- fix incorrect m44 * m34 mul function, there was a typo in the 4th r…

…ow causing incorrect results

src/mat.rs

@@ -1049,10 +1049,10 @@ fn mul4x4_3x4<T: Number>(lhs: Mat4<T>, rhs: Mat34<T>) -> Mat4<T> {
             lhs.m[8] * rhs.m[2] + lhs.m[9] * rhs.m[6] + lhs.m[10] * rhs.m[10],
             lhs.m[8] * rhs.m[3] + lhs.m[9] * rhs.m[7] + lhs.m[10] * rhs.m[11] + lhs.m[11],
 
-            lhs.m[12] * rhs.m[0] + lhs.m[10] * rhs.m[4] + lhs.m[14] * rhs.m[8],
-            lhs.m[12] * rhs.m[1] + lhs.m[10] * rhs.m[5] + lhs.m[14] * rhs.m[9],
-            lhs.m[12] * rhs.m[2] + lhs.m[10] * rhs.m[6] + lhs.m[14] * rhs.m[10],
-            lhs.m[12] * rhs.m[3] + lhs.m[10] * rhs.m[7] + lhs.m[14] * rhs.m[11] + lhs.m[15],
+            lhs.m[12] * rhs.m[0] + lhs.m[13] * rhs.m[4] + lhs.m[14] * rhs.m[8],
+            lhs.m[12] * rhs.m[1] + lhs.m[13] * rhs.m[5] + lhs.m[14] * rhs.m[9],
+            lhs.m[12] * rhs.m[2] + lhs.m[13] * rhs.m[6] + lhs.m[14] * rhs.m[10],
+            lhs.m[12] * rhs.m[3] + lhs.m[13] * rhs.m[7] + lhs.m[14] * rhs.m[11] + lhs.m[15],
         ]
     }
 }

tests/tests.rs

@@ -1712,6 +1712,30 @@ fn matrix_mul() {
     assert_eq!(Mat4f::approx(m4ref * mi, expected, 0.001), true);
     assert_eq!(Mat4f::approx(m4 * miref, expected, 0.001), true);
     assert_eq!(Mat4f::approx(m4ref * miref, expected, 0.001), true);
+
+    // 3x4 * 4x4 parity with 4x4 * 4x4
+
+    let m34 = Mat34f::new(
+        -0.00078125, 0.0, 0.00078125, 0.0,
+        0.00072463776, 0.0014492755, 0.00072463776, 0.0,
+        0.00037593985, -0.00037593985, 0.00037593985, 0.5
+    );
+
+    let m44 = Mat4f::new(
+        -0.00078125, 0.0, 0.00078125, 0.0,
+        0.00072463776, 0.0014492755, 0.00072463776, 0.0,
+        0.00037593985, -0.00037593985, 0.00037593985, 0.5,
+        0.0, 0.0, 0.0, 1.0
+    );
+
+    let proj = Mat4f::new(
+        0.0013531648, 0.0, 0.0, -0.0,
+        0.0, 0.0021739134, 0.0, -0.0,
+        0.0, 0.0, -0.0006511469, 0.5,
+        0.0, 0.0, 0.0, 1.0
+    );
+
+    assert_eq!(proj * m34, proj * m44);
 }
 
 #[test]