Add worker-thread image decoder

- Decodes DDS, PNG, JPG, TGA, BMP formats
- Thread-safe for use in worker threads
- Uses stb_image for common formats
- Custom DDS header parsing

src/EterLib/ImageDecoder.cpp

@@ -0,0 +1,92 @@
+#include "StdAfx.h"
+#include "ImageDecoder.h"
+#include "EterImageLib/DDSTextureLoader9.h"
+#include <stb_image.h>
+
+bool CImageDecoder::DecodeImage(const void* pData, size_t dataSize, TDecodedImageData& outImage)
+{
+	if (!pData || dataSize == 0)
+		return false;
+
+	outImage.Clear();
+
+	if (DecodeDDS(pData, dataSize, outImage))
+		return true;
+
+	if (DecodeSTB(pData, dataSize, outImage))
+		return true;
+
+	return false;
+}
+
+bool CImageDecoder::DecodeDDS(const void* pData, size_t dataSize, TDecodedImageData& outImage)
+{
+	if (dataSize < 4)
+		return false;
+
+	const uint32_t DDS_MAGIC = 0x20534444;
+	uint32_t magic = *(const uint32_t*)pData;
+
+	if (magic != DDS_MAGIC)
+		return false;
+
+	if (dataSize < 128)
+		return false;
+
+	struct DDSHeader
+	{
+		uint32_t magic;
+		uint32_t size;
+		uint32_t flags;
+		uint32_t height;
+		uint32_t width;
+		uint32_t pitchOrLinearSize;
+		uint32_t depth;
+		uint32_t mipMapCount;
+		uint32_t reserved1[11];
+	};
+
+	const DDSHeader* header = (const DDSHeader*)pData;
+
+	outImage.width = header->width;
+	outImage.height = header->height;
+	outImage.mipLevels = (header->mipMapCount > 0) ? header->mipMapCount : 1;
+	outImage.isDDS = true;
+	outImage.format = TDecodedImageData::FORMAT_DDS;
+
+	outImage.pixels.resize(dataSize);
+	memcpy(outImage.pixels.data(), pData, dataSize);
+
+	return true;
+}
+
+bool CImageDecoder::DecodeSTB(const void* pData, size_t dataSize, TDecodedImageData& outImage)
+{
+	int width, height, channels;
+
+	unsigned char* imageData = stbi_load_from_memory(
+		(const stbi_uc*)pData,
+		(int)dataSize,
+		&width,
+		&height,
+		&channels,
+		4
+	);
+
+	if (!imageData)
+		return false;
+
+	outImage.width = width;
+	outImage.height = height;
+	outImage.format = TDecodedImageData::FORMAT_RGBA8;
+	outImage.isDDS = false;
+	outImage.mipLevels = 1;
+
+	size_t pixelDataSize = width * height * 4;
+	outImage.pixels.resize(pixelDataSize);
+	memcpy(outImage.pixels.data(), imageData, pixelDataSize);
+
+	stbi_image_free(imageData);
+
+	return true;
+}

src/EterLib/ImageDecoder.h

@@ -0,0 +1,18 @@
+#ifndef __INC_ETERLIB_IMAGEDECODER_H__
+#define __INC_ETERLIB_IMAGEDECODER_H__
+
+#include "DecodedImageData.h"
+
+// Image decoder for worker threads
+class CImageDecoder
+{
+public:
+	// Decode image from memory (DDS, PNG, JPG, TGA, BMP)
+	static bool DecodeImage(const void* pData, size_t dataSize, TDecodedImageData& outImage);
+
+private:
+	static bool DecodeDDS(const void* pData, size_t dataSize, TDecodedImageData& outImage);
+	static bool DecodeSTB(const void* pData, size_t dataSize, TDecodedImageData& outImage);
+};
+
+#endif // __INC_ETERLIB_IMAGEDECODER_H__