From 5a89d97b750123842d1948ca000d0ca8964fab53 Mon Sep 17 00:00:00 2001
From: MihailRis <mexaruc@gmail.com>
Date: Tue, 8 Oct 2024 05:44:36 +0300
Subject: [PATCH] fix line placement

---
 res/generators/default.files/script.lua |  2 +-
 src/world/generator/WorldGenerator.cpp  | 53 ++++++++++++++++---------
 2 files changed, 35 insertions(+), 20 deletions(-)

diff --git a/res/generators/default.files/script.lua b/res/generators/default.files/script.lua
index 3af69134..1bec4cab 100644
--- a/res/generators/default.files/script.lua
+++ b/res/generators/default.files/script.lua
@@ -17,7 +17,7 @@ function place_structures(x, z, w, d, seed, hmap, chunk_height)
         local sz = z + math.random() * 20 - 10
         local ez = z + math.random() * 20 - 10
         table.insert(placements, 
-            {":line", 0, {sx - 10, sy, sz - 10}, {ex + 10, ey, ez + 10}, 2})
+            {":line", 0, {sx - 10, sy, sz - 10}, {ex + 10, ey, ez + 10}, 3})
     end
     return placements
 end
diff --git a/src/world/generator/WorldGenerator.cpp b/src/world/generator/WorldGenerator.cpp
index cb981c01..f1157343 100644
--- a/src/world/generator/WorldGenerator.cpp
+++ b/src/world/generator/WorldGenerator.cpp
@@ -178,17 +178,7 @@ void WorldGenerator::placeLine(const LinePlacement& line) {
     for (int cz = cza; cz <= czb; cz++) {
         for (int cx = cxa; cx <= cxb; cx++) {
             auto& otherPrototype = requirePrototype(cx, cz);
-            auto chunkAABB = gen_chunk_aabb(cx, cz);
-            chunkAABB.a -= line.radius;
-            chunkAABB.b += line.radius;
-            auto found = util::closest_point_on_segment(line.a, line.b, {
-                cx * CHUNK_W + CHUNK_W / 2,
-                0,
-                cz * CHUNK_D + CHUNK_D / 2
-            });
-            if (chunkAABB.contains(found)) {
-                otherPrototype.lines.push_back(line);
-            }
+            otherPrototype.lines.push_back(line);
         }
     }
 }
@@ -315,6 +305,14 @@ void WorldGenerator::update(int centerX, int centerY, int loadDistance) {
     surroundMap.setCenter(centerX, centerY);
 }
 
+/// @return integer square of distance between two points
+/// @note glm::distance2 does not support integer vectors
+static inline int distance2(const glm::ivec3& a, const glm::ivec3& b) {
+    return (b.x - a.x) * (b.x - a.x) +
+           (b.y - a.y) * (b.y - a.y) +
+           (b.z - a.z) * (b.z - a.z);
+}
+
 void WorldGenerator::generate(voxel* voxels, int chunkX, int chunkZ) {
     surroundMap.completeAt(chunkX, chunkZ);
 
@@ -391,15 +389,32 @@ void WorldGenerator::generate(voxel* voxels, int chunkX, int chunkZ) {
         }
     }
     for (const auto& line : prototype.lines) {
-        int minY = std::max(0, std::min(line.a.y-line.radius, line.b.y-line.radius));
-        int maxY = std::min(CHUNK_H, std::max(line.a.y+line.radius, line.b.y+line.radius));
-        for (int y = minY; y < maxY; y++) {
-            for (int z = 0; z < CHUNK_D; z++) {
-                for (int x = 0; x < CHUNK_W; x++) {
-                    int gx = x + chunkX * CHUNK_W;
-                    int gz = z + chunkZ * CHUNK_D;
+        int cgx = chunkX * CHUNK_W;
+        int cgz = chunkZ * CHUNK_D;
 
-                    if (glm::distance2(util::closest_point_on_segment(line.a, line.b, {gx, y, gz}), {gx, y, gz}) <= line.radius*line.radius) {
+        int radius = line.radius;
+
+        int minX = std::max(0, std::min(line.a.x-radius-cgx, line.b.x-radius-cgx));
+        int maxX = std::min(CHUNK_W, std::max(line.a.x+radius-cgx, line.b.x+radius-cgx));
+
+        int minZ = std::max(0, std::min(line.a.z-radius-cgz, line.b.z-radius-cgz));
+        int maxZ = std::min(CHUNK_D, std::max(line.a.z+radius-cgz, line.b.z+radius-cgz));
+
+        int minY = std::max(0, std::min(line.a.y-radius, line.b.y-radius));
+        int maxY = std::min(CHUNK_H, std::max(line.a.y+radius, line.b.y+radius));
+
+        auto a = line.a;
+        auto b = line.b;
+
+        for (int y = minY; y < maxY; y++) {
+            for (int z = minZ; z < maxZ; z++) {
+                for (int x = minX; x < maxX; x++) {
+                    int gx = x + cgx;
+                    int gz = z + cgz;
+                    glm::ivec3 point {gx, y, gz};
+                    glm::ivec3 closest = util::closest_point_on_segment(
+                        a, b, point);
+                    if (distance2(closest, point) <= radius*radius) {
                         voxels[vox_index(x, y, z)] = {line.block, {}};
                     }
                 }