101 lines
2.8 KiB
C++
101 lines
2.8 KiB
C++
/*
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* \brief Functor for converting pixel formats by applying dithering
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* \author Norman Feske
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* \date 2014-09-10
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*/
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/*
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* Copyright (C) 2014-2017 Genode Labs GmbH
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*
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* This file is part of the Genode OS framework, which is distributed
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* under the terms of the GNU Affero General Public License version 3.
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*/
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#ifndef _INCLUDE__OS__DITHER_PAINTER_H_
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#define _INCLUDE__OS__DITHER_PAINTER_H_
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/* Genode includes */
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#include <util/dither_matrix.h>
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#include <os/surface.h>
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#include <os/texture.h>
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struct Dither_painter
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{
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/*
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* Surface and texture must have the same size
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*/
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template <typename DST_PT, typename SRC_PT>
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static inline void paint(Genode::Surface<DST_PT> &surface,
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Genode::Texture<SRC_PT> const &texture,
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Genode::Surface_base::Point const &pos)
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{
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Genode::Surface_base::Rect const clipped = surface.clip();
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if (!clipped.valid()) return;
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using Genode::min;
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using Genode::max;
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unsigned const dst_x = max(pos.x(), clipped.x1());
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unsigned const dst_y = max(pos.y(), clipped.y1());
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unsigned const dst_line_len = surface.size().w();
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unsigned const dst_offset = dst_line_len*dst_y + dst_x;
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unsigned const src_line_len = texture.size().w();
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unsigned const src_offset = src_line_len*clipped.y1() + clipped.x1();
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DST_PT *dst, *dst_line = surface.addr() + dst_offset;
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SRC_PT const *src_pixel, *src_pixel_line = texture.pixel() + src_offset;
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unsigned char const *src_alpha, *src_alpha_line = texture.alpha() + src_offset;
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bool const src_has_alpha = texture.alpha() != nullptr;
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unsigned const x_max = min((unsigned)clipped.x2(), dst_x + texture.size().w() - 1);
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unsigned const y_max = min((unsigned)clipped.y2(), dst_y + texture.size().h() - 1);
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for (unsigned y = dst_y; y <= y_max; y++) {
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src_pixel = src_pixel_line;
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src_alpha = src_alpha_line;
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dst = dst_line;
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if (src_has_alpha) {
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for (unsigned x = dst_x; x <= x_max; x++) {
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int const v = Genode::Dither_matrix::value(x, y) >> 4;
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SRC_PT const pixel = *src_pixel++;
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unsigned char const alpha = *src_alpha++;
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int const r = pixel.r() - v;
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int const g = pixel.g() - v;
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int const b = pixel.b() - v;
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int const a = alpha ? (int)alpha - v : 0;
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*dst++ = DST_PT(max(0, r), max(0, g), max(0, b), max(0, a));
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}
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} else {
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for (unsigned x = dst_x; x <= x_max; x++) {
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int const v = Genode::Dither_matrix::value(x, y) >> 4;
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SRC_PT const pixel = *src_pixel++;
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int const r = pixel.r() - v;
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int const g = pixel.g() - v;
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int const b = pixel.b() - v;
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*dst++ = DST_PT(max(0, r), max(0, g), max(0, b));
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}
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}
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src_pixel_line += src_line_len;
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src_alpha_line += src_line_len;
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dst_line += dst_line_len;
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}
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}
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};
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#endif /* _INCLUDE__OS__DITHER_PAINTER_H_ */
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