Spectrum MIPMap::getValue(Float u, Float v,
Float dudx, Float dudy, Float dvdx, Float dvdy) const {
if (m_filterType == ETrilinear) {
++mipmapLookups;
/* Conservatively estimate a square lookup region */
Float width = 2.0f * std::max(
std::max(std::abs(dudx), std::abs(dudy)),
std::max(std::abs(dvdx), std::abs(dvdy)));
Float mipmapLevel = m_levels - 1 +
log2(std::max(width, (Float) 1e-8f));
if (mipmapLevel < 0) {
/* The lookup is smaller than one pixel */
return triangle(0, u, v);
} else if (mipmapLevel >= m_levels - 1) {
/* The lookup is larger than the whole texture */
return getTexel(m_levels - 1, 0, 0);
} else {
/* Tri-linear interpolation */
int level = (int) mipmapLevel;
Float delta = mipmapLevel - level;
return triangle(level, u, v) * (1.0f - delta)
+ triangle(level, u, v) * delta;
}
} else if (m_filterType == EEWA) {
if (dudx*dudx + dudy*dudy < dvdx*dvdx + dvdy*dvdy) {
std::swap(dudx, dvdx);
std::swap(dudy, dvdy);
}
Float majorLength = std::sqrt(dudx * dudx + dudy * dudy);
Float minorLength = std::sqrt(dvdx * dvdx + dvdy * dvdy);
if (minorLength * m_maxAnisotropy < majorLength && minorLength > 0.0f) {
Float scale = majorLength / (minorLength * m_maxAnisotropy);
dvdx *= scale; dvdy *= scale;
minorLength *= scale;
}
if (minorLength == 0)
return triangle(0, u, v);
// The min() below avoids overflow in the int conversion when lod=inf
Float lod =
std::min(std::max((Float) 0, m_levels - 1 + log2(minorLength)),
(Float) (m_levels-1));
int ilod = floorToInt(lod);
Float d = lod - ilod;
return EWA(u, v, dudx, dudy, dvdx, dvdy, ilod) * (1-d) +
EWA(u, v, dudx, dudy, dvdx, dvdy, ilod+1) * d;
} else {
int xPos = floorToInt(u*m_levelWidth[0]),
yPos = floorToInt(v*m_levelHeight[0]);
return getTexel(0, xPos, yPos);
}
}
void ESPSerialWiFiManager::_write_config(){
EWA(_eeprom_offset + 1, _network_config);
}
