LibGL: Return white texel when sampling uninitialized texture

Author: https://github.com/sunverwerth
Commit: 59998ff0b2
Pull-request: https://github.com/SerenityOS/serenity/pull/9451
Reviewed-by: https://github.com/Quaker762 ✅
Reviewed-by: https://github.com/alimpfard

Userland/Libraries/LibGL/Tex/MipMap.h

@@ -42,8 +42,8 @@ public:
     }
 
 private:
-    GLsizei m_width;
-    GLsizei m_height;
+    GLsizei m_width { 0 };
+    GLsizei m_height { 0 };
     Vector<u32> m_pixel_data;
 };
 }

Userland/Libraries/LibGL/Tex/Sampler2D.cpp

@@ -57,6 +57,9 @@ FloatVector4 Sampler2D::sample(FloatVector2 const& uv) const
 
     MipMap const& mip = m_texture.mipmap(lod);
 
+    if (mip.width() < 1 || mip.height() < 1)
+        return { 1, 1, 1, 1 };
+
     float x = wrap(uv.x(), m_wrap_t_mode);
     float y = wrap(uv.y(), m_wrap_s_mode);