Initial commit

LibImage/Netbpm.cpp

@@ -0,0 +1,140 @@
+#include <BAN/Optional.h>
+
+#include <LibImage/Netbpm.h>
+
+#include <ctype.h>
+#include <inttypes.h>
+#include <stdio.h>
+
+namespace LibImage
+{
+
+	static BAN::Optional<uint64_t> parse_u64(BAN::ConstByteSpan& data)
+	{
+		size_t digit_count = 0;
+		while (digit_count < data.size() && isdigit(data[digit_count]))
+			digit_count++;
+		if (digit_count == 0)
+			return {};
+
+		uint64_t result = 0;
+		for (size_t i = 0; i < digit_count; i++)
+		{
+			if (BAN::Math::will_multiplication_overflow<uint64_t>(result, 10))
+				return {};
+			result *= 10;
+
+			if (BAN::Math::will_addition_overflow<uint64_t>(result, data[i] - '0'))
+				return {};
+			result += data[i] - '0';
+		}
+
+		data = data.slice(digit_count);
+
+		return result;
+	}
+
+
+	bool probe_netbpm(BAN::ConstByteSpan image_data)
+	{
+		if (image_data.size() < 2)
+			return false;
+		uint16_t u16_signature = image_data.as<const uint16_t>();
+		switch (u16_signature)
+		{
+			case 0x3650:
+			case 0x3550:
+			case 0x3450:
+			case 0x3350:
+			case 0x3250:
+			case 0x3150:
+				return true;
+			default:
+				return false;
+		}
+	}
+
+	BAN::ErrorOr<BAN::UniqPtr<Image>> load_netbpm(BAN::ConstByteSpan image_data)
+	{
+		if (image_data.size() < 11)
+		{
+			fprintf(stddbg, "invalid Netbpm image (too small)\n");
+			return BAN::Error::from_errno(EINVAL);
+		}
+
+		if (image_data[0] != 'P')
+		{
+			fprintf(stddbg, "not Netbpm image\n");
+			return BAN::Error::from_errno(EINVAL);
+		}
+		if (image_data[1] != '6')
+		{
+			fprintf(stddbg, "unsupported Netbpm image\n");
+			return BAN::Error::from_errno(EINVAL);
+		}
+		if (image_data[2] != '\n')
+		{
+			fprintf(stddbg, "invalid Netbpm image (invalid header)\n");
+			return BAN::Error::from_errno(EINVAL);
+		}
+		image_data = image_data.slice(3);
+
+		auto opt_width = parse_u64(image_data);
+		if (!opt_width.has_value() || image_data[0] != ' ')
+		{
+			fprintf(stddbg, "invalid Netbpm image (invalid width)\n");
+			return BAN::Error::from_errno(EINVAL);
+		}
+		image_data = image_data.slice(1);
+		auto width = opt_width.value();
+
+		auto opt_height = parse_u64(image_data);
+		if (!opt_height.has_value() || image_data[0] != '\n')
+		{
+			fprintf(stddbg, "invalid Netbpm image (invalid height)\n");
+			return BAN::Error::from_errno(EINVAL);
+		}
+		image_data = image_data.slice(1);
+		auto height = opt_height.value();
+
+		if (!Image::validate_size(width, height))
+		{
+			fprintf(stddbg, "invalid Netbpm image size\n");
+			return BAN::Error::from_errno(EINVAL);
+		}
+
+		auto header_end = parse_u64(image_data);
+		if (!header_end.has_value() || *header_end != 255 || image_data[0] != '\n')
+		{
+			fprintf(stddbg, "invalid Netbpm image (invalid header end)\n");
+			return BAN::Error::from_errno(EINVAL);
+		}
+		image_data = image_data.slice(1);
+
+		if (image_data.size() < width * height * 3)
+		{
+			fprintf(stddbg, "invalid Netbpm image (too small file size)\n");
+			return BAN::Error::from_errno(EINVAL);
+		}
+
+		BAN::Vector<Image::Color> bitmap;
+		TRY(bitmap.resize(width * height));
+
+		// Fill bitmap
+		for (uint64_t y = 0; y < height; y++)
+		{
+			for (uint64_t x = 0; x < width; x++)
+			{
+				const uint64_t index = y * width + x;
+				auto& pixel = bitmap[index];
+				pixel.r = image_data[index * 3 + 0];
+				pixel.g = image_data[index * 3 + 1];
+				pixel.b = image_data[index * 3 + 2];
+				pixel.a = 0xFF;
+			}
+		}
+
+		return TRY(BAN::UniqPtr<Image>::create(width, height, BAN::move(bitmap)));
+	}
+
+}