Removed the DevIL backend from love.image. Replaced it with PNG and JPEG encoders/decoders via LodePNG, zlib, and libjpeg-turbo.

PNG and JPEG are now the only two supported image formats, aside from compressed DDS (DXT, etc.)

--HG--
branch : minor

src/modules/image/magpie/PNGHandler.cpp

@@ -0,0 +1,218 @@
+/**
+ * Copyright (c) 2006-2014 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 "PNGHandler.h"
+
+// LOVE
+#include "common/Exception.h"
+#include "common/math.h"
+
+// LodePNG
+#include "lodepng/lodepng.h"
+
+// zlib
+#include <zlib.h>
+
+// C++
+#include <algorithm>
+
+namespace love
+{
+namespace image
+{
+namespace magpie
+{
+
+// Custom PNG decompression function for LodePNG, using zlib.
+static unsigned zlibDecompress(unsigned char **out, size_t *outsize, const unsigned char *in,
+                               size_t insize, const LodePNGDecompressSettings* /*settings*/)
+{
+	int status = Z_OK;
+
+	size_t outdataSize = insize;
+	size_t sizeMultiplier = 0;
+	unsigned char *outdata = nullptr;
+
+	while (true)
+	{
+		// Enough size to hold the decompressed data, hopefully.
+		outdataSize = insize << (++sizeMultiplier);
+
+		try
+		{
+			outdata = new unsigned char[outdataSize];
+		}
+		catch (std::bad_alloc &)
+		{
+			return 83; // "Memory allocation failed" error code for LodePNG.
+		}
+
+		// Use zlib to decompress the PNG data.
+		status = uncompress(outdata, &outdataSize, in, insize);
+
+		// If the out buffer was big enough, break out of the loop.
+		if (status != Z_BUF_ERROR)
+			break;
+
+		// Otherwise delete the out buffer and try again with a larger size...
+		delete[] outdata;
+		outdata = nullptr;
+	}
+
+	if (status != Z_OK)
+	{
+		delete[] outdata;
+		return 10000; // "Unknown error code" for LodePNG.
+	}
+
+	if (out != nullptr)
+		*out = outdata;
+
+	if (outsize != nullptr)
+		*outsize = outdataSize;
+
+	return 0; // Success.
+}
+
+// Custom PNG compression function for LodePNG, using zlib.
+static unsigned zlibCompress(unsigned char **out, size_t *outsize, const unsigned char *in,
+							 size_t insize, const LodePNGCompressSettings* /*settings*/)
+{
+	// Get the maximum compressed size of the data.
+	uLongf outdataSize = compressBound(insize);
+	unsigned char *outdata = nullptr;
+
+	try
+	{
+		outdata = new unsigned char[outdataSize];
+	}
+	catch (std::bad_alloc &)
+	{
+		return 83; // "Memory allocation failed" error code for LodePNG.
+	}
+
+	// Use zlib to compress the PNG data.
+	int status = compress(outdata, &outdataSize, in, insize);
+
+	if (status != Z_OK)
+	{
+		delete[] outdata;
+		return 10000; // "Unknown error code" for LodePNG.
+	}
+
+	if (out != nullptr)
+		*out = outdata;
+
+	if (outsize != nullptr)
+		*outsize = (size_t) outdataSize;
+
+	return 0; // Success.
+}
+
+bool PNGHandler::canDecode(love::filesystem::FileData *data)
+{
+	std::string ext = data->getExtension();
+	std::transform(ext.begin(), ext.end(), ext.begin(), tolower);
+
+	return ext.compare("png") == 0;
+}
+
+bool PNGHandler::canEncode(ImageData::Format format)
+{
+	return format == ImageData::FORMAT_PNG;
+}
+
+PNGHandler::DecodedImage PNGHandler::decode(love::filesystem::FileData *fdata)
+{
+	unsigned int width = 0, height = 0;
+	unsigned char *indata = (unsigned char *) fdata->getData();
+	size_t insize = fdata->getSize();
+
+	DecodedImage img;
+
+	LodePNGState state;
+	lodepng_state_init(&state);
+
+	state.info_raw.colortype = LCT_RGBA;
+	state.info_raw.bitdepth = 8;
+
+	state.decoder.zlibsettings.custom_zlib = zlibDecompress;
+
+	unsigned status = lodepng_decode(&img.data, &width, &height,
+	                                 &state, indata, insize);
+
+	lodepng_state_cleanup(&state);
+
+	if (status != 0)
+	{
+		const char *err = lodepng_error_text(status);
+		throw love::Exception("Could not decode PNG image (%s)", err);
+	}
+
+	img.width = (int) width;
+	img.height = (int) height;
+	img.size = width * height * 4;
+
+	return img;
+}
+
+PNGHandler::EncodedImage PNGHandler::encode(const DecodedImage &img, ImageData::Format format)
+{
+	if (format != ImageData::FORMAT_PNG)
+		throw love::Exception("PNG encoder cannot encode to non-PNG format.");
+
+	EncodedImage encimg;
+
+	LodePNGState state;
+	lodepng_state_init(&state);
+
+	state.info_raw.colortype = LCT_RGBA;
+	state.info_raw.bitdepth = 8;
+
+	// TODO: support plain RGB (24-bit) encoding in the future?
+	state.info_png.color.colortype = LCT_RGBA;
+	state.info_png.color.bitdepth = 8;
+
+	state.encoder.zlibsettings.custom_zlib = zlibCompress;
+
+	unsigned status = lodepng_encode(&encimg.data, &encimg.size,
+	                                 img.data, img.width, img.height, &state);
+
+	lodepng_state_cleanup(&state);
+
+	if (status != 0)
+	{
+		const char *err = lodepng_error_text(status);
+		throw love::Exception("Could not encode PNG image (%s)", err);
+	}
+
+	return encimg;
+}
+
+void PNGHandler::free(unsigned char *mem)
+{
+	// LodePNG uses malloc, realloc, and free.
+	if (mem)
+		::free(mem);
+}
+
+} // magpie
+} // image
+} // love