feat: Started on webp implementationwebp

Currently very basic, can only read simple things such as width and height

2 files changed, 140 insertions, 0 deletions

diff --git a/src/WEBPImage.cpp b/src/WEBPImage.cpp
new file mode 100644
index 0000000..4c4652e
--- /dev/null
+++ b/src/WEBPImage.cpp
@@ -0,0 +1,102 @@
+#include "WEBPImage.h"
+#include "reader.h"
+
+#define ENABLE_DEBUG
+#include "debug.h"
+
+#include <iostream>
+
+using std::cout, std::endl;
+
+namespace TehImage
+{
+	int WEBPImage::writeToFile(std::string filename)
+	{
+		cout << "Not implemented" << endl;
+		return 1;
+	}
+	
+	int WEBPImage::readFromFile(std::string filename)
+	{
+		static_assert(std::endian::native == std::endian::little, "Must use little endian");
+		reader = std::make_unique<Reader>(filename, FileEndianness::LITTLE);
+		
+		refreshBitBuffer();
+
+		char RIFF[4], WEBP[4];
+		char RIFFExpected[] = {'R','I','F','F'};
+		readFourCC(RIFF);
+		uint32_t imgSize = readBits(32);
+		readFourCC(WEBP);
+		char WEBPExpected[] = {'W','E','B','P'};
+		if(strncmp(RIFF, RIFFExpected, 4) != 0 || strncmp(WEBP, WEBPExpected, 4) != 0)
+		{
+			cout << "Not a webp" << endl;
+			// cout << '#' << std::hex << RIFF.raw << " #" << RIFFExpected.raw << std::dec << endl;
+			// cout << '#' << std::hex << WEBP.raw << " #" << WEBPExpected.raw << std::dec << endl;
+			return 1;
+		}
+
+		// refreshBitBuffer();
+
+		char VP8L[4];
+		readFourCC(VP8L);
+		char VP8LExpected[] = {'V', 'P', '8', 'L'};
+		uint32_t VP8LSize = readBits(32);
+		uint8_t signature = readBits(8);
+		if(strncmp(VP8L, VP8LExpected, 4) != 0)
+		{
+			cout << "VP8L error" << endl;
+			return 1;
+		}
+
+		uint16_t width = readBits(14) + 1;
+		uint16_t height = readBits(14) + 1;
+
+		cout << width << " " << height << endl;
+
+		bool alpha = readBits(1);
+		uint8_t versionNumber = readBits(3);
+
+		cout << "Alpha: " << (alpha?"Y":"N") << ", version: " << 0+versionNumber << endl;
+
+		if (readBits(1)) {
+			cout << (int) readBits(2) << endl;
+		}
+		
+		cout << "Not finished" << endl;
+		return 1;
+	}
+
+	bool WEBPImage::readBit()
+	{
+		bool res = bitBuffer & (1 << (bitBufferPos++));
+		if(bitBufferPos >= 8)
+			refreshBitBuffer();
+		return res?1:0;
+	}
+
+	uint32_t WEBPImage::readBits(size_t count)
+	{
+		uint32_t out = 0;
+		for(int i = 0; i < count; i++)
+		{
+			out |= readBit() << i;
+		}
+		return out;
+	}
+
+	void WEBPImage::readFourCC(char* dest)
+	{
+		for(int i = 0; i < 4; i++)
+		{
+			dest[i] = readBits(8);
+		}
+	}
+
+	void WEBPImage::refreshBitBuffer()
+	{
+		bitBuffer = reader->readByte();
+		bitBufferPos = 0;
+	}
+}
diff --git a/src/WEBPImage.h b/src/WEBPImage.h
new file mode 100644
index 0000000..8a87b08
--- /dev/null
+++ b/src/WEBPImage.h
@@ -0,0 +1,38 @@
+#pragma once
+
+#include "image.h"
+#include "reader.h"
+
+#define BIT_BUFFER_SIZE 1024
+
+namespace TehImage
+{
+	typedef enum {
+		PREDICTOR_TRANSFORM             = 0,
+		COLOR_TRANSFORM                 = 1,
+		SUBTRACT_GREEN_TRANSFORM        = 2,
+		COLOR_INDEXING_TRANSFORM        = 3,
+	} TransformType;
+	
+	class WEBPImage : public Image
+	{
+	public:
+		WEBPImage() = default;
+		~WEBPImage() = default;
+		
+		WEBPImage(const Image& other) : Image(other) {}
+		
+		int readFromFile(std::string filename) override;
+		int writeToFile(std::string filename) override;
+
+	private:
+		std::unique_ptr<Reader> reader;
+		uint8_t bitBuffer;
+		size_t bitBufferPos = 0;
+
+		bool readBit();
+		uint32_t readBits(size_t count);
+		void readFourCC(char* dest);
+		void refreshBitBuffer();
+	};
+}