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/wrap_CompressedData.cpp

@@ -0,0 +1,129 @@
+/**
+ * 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 "wrap_CompressedData.h"
+#include "common/wrap_Data.h"
+
+namespace love
+{
+namespace image
+{
+
+CompressedData *luax_checkcompresseddata(lua_State *L, int idx)
+{
+	return luax_checktype<CompressedData>(L, idx, "CompressedData", IMAGE_COMPRESSED_DATA_T);
+}
+
+int w_CompressedData_getWidth(lua_State *L)
+{
+	CompressedData *t = luax_checkcompresseddata(L, 1);
+	int miplevel = luaL_optinteger(L, 2, 1);
+	int width = 0;
+	try
+	{
+		width = t->getWidth(miplevel >= 1 ? miplevel - 1 : 0);
+	}
+	catch (love::Exception &e)
+	{
+		return luaL_error(L, "%s", e.what());
+	}
+	lua_pushinteger(L, width);
+	return 1;
+}
+
+int w_CompressedData_getHeight(lua_State *L)
+{
+	CompressedData *t = luax_checkcompresseddata(L, 1);
+	int miplevel = luaL_optinteger(L, 2, 1);
+	int height = 0;
+	try
+	{
+		height = t->getHeight(miplevel >= 1 ? miplevel - 1 : 0);
+	}
+	catch (love::Exception &e)
+	{
+		return luaL_error(L, "%s", e.what());
+	}
+	lua_pushinteger(L, height);
+	return 1;
+}
+
+int w_CompressedData_getDimensions(lua_State *L)
+{
+	CompressedData *t = luax_checkcompresseddata(L, 1);
+	int miplevel = luaL_optinteger(L, 2, 1);
+	int width = 0, height = 0;
+	try
+	{
+		width = t->getWidth(miplevel >= 1 ? miplevel - 1 : 0);
+		height = t->getHeight(miplevel >= 1 ? miplevel - 1 : 0);
+	}
+	catch (love::Exception &e)
+	{
+		return luaL_error(L, "%s", e.what());
+	}
+	lua_pushinteger(L, width);
+	lua_pushinteger(L, height);
+	return 2;
+}
+
+int w_CompressedData_getNumMipmaps(lua_State *L)
+{
+	CompressedData *t = luax_checkcompresseddata(L, 1);
+	lua_pushinteger(L, t->getNumMipmaps());
+	return 1;
+}
+
+int w_CompressedData_getType(lua_State *L)
+{
+	CompressedData *t = luax_checkcompresseddata(L, 1);
+
+	image::CompressedData::TextureType type = t->getType();
+	const char *str;
+
+	if (image::CompressedData::getConstant(type, str))
+		lua_pushstring(L, str);
+	else
+		lua_pushstring(L, "unknown");
+
+	return 1;
+}
+
+static const luaL_Reg functions[] =
+{
+	// Data
+	{ "getPointer", w_Data_getPointer },
+	{ "getSize", w_Data_getSize },
+
+	{ "getWidth", w_CompressedData_getWidth },
+	{ "getHeight", w_CompressedData_getHeight },
+	{ "getDimensions", w_CompressedData_getDimensions },
+	{ "getNumMipmaps", w_CompressedData_getNumMipmaps },
+	{ "getType", w_CompressedData_getType },
+	{ 0, 0 },
+};
+
+extern "C" int luaopen_compresseddata(lua_State *L)
+{
+	return luax_register_type(L, "CompressedData", functions);
+}
+
+} // image
+} // love