From d7c10b66d39adb330612da0da6d9c8ed993fe588 Mon Sep 17 00:00:00 2001 From: Paramat Date: Thu, 15 Aug 2019 20:32:28 +0100 Subject: [PATCH] Mapgen v6: Fix mudflow iteration and iterate twice (#8795) In MapgenV6::flowMud(), the previous implementation of coordinate inversion caused the 2 inverted mudflow iterations (out of the 3 iterations) to not loop over the area, so only 1 non-inverted iteration occurred. Fix this bug but only iterate mudflow twice, as mapgen v6 has only had 1 iteration for many years. There is now a good balance of 1 non-inverted iteration and 1 inverted iteration. --- src/mapgen/mapgen_v6.cpp | 24 ++++++++++++------------ 1 file changed, 12 insertions(+), 12 deletions(-) diff --git a/src/mapgen/mapgen_v6.cpp b/src/mapgen/mapgen_v6.cpp index ae87b094d..28ca8faa2 100644 --- a/src/mapgen/mapgen_v6.cpp +++ b/src/mapgen/mapgen_v6.cpp @@ -773,22 +773,22 @@ void MapgenV6::addMud() void MapgenV6::flowMud(s16 &mudflow_minpos, s16 &mudflow_maxpos) { - // 340ms @cs=8 - //TimeTaker timer1("flow mud"); - - // Iterate a few times - for (s16 k = 0; k < 3; k++) { + // Iterate twice + for (s16 k = 0; k < 2; k++) { for (s16 z = mudflow_minpos; z <= mudflow_maxpos; z++) for (s16 x = mudflow_minpos; x <= mudflow_maxpos; x++) { - // Invert coordinates every 2nd iteration - if (k % 2 == 0) { - x = mudflow_maxpos - (x - mudflow_minpos); - z = mudflow_maxpos - (z - mudflow_minpos); + // Node column position + v2s16 p2d; + // Invert coordinates on second iteration to process columns in + // opposite order, to avoid a directional bias. + if (k == 1) { + p2d = v2s16(node_min.X, node_min.Z) + v2s16( + mudflow_maxpos - (x - mudflow_minpos), + mudflow_maxpos - (z - mudflow_minpos)); + } else { + p2d = v2s16(node_min.X, node_min.Z) + v2s16(x, z); } - // Node position in 2d - v2s16 p2d = v2s16(node_min.X, node_min.Z) + v2s16(x, z); - const v3s16 &em = vm->m_area.getExtent(); u32 i = vm->m_area.index(p2d.X, node_max.Y, p2d.Y); s16 y = node_max.Y;