Rewrite MakeIco

There is some cursed memory problem that only ever manifests in ghactions workflows and for cursed people. I'm neither so I just rewrote the whole thing from scratch, slightly better than last time.
This commit is contained in:
Tamás Bálint Misius 2024-01-21 12:39:38 +01:00
parent 452b553350
commit 1ef0c1a3e0
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@ -1,67 +1,137 @@
#include <fstream>
#include <vector>
#include <cstdint> #include <cstdint>
#include <cstring>
#include <fstream>
#include <iostream>
#include <string>
#include <vector>
static void writeU32LE(uint8_t *dest, uint32_t value)
{
dest[0] = uint8_t( value & 0xFF);
dest[1] = uint8_t((value >> 8) & 0xFF);
dest[2] = uint8_t((value >> 16) & 0xFF);
dest[3] = uint8_t((value >> 24) & 0xFF);
}
static uint32_t readU32BE(const uint8_t *src)
{
return uint32_t(src[3]) |
(uint32_t(src[2]) << 8) |
(uint32_t(src[1]) << 16) |
(uint32_t(src[0]) << 24);
}
int main(int argc, char *argv[]) int main(int argc, char *argv[])
{ {
if (argc < 3) if (argc < 3)
{ {
return 1; std::cerr << "usage: " << argv[0] << " OUTPUT INPUT..." << std::endl;
} exit(1);
auto *outputIcoPath = argv[1];
std::ofstream outputIco(outputIcoPath, std::ios::binary);
if (!outputIco)
{
return 2;
} }
auto images = argc - 2; auto images = argc - 2;
std::vector<char> header(22 + images * 16); if (images > 255)
auto *incondir = &header[0];
*reinterpret_cast<uint16_t *>(&incondir[0]) = 0; // reserved
*reinterpret_cast<uint16_t *>(&incondir[2]) = 1; // icon
*reinterpret_cast<uint16_t *>(&incondir[4]) = uint16_t(images);
std::vector<char> allData;
for (auto i = 0; i < images; ++i)
{ {
auto *inputAnyPath = argv[i + 2]; std::cerr << "too many images specified" << std::endl;
std::ifstream inputAny(inputAnyPath, std::ios::binary); exit(1);
std::vector<char> data;
while (true)
{
char ch;
inputAny.read(&ch, 1);
if (inputAny.eof())
{
break;
}
if (!inputAny)
{
return 3;
}
data.push_back(ch);
}
if (*reinterpret_cast<uint64_t *>(&data[0]) != UINT64_C(0x0A1A0A0D474E5089)) // png magic
{
return 5;
}
auto width = uint8_t(data[19]);
auto height = uint8_t(data[23]);
auto *incondirentry = &header[6 + i * 16];
*reinterpret_cast<uint8_t *>(&incondirentry[0]) = width;
*reinterpret_cast<uint8_t *>(&incondirentry[1]) = height;
*reinterpret_cast<uint8_t *>(&incondirentry[2]) = 0; // no color palette
*reinterpret_cast<uint8_t *>(&incondirentry[3]) = 0; // reserved
*reinterpret_cast<uint16_t *>(&incondirentry[4]) = 1; // 1 color plane
*reinterpret_cast<uint16_t *>(&incondirentry[6]) = 32; // 32 bits per pixel
*reinterpret_cast<uint32_t *>(&incondirentry[8]) = uint32_t(data.size()); // data size
*reinterpret_cast<uint32_t *>(&incondirentry[12]) = uint32_t(header.size() + allData.size()); // data offset
allData.insert(allData.end(), data.begin(), data.end());
} }
outputIco.write(&header[0], header.size()); std::string outputPath = argv[1];
outputIco.write(&allData[0], allData.size()); std::ofstream output(outputPath, std::ios::binary);
if (!outputIco) auto outputFailure = [&outputPath](std::string action) {
std::cerr << "failed to " << action << " " << outputPath << ": " << strerror(errno) << std::endl;
exit(1);
};
if (!output)
{ {
return 4; outputFailure("open");
} }
std::vector<char> header(6 + images * 16, 0);
auto writeHeader = [&header, &output, &outputFailure]() {
output.seekp(0, std::ios_base::beg);
output.write(&header[0], header.size());
if (!output)
{
outputFailure("write");
}
};
writeHeader(); // make space for header
auto *headerU8 = reinterpret_cast<uint8_t *>(&header[0]);
headerU8[2] = 1;
headerU8[4] = images;
for (auto image = 0; image < images; ++image)
{
std::string inputPath = argv[2 + image];
std::ifstream input(inputPath, std::ios::binary);
auto inputFailure = [&inputPath](std::string action) {
std::cerr << "failed to " << action << " " << inputPath << ": " << strerror(errno) << std::endl;
exit(1);
};
auto imageFailure = [&inputPath](std::string failure) {
std::cerr << "failed to process " << inputPath << ": " << failure << std::endl;
exit(1);
};
if (!input)
{
inputFailure("open");
}
std::vector<char> buf;
input.seekg(0, std::ios_base::end);
buf.resize(input.tellg());
input.seekg(0, std::ios_base::beg);
input.read(&buf[0], buf.size());
if (!input)
{
inputFailure("read");
}
auto *bufU8 = reinterpret_cast<uint8_t *>(&buf[0]);
if (buf.size() < 0x21 ||
readU32BE(&bufU8[0]) != UINT32_C(0x89504E47) ||
readU32BE(&bufU8[4]) != UINT32_C(0x0D0A1A0A) ||
bufU8[0x18] != 8 ||
bufU8[0x19] != 6)
{
imageFailure("not a 32bpp RGBA PNG");
}
auto writeOffset = output.tellp();
output.write(&buf[0], buf.size());
if (!output)
{
outputFailure("write");
}
auto width = readU32BE(&bufU8[0x10]);
auto height = readU32BE(&bufU8[0x14]);
if (width == 256)
{
width = 0;
}
if (width > 255)
{
imageFailure("width exceeds U8 limit");
}
if (height == 256)
{
height = 0;
}
if (height > 255)
{
imageFailure("height exceeds U8 limit");
}
auto *entryU8 = headerU8 + 6 + image * 16;
entryU8[0] = width;
entryU8[1] = height;
entryU8[4] = 1;
entryU8[6] = 32;
if (buf.size() > UINT32_MAX)
{
imageFailure("data size exceeds U32 limit");
}
writeU32LE(&entryU8[8], uint32_t(buf.size()));
if (writeOffset > UINT32_MAX)
{
std::cerr << "output data size exceeds U32 limit" << std::endl;
exit(1);
}
writeU32LE(&entryU8[12], uint32_t(writeOffset));
}
writeHeader(); // actually write it out
return 0; return 0;
} }