banan-os/userspace/image/Netbpm.cpp

109 lines
2.5 KiB
C++

#include "Netbpm.h"
#include <BAN/Optional.h>
#include <ctype.h>
#include <stdio.h>
BAN::Optional<uint64_t> parse_u64(const uint8_t*& data, size_t data_size)
{
uint64_t result = 0;
// max supported size 10^20 - 1
for (size_t i = 0; i < 19; i++)
{
if (i >= data_size)
{
if (isdigit(*data))
return {};
return result;
}
if (!isdigit(*data))
return result;
result = (result * 10) + (*data - '0');
data++;
}
return {};
}
BAN::ErrorOr<BAN::UniqPtr<Netbpm>> Netbpm::create(const void* mmap_addr, size_t size)
{
if (size < 11)
{
fprintf(stderr, "invalid Netbpm image (too small)\n");
return BAN::Error::from_errno(EINVAL);
}
const uint8_t* u8_ptr = reinterpret_cast<const uint8_t*>(mmap_addr);
if (u8_ptr[0] != 'P')
{
fprintf(stderr, "not Netbpm image\n");
return BAN::Error::from_errno(EINVAL);
}
if (u8_ptr[1] != '6')
{
fprintf(stderr, "unsupported Netbpm image\n");
return BAN::Error::from_errno(EINVAL);
}
if (u8_ptr[2] != '\n')
{
fprintf(stderr, "invalid Netbpm image (invalid header)\n");
return BAN::Error::from_errno(EINVAL);
}
u8_ptr += 3;
auto width = parse_u64(u8_ptr, size - (u8_ptr - reinterpret_cast<const uint8_t*>(mmap_addr)));
if (!width.has_value() || *u8_ptr != ' ')
{
fprintf(stderr, "invalid Netbpm image (invalid width)\n");
return BAN::Error::from_errno(EINVAL);
}
u8_ptr++;
auto height = parse_u64(u8_ptr, size - (u8_ptr - reinterpret_cast<const uint8_t*>(mmap_addr)));
if (!height.has_value() || *u8_ptr != '\n')
{
fprintf(stderr, "invalid Netbpm image (invalid height)\n");
return BAN::Error::from_errno(EINVAL);
}
u8_ptr++;
auto header_end = parse_u64(u8_ptr, size - (u8_ptr - reinterpret_cast<const uint8_t*>(mmap_addr)));
if (!header_end.has_value() || *header_end != 255 || *u8_ptr != '\n')
{
fprintf(stderr, "invalid Netbpm image (invalid header end)\n");
return BAN::Error::from_errno(EINVAL);
}
u8_ptr++;
if (size - (u8_ptr - reinterpret_cast<const uint8_t*>(mmap_addr)) < *width * *height * 3)
{
fprintf(stderr, "invalid Netbpm image (too small file size)\n");
return BAN::Error::from_errno(EINVAL);
}
printf("Netbpm image %llux%llu\n", *width, *height);
BAN::Vector<Color> bitmap;
TRY(bitmap.resize(*width * *height));
// Fill bitmap
for (uint64_t y = 0; y < *height; y++)
{
for (uint64_t x = 0; x < *width; x++)
{
auto& pixel = bitmap[y * *width + x];
pixel.r = *u8_ptr++;
pixel.g = *u8_ptr++;
pixel.b = *u8_ptr++;
pixel.a = 0xFF;
}
}
return TRY(BAN::UniqPtr<Netbpm>::create(*width, *height, BAN::move(bitmap)));
}