src/client/shadows/dynamicshadows.cpp

   1 /*
   2 Minetest
   3 Copyright (C) 2021 Liso <anlismon@gmail.com>
   4
   5 This program is free software; you can redistribute it and/or modify
   6 it under the terms of the GNU Lesser General Public License as published by
   7 the Free Software Foundation; either version 2.1 of the License, or
   8 (at your option) any later version.
   9
  10 This program is distributed in the hope that it will be useful,
  11 but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 GNU Lesser General Public License for more details.
  14
  15 You should have received a copy of the GNU Lesser General Public License along
  16 with this program; if not, write to the Free Software Foundation, Inc.,
  17 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  18 */
  19
  20 #include <cmath>
  21
  22 #include "client/shadows/dynamicshadows.h"
  23 #include "client/client.h"
  24 #include "client/clientenvironment.h"
  25 #include "client/clientmap.h"
  26 #include "client/camera.h"
  27
  28 using m4f = core::matrix4;
  29
  30 static v3f quantizeDirection(v3f direction, float step)
  31 {
  32
  33         float yaw = std::atan2(direction.Z, direction.X);
  34         float pitch = std::asin(direction.Y); // assume look is normalized
  35
  36         yaw = std::floor(yaw / step) * step;
  37         pitch = std::floor(pitch / step) * step;
  38
  39         return v3f(std::cos(yaw)*std::cos(pitch), std::sin(pitch), std::sin(yaw)*std::cos(pitch));
  40 }
  41
  42 void DirectionalLight::createSplitMatrices(const Camera *cam)
  43 {
  44         const float DISTANCE_STEP = BS * 2.0; // 2 meters
  45         v3f newCenter;
  46         v3f look = cam->getDirection();
  47         look = quantizeDirection(look, M_PI / 12.0); // 15 degrees
  48
  49         // camera view tangents
  50         float tanFovY = tanf(cam->getFovY() * 0.5f);
  51         float tanFovX = tanf(cam->getFovX() * 0.5f);
  52
  53         // adjusted frustum boundaries
  54         float sfNear = future_frustum.zNear;
  55         float sfFar = adjustDist(future_frustum.zFar, cam->getFovY());
  56
  57         // adjusted camera positions
  58         v3f cam_pos_world = cam->getPosition();
  59         cam_pos_world = v3f(
  60                         floor(cam_pos_world.X / DISTANCE_STEP) * DISTANCE_STEP,
  61                         floor(cam_pos_world.Y / DISTANCE_STEP) * DISTANCE_STEP,
  62                         floor(cam_pos_world.Z / DISTANCE_STEP) * DISTANCE_STEP);
  63         v3f cam_pos_scene = v3f(cam_pos_world.X - cam->getOffset().X * BS,
  64                         cam_pos_world.Y - cam->getOffset().Y * BS,
  65                         cam_pos_world.Z - cam->getOffset().Z * BS);
  66         cam_pos_scene += look * sfNear;
  67         cam_pos_world += look * sfNear;
  68
  69         // center point of light frustum
  70         v3f center_scene = cam_pos_scene + look * 0.35 * (sfFar - sfNear);
  71         v3f center_world = cam_pos_world + look * 0.35 * (sfFar - sfNear);
  72
  73         // Create a vector to the frustum far corner
  74         const v3f &viewUp = cam->getCameraNode()->getUpVector();
  75         v3f viewRight = look.crossProduct(viewUp);
  76
  77         v3f farCorner = (look + viewRight * tanFovX + viewUp * tanFovY).normalize();
  78         // Compute the frustumBoundingSphere radius
  79         v3f boundVec = (cam_pos_scene + farCorner * sfFar) - center_scene;
  80         float radius = boundVec.getLength();
  81         float length = radius * 3.0f;
  82         v3f eye_displacement = quantizeDirection(direction, M_PI / 2880 /*15 seconds*/) * length;
  83
  84         // we must compute the viewmat with the position - the camera offset
  85         // but the future_frustum position must be the actual world position
  86         v3f eye = center_scene - eye_displacement;
  87         future_frustum.player = cam_pos_scene;
  88         future_frustum.position = center_world - eye_displacement;
  89         future_frustum.length = length;
  90         future_frustum.radius = radius;
  91         future_frustum.ViewMat.buildCameraLookAtMatrixLH(eye, center_scene, v3f(0.0f, 1.0f, 0.0f));
  92         future_frustum.ProjOrthMat.buildProjectionMatrixOrthoLH(radius, radius,
  93                         0.0f, length, false);
  94         future_frustum.camera_offset = cam->getOffset();
  95 }
  96
  97 DirectionalLight::DirectionalLight(const u32 shadowMapResolution,
  98                 const v3f &position, video::SColorf lightColor,
  99                 f32 farValue) :
 100                 diffuseColor(lightColor),
 101                 farPlane(farValue), mapRes(shadowMapResolution), pos(position)
 102 {}
 103
 104 void DirectionalLight::update_frustum(const Camera *cam, Client *client, bool force)
 105 {
 106         if (dirty && !force)
 107                 return;
 108
 109         float zNear = cam->getCameraNode()->getNearValue();
 110         float zFar = getMaxFarValue();
 111         if (!client->getEnv().getClientMap().getControl().range_all)
 112                 zFar = MYMIN(zFar, client->getEnv().getClientMap().getControl().wanted_range * BS);
 113
 114         ///////////////////////////////////
 115         // update splits near and fars
 116         future_frustum.zNear = zNear;
 117         future_frustum.zFar = zFar;
 118
 119         // update shadow frustum
 120         createSplitMatrices(cam);
 121         // get the draw list for shadows
 122         client->getEnv().getClientMap().updateDrawListShadow(
 123                         getPosition(), getDirection(), future_frustum.radius, future_frustum.length);
 124         should_update_map_shadow = true;
 125         dirty = true;
 126
 127         // when camera offset changes, adjust the current frustum view matrix to avoid flicker
 128         v3s16 cam_offset = cam->getOffset();
 129         if (cam_offset != shadow_frustum.camera_offset) {
 130                 v3f rotated_offset;
 131                 shadow_frustum.ViewMat.rotateVect(rotated_offset, intToFloat(cam_offset - shadow_frustum.camera_offset, BS));
 132                 shadow_frustum.ViewMat.setTranslation(shadow_frustum.ViewMat.getTranslation() + rotated_offset);
 133                 shadow_frustum.player += intToFloat(shadow_frustum.camera_offset - cam->getOffset(), BS);
 134                 shadow_frustum.camera_offset = cam_offset;
 135         }
 136 }
 137
 138 void DirectionalLight::commitFrustum()
 139 {
 140         if (!dirty)
 141                 return;
 142
 143         shadow_frustum = future_frustum;
 144         dirty = false;
 145 }
 146
 147 void DirectionalLight::setDirection(v3f dir)
 148 {
 149         direction = -dir;
 150         direction.normalize();
 151 }
 152
 153 v3f DirectionalLight::getPosition() const
 154 {
 155         return shadow_frustum.position;
 156 }
 157
 158 v3f DirectionalLight::getPlayerPos() const
 159 {
 160         return shadow_frustum.player;
 161 }
 162
 163 v3f DirectionalLight::getFuturePlayerPos() const
 164 {
 165         return future_frustum.player;
 166 }
 167
 168 const m4f &DirectionalLight::getViewMatrix() const
 169 {
 170         return shadow_frustum.ViewMat;
 171 }
 172
 173 const m4f &DirectionalLight::getProjectionMatrix() const
 174 {
 175         return shadow_frustum.ProjOrthMat;
 176 }
 177
 178 const m4f &DirectionalLight::getFutureViewMatrix() const
 179 {
 180         return future_frustum.ViewMat;
 181 }
 182
 183 const m4f &DirectionalLight::getFutureProjectionMatrix() const
 184 {
 185         return future_frustum.ProjOrthMat;
 186 }
 187
 188 m4f DirectionalLight::getViewProjMatrix()
 189 {
 190         return shadow_frustum.ProjOrthMat * shadow_frustum.ViewMat;
 191 }