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 "Pixel Overlay" mode on B_RGBA32.
7 *
8 */
9
10#ifndef DRAWING_MODE_ALPHA_PO_SUBPIX_H
11#define DRAWING_MODE_ALPHA_PO_SUBPIX_H
12
13#include "DrawingMode.h"
14#include "GlobalSubpixelSettings.h"
15
16// BLEND_ALPHA_PO_SUBPIX
17#define BLEND_ALPHA_PO_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_po_subpix
24void
25blend_solid_hspan_alpha_po_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	uint16 alphaRed;
31	uint16 alphaGreen;
32	uint16 alphaBlue;
33	const int subpixelL = gSubpixelOrderingRGB ? 2 : 0;
34	const int subpixelM = 1;
35	const int subpixelR = gSubpixelOrderingRGB ? 0 : 2;
36	do {
37		rgb_color color = pattern->ColorAt(x, y);
38		alphaRed = color.alpha * covers[subpixelL];
39		alphaGreen = color.alpha * covers[subpixelM];
40		alphaBlue = color.alpha * covers[subpixelR];
41		BLEND_ALPHA_PO_SUBPIX(p, color.red, color.green, color.blue,
42			alphaBlue, alphaGreen, alphaRed);
43		covers += 3;
44		p += 4;
45		x++;
46		len -= 3;
47	} while (len);
48}
49
50#endif // DRAWING_MODE_ALPHA_PO_SUBPIX_H
51
52