ref: 3db3421f070670e0f83ca0aad56dfa41a63d52f2
dir: /src/gfx/reverse.cpp/
/*
* This file is part of RGBDS.
*
* Copyright (c) 2022, Eldred Habert and RGBDS contributors.
*
* SPDX-License-Identifier: MIT
*/
#include "gfx/reverse.hpp"
#include <algorithm>
#include <array>
#include <assert.h>
#include <cinttypes>
#include <errno.h>
#include <fstream>
#include <optional>
#include <png.h>
#include <string.h>
#include <tuple>
#include <vector>
#include "defaultinitalloc.hpp"
#include "helpers.h"
#include "itertools.hpp"
#include "gfx/main.hpp"
static DefaultInitVec<uint8_t> readInto(std::string path) {
std::filebuf file;
if (!file.open(path, std::ios::in | std::ios::binary)) {
fatal("Failed to open \"%s\": %s", path.c_str(), strerror(errno));
}
DefaultInitVec<uint8_t> data(128 * 16); // Begin with some room pre-allocated
size_t curSize = 0;
for (;;) {
size_t oldSize = curSize;
curSize = data.size();
// Fill the new area ([oldSize; curSize[) with bytes
size_t nbRead =
file.sgetn(reinterpret_cast<char *>(&data.data()[oldSize]), curSize - oldSize);
if (nbRead != curSize - oldSize) {
// Shrink the vector to discard bytes that weren't read
data.resize(oldSize + nbRead);
break;
}
// If the vector has some capacity left, use it; otherwise, double the current size
// Arbitrary, but if you got a better idea...
size_t newSize = oldSize != data.capacity() ? data.capacity() : oldSize * 2;
assert(oldSize != newSize);
data.resize(newSize);
}
return data;
}
[[noreturn]] static void pngError(png_structp png, char const *msg) {
fatal("Error writing reversed image (\"%s\"): %s",
static_cast<char const *>(png_get_error_ptr(png)), msg);
}
static void pngWarning(png_structp png, char const *msg) {
warning("While writing reversed image (\"%s\"): %s",
static_cast<char const *>(png_get_error_ptr(png)), msg);
}
void writePng(png_structp png, png_bytep data, size_t length) {
auto &pngFile = *static_cast<std::filebuf *>(png_get_io_ptr(png));
pngFile.sputn(reinterpret_cast<char *>(data), length);
}
void flushPng(png_structp png) {
auto &pngFile = *static_cast<std::filebuf *>(png_get_io_ptr(png));
pngFile.pubsync();
}
void reverse() {
options.verbosePrint(Options::VERB_CFG, "Using libpng %s\n", png_get_libpng_ver(nullptr));
// Check for weird flag combinations
if (options.output.empty()) {
fatal("Tile data must be provided when reversing an image!");
}
if (options.allowDedup && options.tilemap.empty()) {
warning("Tile deduplication is enabled, but no tilemap is provided?");
}
if (options.useColorCurve) {
warning("The color curve is not yet supported in reverse mode...");
}
if (options.inputSlice.left != 0 || options.inputSlice.top != 0
|| options.inputSlice.height != 0) {
warning("\"Sliced-off\" pixels are ignored in reverse mode");
}
if (options.inputSlice.width != 0 && options.inputSlice.width != options.reversedWidth * 8) {
warning("Specified input slice width (%" PRIu16
") doesn't match provided reversing width (%" PRIu8 " * 8)",
options.inputSlice.width, options.reversedWidth);
}
options.verbosePrint(Options::VERB_LOG_ACT, "Reading tiles...\n");
auto const tiles = readInto(options.output);
uint8_t tileSize = 8 * options.bitDepth;
if (tiles.size() % tileSize != 0) {
fatal("Tile data size must be a multiple of %" PRIu8 " bytes! (Read %zu)", tileSize,
tiles.size());
}
// By default, assume tiles are not deduplicated, and add the (allegedly) trimmed tiles
size_t nbTileInstances = tiles.size() / tileSize + options.trim; // Image size in tiles
options.verbosePrint(Options::VERB_INTERM, "Read %zu tiles.\n", nbTileInstances);
std::optional<DefaultInitVec<uint8_t>> tilemap;
if (!options.tilemap.empty()) {
tilemap = readInto(options.tilemap);
nbTileInstances = tilemap->size();
options.verbosePrint(Options::VERB_INTERM, "Read %zu tilemap entries.\n", nbTileInstances);
}
if (nbTileInstances == 0) {
fatal("Cannot generate empty image");
}
if (nbTileInstances > options.maxNbTiles[0] + options.maxNbTiles[1]) {
warning("Read %zu tiles, more than the limit of %zu + %zu", nbTileInstances,
options.maxNbTiles[0], options.maxNbTiles[1]);
}
size_t width = options.reversedWidth, height; // In tiles
if (nbTileInstances % width != 0) {
fatal("Total number of tiles read (%zu) cannot be divided by image width (%zu tiles)",
nbTileInstances, width);
}
height = nbTileInstances / width;
options.verbosePrint(Options::VERB_INTERM, "Reversed image dimensions: %zux%zu tiles\n", width,
height);
// TODO: -U
std::vector<std::array<Rgba, 4>> palettes{
{Rgba(0xffffffff), Rgba(0xaaaaaaff), Rgba(0x555555ff), Rgba(0x000000ff)}
};
if (!options.palettes.empty()) {
std::filebuf file;
file.open(options.palettes, std::ios::in | std::ios::binary);
palettes.clear();
std::array<uint8_t, sizeof(uint16_t) * 4> buf; // 4 colors
size_t nbRead;
do {
nbRead = file.sgetn(reinterpret_cast<char *>(buf.data()), buf.size());
if (nbRead == buf.size()) {
// Expand the colors
auto &palette = palettes.emplace_back();
std::generate(palette.begin(), palette.begin() + options.nbColorsPerPal,
[&buf, i = 0]() mutable {
i += 2;
return Rgba::fromCGBColor(buf[i - 2] + (buf[i - 1] << 8));
});
} else if (nbRead != 0) {
fatal("Palette data size (%zu) is not a multiple of %zu bytes!\n",
palettes.size() * buf.size() + nbRead, buf.size());
}
} while (nbRead != 0);
if (palettes.size() > options.nbPalettes) {
warning("Read %zu palettes, more than the specified limit of %zu", palettes.size(),
options.nbPalettes);
}
}
std::optional<DefaultInitVec<uint8_t>> attrmap;
if (!options.attrmap.empty()) {
attrmap = readInto(options.attrmap);
if (attrmap->size() != nbTileInstances) {
fatal("Attribute map size (%zu tiles) doesn't match image's (%zu)", attrmap->size(),
nbTileInstances);
}
// Scan through the attributes for inconsistencies
// We do this now for two reasons:
// 1. Checking those during the main loop is harmful to optimization, and
// 2. It clutters the code more, and it's not in great shape to begin with
bool bad = false;
for (auto attr : *attrmap) {
if ((attr & 0b111) > palettes.size()) {
error("Referencing palette %u, but there are only %zu!");
bad = true;
}
if (attr & 0x08 && !tilemap) {
warning("Tile in bank 1 but no tilemap specified; ignoring the bank bit");
}
}
if (bad) {
giveUp();
}
}
if (tilemap) {
if (attrmap) {
for (auto [id, attr] : zip(*tilemap, *attrmap)) {
bool bank = attr & 1 << 3;
if (id >= options.maxNbTiles[bank]) {
warning("Tile #%" PRIu8
" was referenced, but the limit for bank %u is %" PRIu16,
id, bank, options.maxNbTiles[bank]);
}
}
} else {
for (auto id : *tilemap) {
if (id >= options.maxNbTiles[0]) {
warning("Tile #%" PRIu8 " was referenced, but the limit is %" PRIu16, id,
options.maxNbTiles[0]);
}
}
}
}
std::optional<DefaultInitVec<uint8_t>> palmap;
if (!options.palmap.empty()) {
palmap = readInto(options.palmap);
if (palmap->size() != nbTileInstances) {
fatal("Palette map size (%zu tiles) doesn't match image's (%zu)", palmap->size(),
nbTileInstances);
}
}
options.verbosePrint(Options::VERB_LOG_ACT, "Writing image...\n");
std::filebuf pngFile;
pngFile.open(options.input, std::ios::out | std::ios::binary);
png_structp png = png_create_write_struct(
PNG_LIBPNG_VER_STRING,
const_cast<png_voidp>(static_cast<void const *>(options.input.c_str())), pngError,
pngWarning);
if (!png) {
fatal("Couldn't create PNG write struct: %s", strerror(errno));
}
png_infop pngInfo = png_create_info_struct(png);
if (!pngInfo) {
fatal("Couldn't create PNG info struct: %s", strerror(errno));
}
png_set_write_fn(png, &pngFile, writePng, flushPng);
png_set_IHDR(png, pngInfo, options.reversedWidth * 8, height * 8, 8, PNG_COLOR_TYPE_RGB_ALPHA,
PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
png_write_info(png, pngInfo);
png_color_8 sbitChunk;
sbitChunk.red = 5;
sbitChunk.green = 5;
sbitChunk.blue = 5;
sbitChunk.alpha = 1;
png_set_sBIT(png, pngInfo, &sbitChunk);
constexpr uint8_t SIZEOF_PIXEL = 4; // Each pixel is 4 bytes (RGBA @ 8 bits/component)
size_t const SIZEOF_ROW = options.reversedWidth * 8 * SIZEOF_PIXEL;
std::vector<uint8_t> tileRow(8 * SIZEOF_ROW, 0xFF); // Data for 8 rows of pixels
uint8_t * const rowPtrs[8] = {
&tileRow.data()[0 * SIZEOF_ROW], &tileRow.data()[1 * SIZEOF_ROW],
&tileRow.data()[2 * SIZEOF_ROW], &tileRow.data()[3 * SIZEOF_ROW],
&tileRow.data()[4 * SIZEOF_ROW], &tileRow.data()[5 * SIZEOF_ROW],
&tileRow.data()[6 * SIZEOF_ROW], &tileRow.data()[7 * SIZEOF_ROW],
};
for (size_t ty = 0; ty < height; ++ty) {
for (size_t tx = 0; tx < width; ++tx) {
size_t index = options.columnMajor ? ty + tx * width : ty * width + tx;
// By default, a tile is unflipped, in bank 0, and uses palette #0
uint8_t attribute = attrmap.has_value() ? (*attrmap)[index] : 0x00;
bool bank = attribute & 0x08;
// Get the tile ID at this location
size_t tileID = index;
if (tilemap.has_value()) {
tileID =
(*tilemap)[index] - options.baseTileIDs[bank] + bank * options.maxNbTiles[0];
}
assert(tileID < nbTileInstances); // Should have been checked earlier
size_t palID = palmap ? (*palmap)[index] : attribute & 0b111;
assert(palID < palettes.size()); // Should be ensured on data read
// We do not have data for tiles trimmed with `-x`, so assume they are "blank"
static std::array<uint8_t, 16> const trimmedTile{
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
};
uint8_t const *tileData = tileID > nbTileInstances - options.trim
? trimmedTile.data()
: &tiles[tileID * tileSize];
auto const &palette = palettes[palID];
for (uint8_t y = 0; y < 8; ++y) {
// If vertically mirrored, fetch the bytes from the other end
uint8_t realY = attribute & 0x40 ? 7 - y : y;
uint8_t bitplane0 = tileData[realY * 2], bitplane1 = tileData[realY * 2 + 1];
if (attribute & 0x20) { // Handle horizontal flip
bitplane0 = flipTable[bitplane0];
bitplane1 = flipTable[bitplane1];
}
uint8_t *ptr = &rowPtrs[y][tx * 8 * SIZEOF_PIXEL];
for (uint8_t x = 0; x < 8; ++x) {
uint8_t bit0 = bitplane0 & 0x80, bit1 = bitplane1 & 0x80;
Rgba const &pixel = palette[bit0 >> 7 | bit1 >> 6];
*ptr++ = pixel.red;
*ptr++ = pixel.green;
*ptr++ = pixel.blue;
*ptr++ = pixel.alpha;
// Shift the pixel out
bitplane0 <<= 1;
bitplane1 <<= 1;
}
}
}
// We never modify the pointers, and neither should libpng, despite the overly lax function
// signature.
// (AIUI, casting away const-ness is okay as long as you don't actually modify the
// pointed-to data)
png_write_rows(png, const_cast<png_bytepp>(rowPtrs), 8);
}
// Finalize the write
png_write_end(png, pngInfo);
png_destroy_write_struct(&png, &pngInfo);
pngFile.close();
}