serenity/Userland/Applications/PixelPaint/Mask.h
Jelle Raaijmakers f391ccfe53 LibGfx+Everywhere: Change Gfx::Rect to be endpoint exclusive
Previously, calling `.right()` on a `Gfx::Rect` would return the last
column's coordinate still inside the rectangle, or `left + width - 1`.
This is called 'endpoint inclusive' and does not make a lot of sense for
`Gfx::Rect<float>` where a rectangle of width 5 at position (0, 0) would
return 4 as its right side. This same problem exists for `.bottom()`.

This changes `Gfx::Rect` to be endpoint exclusive, which gives us the
nice property that `width = right - left` and `height = bottom - top`.
It enables us to treat `Gfx::Rect<int>` and `Gfx::Rect<float>` exactly
the same.

All users of `Gfx::Rect` have been updated accordingly.
2023-05-23 12:35:42 +02:00

123 lines
3.6 KiB
C++

/*
* Copyright (c) 2021, Davipb <daviparca@gmail.com>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <AK/Vector.h>
#include <LibGfx/Point.h>
#include <LibGfx/Rect.h>
namespace PixelPaint {
class Mask {
public:
Mask() = default;
Mask(Mask const&) = default;
Mask& operator=(Mask const&) = default;
Mask(Mask&&) = default;
Mask& operator=(Mask&&) = default;
[[nodiscard]] static Mask empty(Gfx::IntRect rect) { return { rect, 0x00 }; }
[[nodiscard]] static Mask full(Gfx::IntRect rect) { return { rect, 0xFF }; }
[[nodiscard]] bool is_null() const { return m_data.is_empty(); }
[[nodiscard]] Gfx::IntRect bounding_rect() const { return m_bounding_rect; }
[[nodiscard]] u8 get(int x, int y) const
{
if (is_null() || !m_bounding_rect.contains(x, y))
return 0;
return m_data[to_index(x, y)];
}
[[nodiscard]] u8 get(Gfx::IntPoint point) const { return get(point.x(), point.y()); }
[[nodiscard]] float getf(int x, int y) const { return (float)get(x, y) / 255.0f; }
[[nodiscard]] float getf(Gfx::IntPoint point) const { return getf(point.x(), point.y()); }
void set(int x, int y, u8 value)
{
VERIFY(!is_null());
VERIFY(m_bounding_rect.contains(x, y));
m_data[to_index(x, y)] = value;
}
void set(Gfx::IntPoint point, u8 value) { set(point.x(), point.y(), value); }
void setf(int x, int y, float value) { set(x, y, (u8)clamp(value * 255.0f, 0.0f, 255.0f)); }
void setf(Gfx::IntPoint point, float value) { setf(point.x(), point.y(), value); }
void shrink_to_fit();
[[nodiscard]] Mask with_bounding_rect(Gfx::IntRect) const;
void invert();
void add(Mask const& other);
void subtract(Mask const& other);
void intersect(Mask const& other);
template<typename Func>
void for_each_pixel(Func func) const
{
for (int x = m_bounding_rect.left(); x < m_bounding_rect.right(); x++) {
for (int y = m_bounding_rect.top(); y < m_bounding_rect.bottom(); y++)
func(x, y);
}
}
private:
Gfx::IntRect m_bounding_rect {};
Vector<u8> m_data {};
Mask(Gfx::IntRect, u8 default_value);
[[nodiscard]] size_t to_index(int x, int y) const
{
VERIFY(m_bounding_rect.contains(x, y));
int dx = x - m_bounding_rect.x();
int dy = y - m_bounding_rect.y();
return dy * m_bounding_rect.width() + dx;
}
template<typename Func>
void combine(Mask const& other, Func func)
{
auto new_bounding_rect = m_bounding_rect.united(other.m_bounding_rect);
auto new_me = Mask::empty(new_bounding_rect);
new_me.for_each_pixel([&](auto x, auto y) {
// Widen to int then clamp before narrowing back to avoid annoying overflow checks in the combine functions
auto my_alpha = static_cast<int>(get(x, y));
auto other_alpha = static_cast<int>(other.get(x, y));
auto new_alpha = static_cast<u8>(clamp(func(my_alpha, other_alpha), 0, 0xFF));
new_me.set(x, y, new_alpha);
});
*this = move(new_me);
shrink_to_fit();
}
template<typename Func>
void combinef(Mask const& other, Func func)
{
auto new_bounding_rect = m_bounding_rect.united(other.m_bounding_rect);
auto new_me = Mask::empty(new_bounding_rect);
new_me.for_each_pixel([&](auto x, auto y) {
auto my_alpha = getf(x, y);
auto other_alpha = other.getf(x, y);
auto new_alpha = func(my_alpha, other_alpha);
new_me.setf(x, y, new_alpha);
});
*this = move(new_me);
shrink_to_fit();
}
};
}