Added the ability to use ASTC compressed textures, when the system supports them.

src/modules/image/magpie/ASTCHandler.cpp

@@ -0,0 +1,166 @@
+/**
+ * Copyright (c) 2006-2015 LOVE Development Team
+ *
+ * This software is provided 'as-is', without any express or implied
+ * warranty.  In no event will the authors be held liable for any damages
+ * arising from the use of this software.
+ *
+ * Permission is granted to anyone to use this software for any purpose,
+ * including commercial applications, and to alter it and redistribute it
+ * freely, subject to the following restrictions:
+ *
+ * 1. The origin of this software must not be misrepresented; you must not
+ *    claim that you wrote the original software. If you use this software
+ *    in a product, an acknowledgment in the product documentation would be
+ *    appreciated but is not required.
+ * 2. Altered source versions must be plainly marked as such, and must not be
+ *    misrepresented as being the original software.
+ * 3. This notice may not be removed or altered from any source distribution.
+ **/
+
+// LOVE
+#include "ASTCHandler.h"
+#include "common/int.h"
+
+namespace love
+{
+namespace image
+{
+namespace magpie
+{
+
+namespace
+{
+
+static const uint32 ASTC_IDENTIFIER = 0x5CA1AB13;
+
+#pragma pack(push, 1)
+struct ASTCHeader
+{
+	uint8 identifier[4];
+	uint8 blockdimX;
+	uint8 blockdimY;
+	uint8 blockdimZ;
+	uint8 sizeX[3];
+	uint8 sizeY[3];
+	uint8 sizeZ[3];
+};
+#pragma pack(pop)
+
+static CompressedImageData::Format convertFormat(uint32 blockX, uint32 blockY, uint32 blockZ)
+{
+	if (blockZ > 1)
+		return CompressedImageData::FORMAT_UNKNOWN;
+
+	if (blockX == 4 && blockY == 4)
+		return CompressedImageData::FORMAT_ASTC_4x4;
+	else if (blockX == 5 && blockY == 4)
+		return CompressedImageData::FORMAT_ASTC_5x4;
+	else if (blockX == 5 && blockY == 5)
+		return CompressedImageData::FORMAT_ASTC_5x5;
+	else if (blockX == 6 && blockY == 5)
+		return CompressedImageData::FORMAT_ASTC_6x5;
+	else if (blockX == 6 && blockY == 6)
+		return CompressedImageData::FORMAT_ASTC_6x6;
+	else if (blockX == 8 && blockY == 5)
+		return CompressedImageData::FORMAT_ASTC_8x5;
+	else if (blockX == 8 && blockY == 6)
+		return CompressedImageData::FORMAT_ASTC_8x6;
+	else if (blockX == 8 && blockY == 8)
+		return CompressedImageData::FORMAT_ASTC_8x8;
+	else if (blockX == 10 && blockY == 5)
+		return CompressedImageData::FORMAT_ASTC_10x5;
+	else if (blockX == 10 && blockY == 6)
+		return CompressedImageData::FORMAT_ASTC_10x6;
+	else if (blockX == 10 && blockY == 8)
+		return CompressedImageData::FORMAT_ASTC_10x8;
+	else if (blockX == 10 && blockY == 10)
+		return CompressedImageData::FORMAT_ASTC_10x10;
+	else if (blockX == 12 && blockY == 10)
+		return CompressedImageData::FORMAT_ASTC_12x10;
+	else if (blockX == 12 && blockY == 12)
+		return CompressedImageData::FORMAT_ASTC_12x12;
+
+	return CompressedImageData::FORMAT_UNKNOWN;
+}
+
+} // Anonymous namespace.
+
+bool ASTCHandler::canParse(const filesystem::FileData *data)
+{
+	if (data->getSize() <= sizeof(ASTCHeader))
+		return false;
+
+	const ASTCHeader *header = (const ASTCHeader *) data->getData();
+
+	uint32 identifier =  (uint32) header->identifier[0]
+	                  + ((uint32) header->identifier[1] << 8)
+	                  + ((uint32) header->identifier[2] << 16)
+	                  + ((uint32) header->identifier[3] << 24);
+
+	if (identifier != ASTC_IDENTIFIER)
+		return false;
+
+	return true;
+}
+
+uint8 *ASTCHandler::parse(filesystem::FileData *filedata, std::vector<CompressedImageData::SubImage> &images, size_t &dataSize, CompressedImageData::Format &format, bool &sRGB)
+{
+	if (!canParse(filedata))
+		throw love::Exception("Could not decode compressed data (not an .astc file?)");
+
+	ASTCHeader header = *(const ASTCHeader *) filedata->getData();
+
+	CompressedImageData::Format cformat = convertFormat(header.blockdimX, header.blockdimY, header.blockdimZ);
+
+	if (cformat == CompressedImageData::FORMAT_UNKNOWN)
+		throw love::Exception("Could not parse .astc file: unsupported ASTC format %dx%dx%d.", header.blockdimX, header.blockdimY, header.blockdimZ);
+
+	uint32 sizeX = header.sizeX[0] + (header.sizeX[1] << 8) + (header.sizeX[2] << 16);
+	uint32 sizeY = header.sizeY[0] + (header.sizeY[1] << 8) + (header.sizeY[2] << 16);
+	uint32 sizeZ = header.sizeZ[0] + (header.sizeZ[1] << 8) + (header.sizeZ[2] << 16);
+
+	uint32 blocksX = (sizeX + header.blockdimX - 1) / header.blockdimX;
+	uint32 blocksY = (sizeY + header.blockdimY - 1) / header.blockdimY;
+	uint32 blocksZ = (sizeZ + header.blockdimZ - 1) / header.blockdimZ;
+
+	size_t totalsize = blocksX * blocksY * blocksZ * 16;
+
+	if (totalsize + sizeof(header) > filedata->getSize())
+		throw love::Exception("Could not parse .astc file: file is too small.");
+
+	uint8 *data = nullptr;
+
+	try
+	{
+		data = new uint8[totalsize];
+	}
+	catch (std::bad_alloc &)
+	{
+		throw love::Exception("Out of memory.");
+	}
+
+	// .astc files only store a single mipmap level.
+	memcpy(data, (uint8 *) filedata->getData() + sizeof(ASTCHeader), totalsize);
+
+	CompressedImageData::SubImage mip;
+
+	mip.width = sizeX;
+	mip.height = sizeY;
+
+	mip.size = totalsize;
+	mip.data = data;
+
+	images.push_back(mip);
+
+	dataSize = totalsize;
+	format = cformat;
+	sRGB = false;
+
+	return data;
+}
+
+} // magpie
+} // image
+} // love
+