From 358658fa34b9907f03ab59c601e6777573525a04 Mon Sep 17 00:00:00 2001
From: sfan5 <sfan5@live.de>
Date: Sat, 1 Mar 2025 22:13:33 +0100
Subject: [PATCH] Fix cloud-related bugs

First, this reverts 56123b2fbe1ad4e7878556f8d51c551d84fb92e7,
which un-fixes #15031 but fixes #15798 and #15854.

Then we disable culling for the cloud scene node which fixes #15031 again.
---
 src/client/clouds.cpp | 26 +++++++++++++++++++++++---
 src/client/clouds.h   |  7 +++++--
 2 files changed, 28 insertions(+), 5 deletions(-)

diff --git a/src/client/clouds.cpp b/src/client/clouds.cpp
index b65970f95..18b1d281c 100644
--- a/src/client/clouds.cpp
+++ b/src/client/clouds.cpp
@@ -52,6 +52,13 @@ Clouds::Clouds(scene::ISceneManager* mgr, IShaderSource *ssrc,
 
 	updateBox();
 
+	// Neither EAC_BOX (the default) nor EAC_FRUSTUM_BOX will correctly cull
+	// the clouds.
+	// And yes, the bounding box is correct. You can check using the #if 0'd
+	// code in render() and see for yourself.
+	// So I give up and let's disable culling.
+	setAutomaticCulling(scene::EAC_OFF);
+
 	m_meshbuffer.reset(new scene::SMeshBuffer());
 	m_meshbuffer->setHardwareMappingHint(scene::EHM_DYNAMIC);
 }
@@ -366,6 +373,19 @@ void Clouds::render()
 	if (SceneManager->getSceneNodeRenderPass() != scene::ESNRP_TRANSPARENT)
 		return;
 
+#if 0
+	{
+		video::SMaterial tmp;
+		tmp.Thickness = 1.f;
+		driver->setTransform(video::ETS_WORLD, core::IdentityMatrix);
+		driver->setMaterial(tmp);
+		aabb3f tmpbox = m_box;
+		tmpbox.MinEdge.X = tmpbox.MinEdge.Z = -1000 * BS;
+		tmpbox.MaxEdge.X = tmpbox.MaxEdge.Z = 1000 * BS;
+		driver->draw3DBox(tmpbox, video::SColor(255, 255, 0x4d, 0));
+	}
+#endif
+
 	updateMesh();
 
 	// Update position
@@ -425,14 +445,14 @@ void Clouds::update(const v3f &camera_p, const video::SColorf &color_diffuse)
 
 	// is the camera inside the cloud mesh?
 	m_camera_pos = camera_p;
-	m_camera_inside_cloud = false; // default
+	m_camera_inside_cloud = false;
 	if (is3D()) {
 		float camera_height = camera_p.Y - BS * m_camera_offset.Y;
 		if (camera_height >= m_box.MinEdge.Y &&
 				camera_height <= m_box.MaxEdge.Y) {
 			v2f camera_in_noise;
-			camera_in_noise.X = floor((camera_p.X - m_origin.X) / cloud_size + 0.5);
-			camera_in_noise.Y = floor((camera_p.Z - m_origin.Y) / cloud_size + 0.5);
+			camera_in_noise.X = floorf((camera_p.X - m_origin.X) / cloud_size + 0.5f);
+			camera_in_noise.Y = floorf((camera_p.Z - m_origin.Y) / cloud_size + 0.5f);
 			bool filled = gridFilled(camera_in_noise.X, camera_in_noise.Y);
 			m_camera_inside_cloud = filled;
 		}
diff --git a/src/client/clouds.h b/src/client/clouds.h
index d081a4853..ea5c18394 100644
--- a/src/client/clouds.h
+++ b/src/client/clouds.h
@@ -134,8 +134,11 @@ private:
 	{
 		float height_bs    = m_params.height    * BS;
 		float thickness_bs = m_params.thickness * BS;
-		m_box = aabb3f(-BS * 1000000.0f, height_bs, -BS * 1000000.0f,
-				BS * 1000000.0f, height_bs + thickness_bs, BS * 1000000.0f);
+		float far_bs       = 1000000.0f         * BS;
+		m_box = aabb3f(-far_bs, height_bs, -far_bs,
+			far_bs, height_bs + thickness_bs, far_bs);
+		m_box.MinEdge -= v3f::from(m_camera_offset) * BS;
+		m_box.MaxEdge -= v3f::from(m_camera_offset) * BS;
 	}
 
 	void updateMesh();