From bc9bb63aed82fb98eeab641eb8515c4cc1779230 Mon Sep 17 00:00:00 2001 From: Paramat Date: Wed, 18 Jul 2018 03:34:05 +0100 Subject: Mgvalleys: Make river depth variation and humidity drop optional (#7532) Add 2 new mapgen flags to make river depth variation and humidity drop with altitude independently optional, instead of both being enabled by the 'humid rivers' flag. Simplify and clarify related code by removing a low priority optimisation regarding 't_heat'. Remove unnecessary optimisation bools and use spflags directly instead. Improve and fix documentation in settingtypes.txt. A few minor code cleanups. --- src/mapgen/mapgen_valleys.cpp | 66 +++++++++++++++++++++---------------------- 1 file changed, 32 insertions(+), 34 deletions(-) (limited to 'src/mapgen/mapgen_valleys.cpp') diff --git a/src/mapgen/mapgen_valleys.cpp b/src/mapgen/mapgen_valleys.cpp index 341ce3137..0a0f93a75 100644 --- a/src/mapgen/mapgen_valleys.cpp +++ b/src/mapgen/mapgen_valleys.cpp @@ -44,10 +44,12 @@ with this program; if not, write to the Free Software Foundation, Inc., #include -static FlagDesc flagdesc_mapgen_valleys[] = { - {"altitude_chill", MGVALLEYS_ALT_CHILL}, - {"humid_rivers", MGVALLEYS_HUMID_RIVERS}, - {NULL, 0} +FlagDesc flagdesc_mapgen_valleys[] = { + {"altitude_chill", MGVALLEYS_ALT_CHILL}, + {"humid_rivers", MGVALLEYS_HUMID_RIVERS}, + {"vary_river_depth", MGVALLEYS_VARY_RIVER_DEPTH}, + {"altitude_dry", MGVALLEYS_ALT_DRY}, + {NULL, 0} }; @@ -94,8 +96,6 @@ MapgenValleys::MapgenValleys(int mapgenid, MapgenValleysParams *params, MapgenBasic::np_cave2 = params->np_cave2; MapgenBasic::np_cavern = params->np_cavern; - humid_rivers = (spflags & MGVALLEYS_HUMID_RIVERS); - use_altitude_chill = (spflags & MGVALLEYS_ALT_CHILL); humidity_adjust = bp->np_humidity.offset - 50.0f; } @@ -298,10 +298,10 @@ void MapgenValleys::calculateNoise() float heat_offset = 0.0f; float humidity_scale = 1.0f; // Altitude chill tends to reduce the average heat. - if (use_altitude_chill) + if (spflags & MGVALLEYS_ALT_CHILL) heat_offset = 5.0f; // River humidity tends to increase the humidity range. - if (humid_rivers) + if (spflags & MGVALLEYS_HUMID_RIVERS) humidity_scale = 0.8f; for (s32 index = 0; index < csize.X * csize.Z; index++) { @@ -477,17 +477,16 @@ int MapgenValleys::generateTerrain() if (surface_y > surface_max_y) surface_max_y = std::ceil(surface_y); - if (humid_rivers) { - // Derive heat from (base) altitude. This will be most correct - // at rivers, since other surface heights may vary below. - if (use_altitude_chill && (surface_y > 0.0f || river_y > 0.0f)) - t_heat -= alt_to_heat * - std::fmax(surface_y, river_y) / altitude_chill; - - // If humidity is low or heat is high, lower the water table + // Optionally vary river depth according to heat and humidity + if (spflags & MGVALLEYS_VARY_RIVER_DEPTH) { + float heat = ((spflags & MGVALLEYS_ALT_CHILL) && + (surface_y > 0.0f || river_y > 0.0f)) ? + t_heat - alt_to_heat * + std::fmax(surface_y, river_y) / altitude_chill : + t_heat; float delta = m_bgen->humidmap[index_2d] - 50.0f; if (delta < 0.0f) { - float t_evap = (t_heat - 32.0f) / evaporation; + float t_evap = (heat - 32.0f) / evaporation; river_y += delta * std::fmax(t_evap, 0.08f); } } @@ -534,33 +533,32 @@ int MapgenValleys::generateTerrain() } } - if (humid_rivers) { - // Use base ground (water table) in a riverbed, to avoid an - // unnatural rise in humidity. + // Optionally increase humidity around rivers + if (spflags & MGVALLEYS_HUMID_RIVERS) { + // Ground height ignoring riverbeds float t_alt = std::fmax(noise_rivers->result[index_2d], (float)heightmap[index_2d]); - float humid = m_bgen->humidmap[index_2d]; float water_depth = (t_alt - river_y) / humidity_dropoff; - humid *= 1.0f + std::pow(0.5f, std::fmax(water_depth, 1.0f)); + m_bgen->humidmap[index_2d] *= + 1.0f + std::pow(0.5f, std::fmax(water_depth, 1.0f)); + } - // Reduce humidity with altitude (ignoring riverbeds) + // Optionally decrease humidity with altitude + if (spflags & MGVALLEYS_ALT_DRY) { + // Ground height ignoring riverbeds + float t_alt = std::fmax(noise_rivers->result[index_2d], + (float)heightmap[index_2d]); if (t_alt > 0.0f) - humid -= alt_to_humid * t_alt / altitude_chill; - - m_bgen->humidmap[index_2d] = humid; + m_bgen->humidmap[index_2d] -= + alt_to_humid * t_alt / altitude_chill; } - // Assign the heat adjusted by any changed altitudes. - // The altitude will change about half the time. - if (use_altitude_chill) { + // Optionally decrease heat with altitude + if (spflags & MGVALLEYS_ALT_CHILL) { // Ground height ignoring riverbeds float t_alt = std::fmax(noise_rivers->result[index_2d], (float)heightmap[index_2d]); - - if (humid_rivers && heightmap[index_2d] == (s16)myround(surface_y)) - // The altitude hasn't changed. Use the first result - m_bgen->heatmap[index_2d] = t_heat; - else if (t_alt > 0.0f) + if (t_alt > 0.0f) m_bgen->heatmap[index_2d] -= alt_to_heat * t_alt / altitude_chill; } -- cgit v1.2.3