osb/source/game/terrain/StarDisplacementSelector.cpp

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2023-06-20 04:33:09 +00:00
#include "StarDisplacementSelector.hpp"
#include "StarRandom.hpp"
#include "StarJsonExtra.hpp"
namespace Star {
char const* const DisplacementSelector::Name = "displacement";
DisplacementSelector::DisplacementSelector(
Json const& config, TerrainSelectorParameters const& parameters, TerrainDatabase const* database)
: TerrainSelector(Name, config, parameters) {
RandomSource random(parameters.seed);
auto xType = PerlinTypeNames.getLeft(config.getString("xType"));
auto xOctaves = config.getFloat("xOctaves");
auto xFreq = config.getFloat("xFreq");
auto xAmp = config.getFloat("xAmp");
auto xBias = config.getFloat("xBias", 0.0f);
auto xAlpha = config.getFloat("xAlpha", 2.0f);
auto xBeta = config.getFloat("xBeta", 2.0f);
xDisplacementFunction = PerlinF(xType, xOctaves, xFreq, xAmp, xBias, xAlpha, xBeta, random.randu64());
auto yType = PerlinTypeNames.getLeft(config.getString("yType"));
auto yOctaves = config.getFloat("yOctaves");
auto yFreq = config.getFloat("yFreq");
auto yAmp = config.getFloat("yAmp");
auto yBias = config.getFloat("yBias", 0.0f);
auto yAlpha = config.getFloat("yAlpha", 2.0f);
auto yBeta = config.getFloat("yBeta", 2.0f);
yDisplacementFunction = PerlinF(yType, yOctaves, yFreq, yAmp, yBias, yAlpha, yBeta, random.randu64());
xXInfluence = config.getFloat("xXInfluence", 1.0f);
xYInfluence = config.getFloat("xYInfluence", 1.0f);
yXInfluence = config.getFloat("yXInfluence", 1.0f);
yYInfluence = config.getFloat("yYInfluence", 1.0f);
yClamp = config.contains("yClamp");
if (yClamp) {
yClampRange = jsonToVec2F(config.get("yClamp"));
yClampSmoothing = config.getFloat("yClampSmoothing", 0);
}
auto sourceConfig = config.get("source");
String sourceType = sourceConfig.getString("type");
m_source = database->createSelectorType(sourceType, sourceConfig, parameters);
}
float DisplacementSelector::get(int x, int y) const {
auto x_ = x + xDisplacementFunction.get(x * xXInfluence, y * xYInfluence);
auto y_ = y + clampY(yDisplacementFunction.get(x * yXInfluence, y * yYInfluence));
return m_source->get(x_, y_);
}
float DisplacementSelector::clampY(float v) const {
if (!yClamp)
return v;
if (yClampSmoothing == 0)
return clamp(v, yClampRange[0], yClampRange[1]);
return 0.2f * (clamp(v - yClampSmoothing, yClampRange[0], yClampRange[1])
+ clamp(v - 0.5f * yClampSmoothing, yClampRange[0], yClampRange[1])
+ clamp(v, yClampRange[0], yClampRange[1])
+ clamp(v + 0.5f * yClampSmoothing, yClampRange[0], yClampRange[1])
+ clamp(v + yClampSmoothing, yClampRange[0], yClampRange[1]));
}
}