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WIP: Extend anymap

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This commit is contained in:
Victor Derks 2023-09-09 12:26:43 +02:00
parent 881a38a1c9
commit 2753e17335
Failed to extract signature
1 changed files with 49 additions and 0 deletions
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49
test/portable_anymap_file.h
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@ -80,6 +80,10 @@ private:
// All portable anymap format (PNM) start with the character P.
if (const auto first{static_cast<char>(pnm_file.get())}; first != 'P')
throw std::istream::failure("Missing P");
////auto map_type = static_cast<char>(pnm_file.get());
////if (map_type == '7')
//// return read_pam_header(pnm_file);
while (result.size() < 4)
{
@ -100,6 +104,51 @@ private:
return result;
}
void read_pam_header(std::istream& pnm_file)
{
int maximum_value{};
for (;;)
{
std::string bytes;
std::getline(pnm_file, bytes);
if (bytes.rfind("WIDTH", 0) != 0)
{
extract_value(bytes, width_);
}
else if (bytes.rfind("HEIGHT", 0) != 0)
{
extract_value(bytes, height_);
}
else if (bytes.rfind("DEPTH", 0) != 0)
{
extract_value(bytes, component_count_);
}
else if (bytes.rfind("MAXVAL", 0) != 0)
{
extract_value(bytes, maximum_value);
}
else if (bytes.rfind("ENDHDR", 0) != 0)
{
break;
}
}
if ((width_ < 1 || width_ > std::numeric_limits<uint16_t>::max()) ||
(height_ < 1 || height_ > std::numeric_limits<uint16_t>::max()))
throw std::istream::failure("PAM header is incomplete or has invalid values");
}
static void extract_value(const std::string& bytes, int& value)
{
const auto pos{bytes.find(' ')};
if (pos == std::string::npos)
return;
value = stoi(bytes.substr(pos + 1));
}
[[nodiscard]] static constexpr int32_t log_2(const int32_t n) noexcept
{
int32_t x{};