ladybird/SharedGraphics/GraphicsBitmap.h
Andreas Kling 9b71307d49 WindowServer: Support windows with alpha channels. And per-WSWindow opacity.
This patch also adds a Format concept to GraphicsBitmap. For now there are
only two formats: RGB32 and RGBA32. Windows with alpha channel have their
backing stores created in the RGBA32 format.

Use this to make Terminal windows semi-transparent for that comfy rice look.
There is one problem here, in that window compositing overdraw incurs
multiple passes of blending of the same pixels. This leads to a mismatch in
opacity which is obviously not good. I will work on this in a later patch.

The alpha blending is currently straight C++. It should be relatively easy
to optimize this using SSE instructions.

For now I'm just happy with the cute effect. :^)
2019-02-19 01:42:53 +01:00

54 lines
1.7 KiB
C++

#pragma once
#include "Color.h"
#include "Rect.h"
#include "Size.h"
#include <AK/Retainable.h>
#include <AK/RetainPtr.h>
#include <AK/AKString.h>
class GraphicsBitmap : public Retainable<GraphicsBitmap> {
public:
enum class Format { Invalid, RGB32, RGBA32 };
static RetainPtr<GraphicsBitmap> create(Format, const Size&);
static RetainPtr<GraphicsBitmap> create_wrapper(Format, const Size&, RGBA32*);
static RetainPtr<GraphicsBitmap> load_from_file(Format, const String& path, const Size&);
static RetainPtr<GraphicsBitmap> create_with_shared_buffer(Format, int shared_buffer_id, const Size&, RGBA32* buffer = nullptr);
~GraphicsBitmap();
RGBA32* scanline(int y);
const RGBA32* scanline(int y) const;
Rect rect() const { return { {}, m_size }; }
Size size() const { return m_size; }
int width() const { return m_size.width(); }
int height() const { return m_size.height(); }
size_t pitch() const { return m_pitch; }
int shared_buffer_id() const { return m_shared_buffer_id; }
bool has_alpha_channel() const { return m_format == Format::RGBA32; }
private:
GraphicsBitmap(Format, const Size&);
GraphicsBitmap(Format, const Size&, RGBA32*);
GraphicsBitmap(Format, int shared_buffer_id, const Size&, RGBA32*);
Size m_size;
RGBA32* m_data { nullptr };
size_t m_pitch { 0 };
Format m_format { Format::Invalid };
bool m_mmaped { false };
int m_shared_buffer_id { -1 };
};
inline RGBA32* GraphicsBitmap::scanline(int y)
{
return reinterpret_cast<RGBA32*>((((byte*)m_data) + (y * m_pitch)));
}
inline const RGBA32* GraphicsBitmap::scanline(int y) const
{
return reinterpret_cast<const RGBA32*>((((const byte*)m_data) + (y * m_pitch)));
}