_drawn)+1;
+	if (m_draw_control.wanted_max_blocks < 10)
+		m_draw_control.wanted_max_blocks = 10;
+
+	f32 block_draw_ratio = 1.0;
+	if (m_draw_control.blocks_would_have_drawn != 0)
+	{
+		block_draw_ratio = (f32)m_draw_control.blocks_drawn
+			/ (f32)m_draw_control.blocks_would_have_drawn;
+	}
+
+	// Calculate the average frametime in the case that all wanted
+	// blocks had been drawn
+	f32 frametime = m_added_frametime / m_added_frames / block_draw_ratio;
+
+	m_added_frametime = 0.0;
+	m_added_frames = 0;
+
+	f32 wanted_frametime_change = m_wanted_frametime - frametime;
+	dstream<<"wanted_frametime_change="<<wanted_frametime_change<<std::endl;
+
+	// If needed frametime change is small, just return
+	if (fabs(wanted_frametime_change) < m_wanted_frametime*0.4)
+	{
+		dstream<<"ignoring small wanted_frametime_change"<<std::endl;
+		return;
+	}
+
+	f32 range = m_draw_control.wanted_range;
+	f32 new_range = range;
+
+	f32 d_range = range - m_range_old;
+	f32 d_frametime = frametime - m_frametime_old;
+	if (d_range != 0)
+	{
+		m_time_per_range = d_frametime / d_range;
+	}
+
+	// The minimum allowed calculated frametime-range derivative:
+	// Practically this sets the maximum speed of changing the range.
+	// The lower this value, the higher the maximum changing speed.
+	// A low value here results in wobbly range (0.001)
+	// A high value here results in slow changing range (0.0025)
+	// SUGG: This could be dynamically adjusted so that when
+	//       the camera is turning, this is lower
+	//f32 min_time_per_range = 0.0015;
+	f32 min_time_per_range = 0.0010;
+	//f32 min_time_per_range = 0.05 / range;
+	if(m_time_per_range < min_time_per_range)
+	{
+		m_time_per_range = min_time_per_range;
+		dstream<<"m_time_per_range="<<m_time_per_range<<" (min)"<<std::endl;
+	}
+	else
+	{
+		dstream<<"m_time_per_range="<<m_time_per_range<<std::endl;
+	}
+
+	f32 wanted_range_change = wanted_frametime_change / m_time_per_range;
+	// Dampen the change a bit to kill oscillations
+	//wanted_range_change *= 0.9;
+	//wanted_range_change *= 0.75;
+	wanted_range_change *= 0.5;
+	dstream<<"wanted_range_change="<<wanted_range_change<<std::endl;
+
+	// If needed range change is very small, just return
+	if(fabs(wanted_range_change) < 0.001)
+	{
+		dstream<<"ignoring small wanted_range_change"<<std::endl;
+		return;
+	}
+
+	new_range += wanted_range_change;
+	
+	f32 new_range_unclamped = new_range;
+	new_range = MYMAX(new_range, m_viewing_range_min);
+	new_range = MYMIN(new_range, m_viewing_range_max);
+	dstream<<"new_range="<<new_range_unclamped
+			<<", clamped to "<<new_range<<std::endl;
+
+	m_draw_control.wanted_range = new_range;
+
+	m_range_old = new_range;
+	m_frametime_old = frametime;
+}
+
+void Camera::updateSettings()
+{
+	m_viewing_range_min = g_settings.getS16("viewing_range_nodes_min");
+	m_viewing_range_min = MYMAX(5.0, m_viewing_range_min);
+
+	m_viewing_range_max = g_settings.getS16("viewing_range_nodes_max");
+	m_viewing_range_max = MYMAX(m_viewing_range_min, m_viewing_range_max);
+
+	f32 fov_degrees = g_settings.getFloat("fov");
+	fov_degrees = MYMAX(fov_degrees, 10.0);
+	fov_degrees = MYMIN(fov_degrees, 170.0);
+	m_fov_y = fov_degrees * M_PI / 180.0;
+
+	f32 wanted_fps = g_settings.getFloat("wanted_fps");
+	wanted_fps = MYMAX(wanted_fps, 1.0);
+	m_wanted_frametime = 1.0 / wanted_fps;
+}
+
-- 
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