genode/demo/include/scout_gfx/horizontal_shadow_painter.h

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/*
* \brief Functor for drawing a horizonatal shadow onto a surface
* \author Norman Feske
* \date 2005-10-24
*/
/*
* Copyright (C) 2006-2013 Genode Labs GmbH
*
* This file is part of the Genode OS framework, which is distributed
* under the terms of the GNU General Public License version 2.
*/
#ifndef _INCLUDE__SCOUT_GFX__HORIZONTAL_SHADOW_PAINTER_H_
#define _INCLUDE__SCOUT_GFX__HORIZONTAL_SHADOW_PAINTER_H_
#include <os/surface.h>
struct Horizontal_shadow_painter
{
typedef Genode::Surface_base::Rect Rect;
template <typename PT>
static inline void paint(Genode::Surface<PT> &surface, Rect rect,
int intensity)
{
PT *addr = surface.addr();
if (!addr) return;
const int cx1 = surface.clip().x1();
const int cy1 = surface.clip().y1();
const int cx2 = surface.clip().x2();
const int cy2 = surface.clip().y2();
int x = rect.x1();
int y = rect.y1();
int w = rect.w();
int h = rect.h();
int curr_a = intensity;
int step = rect.h() ? (curr_a/rect.h()) : 0;
if (x < cx1) {
w -= cx1 - x;
x = cx1;
}
if (y < cy1) {
h -= cy1 - y;
curr_a -= (cy1 - y)*step;
y = cy1;
}
if (w > cx2 - x + 1)
w = cx2 - x + 1;
if (h > cy2 - y + 1)
h = cy2 - y + 1;
addr += surface.size().w()*y + x;
PT shadow_color(0,0,0);
for (int j = 0; j < h; j++, addr += surface.size().w()) {
PT *d = addr;
for (int i = 0; i < w; i++, d++)
*d = PT::mix(*d, shadow_color, curr_a);
curr_a -= step;
}
}
};
#endif /* _INCLUDE__SCOUT_GFX__HORIZONTAL_SHADOW_PAINTER_H_ */