LibGL: Turn Sampler2D into an actual class

This extracts the sampler functionality into its own class.
Beginning with OpenGL 3 samplers are actual objects, separate
from textures. It makes sense to do this already as it also
cleans up code organization quite a bit.

Userland/Libraries/LibGL/Tex/Sampler2D.h

@@ -0,0 +1,44 @@
+/*
+ * Copyright (c) 2021, Stephan Unverwerth <s.unverwerth@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <LibGL/GL/gl.h>
+#include <LibGfx/Vector2.h>
+#include <LibGfx/Vector4.h>
+
+namespace GL {
+
+class Texture2D;
+
+class Sampler2D final {
+public:
+    Sampler2D(Texture2D const& texture)
+        : m_texture(texture)
+    {
+    }
+
+    GLint min_filter() const { return m_min_filter; }
+    GLint mag_filter() const { return m_mag_filter; }
+    GLint wrap_s_mode() const { return m_wrap_s_mode; }
+    GLint wrap_t_mode() const { return m_wrap_t_mode; }
+
+    void set_min_filter(GLint value) { m_min_filter = value; }
+    void set_mag_filter(GLint value) { m_mag_filter = value; }
+    void set_wrap_s_mode(GLint value) { m_wrap_s_mode = value; }
+    void set_wrap_t_mode(GLint value) { m_wrap_t_mode = value; }
+
+    FloatVector4 sample(FloatVector2 const& uv) const;
+
+private:
+    Texture2D const& m_texture;
+
+    GLint m_min_filter { GL_NEAREST_MIPMAP_LINEAR };
+    GLint m_mag_filter { GL_LINEAR };
+    GLint m_wrap_s_mode { GL_REPEAT };
+    GLint m_wrap_t_mode { GL_REPEAT };
+};
+}