genode/repos/os/include/pointer/dither_painter.h
Norman Feske c629c54153 Make util/geometry.h C++20 friendly
- Move header to base/include to make it applicable for base types
  like 'Affinity' down the road.
- Represent 'Rect' as typle of point and area, which is the most
  common form of initialization, creates in valid 'Rect' by default.
- Turn Point, Area, and Rect into compound types, making x, y, w, h, at,
  area accessible without a method call
- 'Rect::Compound' function for constructing a 'Rect' from two points,
  replacing a former constructor
- Use result type 'Rect::Cut_remainder' instead of out parameters.

Fixes #5239
2024-06-20 12:54:30 +02:00

77 lines
2.0 KiB
C++

/*
* \brief Functor for converting pixel formats by applying dithering
* \author Norman Feske
* \date 2014-09-10
*/
/*
* Copyright (C) 2014-2017 Genode Labs GmbH
*
* This file is part of the Genode OS framework, which is distributed
* under the terms of the GNU Affero General Public License version 3.
*/
#ifndef _DITHER_PAINTER_H_
#define _DITHER_PAINTER_H_
#include <util/dither_matrix.h>
#include <os/surface.h>
struct Dither_painter
{
/*
* Surface and texture must have the same size
*/
template <typename DST_PT, typename SRC_PT>
static inline void paint(Genode::Surface<DST_PT> &surface,
Genode::Texture<SRC_PT> const &texture)
{
if (surface.size() != texture.size()) return;
if (!texture.pixel() || !texture.alpha()) return;
Genode::Surface_base::Rect const clipped = surface.clip();
if (!clipped.valid()) return;
unsigned const offset = surface.size().w*clipped.y1() + clipped.x1();
DST_PT *dst, *dst_line = surface.addr() + offset;
SRC_PT const *src_pixel, *src_pixel_line = texture.pixel() + offset;
unsigned char const *src_alpha, *src_alpha_line = texture.alpha() + offset;
unsigned const line_len = surface.size().w;
for (int y = clipped.y1(), h = clipped.h() ; h--; y++) {
src_pixel = src_pixel_line;
src_alpha = src_alpha_line;
dst = dst_line;
for (int x = clipped.x1(), w = clipped.w(); w--; x++) {
int const v = Genode::Dither_matrix::value(x, y) >> 4;
SRC_PT const pixel = *src_pixel++;
unsigned char const alpha = *src_alpha++;
int const r = pixel.r() - v;
int const g = pixel.g() - v;
int const b = pixel.b() - v;
int const a = alpha ? (int)alpha - v : 0;
using Genode::min;
using Genode::max;
*dst++ = DST_PT(max(0, r), max(0, g), max(0, b), max(0, a));
}
src_pixel_line += line_len;
src_alpha_line += line_len;
dst_line += line_len;
}
}
};
#endif /* _DITHER_PAINTER_H_ */