LibGL: Implement `glLightModel` integer normalization

For the ambient light model, integers need to be remapped to a range of
`-1.` through `1.`. Add the `+` and `-` operators to `VectorN` to make
it a bit easier to normalize 4 values at once.

1 files changed, 20 insertions, 0 deletions

diff --git a/Userland/Libraries/LibGfx/VectorN.h b/Userland/Libraries/LibGfx/VectorN.h
index 7e67a72695..687c0ea7df 100644
--- a/Userland/Libraries/LibGfx/VectorN.h
+++ b/Userland/Libraries/LibGfx/VectorN.h
@@ -159,6 +159,26 @@ public:
     }
 
     template<typename U>
+    [[nodiscard]] constexpr VectorN operator+(U f) const
+    {
+        VectorN result;
+        UNROLL_LOOP
+        for (auto i = 0u; i < N; ++i)
+            result.m_data[i] = m_data[i] + f;
+        return result;
+    }
+
+    template<typename U>
+    [[nodiscard]] constexpr VectorN operator-(U f) const
+    {
+        VectorN result;
+        UNROLL_LOOP
+        for (auto i = 0u; i < N; ++i)
+            result.m_data[i] = m_data[i] - f;
+        return result;
+    }
+
+    template<typename U>
     [[nodiscard]] constexpr VectorN operator*(U f) const
     {
         VectorN result;