mirror of
https://github.com/genodelabs/genode.git
synced 2024-12-21 22:47:50 +00:00
70 lines
2.0 KiB
C++
70 lines
2.0 KiB
C++
/*
|
|
* \brief Texturizing function for polygon painting
|
|
* \date 2015-06-29
|
|
* \author Norman Feske
|
|
*/
|
|
|
|
/*
|
|
* Copyright (C) 2015-2017 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 _INCLUDE__POLYGON_GFX__TEXTURIZE_RGBA_H_
|
|
#define _INCLUDE__POLYGON_GFX__TEXTURIZE_RGBA_H_
|
|
|
|
/* Genode includes */
|
|
#include <util/color.h>
|
|
#include <os/pixel_rgba.h>
|
|
#include <util/geometry.h>
|
|
|
|
namespace Polygon {
|
|
|
|
template <typename PT>
|
|
static inline void texturize_rgba(Genode::Point<>, Genode::Point<>, PT *,
|
|
unsigned char *, unsigned, PT const *,
|
|
unsigned char const *, unsigned);
|
|
}
|
|
|
|
|
|
/**
|
|
* Texturize scanline
|
|
*/
|
|
template <typename PT>
|
|
static inline void Polygon::texturize_rgba(Genode::Point<> start, Genode::Point<> end,
|
|
PT *dst, unsigned char *dst_alpha,
|
|
unsigned num_values,
|
|
PT const *texture_base,
|
|
unsigned char const *alpha_base,
|
|
unsigned texture_width)
|
|
{
|
|
/* sanity check */
|
|
if (num_values <= 0) return;
|
|
|
|
/* use 16.16 fixpoint values for the calculation */
|
|
int tx_ascent = ((end.x() - start.x())<<16)/(int)num_values,
|
|
ty_ascent = ((end.y() - start.y())<<16)/(int)num_values;
|
|
|
|
/* set start values for color components */
|
|
int tx = start.x()<<16,
|
|
ty = start.y()<<16;
|
|
|
|
for ( ; num_values--; dst++, dst_alpha++) {
|
|
|
|
/* blend pixel from texture with destination point on surface */
|
|
unsigned long src_offset = (ty>>16)*texture_width + (tx>>16);
|
|
|
|
int const a = alpha_base[src_offset];
|
|
|
|
*dst = texture_base[src_offset];
|
|
*dst_alpha += (unsigned char)(((255 - *dst_alpha)*a) >> 8);
|
|
|
|
/* walk through texture */
|
|
tx += tx_ascent;
|
|
ty += ty_ascent;
|
|
}
|
|
}
|
|
|
|
#endif /* _INCLUDE__POLYGON_GFX__TEXTURIZE_RGBA_H_ */
|