Take care of miscellaneous commented TODOs (#1676)

src/gfx/main.cpp

@@ -451,9 +451,9 @@ static char *parseArgv(int argc, char *argv[]) {
 			} else {
 				options.palSpecType = Options::EXPLICIT;
 				// Can't parse the file yet, as "flat" color collections need to know the palette
-				// size to be split; thus, we defer that
-				// TODO: this does not validate the `fmt` part of any external spec but the last
-				// one, but I guess that's okay
+				// size to be split; thus, we defer that.
+				// If a following `-c` overrides a previous one, the `fmt` part of an overridden
+				// external palette spec will not be validated, but I guess that's okay.
 				localOptions.externalPalSpec = musl_optarg;
 			}
 			break;

src/gfx/process.cpp

@@ -211,11 +211,6 @@ public:
 		png_set_read_fn(png, this, readData);
 		png_set_sig_bytes(png, pngHeader.size());
 
-		// TODO: png_set_crc_action(png, PNG_CRC_ERROR_QUIT, PNG_CRC_WARN_DISCARD);
-
-		// Skipping chunks we don't use should improve performance
-		// TODO: png_set_keep_unknown_chunks(png, ...);
-
 		// Process all chunks up to but not including the image data
 		png_read_info(png, info);
 
@@ -294,9 +289,7 @@ public:
 			options.verbosePrint(Options::VERB_INTERM, "No embedded palette\n");
 		}
 
-		// Set up transformations; to turn everything into RGBA888
-		// TODO: it's not necessary to uniformize the pixel data (in theory), and not doing
-		// so *might* improve performance, and should reduce memory usage.
+		// Set up transformations to turn everything into RGBA888 for simplicity of handling
 
 		// Convert grayscale to RGB
 		switch (colorType & ~PNG_COLOR_MASK_ALPHA) {
@@ -559,7 +552,6 @@ static void generatePalSpec(Png const &png) {
 static std::tuple<DefaultInitVec<size_t>, std::vector<Palette>>
     generatePalettes(std::vector<ProtoPalette> const &protoPalettes, Png const &png) {
 	// Run a "pagination" problem solver
-	// TODO: allow picking one of several solvers?
 	auto [mappings, nbPalettes] = overloadAndRemove(protoPalettes);
 	assume(mappings.size() == protoPalettes.size());
 

src/gfx/reverse.cpp

@@ -195,8 +195,6 @@ void reverse() {
 	    Options::VERB_INTERM, "Reversed image dimensions: %zux%zu tiles\n", width, height
 	);
 
-	// TODO: `-U` to configure tile size beyond 8x8px ("deduplication units")
-
 	std::vector<std::array<std::optional<Rgba>, 4>> palettes{
 	    {Rgba(0xFFFFFFFF), Rgba(0xAAAAAAFF), Rgba(0x555555FF), Rgba(0x000000FF)}
 	};