LibGfx: Start a very basic anti-aliased Painter implementation

This can currently draw AA lines (and by proxy, AA paths), and passes
all its output through a 2D affine transform to an underlying
Gfx::Painter.

1 files changed, 34 insertions, 0 deletions

diff --git a/Userland/Libraries/LibGfx/AntiAliasingPainter.h b/Userland/Libraries/LibGfx/AntiAliasingPainter.h
new file mode 100644
index 0000000000..68b504b507
--- /dev/null
+++ b/Userland/Libraries/LibGfx/AntiAliasingPainter.h
@@ -0,0 +1,34 @@
+/*
+ * Copyright (c) 2021, Ali Mohammad Pur <mpfard@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <LibGfx/Painter.h>
+
+namespace Gfx {
+
+class AntiAliasingPainter {
+public:
+    explicit AntiAliasingPainter(Painter& painter)
+        : m_underlying_painter(painter)
+    {
+    }
+
+    void draw_line(FloatPoint const&, FloatPoint const&, Color, float thickness = 1, Painter::LineStyle style = Painter::LineStyle::Solid, Color alternate_color = Color::Transparent);
+    void fill_path(Path&, Color, Painter::WindingRule rule = Painter::WindingRule::Nonzero);
+    void stroke_path(Path const&, Color, float thickness);
+    void draw_quadratic_bezier_curve(FloatPoint const& control_point, FloatPoint const&, FloatPoint const&, Color, float thickness = 1, Painter::LineStyle style = Painter::LineStyle::Solid);
+    void draw_elliptical_arc(FloatPoint const& p1, FloatPoint const& p2, FloatPoint const& center, FloatPoint const& radii, float x_axis_rotation, float theta_1, float theta_delta, Color, float thickness = 1, Painter::LineStyle style = Painter::LineStyle::Solid);
+
+    void translate(float dx, float dy) { m_transform.translate(dx, dy); }
+    void translate(FloatPoint const& delta) { m_transform.translate(delta); }
+
+private:
+    Painter& m_underlying_painter;
+    AffineTransform m_transform;
+};
+
+}