1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
|
/**
* crt-calibrator – Calibration utility for CRT monitors
* Copyright © 2014 Mattias Andrée (maandree@member.fsf.org)
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef CRT_CALIBRATOR_FRAMEBUFFER_H
#define CRT_CALIBRATOR_FRAMEBUFFER_H
#include <stddef.h>
#include <stdint.h>
/**
* Framebuffer information
*/
typedef struct framebuffer
{
/**
* The file descriptor used to access the framebuffer, -1 if not opened
*/
int fd;
/**
* The width of the display in pixels
*/
uint32_t width;
/**
* The height of the display in pixels
*/
uint32_t height;
/**
* Increment for `mem` to move to next pixel on the line
*/
uint32_t bytes_per_pixel;
/**
* Increment for `mem` to move down one line but stay in the same column
*/
uint32_t line_length;
/**
* Framebuffer pointer, `MAP_FAILED` (from <sys/mman.h>) if not mapped
*/
int8_t* mem;
} framebuffer_t;
/**
* Figure out how many framebuffers there are on the system
*
* @return The number of framebuffers on the system
*/
size_t fb_count(void);
/**
* Open a framebuffer
*
* @param index The index of the framebuffer to open
* @param fb Framebuffer information to fill in
* @return Zero on success, -1 on error
*/
int fb_open(size_t index, framebuffer_t* restrict fb);
/**
* Close a framebuffer
*
* @param fb The framebuffer information
*/
void fb_close(framebuffer_t* restrict fb);
/**
* Construct an sRGB colour in 32-bit XRGB encoding to
* use when specifying colours
*
* @param red The red component from [0, 255] sRGB
* @param green The green component from [0, 255] sRGB
* @param blue The blue component from [0, 255] sRGB
* @return The colour as one 32-bit integer
*/
uint32_t fb_colour(int red, int green, int blue) __attribute__((const));
/**
* Print a filled in rectangle to a framebuffer
*
* @param fb The framebuffer
* @param colour The colour to use when drawing the rectangle
* @param x The starting pixel on the X axis for the rectangle
* @param y The starting pixel on the Y axis for the rectangle
* @param width The width of the rectangle, in pixels
* @param height The height of the rectangle, in pixels
*/
void fb_fill_rectangle(framebuffer_t* restrict fb, uint32_t colour,
uint32_t x, uint32_t y, uint32_t width, uint32_t height);
/**
* Draw a horizontal line segment on a framebuffer
*
* @param fb The framebuffer
* @param colour The colour to use when drawing the rectangle
* @param x The starting pixel on the X axis for the line segment
* @param y The starting pixel on the Y axis for the line segment
* @param length The length of the line segment, in pixels
*/
void fb_draw_horizontal_line(framebuffer_t* restrict fb, uint32_t colour,
uint32_t x, uint32_t y, uint32_t length);
/**
* Draw a vertical line segment on a framebuffer
*
* @param fb The framebuffer
* @param colour The colour to use when drawing the rectangle
* @param x The starting pixel on the X axis for the line segment
* @param y The starting pixel on the Y axis for the line segment
* @param length The length of the line segment, in pixels
*/
void fb_draw_vertical_line(framebuffer_t* restrict fb, uint32_t colour,
uint32_t x, uint32_t y, uint32_t length);
/**
* Draw a single on a framebuffer
*
* @param fb The framebuffer
* @param colour The colour to use when drawing the rectangle
* @param x The pixel's position on the X axis
* @param y The pixel's position on the Y axis
*/
static inline void fb_draw_pixel(framebuffer_t* restrict fb, uint32_t colour,
uint32_t x, uint32_t y)
{
int8_t* mem = fb->mem + y * fb->line_length + x * fb->bytes_per_pixel;
*(uint32_t*)mem = colour;
}
#endif
|
