/
temperature.go
243 lines (210 loc) · 7.83 KB
/
temperature.go
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package geo
import (
"math"
"github.com/Flokey82/genbiome"
"github.com/Flokey82/genworldvoronoi/various"
"github.com/Flokey82/go_gens/gameconstants"
)
// GetTempFalloffFromAltitude returns the temperature falloff at a given altitude in meters
// above sea level. (approx. 9.8 °C per 1000 m)
// NOTE: This is definitely not correct :)
// Source: https://www.quora.com/At-what-rate-does-temperature-drop-with-altitude
func GetTempFalloffFromAltitude(height float64) float64 {
if height < 0 {
return 0.0
}
return gameconstants.EarthElevationTemperatureFalloff * height
}
const (
MinTemp = genbiome.MinTemperatureC
MaxTemp = genbiome.MaxTemperatureC
RangeTemp = MaxTemp - MinTemp
MaxPrecipitation = genbiome.MaxPrecipitationDM // 450cm
)
// GetMeanAnnualTemp returns the temperature at a given latitude within the range of
// -15 °C to +30°C because that's the range in which the Whittaker biomes are defined.
// For this I assume that light hits the globe exactly from a 90° angle with respect
// to the planitary axis.
// See: https://www.scratchapixel.com/lessons/3d-basic-rendering/introduction-to-shading/shading-normals (facing ratio)
// See: http://www-das.uwyo.edu/~geerts/cwx/notes/chap16/geo_clim.html
// NOTE: -35 °C to +31 °C would be ideally the temp gradient (according to real-life data), but we don't have (yet) any biomes defined for this.
func GetMeanAnnualTemp(lat float64) float64 {
return (math.Sin(various.DegToRad(90-math.Abs(lat))))*RangeTemp + MinTemp
}
const MaxAltitudeFactor = gameconstants.EarthMaxElevation // How tall is the tallest mountain with an elevation of 1.0?
// GetRegTemperature returns the average yearly temperature of the given region at the surface.
func (m *Geo) GetRegTemperature(r int, maxElev float64) float64 {
// TODO: Fix maxElev caching!!!
return GetMeanAnnualTemp(m.LatLon[r][0]) - GetTempFalloffFromAltitude(MaxAltitudeFactor*m.Elevation[r]/maxElev)
}
// GetTriTemperature returns the average yearly temperature of the given triangle at the surface.
func (m *Geo) GetTriTemperature(t int, maxElev float64) float64 {
// TODO: Fix maxElev caching!!!
return GetMeanAnnualTemp(m.TriLatLon[t][0]) - GetTempFalloffFromAltitude(MaxAltitudeFactor*m.TriElevation[t]/maxElev)
}
func (m *Geo) initRegionAirTemperature() {
_, maxElev := minMax(m.Elevation)
for r := 0; r < m.SphereMesh.NumRegions; r++ {
m.AirTemperature[r] = m.GetRegTemperature(r, maxElev)
}
}
func (m *Geo) assignRegionAirTemperature() {
// TODO: Deduplicate this code with assignRegionWaterTemperature.
newTemperature := make([]float64, m.SphereMesh.NumRegions)
baseTemperature := make([]float64, m.SphereMesh.NumRegions)
outregs := make([]int, 0, 8)
for r := 0; r < m.SphereMesh.NumRegions; r++ {
// base
// lat := m.LatLon[r][0]
// absLat := math.Abs(lat)
// lon := m.LatLon[r][1]
// absLat := math.Abs(lat - m.getSunLattitude())
startTemp := m.AirTemperature[r]
newTemperature[r] = startTemp
baseTemperature[r] = startTemp
// diffusion
neighbors := m.SphereMesh.R_circulate_r(outregs, r)
neighborAverage := newTemperature[r]
neighborCount := 1
for i := 0; i < len(neighbors); i++ {
nr := neighbors[i]
neighborAverage += newTemperature[nr]
neighborCount++
}
neighborAverage /= float64(neighborCount)
newTemperature[r] = 0.75*newTemperature[r] + 0.25*neighborAverage
// newTemperature[r] = clamp(0, 1, newTemperature[r] - map.r_clouds[r]/2)
}
const (
transferIn = 0.001
transferOut = 1.0 - transferIn
numSteps = 5
)
// Initialize the movedTemp slice.
movedTemp := make([]float64, m.SphereMesh.NumRegions)
movedCount := make([]int, m.SphereMesh.NumRegions)
for step := 0; step < numSteps; step++ {
for r, nt := range newTemperature {
// add in the "pulled temp"
movedTemp[r] += nt
movedCount[r]++
pr := m.getPreviousNeighbor(outregs, r, m.RegionToWindVecLocal[r])
movedTemp[r] += m.AirTemperature[pr]
movedCount[r]++
// add in pushed temp
nr := m.GetClosestNeighbor(outregs, r, m.RegionToWindVecLocal[r])
if nr == r {
continue
}
// const heldHeat = newTemperature[r] - baseTemperature[r]
// const potentialHeat = newTemperature[r] - baseTemperature[nr]
// movedTemp[nr] = movedTemp[nr]? movedTemp[nr] : 0
// movedTemp[r] -= map.r_currents[r]*heldHeat
// movedTemp[nr] += map.r_currents[r]*potentialHeat
// movedTemp[nr] = movedTemp[nr]? movedTemp[nr] : []float64{}
movedTemp[nr] += transferOut*m.AirTemperature[r] + transferIn*nt
movedCount[nr]++
}
for r, mc := range movedCount {
if mc > 0 {
newTemperature[r] = movedTemp[r] / float64(mc)
// Reset movedTemp after every step for the next step.
movedTemp[r] = 0
movedCount[r] = 0
}
// if (movedTemp[r] !== undefined && movedTemp[r].length > 0) newTemperature[r] = movedTemp[r].reduce((acc, temp) => acc + temp, 0) / movedTemp[r].length
}
m.AirTemperature = newTemperature
}
m.AirTemperature = newTemperature
}
func (m *Geo) initRegionWaterTemperature() {
_, maxElev := minMax(m.Elevation)
for r := 0; r < m.SphereMesh.NumRegions; r++ {
if m.Elevation[r] <= 0 {
m.OceanTemperature[r] = m.GetRegTemperature(r, maxElev)
}
}
}
func (m *Geo) transportRegionWaterTemperature() {
// TODO: Deduplicate this code with assignRegionAirTemperature.
newTemperature := make([]float64, m.SphereMesh.NumRegions)
baseTemperature := make([]float64, m.SphereMesh.NumRegions)
for r := 0; r < m.SphereMesh.NumRegions; r++ {
if m.Elevation[r] > 0 {
newTemperature[r] = 0.5
}
}
outregs := make([]int, 0, 8)
for r := 0; r < m.SphereMesh.NumRegions; r++ {
if m.Elevation[r] > 0 {
continue
}
// base
// lat := m.LatLon[r][0]
// absLat := math.Abs(lat)
// lon := m.LatLon[r][1]
// absLat := math.Abs(lat - m.getSunLattitude())
startTemp := m.OceanTemperature[r]
newTemperature[r] = startTemp
baseTemperature[r] = startTemp
// diffusion
neighbors := m.SphereMesh.R_circulate_r(outregs, r)
neighborAverage := newTemperature[r]
neighborCount := 1
for i := 0; i < len(neighbors); i++ {
nr := neighbors[i]
if m.Elevation[nr] <= 0 {
neighborAverage += newTemperature[nr]
neighborCount++
}
}
neighborAverage /= float64(neighborCount)
newTemperature[r] = 0.75*newTemperature[r] + 0.25*neighborAverage
// newTemperature[r] = clamp(0, 1, newTemperature[r] - map.r_clouds[r]/2)
}
const (
transferIn = 0.001
transferOut = 1.0 - transferIn
numSteps = 5
)
// Initialize the movedTemp slice.
movedTemp := make([]float64, m.SphereMesh.NumRegions)
movedCount := make([]int, m.SphereMesh.NumRegions)
for step := 0; step < numSteps; step++ {
for r, nt := range newTemperature {
// add in the "pulled temp"
movedTemp[r] += nt
movedCount[r]++
pr := m.getPreviousNeighbor(outregs, r, m.RegionToOceanVec[r])
if m.Elevation[pr] <= 0 {
movedTemp[r] += m.OceanTemperature[pr]
movedCount[r]++
}
// add in pushed temp
nr := m.GetClosestNeighbor(outregs, r, m.RegionToOceanVec[r])
if nr == r || m.Elevation[nr] > 0 {
continue
}
// const heldHeat = newTemperature[r] - baseTemperature[r]
// const potentialHeat = newTemperature[r] - baseTemperature[nr]
// movedTemp[nr] = movedTemp[nr]? movedTemp[nr] : 0
// movedTemp[r] -= map.r_currents[r]*heldHeat
// movedTemp[nr] += map.r_currents[r]*potentialHeat
// movedTemp[nr] = movedTemp[nr]? movedTemp[nr] : []float64{}
movedTemp[nr] += transferOut*m.OceanTemperature[r] + transferIn*nt
movedCount[nr]++
}
for r, mc := range movedCount {
if mc > 0 {
newTemperature[r] = movedTemp[r] / float64(mc)
// Reset movedTemp after every step for the next step.
movedTemp[r] = 0
movedCount[r] = 0
}
// if (movedTemp[r] !== undefined && movedTemp[r].length > 0) newTemperature[r] = movedTemp[r].reduce((acc, temp) => acc + temp, 0) / movedTemp[r].length
}
m.OceanTemperature = newTemperature
}
m.OceanTemperature = newTemperature
}