ref: 3db3421f070670e0f83ca0aad56dfa41a63d52f2
dir: /src/gfx/pal_spec.cpp/
/*
* This file is part of RGBDS.
*
* Copyright (c) 2022, Eldred Habert and RGBDS contributors.
*
* SPDX-License-Identifier: MIT
*/
#include "gfx/pal_spec.hpp"
#include <algorithm>
#include <cassert>
#include <cinttypes>
#include <climits>
#include <cstdint>
#include <cstdio>
#include <cstring>
#include <fstream>
#include <ostream>
#include <streambuf>
#include <string>
#include <string_view>
#include <tuple>
#include <type_traits>
#include <unordered_map>
#include "platform.h"
#include "gfx/main.hpp"
using namespace std::string_view_literals;
constexpr uint8_t nibble(char c) {
if (c >= 'a') {
assert(c <= 'f');
return c - 'a' + 10;
} else if (c >= 'A') {
assert(c <= 'F');
return c - 'A' + 10;
} else {
assert(c >= '0' && c <= '9');
return c - '0';
}
}
constexpr uint8_t toHex(char c1, char c2) {
return nibble(c1) * 16 + nibble(c2);
}
constexpr uint8_t singleToHex(char c) {
return toHex(c, c);
}
template<typename Str> // Should be std::string or std::string_view
static void skipWhitespace(Str const &str, typename Str::size_type &pos) {
pos = std::min(str.find_first_not_of(" \t", pos), str.length());
}
void parseInlinePalSpec(char const * const rawArg) {
// List of #rrggbb/#rgb colors, comma-separated, palettes are separated by colons
std::string_view arg(rawArg);
using size_type = decltype(arg)::size_type;
auto parseError = [&rawArg, &arg](size_type ofs, size_type len, char const *fmt,
auto &&...args) {
(void)arg; // With NDEBUG, `arg` is otherwise not used
assert(ofs <= arg.length());
assert(len <= arg.length());
error(fmt, args...);
fprintf(stderr,
"In inline palette spec: %s\n"
" ",
rawArg);
for (auto i = ofs; i; --i) {
putc(' ', stderr);
}
for (auto i = len; i; --i) {
putc('^', stderr);
}
putc('\n', stderr);
};
options.palSpec.clear();
options.palSpec.emplace_back(); // Value-initialized, not default-init'd, so we get zeros
size_type n = 0; // Index into the argument
// TODO: store max `nbColors` ever reached, and compare against palette size later
size_t nbColors = 0; // Number of colors in the current palette
for (;;) {
++n; // Ignore the '#' (checked either by caller or previous loop iteration)
Rgba &color = options.palSpec.back()[nbColors];
auto pos = std::min(arg.find_first_not_of("0123456789ABCDEFabcdef"sv, n), arg.length());
switch (pos - n) {
case 3:
color = Rgba(singleToHex(arg[n + 0]), singleToHex(arg[n + 1]), singleToHex(arg[n + 2]),
0xFF);
break;
case 6:
color = Rgba(toHex(arg[n + 0], arg[n + 1]), toHex(arg[n + 2], arg[n + 3]),
toHex(arg[n + 4], arg[n + 5]), 0xFF);
break;
case 0:
parseError(n - 1, 1, "Missing color after '#'");
return;
default:
parseError(n, pos - n, "Unknown color specification");
return;
}
n = pos;
// Skip whitespace, if any
skipWhitespace(arg, n);
// Skip comma/semicolon, or end
if (n == arg.length()) {
break;
}
switch (arg[n]) {
case ',':
++n; // Skip it
++nbColors;
// A trailing comma may be followed by a semicolon
skipWhitespace(arg, n);
if (n == arg.length()) {
break;
} else if (arg[n] != ';' && arg[n] != ':') {
if (nbColors == 4) {
parseError(n, 1, "Each palette can only contain up to 4 colors");
return;
}
break;
}
[[fallthrough]];
case ':':
case ';':
++n;
skipWhitespace(arg, n);
nbColors = 0; // Start a new palette
// Avoid creating a spurious empty palette
if (n != arg.length()) {
options.palSpec.emplace_back();
}
break;
default:
parseError(n, 1, "Unexpected character, expected ',', ';', or end of argument");
return;
}
// Check again to allow trailing a comma/semicolon
if (n == arg.length()) {
break;
}
if (arg[n] != '#') {
parseError(n, 1, "Unexpected character, expected '#'");
return;
}
}
}
/**
* Tries to read some magic bytes from the provided `file`.
* Returns whether the magic was correctly read.
*/
template<size_t n>
static bool readMagic(std::filebuf &file, char const *magic) {
assert(strlen(magic) == n);
char magicBuf[n];
return file.sgetn(magicBuf, n) == n && memcmp(magicBuf, magic, n);
}
// Like `readMagic`, but automatically determines the size from the string literal's length.
// Don't worry if you make a mistake, an `assert`'s got your back!
#define READ_MAGIC(file, magic) \
readMagic<sizeof(magic) - 1>(file, magic) // Don't count the terminator
template<typename T, typename U>
static T readBE(U const *bytes) {
T val = 0;
for (size_t i = 0; i < sizeof(val); ++i) {
val = val << 8 | static_cast<uint8_t>(bytes[i]);
}
return val;
}
/**
* **Appends** the first line read from `file` to the end of the provided `buffer`.
*/
static void readLine(std::filebuf &file, std::string &buffer) {
// TODO: maybe this can be optimized to bulk reads?
for (;;) {
auto c = file.sbumpc();
if (c == std::filebuf::traits_type::eof()) {
return;
}
if (c == '\n') {
// Discard a trailing CRLF
if (!buffer.empty() && buffer.back() == '\r') {
buffer.pop_back();
}
return;
}
buffer.push_back(c);
}
}
// FIXME: Normally we'd use `std::from_chars`, but that's not available with GCC 7
/**
* Parses the initial part of a string_view, advancing the "read index" as it does
*/
static uint16_t parseDec(std::string const &str, std::string::size_type &n) {
uint32_t value = 0; // Use a larger type to handle overflow more easily
for (auto end = std::min(str.length(), str.find_first_not_of("0123456789", n)); n < end; ++n) {
value = std::min<uint32_t>(value * 10 + (str[n] - '0'), UINT16_MAX);
}
return value;
}
static void parsePSPFile(std::filebuf &file) {
// https://www.selapa.net/swatches/colors/fileformats.php#psp_pal
std::string line;
readLine(file, line);
if (line != "JASC-PAL") {
error("Palette file does not appear to be a PSP palette file");
return;
}
line.clear();
readLine(file, line);
if (line != "0100") {
error("Unsupported PSP palette file version \"%s\"", line.c_str());
return;
}
line.clear();
readLine(file, line);
std::string::size_type n = 0;
uint16_t nbColors = parseDec(line, n);
if (n != line.length()) {
error("Invalid \"number of colors\" line in PSP file (%s)", line.c_str());
return;
}
if (nbColors > options.nbColorsPerPal * options.nbPalettes) {
warning("PSP file contains %" PRIu16 " colors, but there can only be %" PRIu16
"; ignoring extra",
nbColors, options.nbColorsPerPal * options.nbPalettes);
nbColors = options.nbColorsPerPal * options.nbPalettes;
}
options.palSpec.clear();
for (uint16_t i = 0; i < nbColors; ++i) {
line.clear();
readLine(file, line);
n = 0;
uint8_t r = parseDec(line, n);
skipWhitespace(line, n);
if (n == line.length()) {
error("Failed to parse color #%" PRIu16 " (\"%s\"): missing green component", i + 1,
line.c_str());
return;
}
uint8_t g = parseDec(line, n);
if (n == line.length()) {
error("Failed to parse color #%" PRIu16 " (\"%s\"): missing green component", i + 1,
line.c_str());
return;
}
skipWhitespace(line, n);
uint8_t b = parseDec(line, n);
if (n != line.length()) {
error("Failed to parse color #%" PRIu16
" (\"%s\"): trailing characters after blue component",
i + 1, line.c_str());
return;
}
if (i % options.nbColorsPerPal == 0) {
options.palSpec.emplace_back();
}
options.palSpec.back()[i % options.nbColorsPerPal] = Rgba(r, g, b, 0xFF);
}
}
void parseACTFile(std::filebuf &file) {
// https://www.adobe.com/devnet-apps/photoshop/fileformatashtml/#50577411_pgfId-1070626
std::array<char, 772> buf;
auto len = file.sgetn(buf.data(), buf.size());
uint16_t nbColors = 256;
if (len == 772) {
nbColors = readBE<uint16_t>(&buf[768]);
// TODO: apparently there is a "transparent color index"? What?
if (nbColors > 256 || nbColors == 0) {
error("Invalid number of colors in ACT file (%" PRIu16 ")", nbColors);
return;
}
} else if (len != 768) {
error("Invalid file size for ACT file (expected 768 or 772 bytes, got %zu", len);
return;
}
if (nbColors > options.nbColorsPerPal * options.nbPalettes) {
warning("ACT file contains %" PRIu16 " colors, but there can only be %" PRIu16
"; ignoring extra",
nbColors, options.nbColorsPerPal * options.nbPalettes);
nbColors = options.nbColorsPerPal * options.nbPalettes;
}
options.palSpec.clear();
options.palSpec.emplace_back();
char const *ptr = buf.data();
size_t colorIdx = 0;
for (uint16_t i = 0; i < nbColors; ++i) {
Rgba &color = options.palSpec.back()[colorIdx];
color = Rgba(ptr[0], ptr[1], ptr[2], 0xFF);
ptr += 3;
++colorIdx;
if (colorIdx == options.nbColorsPerPal) {
options.palSpec.emplace_back();
colorIdx = 0;
}
}
// Remove the spurious empty palette if there is one
if (colorIdx == 0) {
options.palSpec.pop_back();
}
}
void parseACOFile(std::filebuf &file) {
// rhttps://www.adobe.com/devnet-apps/photoshop/fileformatashtml/#50577411_pgfId-1055819
// http://www.nomodes.com/aco.html
char buf[10];
if (file.sgetn(buf, 2) != 2) {
error("Couldn't read ACO file version");
return;
}
if (readBE<uint16_t>(buf) != 1) {
error("Palette file does not appear to be an ACO file");
return;
}
if (file.sgetn(buf, 2) != 2) {
error("Couldn't read number of colors in palette file");
return;
}
uint16_t nbColors = readBE<uint16_t>(buf);
if (nbColors > options.nbColorsPerPal * options.nbPalettes) {
warning("ACO file contains %" PRIu16 " colors, but there can only be %" PRIu16
"; ignoring extra",
nbColors, options.nbColorsPerPal * options.nbPalettes);
nbColors = options.nbColorsPerPal * options.nbPalettes;
}
options.palSpec.clear();
for (uint16_t i = 0; i < nbColors; ++i) {
if (file.sgetn(buf, 10) != 10) {
error("Failed to read color #%" PRIu16 " from palette file", i + 1);
return;
}
if (i % options.nbColorsPerPal == 0) {
options.palSpec.emplace_back();
}
Rgba &color = options.palSpec.back()[i % options.nbColorsPerPal];
uint16_t colorType = readBE<uint16_t>(buf);
switch (colorType) {
case 0: // RGB
color = Rgba(buf[0], buf[2], buf[4], 0xFF);
break;
case 1: // HSB
error("Unsupported color type (HSB) for ACO file");
return;
case 2: // CMYK
error("Unsupported color type (CMYK) for ACO file");
return;
case 7: // Lab
error("Unsupported color type (lab) for ACO file");
return;
case 8: // Grayscale
error("Unsupported color type (grayscale) for ACO file");
return;
default:
error("Unknown color type (%" PRIu16 ") for ACO file", colorType);
return;
}
}
// TODO: maybe scan the v2 data instead (if present)
// `codecvt` can be used to convert from UTF-16 to UTF-8
}
void parseExternalPalSpec(char const *arg) {
// `fmt:path`, parse the file according to the given format
// Split both parts, error out if malformed
char const *ptr = strchr(arg, ':');
if (ptr == nullptr) {
error("External palette spec must have format `fmt:path` (missing colon)");
return;
}
char const *path = ptr + 1;
static std::array parsers{
std::tuple{"PSP", &parsePSPFile, std::ios::in },
std::tuple{"ACT", &parseACTFile, std::ios::binary},
std::tuple{"ACO", &parseACOFile, std::ios::binary},
};
auto iter = std::find_if(parsers.begin(), parsers.end(),
[&arg, &ptr](decltype(parsers)::value_type const &parser) {
return strncasecmp(arg, std::get<0>(parser), ptr - arg) == 0;
});
if (iter == parsers.end()) {
error("Unknown external palette format \"%.*s\"",
static_cast<int>(std::min(ptr - arg, static_cast<decltype(ptr - arg)>(INT_MAX))),
arg);
return;
}
std::filebuf file;
// Some parsers read the file in text mode, others in binary mode
if (!file.open(path, std::ios::in | std::get<2>(*iter))) {
error("Failed to open palette file \"%s\"", path);
return;
}
std::get<1> (*iter)(file);
}