1 files changed, 35 insertions, 7 deletions

diff --git a/src/world.c b/src/world.c
index 2130468..fa676c8 100644
--- a/src/world.c
+++ b/src/world.c
@@ -473,6 +473,22 @@ Seed generateWorldPlants(World* world, Seed seed, int start, int end)
   return seed;
 }
 
+// Use sin wave for computing pole positions.
+// Does not set y position.
+// Index as in World.utilityPoleTransforms index.
+Vector3 utilityPoleIndexToPosition(int index, const World* world)
+{
+  float centerZ = (float)world->size.z / 2.0;
+  float spacing = (float)world->size.x / WORLD_UTILITY_POLE_COUNT;
+
+  Vector3 position;
+  position.x = index * spacing;
+  position.y = 0.0;
+  position.z = sinf(position.x) * centerZ + centerZ;
+
+  return position;
+}
+
 Seed generateWorldUtilityPoles(World* world, const Assets* assets, Seed seed,
                                int start, int end)
 {
@@ -480,20 +496,32 @@ Seed generateWorldUtilityPoles(World* world, const Assets* assets, Seed seed,
     assets->shaders[INSTANCING_SHADER];
   assets->models[UTILITY_POLE_MODEL].materials[0]
     .maps[MATERIAL_MAP_DIFFUSE].color = BROWN;
-
-  float centerZ = world->size.z / 2.0;
-  float spacing = (float)world->size.x / WORLD_UTILITY_POLE_COUNT;
   
   for (int index = start; index < end; ++index)
   {
     FT_RANDOM16(seed);
 
-    Entity entity = createEntity(UTILITY_POLE, Vector3Zero());
-    seed = putEntityInRandomPlace(world, seed, &entity);
+    Vector3 position = utilityPoleIndexToPosition(index - start, world);
+
+    // Create pole.
+    Entity entity = createEntity(UTILITY_POLE, position);
+    placeEntityOnGround(&entity, world);
     world->entities[index] = entity;
 
-    world->utilityPoleTransforms[index - start] = MatrixTranslate(
-      entity.position.x, entity.position.y, entity.position.z);
+    // Get direction to next pole.
+    Vector3 nextPosition = utilityPoleIndexToPosition(index - start + 1,
+                                                      world);
+    Matrix lookat = MatrixLookAt(position, nextPosition,
+                                 (Vector3){0.0, 1.0, 0.0});
+    // Hack for it to not effect position. Likely this isn't in a update look.
+    lookat = QuaternionToMatrix(QuaternionFromMatrix(MatrixInvert(lookat)));
+    
+    // Add pole to instancing data.
+    Matrix translation = MatrixTranslate(entity.position.x,
+                                         entity.position.y,
+                                         entity.position.z);
+    Matrix matrix = MatrixMultiply(lookat, translation);
+    world->utilityPoleTransforms[index - start] = matrix;
   }
 
   return seed;