ifc_lite_geometry/processors/
extrusion.rs

1// This Source Code Form is subject to the terms of the Mozilla Public
2// License, v. 2.0. If a copy of the MPL was not distributed with this
3// file, You can obtain one at https://mozilla.org/MPL/2.0/.
4
5//! ExtrudedAreaSolid processor - extrusion of 2D profiles.
6
7use crate::{
8    extrusion::{apply_transform, extrude_profile},
9    profiles::ProfileProcessor,
10    Error, Mesh, Result, Vector3,
11};
12use ifc_lite_core::{DecodedEntity, EntityDecoder, IfcSchema, IfcType};
13use nalgebra::Matrix4;
14
15use crate::router::GeometryProcessor;
16use super::helpers::parse_axis2_placement_3d;
17
18/// ExtrudedAreaSolid processor (P0)
19/// Handles IfcExtrudedAreaSolid - extrusion of 2D profiles
20pub struct ExtrudedAreaSolidProcessor {
21    profile_processor: ProfileProcessor,
22}
23
24impl ExtrudedAreaSolidProcessor {
25    /// Create new processor
26    pub fn new(schema: IfcSchema) -> Self {
27        Self {
28            profile_processor: ProfileProcessor::new(schema),
29        }
30    }
31}
32
33impl GeometryProcessor for ExtrudedAreaSolidProcessor {
34    fn process(
35        &self,
36        entity: &DecodedEntity,
37        decoder: &mut EntityDecoder,
38        _schema: &IfcSchema,
39    ) -> Result<Mesh> {
40        // IfcExtrudedAreaSolid attributes:
41        // 0: SweptArea (IfcProfileDef)
42        // 1: Position (IfcAxis2Placement3D)
43        // 2: ExtrudedDirection (IfcDirection)
44        // 3: Depth (IfcPositiveLengthMeasure)
45
46        // Get profile
47        let profile_attr = entity
48            .get(0)
49            .ok_or_else(|| Error::geometry("ExtrudedAreaSolid missing SweptArea".to_string()))?;
50
51        let profile_entity = decoder
52            .resolve_ref(profile_attr)?
53            .ok_or_else(|| Error::geometry("Failed to resolve SweptArea".to_string()))?;
54
55        let profile = self.profile_processor.process(&profile_entity, decoder)?;
56
57        if profile.outer.is_empty() {
58            return Ok(Mesh::new());
59        }
60
61        // Get extrusion direction
62        let direction_attr = entity.get(2).ok_or_else(|| {
63            Error::geometry("ExtrudedAreaSolid missing ExtrudedDirection".to_string())
64        })?;
65
66        let direction_entity = decoder
67            .resolve_ref(direction_attr)?
68            .ok_or_else(|| Error::geometry("Failed to resolve ExtrudedDirection".to_string()))?;
69
70        if direction_entity.ifc_type != IfcType::IfcDirection {
71            return Err(Error::geometry(format!(
72                "Expected IfcDirection, got {}",
73                direction_entity.ifc_type
74            )));
75        }
76
77        // Parse direction
78        let ratios_attr = direction_entity
79            .get(0)
80            .ok_or_else(|| Error::geometry("IfcDirection missing ratios".to_string()))?;
81
82        let ratios = ratios_attr
83            .as_list()
84            .ok_or_else(|| Error::geometry("Expected ratio list".to_string()))?;
85
86        use ifc_lite_core::AttributeValue;
87        let dir_x = ratios
88            .first()
89            .and_then(|v: &AttributeValue| v.as_float())
90            .unwrap_or(0.0);
91        let dir_y = ratios
92            .get(1)
93            .and_then(|v: &AttributeValue| v.as_float())
94            .unwrap_or(0.0);
95        let dir_z = ratios
96            .get(2)
97            .and_then(|v: &AttributeValue| v.as_float())
98            .unwrap_or(1.0);
99
100        let local_direction = Vector3::new(dir_x, dir_y, dir_z).normalize();
101
102        // Get depth
103        let depth = entity
104            .get_float(3)
105            .ok_or_else(|| Error::geometry("ExtrudedAreaSolid missing Depth".to_string()))?;
106
107        // Parse Position transform first (attribute 1: IfcAxis2Placement3D)
108        // We need Position's rotation to transform ExtrudedDirection to world coordinates
109        let pos_transform = if let Some(pos_attr) = entity.get(1) {
110            if !pos_attr.is_null() {
111                if let Some(pos_entity) = decoder.resolve_ref(pos_attr)? {
112                    if pos_entity.ifc_type == IfcType::IfcAxis2Placement3D {
113                        Some(parse_axis2_placement_3d(&pos_entity, decoder)?)
114                    } else {
115                        None
116                    }
117                } else {
118                    None
119                }
120            } else {
121                None
122            }
123        } else {
124            None
125        };
126
127        // ExtrudedDirection is in the LOCAL coordinate system (before Position transform).
128        // We need to determine when to add an extrusion rotation vs. letting Position handle it.
129        //
130        // Two key cases:
131        // 1. Opening: local_direction=(0,0,-1), Position rotates local Z to world Y
132        //    -> local_direction IS along Z, so no rotation needed; Position handles orientation
133        // 2. Roof slab: local_direction=(0,-0.5,0.866), Position tilts the profile
134        //    -> world_direction = Position.rotation * local_direction = (0,0,1) (along world Z!)
135        //    -> No extra rotation needed; Position handles the tilt
136        //
137        // Check if local direction is along Z axis
138        // Note: We only check local direction because extrusion happens in LOCAL coordinates
139        // before the Position transform is applied. What the direction becomes in world
140        // space is irrelevant to the extrusion operation.
141        let is_local_z_aligned = local_direction.x.abs() < 0.001 && local_direction.y.abs() < 0.001;
142
143        let transform = if is_local_z_aligned {
144            // Local direction is along Z - no extra rotation needed.
145            // Position transform will handle the correct orientation.
146            // Only need translation if extruding in negative direction.
147            if local_direction.z < 0.0 {
148                // Downward extrusion: shift the extrusion down by depth
149                Some(Matrix4::new_translation(&Vector3::new(0.0, 0.0, -depth)))
150            } else {
151                None
152            }
153        } else {
154            // Local direction is NOT along Z - use SHEAR matrix (not rotation!)
155            // A shear preserves the profile plane orientation while redirecting extrusion.
156            //
157            // For ExtrudedDirection (dx, dy, dz), the shear matrix is:
158            // | 1    0    dx |
159            // | 0    1    dy |
160            // | 0    0    dz |
161            //
162            // This transforms (x, y, depth) to (x + dx*depth, y + dy*depth, dz*depth)
163            // while keeping (x, y, 0) unchanged.
164            let mut shear_mat = Matrix4::identity();
165            shear_mat[(0, 2)] = local_direction.x;  // X shear from Z
166            shear_mat[(1, 2)] = local_direction.y;  // Y shear from Z
167            shear_mat[(2, 2)] = local_direction.z;  // Z scale
168
169            Some(shear_mat)
170        };
171
172        // Extrude the profile
173        let mut mesh = extrude_profile(&profile, depth, transform)?;
174
175        // Apply Position transform
176        if let Some(pos) = pos_transform {
177            apply_transform(&mut mesh, &pos);
178        }
179
180        Ok(mesh)
181    }
182
183    fn supported_types(&self) -> Vec<IfcType> {
184        vec![IfcType::IfcExtrudedAreaSolid]
185    }
186}
ifc_lite_geometry/processors/extrusion.rs

ifc_lite_geometry/processors/
extrusion.rs
