LibGfx: Add simple VectorGraphic abstract base class

This is currently very bare-bones with just the size and a few methods
to rasterize/draw the graphic.

Userland/Libraries/LibGfx/CMakeLists.txt

@@ -64,6 +64,7 @@ set(SOURCES
     TextDirection.cpp
     TextLayout.cpp
     Triangle.cpp
+    VectorGraphic.cpp
     WindowTheme.cpp
 )
 

Userland/Libraries/LibGfx/VectorGraphic.cpp

@@ -0,0 +1,35 @@
+/*
+ * Copyright (c) 2023, MacDue <macdue@dueutil.tech>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <LibGfx/Painter.h>
+#include <LibGfx/VectorGraphic.h>
+
+namespace Gfx {
+
+void VectorGraphic::draw_into(Painter& painter, IntRect const& dest, AffineTransform transform) const
+{
+    // Apply the transform then center within destination rectangle (this ignores any translation from the transform):
+    // This allows you to easily rotate or flip the image before painting.
+    auto transformed_rect = transform.map(FloatRect { {}, size() });
+    auto scale = min(float(dest.width()) / transformed_rect.width(), float(dest.height()) / transformed_rect.height());
+    auto centered = FloatRect { {}, transformed_rect.size().scaled_by(scale) }.centered_within(dest.to_type<float>());
+    auto view_transform = AffineTransform {}
+                              .translate(centered.location())
+                              .multiply(AffineTransform {}.scale(scale, scale))
+                              .multiply(AffineTransform {}.translate(-transformed_rect.location()))
+                              .multiply(transform);
+    return draw_transformed(painter, view_transform);
+}
+
+ErrorOr<NonnullRefPtr<Gfx::Bitmap>> VectorGraphic::bitmap(IntSize size, AffineTransform transform) const
+{
+    auto bitmap = TRY(Bitmap::create(Gfx::BitmapFormat::BGRA8888, size));
+    Painter painter { *bitmap };
+    draw_into(painter, IntRect { {}, size }, transform);
+    return bitmap;
+}
+
+}

Userland/Libraries/LibGfx/VectorGraphic.h

@@ -0,0 +1,30 @@
+/*
+ * Copyright (c) 2023, MacDue <macdue@dueutil.tech>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <AK/RefCounted.h>
+#include <LibGfx/Bitmap.h>
+#include <LibGfx/Forward.h>
+#include <LibGfx/Size.h>
+
+namespace Gfx {
+
+class VectorGraphic : public RefCounted<VectorGraphic> {
+public:
+    virtual IntSize intrinsic_size() const = 0;
+    virtual void draw_transformed(Painter&, AffineTransform) const = 0;
+
+    IntSize size() const { return intrinsic_size(); }
+    IntRect rect() const { return { {}, size() }; }
+
+    ErrorOr<NonnullRefPtr<Gfx::Bitmap>> bitmap(IntSize size, AffineTransform = {}) const;
+    void draw_into(Painter&, IntRect const& dest, AffineTransform = {}) const;
+
+    virtual ~VectorGraphic() = default;
+};
+
+};