1 /*
2  *  linux/drivers/video/console/fbcon_rotate.h -- Software Display Rotation
3  *
4  *	Copyright (C) 2005 Antonino Daplas <adaplas@pol.net>
5  *
6  *  This file is subject to the terms and conditions of the GNU General Public
7  *  License.  See the file COPYING in the main directory of this archive
8  *  for more details.
9  */
10 
11 #ifndef _FBCON_ROTATE_H
12 #define _FBCON_ROTATE_H
13 
14 static inline int pattern_test_bit(u32 x, u32 y, u32 pitch, const char *pat)
15 {
16 	u32 tmp = (y * pitch) + x, index = tmp / 8,  bit = tmp % 8;
17 
18 	pat +=index;
19 	return (*pat) & (0x80 >> bit);
20 }
21 
22 static inline void pattern_set_bit(u32 x, u32 y, u32 pitch, char *pat)
23 {
24 	u32 tmp = (y * pitch) + x, index = tmp / 8, bit = tmp % 8;
25 
26 	pat += index;
27 
28 	(*pat) |= 0x80 >> bit;
29 }
30 
31 static inline void rotate_ud(const char *in, char *out, u32 width, u32 height)
32 {
33 	int i, j;
34 	int shift = (8 - (width % 8)) & 7;
35 
36 	width = (width + 7) & ~7;
37 
38 	for (i = 0; i < height; i++) {
39 		for (j = 0; j < width - shift; j++) {
40 			if (pattern_test_bit(j, i, width, in))
41 				pattern_set_bit(width - (1 + j + shift),
42 						height - (1 + i),
43 						width, out);
44 		}
45 
46 	}
47 }
48 
49 static inline void rotate_cw(const char *in, char *out, u32 width, u32 height)
50 {
51 	int i, j, h = height, w = width;
52 	int shift = (8 - (height % 8)) & 7;
53 
54 	width = (width + 7) & ~7;
55 	height = (height + 7) & ~7;
56 
57 	for (i = 0; i < h; i++) {
58 		for (j = 0; j < w; j++) {
59 			if (pattern_test_bit(j, i, width, in))
60 				pattern_set_bit(height - 1 - i - shift, j,
61 						height, out);
62 
63 		}
64 	}
65 }
66 
67 static inline void rotate_ccw(const char *in, char *out, u32 width, u32 height)
68 {
69 	int i, j, h = height, w = width;
70 	int shift = (8 - (width % 8)) & 7;
71 
72 	width = (width + 7) & ~7;
73 	height = (height + 7) & ~7;
74 
75 	for (i = 0; i < h; i++) {
76 		for (j = 0; j < w; j++) {
77 			if (pattern_test_bit(j, i, width, in))
78 				pattern_set_bit(i, width - 1 - j - shift,
79 						height, out);
80 		}
81 	}
82 }
83 
84 extern void fbcon_rotate_cw(struct fbcon_ops *ops);
85 extern void fbcon_rotate_ud(struct fbcon_ops *ops);
86 extern void fbcon_rotate_ccw(struct fbcon_ops *ops);
87 #endif
88