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
|
/*
* Copyright (c) 2020, Ben Jilks <benjyjilks@gmail.com>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <LibGfx/BMPWriter.h>
#include <LibGfx/Bitmap.h>
namespace Gfx {
class OutputStreamer {
public:
OutputStreamer(u8* data)
: m_data(data)
{
}
void write_u8(u8 i)
{
*(m_data++) = i;
}
void write_u16(u16 i)
{
*(m_data++) = i & 0xFF;
*(m_data++) = (i >> 8) & 0xFF;
}
void write_u32(u32 i)
{
write_u16(i & 0xFFFF);
write_u16((i >> 16) & 0xFFFF);
}
void write_i32(i32 i)
{
write_u32(static_cast<u32>(i));
}
private:
u8* m_data;
};
static ByteBuffer write_pixel_data(const RefPtr<Bitmap> bitmap, int pixel_row_data_size, int bytes_per_pixel, bool include_alpha_channel)
{
int image_size = pixel_row_data_size * bitmap->height();
auto buffer = ByteBuffer::create_uninitialized(image_size);
int current_row = 0;
for (int y = bitmap->physical_height() - 1; y >= 0; --y) {
auto* row = buffer.data() + (pixel_row_data_size * current_row++);
for (int x = 0; x < bitmap->physical_width(); x++) {
auto pixel = bitmap->get_pixel(x, y);
row[x * bytes_per_pixel + 0] = pixel.blue();
row[x * bytes_per_pixel + 1] = pixel.green();
row[x * bytes_per_pixel + 2] = pixel.red();
if (include_alpha_channel)
row[x * bytes_per_pixel + 3] = pixel.alpha();
}
}
return buffer;
}
static ByteBuffer compress_pixel_data(const ByteBuffer& pixel_data, BMPWriter::Compression compression)
{
switch (compression) {
case BMPWriter::Compression::BI_BITFIELDS:
case BMPWriter::Compression::BI_RGB:
return pixel_data;
}
VERIFY_NOT_REACHED();
}
ByteBuffer BMPWriter::dump(const RefPtr<Bitmap> bitmap, DibHeader dib_header)
{
switch (dib_header) {
case DibHeader::Info:
m_compression = Compression::BI_RGB;
m_bytes_per_pixel = 3;
m_include_alpha_channel = false;
break;
case DibHeader::V3:
case DibHeader::V4:
m_compression = Compression::BI_BITFIELDS;
m_bytes_per_pixel = 4;
m_include_alpha_channel = true;
}
const size_t file_header_size = 14;
size_t pixel_data_offset = file_header_size + (u32)dib_header;
int pixel_row_data_size = (m_bytes_per_pixel * 8 * bitmap->width() + 31) / 32 * 4;
int image_size = pixel_row_data_size * bitmap->height();
auto buffer = ByteBuffer::create_uninitialized(pixel_data_offset);
auto pixel_data = write_pixel_data(bitmap, pixel_row_data_size, m_bytes_per_pixel, m_include_alpha_channel);
pixel_data = compress_pixel_data(pixel_data, m_compression);
size_t file_size = pixel_data_offset + pixel_data.size();
OutputStreamer streamer(buffer.data());
streamer.write_u8('B');
streamer.write_u8('M');
streamer.write_u32(file_size);
streamer.write_u32(0);
streamer.write_u32(pixel_data_offset);
streamer.write_u32((u32)dib_header); // Header size
streamer.write_i32(bitmap->width()); // ImageWidth
streamer.write_i32(bitmap->height()); // ImageHeight
streamer.write_u16(1); // Planes
streamer.write_u16(m_bytes_per_pixel * 8); // BitsPerPixel
streamer.write_u32((u32)m_compression); // Compression
streamer.write_u32(image_size); // ImageSize
streamer.write_i32(0); // XpixelsPerMeter
streamer.write_i32(0); // YpixelsPerMeter
streamer.write_u32(0); // TotalColors
streamer.write_u32(0); // ImportantColors
if (dib_header == DibHeader::V3 || dib_header == DibHeader::V4) {
streamer.write_u32(0x00ff0000); // Red bitmask
streamer.write_u32(0x0000ff00); // Green bitmask
streamer.write_u32(0x000000ff); // Blue bitmask
streamer.write_u32(0xff000000); // Alpha bitmask
}
if (dib_header == DibHeader::V4) {
streamer.write_u32(0); // Colorspace
for (int i = 0; i < 12; i++) {
streamer.write_u32(0); // Endpoints
}
}
if (!buffer.try_append(pixel_data.data(), pixel_data.size()))
dbgln("Failed to write {} bytes of pixel data to buffer", pixel_data.size());
return buffer;
}
}
|
