Added support for DXT1/3/5 and BC5/7 compressed textures via love.image.CompressedData. Some internals are still iffy.

- added a new CompressedData type to love.image
- added love.image.isCompressed(file or data)
- love.graphics.newImage automatically tests for compression when loading a file
- added love.graphics.isSupported strings for DXT, BC5, and BC7

Compressed textures meant to be used on the GPU offer huge performance gains when
- loading the texture from a file
- loading the texture from RAM to VRAM
- loading mipmaps
- rendering

--HG--
branch : image-CompressedData

src/modules/image/CompressedData.cpp

@@ -0,0 +1,123 @@
+/**
+ * Copyright (c) 2006-2013 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.
+ **/
+
+#include "CompressedData.h"
+
+namespace love
+{
+namespace image
+{
+
+CompressedData::CompressedData()
+	: type(TYPE_MAX_ENUM)
+{
+	
+}
+
+CompressedData::~CompressedData()
+{
+	
+}
+
+int CompressedData::getSize() const
+{
+	size_t totalsize = sizeof(MipmapInfo) * dataMipmapInfo.size();
+
+	for (size_t i = 0; i < dataMipmapInfo.size(); i++)
+		totalsize += dataMipmapInfo[i].size;
+
+	return totalsize;
+}
+
+void *CompressedData::getData() const
+{
+	// ?
+	return (void *) &dataMipmapInfo[0].data[0];
+}
+
+int CompressedData::getNumMipmaps() const
+{
+	return dataMipmapInfo.size();
+}
+
+int CompressedData::getSize(int miplevel) const
+{
+	checkMipmapLevelExists(miplevel);
+
+	return dataMipmapInfo[miplevel].size;
+}
+
+void *CompressedData::getData(int miplevel) const
+{
+	checkMipmapLevelExists(miplevel);
+
+	return (void *) &dataMipmapInfo[miplevel].data[0];
+}
+
+int CompressedData::getWidth(int miplevel) const
+{
+	checkMipmapLevelExists(miplevel);
+
+	return dataMipmapInfo[miplevel].width;
+}
+
+int CompressedData::getHeight(int miplevel) const
+{
+	checkMipmapLevelExists(miplevel);
+
+	return dataMipmapInfo[miplevel].height;
+}
+
+CompressedData::TextureType CompressedData::getType() const
+{
+	return type;
+}
+
+void CompressedData::checkMipmapLevelExists(int miplevel) const
+{
+	if (miplevel < 0 || miplevel >= dataMipmapInfo.size())
+		throw love::Exception("Mipmap level %d does not exist", miplevel);
+}
+
+bool CompressedData::getConstant(const char *in, CompressedData::TextureType &out)
+{
+	return types.find(in, out);
+}
+
+bool CompressedData::getConstant(CompressedData::TextureType in, const char *&out)
+{
+	return types.find(in, out);
+}
+
+StringMap<CompressedData::TextureType, CompressedData::TYPE_MAX_ENUM>::Entry CompressedData::typeEntries[] =
+{
+	{"dxt1", CompressedData::TYPE_DXT1},
+	{"dxt3", CompressedData::TYPE_DXT3},
+	{"dxt5", CompressedData::TYPE_DXT5},
+	{"bc5s", CompressedData::TYPE_BC5s},
+	{"bc5u", CompressedData::TYPE_BC5u},
+	{"bc7", CompressedData::TYPE_BC7},
+	{"bc7srgb", CompressedData::TYPE_BC7srgb},
+};
+
+StringMap<CompressedData::TextureType, CompressedData::TYPE_MAX_ENUM> CompressedData::types(CompressedData::typeEntries, sizeof(CompressedData::typeEntries));
+
+} // image
+} // love