1/*
2 * Copyright 2005, Stephan Aßmus <superstippi@gmx.de>.
3 * Copyright 2008, Andrej Spielmann <andrej.spielmann@seh.ox.ac.uk>.
4 * All rights reserved. Distributed under the terms of the MIT License.
5 *
6 * DrawingMode implementing B_OP_ALPHA in "Constant Overlay" mode on B_RGBA32.
7 *
8 */
9
10#ifndef DRAWING_MODE_ALPHA_CO_SUBPIX_H
11#define DRAWING_MODE_ALPHA_CO_SUBPIX_H
12
13#include "DrawingMode.h"
14#include "GlobalSubpixelSettings.h"
15
16// BLEND_ALPHA_CO_SUBPIX
17#define BLEND_ALPHA_CO_SUBPIX(d, r, g, b, a1, a2, a3) \
18{ \
19	BLEND16_SUBPIX(d, r, g, b, a1, a2, a3); \
20}
21
22
23// blend_solid_hspan_alpha_co_subpix
24void
25blend_solid_hspan_alpha_co_subpix(int x, int y, unsigned len,
26	const color_type& c, const uint8* covers, agg_buffer* buffer,
27	const PatternHandler* pattern)
28{
29	uint8* p = buffer->row_ptr(y) + (x << 2);
30	uint8 hAlpha = pattern->HighColor().alpha;
31	uint16 alphaRed;
32	uint16 alphaGreen;
33	uint16 alphaBlue;
34	const int subpixelL = gSubpixelOrderingRGB ? 2 : 0;
35	const int subpixelM = 1;
36	const int subpixelR = gSubpixelOrderingRGB ? 0 : 2;
37	do {
38		alphaRed = hAlpha * covers[subpixelL];
39		alphaGreen = hAlpha * covers[subpixelM];
40		alphaBlue = hAlpha * covers[subpixelR];
41		rgb_color color = pattern->ColorAt(x, y);
42		BLEND_ALPHA_CO_SUBPIX(p, color.red, color.green, color.blue,
43			alphaBlue, alphaGreen, alphaRed);
44		covers += 3;
45		p += 4;
46		x++;
47		len -= 3;
48	} while (len);
49}
50
51#endif // DRAWING_MODE_ALPHA_CO_SUBPIX_H
52
53