3 Copyright (C) 2010-2013 celeron55, Perttu Ahola <celeron55@gmail.com>
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.
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.
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.
23 #include "constants.h" // BS, MAP_BLOCKSIZE
24 #include "noise.h" // PseudoRandom, PcgRandom
25 #include "threading/mutex_auto_lock.h"
36 return g_pcgrand.next();
39 void mysrand(unsigned int seed)
44 void myrand_bytes(void *out, size_t len)
46 g_pcgrand.bytes(out, len);
51 u32 uv = g_pcgrand.next();
52 return (float)uv / (float)U32_MAX;
55 int myrand_range(int min, int max)
57 return g_pcgrand.range(min, max);
60 float myrand_range(float min, float max)
62 return (max-min) * myrand_float() + min;
67 64-bit unaligned version of MurmurHash
69 u64 murmur_hash_64_ua(const void *key, int len, unsigned int seed)
71 const u64 m = 0xc6a4a7935bd1e995ULL;
73 u64 h = seed ^ (len * m);
75 const u8 *data = (const u8 *)key;
76 const u8 *end = data + (len / 8) * 8;
80 memcpy(&k, data, sizeof(u64));
91 const unsigned char *data2 = (const unsigned char *)data;
93 case 7: h ^= (u64)data2[6] << 48;
94 case 6: h ^= (u64)data2[5] << 40;
95 case 5: h ^= (u64)data2[4] << 32;
96 case 4: h ^= (u64)data2[3] << 24;
97 case 3: h ^= (u64)data2[2] << 16;
98 case 2: h ^= (u64)data2[1] << 8;
99 case 1: h ^= (u64)data2[0];
111 blockpos_b: position of block in block coordinates
112 camera_pos: position of camera in nodes
113 camera_dir: an unit vector pointing to camera direction
115 distance_ptr: return location for distance from the camera
117 bool isBlockInSight(v3s16 blockpos_b, v3f camera_pos, v3f camera_dir,
118 f32 camera_fov, f32 range, f32 *distance_ptr)
120 v3s16 blockpos_nodes = blockpos_b * MAP_BLOCKSIZE;
122 // Block center position
124 ((float)blockpos_nodes.X + MAP_BLOCKSIZE/2) * BS,
125 ((float)blockpos_nodes.Y + MAP_BLOCKSIZE/2) * BS,
126 ((float)blockpos_nodes.Z + MAP_BLOCKSIZE/2) * BS
129 // Block position relative to camera
130 v3f blockpos_relative = blockpos - camera_pos;
133 f32 d = MYMAX(0, blockpos_relative.getLength() - BLOCK_MAX_RADIUS);
138 // If block is far away, it's not in sight
142 // If block is (nearly) touching the camera, don't
143 // bother validating further (that is, render it anyway)
147 // Adjust camera position, for purposes of computing the angle,
148 // such that a block that has any portion visible with the
149 // current camera position will have the center visible at the
151 f32 adjdist = BLOCK_MAX_RADIUS / cos((M_PI - camera_fov) / 2);
153 // Block position relative to adjusted camera
154 v3f blockpos_adj = blockpos - (camera_pos - camera_dir * adjdist);
156 // Distance in camera direction (+=front, -=back)
157 f32 dforward = blockpos_adj.dotProduct(camera_dir);
159 // Cosine of the angle between the camera direction
160 // and the block direction (camera_dir is an unit vector)
161 f32 cosangle = dforward / blockpos_adj.getLength();
163 // If block is not in the field of view, skip it
164 // HOTFIX: use sligthly increased angle (+10%) to fix too agressive
165 // culling. Somebody have to find out whats wrong with the math here.
166 // Previous value: camera_fov / 2
167 if (cosangle < std::cos(camera_fov * 0.55f))
173 inline float adjustDist(float dist, float zoom_fov)
175 // 1.775 ~= 72 * PI / 180 * 1.4, the default FOV on the client.
176 // The heuristic threshold for zooming is half of that.
177 static constexpr const float threshold_fov = 1.775f / 2.0f;
178 if (zoom_fov < 0.001f || zoom_fov > threshold_fov)
181 return dist * std::cbrt((1.0f - std::cos(threshold_fov)) /
182 (1.0f - std::cos(zoom_fov / 2.0f)));
185 s16 adjustDist(s16 dist, float zoom_fov)
187 return std::round(adjustDist((float)dist, zoom_fov));
190 void setPitchYawRollRad(core::matrix4 &m, const v3f &rot)
192 f64 a1 = rot.Z, a2 = rot.X, a3 = rot.Y;
193 f64 c1 = cos(a1), s1 = sin(a1);
194 f64 c2 = cos(a2), s2 = sin(a2);
195 f64 c3 = cos(a3), s3 = sin(a3);
196 f32 *M = m.pointer();
198 M[0] = s1 * s2 * s3 + c1 * c3;
200 M[2] = s1 * s2 * c3 - c1 * s3;
202 M[4] = c1 * s2 * s3 - s1 * c3;
204 M[6] = c1 * s2 * c3 + s1 * s3;
211 v3f getPitchYawRollRad(const core::matrix4 &m)
213 const f32 *M = m.pointer();
215 f64 a1 = atan2(M[1], M[5]);
216 f32 c2 = std::sqrt((f64)M[10]*M[10] + (f64)M[8]*M[8]);
217 f32 a2 = atan2f(-M[9], c2);
220 f32 a3 = atan2f(s1*M[6] - c1*M[2], c1*M[0] - s1*M[4]);
222 return v3f(a2, a3, a1);