pose to bone transform

examples/parse.rs

@@ -1,3 +1,4 @@
+use cgmath::{Matrix4, Quaternion};
 use std::env::args;
 use std::fs;
 use std::path::PathBuf;
@@ -22,7 +23,10 @@ fn main() -> Result<(), vmdl::ModelError> {
     for bone in mdl.bones {
         println!(
             "{}: from {} at\n\t{:?}\n\t{:?}",
-            bone.name, bone.parent, bone.rot, bone.contents
+            bone.name,
+            bone.parent,
+            bone.quaternion,
+            bone.pose_to_bone.rotation()
         );
     }
 

src/mdl/raw/bones.rs

@@ -1,4 +1,4 @@
-use crate::{ModelError, Quaternion, RadianEuler, ReadRelative, Readable, Vector};
+use crate::{ModelError, Quaternion, RadianEuler, ReadRelative, Readable, Transform3x4, Vector};
 use bitflags::bitflags;
 use bytemuck::{Pod, Zeroable};
 use num_enum::TryFromPrimitive;
@@ -17,7 +17,7 @@ pub struct BoneHeader {
     pub pos_scale: Vector,
     pub rot_scale: Vector,
 
-    pub pose_to_bone: [[f32; 3]; 4], // 3x4 matrix
+    pub pose_to_bone: Transform3x4,
     pub q_alignment: Quaternion,
     pub flags: BoneFlags,
     pub proc_type: i32,
@@ -45,7 +45,7 @@ pub struct Bone {
     pub pos_scale: Vector,
     pub rot_scale: Vector,
 
-    pub pose_to_bone: [[f32; 3]; 4], // 3x4 matrix
+    pub pose_to_bone: Transform3x4,
     pub q_alignment: Quaternion,
     pub flags: BoneFlags,
     pub procedural_rules: Option<ProceduralBone>,

src/shared.rs

@@ -1,7 +1,7 @@
 use crate::{ModelError, StringError};
 use arrayvec::ArrayString;
 use bytemuck::{Pod, Zeroable};
-use cgmath::{Deg, Euler, Rad, Rotation3, Vector3};
+use cgmath::{Deg, Euler, Matrix3, Matrix4, Rad, Rotation3, Vector3};
 use std::fmt;
 use std::fmt::{Display, Formatter};
 use std::ops::{Add, Mul};
@@ -199,3 +199,53 @@ impl<const LEN: usize> Display for FixedString<LEN> {
         Display::fmt(&self.0, f)
     }
 }
+
+#[derive(Debug, Clone, Copy, Zeroable, Pod, PartialEq)]
+#[repr(C)]
+pub struct Transform3x4 {
+    transform: [[f32; 4]; 3],
+}
+
+impl Transform3x4 {
+    pub fn rotation_matrix(&self) -> Matrix3<f32> {
+        Matrix3 {
+            x: Vector3 {
+                x: self.transform[0][0],
+                y: self.transform[0][1],
+                z: self.transform[0][2],
+            },
+            y: Vector3 {
+                x: self.transform[1][0],
+                y: self.transform[1][1],
+                z: self.transform[1][2],
+            },
+            z: Vector3 {
+                x: self.transform[2][0],
+                y: self.transform[2][1],
+                z: self.transform[2][2],
+            },
+        }
+    }
+
+    pub fn rotation(&self) -> Quaternion {
+        cgmath::Quaternion::from(self.rotation_matrix()).into()
+    }
+
+    pub fn translate(&self) -> Vector {
+        [
+            self.transform[0][3],
+            self.transform[1][3],
+            self.transform[2][3],
+        ]
+        .into()
+    }
+}
+
+impl From<Transform3x4> for Matrix4<f32> {
+    fn from(value: Transform3x4) -> Self {
+        let translate = value.translate();
+        let rotate = value.rotation_matrix();
+        let rotate = Matrix4::from(rotate);
+        rotate * Matrix4::from_translation(translate.into())
+    }
+}