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mirror of https://github.com/moparisthebest/minetest synced 2024-11-08 02:15:07 -05:00
minetest/src/utility.cpp
2011-01-17 23:35:09 +02:00

386 lines
8.6 KiB
C++

/*
Minetest-c55
Copyright (C) 2010 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.
*/
/*
(c) 2010 Perttu Ahola <celeron55@gmail.com>
*/
#include "utility.h"
#include "irrlichtwrapper.h"
#include "gettime.h"
TimeTaker::TimeTaker(const char *name, u32 *result)
{
m_name = name;
m_result = result;
m_running = true;
m_time1 = getTimeMs();
}
u32 TimeTaker::stop(bool quiet)
{
if(m_running)
{
u32 time2 = getTimeMs();
u32 dtime = time2 - m_time1;
if(m_result != NULL)
{
(*m_result) += dtime;
}
else
{
if(quiet == false)
std::cout<<m_name<<" took "<<dtime<<"ms"<<std::endl;
}
m_running = false;
return dtime;
}
return 0;
}
const v3s16 g_26dirs[26] =
{
// +right, +top, +back
v3s16( 0, 0, 1), // back
v3s16( 0, 1, 0), // top
v3s16( 1, 0, 0), // right
v3s16( 0, 0,-1), // front
v3s16( 0,-1, 0), // bottom
v3s16(-1, 0, 0), // left
// 6
v3s16(-1, 1, 0), // top left
v3s16( 1, 1, 0), // top right
v3s16( 0, 1, 1), // top back
v3s16( 0, 1,-1), // top front
v3s16(-1, 0, 1), // back left
v3s16( 1, 0, 1), // back right
v3s16(-1, 0,-1), // front left
v3s16( 1, 0,-1), // front right
v3s16(-1,-1, 0), // bottom left
v3s16( 1,-1, 0), // bottom right
v3s16( 0,-1, 1), // bottom back
v3s16( 0,-1,-1), // bottom front
// 18
v3s16(-1, 1, 1), // top back-left
v3s16( 1, 1, 1), // top back-right
v3s16(-1, 1,-1), // top front-left
v3s16( 1, 1,-1), // top front-right
v3s16(-1,-1, 1), // bottom back-left
v3s16( 1,-1, 1), // bottom back-right
v3s16(-1,-1,-1), // bottom front-left
v3s16( 1,-1,-1), // bottom front-right
// 26
};
static unsigned long next = 1;
/* RAND_MAX assumed to be 32767 */
int myrand(void)
{
next = next * 1103515245 + 12345;
return((unsigned)(next/65536) % 32768);
}
void mysrand(unsigned seed)
{
next = seed;
}
// Float with distance
struct DFloat
{
float v;
u32 d;
};
float PointAttributeList::getInterpolatedFloat(v3s16 p)
{
const u32 near_wanted_count = 5;
// Last is nearest, first is farthest
core::list<DFloat> near_list;
for(core::list<PointWithAttr>::Iterator
i = m_points.begin();
i != m_points.end(); i++)
{
PointWithAttr &pwa = *i;
u32 d = pwa.p.getDistanceFrom(p);
DFloat df;
df.v = pwa.attr.getFloat();
df.d = d;
// If near list is empty, add directly and continue
if(near_list.size() == 0)
{
near_list.push_back(df);
continue;
}
// Get distance of farthest in near list
u32 near_d = 100000;
if(near_list.size() > 0)
{
core::list<DFloat>::Iterator i = near_list.begin();
near_d = i->d;
}
/*
If point is closer than the farthest in the near list or
there are not yet enough points on the list
*/
if(d < near_d || near_list.size() < near_wanted_count)
{
// Find the right place in the near list and put it there
// Go from farthest to near in the near list
core::list<DFloat>::Iterator i = near_list.begin();
for(; i != near_list.end(); i++)
{
// Stop when i is at the first nearer node
if(i->d < d)
break;
}
// Add df to before i
if(i == near_list.end())
near_list.push_back(df);
else
near_list.insert_before(i, df);
// Keep near list at right size
if(near_list.size() > near_wanted_count)
{
core::list<DFloat>::Iterator j = near_list.begin();
near_list.erase(j);
}
}
}
// Return if no values found
if(near_list.size() == 0)
return 0.0;
/*
20:58:29 < tejeez> joka pisteelle a += arvo / etäisyys^6; b += 1 / etäisyys^6; ja
lopuks sit otetaan a/b
*/
float a = 0;
float b = 0;
for(core::list<DFloat>::Iterator i = near_list.begin();
i != near_list.end(); i++)
{
if(i->d == 0)
return i->v;
//float dd = pow((float)i->d, 6);
float dd = pow((float)i->d, 5);
float v = i->v;
//dstream<<"dd="<<dd<<", v="<<v<<std::endl;
a += v / dd;
b += 1 / dd;
}
return a / b;
}
#if 0
float PointAttributeList::getInterpolatedFloat(v3s16 p)
{
const u32 near_wanted_count = 2;
const u32 nearest_wanted_count = 2;
// Last is near
core::list<DFloat> near;
for(core::list<PointWithAttr>::Iterator
i = m_points.begin();
i != m_points.end(); i++)
{
PointWithAttr &pwa = *i;
u32 d = pwa.p.getDistanceFrom(p);
DFloat df;
df.v = pwa.attr.getFloat();
df.d = d;
// If near list is empty, add directly and continue
if(near_list.size() == 0)
{
near_list.push_back(df);
continue;
}
// Get distance of farthest in near list
u32 near_d = 100000;
if(near_list.size() > 0)
{
core::list<DFloat>::Iterator i = near_list.begin();
near_d = i->d;
}
/*
If point is closer than the farthest in the near list or
there are not yet enough points on the list
*/
if(d < near_d || near_list.size() < near_wanted_count)
{
// Find the right place in the near list and put it there
// Go from farthest to near in the near list
core::list<DFloat>::Iterator i = near_list.begin();
for(; i != near_list.end(); i++)
{
// Stop when i is at the first nearer node
if(i->d < d)
break;
}
// Add df to before i
if(i == near_list.end())
near_list.push_back(df);
else
near_list.insert_before(i, df);
// Keep near list at right size
if(near_list.size() > near_wanted_count)
{
core::list<DFloat>::Iterator j = near_list.begin();
near_list.erase(j);
}
}
}
// Return if no values found
if(near_list.size() == 0)
return 0.0;
/*
Get nearest ones
*/
u32 nearest_count = nearest_wanted_count;
if(nearest_count > near_list.size())
nearest_count = near_list.size();
core::list<DFloat> nearest;
{
core::list<DFloat>::Iterator i = near_list.getLast();
for(u32 j=0; j<nearest_count; j++)
{
nearest.push_front(*i);
i--;
}
}
/*
TODO: Try this:
20:58:29 < tejeez> joka pisteelle a += arvo / etäisyys^6; b += 1 / etäisyys^6; ja
lopuks sit otetaan a/b
*/
/*
Get total distance to nearest points
*/
float nearest_d_sum = 0;
for(core::list<DFloat>::Iterator i = nearest.begin();
i != nearest.end(); i++)
{
nearest_d_sum += (float)i->d;
}
/*
Interpolate a value between the first ones
*/
dstream<<"nearest.size()="<<nearest.size()<<std::endl;
float interpolated = 0;
for(core::list<DFloat>::Iterator i = nearest.begin();
i != nearest.end(); i++)
{
float weight;
if(nearest_d_sum > 0.001)
weight = (float)i->d / nearest_d_sum;
else
weight = 1. / nearest.size();
/*dstream<<"i->d="<<i->d<<" nearest_d_sum="<<nearest_d_sum
<<" weight="<<weight<<std::endl;*/
interpolated += weight * i->v;
}
return interpolated;
}
#endif
/*
blockpos: position of block in block coordinates
camera_pos: position of camera in nodes
camera_dir: an unit vector pointing to camera direction
range: viewing range
*/
bool isBlockInSight(v3s16 blockpos_b, v3f camera_pos, v3f camera_dir, f32 range)
{
v3s16 blockpos_nodes = blockpos_b * MAP_BLOCKSIZE;
// Block center position
v3f blockpos(
((float)blockpos_nodes.X + MAP_BLOCKSIZE/2) * BS,
((float)blockpos_nodes.Y + MAP_BLOCKSIZE/2) * BS,
((float)blockpos_nodes.Z + MAP_BLOCKSIZE/2) * BS
);
// Block position relative to camera
v3f blockpos_relative = blockpos - camera_pos;
// Distance in camera direction (+=front, -=back)
f32 dforward = blockpos_relative.dotProduct(camera_dir);
// Total distance
f32 d = blockpos_relative.getLength();
// If block is far away, it's not in sight
if(d > range * BS)
return false;
// Maximum radius of a block
f32 block_max_radius = 0.5*1.44*1.44*MAP_BLOCKSIZE*BS;
// If block is (nearly) touching the camera, don't
// bother validating further (that is, render it anyway)
if(d > block_max_radius * 1.5)
{
// Cosine of the angle between the camera direction
// and the block direction (camera_dir is an unit vector)
f32 cosangle = dforward / d;
// Compensate for the size of the block
// (as the block has to be shown even if it's a bit off FOV)
// This is an estimate.
cosangle += block_max_radius / dforward;
// If block is not in the field of view, skip it
//if(cosangle < cos(FOV_ANGLE/2))
if(cosangle < cos(FOV_ANGLE/2. * 4./3.))
return false;
}
return true;
}