[Bf-blender-cvs] [04496a2e01f] soc-2021-adaptive-cloth: float2x2: inverse

[ishbosamiya]

Commit: 04496a2e01f34a48e838cafe742bbbd2fe789ead
Author: ishbosamiya
Date:   Sun Sep 5 10:55:38 2021 +0530
Branches: soc-2021-adaptive-cloth
https://developer.blender.org/rB04496a2e01f34a48e838cafe742bbbd2fe789ead

float2x2: inverse

===================================================================

M	source/blender/blenlib/BLI_float2x2.hh

===================================================================

diff --git a/source/blender/blenlib/BLI_float2x2.hh b/source/blender/blenlib/BLI_float2x2.hh
index 9bf27d50d49..dd7ebe06826 100644
--- a/source/blender/blenlib/BLI_float2x2.hh
+++ b/source/blender/blenlib/BLI_float2x2.hh
@@ -215,6 +215,19 @@ struct float2x2 {
     return {q, lambda};
   }
 
+  float2x2 inverse() const
+  {
+    const auto a = this->ptr()[0][0];
+    const auto b = this->ptr()[1][0];
+    const auto c = this->ptr()[0][1];
+    const auto d = this->ptr()[1][1];
+
+    const auto det = a * d - b * c;
+    BLI_assert(det != 0.0);
+
+    return float2x2(d, -c, -b, a) * (1.0 / det);
+  }
+
   uint64_t hash() const
   {
     uint64_t h = 435109;