259b127f96
This patch adds two new painters located at gems/include/polygon_gfx. Both painters draw convex polygons with an arbirary number of points. The shaded-polygon painter interpolates the color and alpha values whereas the textured-polygon painter applies a texture to the polygon. The painters are accompanied by simplistic 3D routines located at gems/include/nano3d/ and a corresponding example (gems/run/nano3d.run).
77 lines
2.2 KiB
C++
77 lines
2.2 KiB
C++
/*
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* \brief RGB565-optimized interpolation functions for polygon painting
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* \date 2015-06-19
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* \author Norman Feske
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*/
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/*
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* Copyright (C) 2015 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 General Public License version 2.
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*/
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#ifndef _INCLUDE__POLYGON_GFX__INTERPOLATE_RGB565_H_
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#define _INCLUDE__POLYGON_GFX__INTERPOLATE_RGB565_H_
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/* Genode includes */
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#include <util/dither_matrix.h>
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#include <os/pixel_rgb565.h>
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#include <polygon_gfx/interpolate_rgba.h>
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namespace Polygon {
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using Genode::Pixel_rgb565;
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template <>
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inline void interpolate_rgba(Color, Color, Pixel_rgb565 *,
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unsigned char *, unsigned, int, int);
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}
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/**
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* Specialization that employs dithering
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*/
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template <>
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inline void Polygon::interpolate_rgba(Color start, Color end, Pixel_rgb565 *dst,
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unsigned char *dst_alpha,
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unsigned num_values, int x, int y)
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{
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/* sanity check */
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if (num_values <= 0) return;
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/* use 16.16 fixpoint values for the calculation */
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int r_ascent = ((end.r - start.r)<<16) / (int)num_values,
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g_ascent = ((end.g - start.g)<<16) / (int)num_values,
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b_ascent = ((end.b - start.b)<<16) / (int)num_values,
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a_ascent = ((end.a - start.a)<<16) / (int)num_values;
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/* set start values for color components */
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int r = start.r<<16,
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g = start.g<<16,
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b = start.b<<16,
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a = start.a<<16;
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for ( ; num_values--; dst++, dst_alpha++, x++) {
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int const dither_value = Genode::Dither_matrix::value(x, y) << 12;
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/* combine current color value with existing pixel via alpha blending */
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*dst = Pixel_rgb565::mix(*dst,
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Pixel_rgb565((r + dither_value) >> 16,
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(g + dither_value) >> 16,
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(b + dither_value) >> 16),
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(a + dither_value) >> 16);
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*dst_alpha += ((255 - *dst_alpha)*(a + dither_value)) >> (16 + 8);
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/* increment color-component values by ascent */
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r += r_ascent;
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g += g_ascent;
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b += b_ascent;
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a += a_ascent;
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}
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}
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#endif /* _INCLUDE__POLYGON_GFX__INTERPOLATE_RGB565_H_ */
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