LibGL+LibSoftGPU+LibGfx: Reimplement normal transformation

We now support generating top-left submatrices from a `Gfx::Matrix`
and we move the normal transformation calculation into
`SoftGPU::Device`. No functional changes.

1 files changed, 14 insertions, 0 deletions

diff --git a/Userland/Libraries/LibGfx/Matrix.h b/Userland/Libraries/LibGfx/Matrix.h
index 2e251de293..78be55f48f 100644
--- a/Userland/Libraries/LibGfx/Matrix.h
+++ b/Userland/Libraries/LibGfx/Matrix.h
@@ -13,6 +13,9 @@ namespace Gfx {
 
 template<size_t N, typename T>
 class Matrix {
+    template<size_t U, typename V>
+    friend class Matrix;
+
 public:
     static constexpr size_t Size = N;
 
@@ -173,6 +176,17 @@ public:
         return result;
     }
 
+    template<size_t U>
+    [[nodiscard]] constexpr Matrix<U, T> submatrix_from_topleft() const requires(U > 0 && U < N)
+    {
+        Matrix<U, T> result;
+        for (size_t i = 0; i < U; ++i) {
+            for (size_t j = 0; j < U; ++j)
+                result.m_elements[i][j] = m_elements[i][j];
+        }
+        return result;
+    }
+
 private:
     T m_elements[N][N];
 };