LibGfx: Add CMYKBitmap

This is a simple container for 2d CMYK data.

This is a new class instead of a new format in Bitmap because:
* Almost all clients of Bitmap will want to deal with RGB data
* It keeps the ARGB32 typedef working
* Bitmap already does a lot of things

The idea is that a few select places will be able to use
CMYKBitmap and a color profile to do a better CMYK -> RGB conversion
than an image decoder could do, and then store the result in a Bitmap
for later display then.

CMYKBitmap misses some of Bitmap's features, such as shared
memory support, high-dpi scaling capability, etc.

Userland/Libraries/LibGfx/CMYKBitmap.cpp

@@ -0,0 +1,18 @@
+/*
+ * Copyright (c) 2024, Nico Weber <thakis@chromium.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <LibGfx/CMYKBitmap.h>
+
+namespace Gfx {
+
+ErrorOr<NonnullRefPtr<CMYKBitmap>> CMYKBitmap::create_with_size(IntSize const& size)
+{
+    VERIFY(size.width() >= 0 && size.height() >= 0);
+    auto data = TRY(ByteBuffer::create_uninitialized(size.width() * size.height() * sizeof(CMYK)));
+    return adopt_ref(*new CMYKBitmap(size, move(data)));
+}
+
+}

Userland/Libraries/LibGfx/CMYKBitmap.h

@@ -0,0 +1,68 @@
+/*
+ * Copyright (c) 2024, Nico Weber <thakis@chromium.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <AK/ByteBuffer.h>
+#include <AK/NonnullRefPtr.h>
+#include <AK/RefCounted.h>
+#include <LibGfx/Size.h>
+
+namespace Gfx {
+
+struct CMYK {
+    u8 c;
+    u8 m;
+    u8 y;
+    u8 k;
+};
+
+class CMYKBitmap : public RefCounted<CMYKBitmap> {
+public:
+    static ErrorOr<NonnullRefPtr<CMYKBitmap>> create_with_size(IntSize const& size);
+
+    IntSize const& size() const { return m_size; }
+
+    [[nodiscard]] CMYK* scanline(int y);
+    [[nodiscard]] CMYK const* scanline(int y) const;
+
+    [[nodiscard]] CMYK* begin();
+    [[nodiscard]] CMYK* end();
+
+private:
+    CMYKBitmap(IntSize const& size, ByteBuffer data)
+        : m_size(size)
+        , m_data(move(data))
+    {
+    }
+
+    IntSize m_size;
+    ByteBuffer m_data;
+};
+
+inline CMYK* CMYKBitmap::scanline(int y)
+{
+    VERIFY(y >= 0 && y < m_size.height());
+    return reinterpret_cast<CMYK*>(m_data.data() + y * m_size.width() * sizeof(CMYK));
+}
+
+inline CMYK const* CMYKBitmap::scanline(int y) const
+{
+    VERIFY(y >= 0 && y < m_size.height());
+    return reinterpret_cast<CMYK const*>(m_data.data() + y * m_size.width() * sizeof(CMYK));
+}
+
+inline CMYK* CMYKBitmap::begin()
+{
+    return reinterpret_cast<CMYK*>(m_data.data());
+}
+
+inline CMYK* CMYKBitmap::end()
+{
+    return reinterpret_cast<CMYK*>(m_data.data() + m_data.size());
+}
+
+}

Userland/Libraries/LibGfx/CMakeLists.txt

@@ -3,6 +3,7 @@ set(SOURCES
     AntiAliasingPainter.cpp
     Bitmap.cpp
     BitmapMixer.cpp
+    CMYKBitmap.cpp
     ClassicStylePainter.cpp
     ClassicWindowTheme.cpp
     Color.cpp

Userland/Libraries/LibGfx/Forward.h

@@ -9,6 +9,7 @@
 namespace Gfx {
 
 class Bitmap;
+class CMYKBitmap;
 class ImmutableBitmap;
 class CharacterBitmap;
 class Color;