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image/png.h

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+/* ScummVM - Graphic Adventure Engine
+ *
+ * ScummVM is the legal property of its developers, whose names
+ * are too numerous to list here. Please refer to the COPYRIGHT
+ * file distributed with this source distribution.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#ifndef IMAGE_PNG_H
+#define IMAGE_PNG_H
+
+#include "common/scummsys.h"
+#include "common/textconsole.h"
+#include "graphics/palette.h"
+#include "graphics/pixelformat.h"
+#include "image/image_decoder.h"
+
+namespace Common {
+class SeekableReadStream;
+class WriteStream;
+}
+
+namespace Graphics {
+struct Surface;
+}
+
+namespace Image {
+
+/**
+ * @defgroup image_png PNG decoder
+ * @ingroup image
+ *
+ * @brief Decoder for PNG images.
+ *
+ * This decoder has a dependency on the libpng library.
+ *
+ * Used in engines:
+ * - Sword25
+ * - TwinE
+ * - Wintermute
+ * @{
+ */
+
+class PNGDecoder : public ImageDecoder {
+public:
+	PNGDecoder();
+	~PNGDecoder();
+
+	bool loadStream(Common::SeekableReadStream &stream) override;
+	void destroy() override;
+	const Graphics::Surface *getSurface() const override { return _outputSurface; }
+	const Graphics::Palette &getPalette() const override { return _palette; }
+	bool hasTransparentColor() const override { return _hasTransparentColor; }
+	uint32 getTransparentColor() const override { return _transparentColor; }
+	void setSkipSignature(bool skip) { _skipSignature = skip; }
+	void setKeepTransparencyPaletted(bool keep) { _keepTransparencyPaletted = keep; }
+private:
+	Graphics::PixelFormat getByteOrderRgbaPixelFormat(bool isAlpha) const;
+
+	Graphics::Palette _palette;
+
+	// flag to skip the png signature check for headless png files
+	bool _skipSignature;
+
+	// Flag to keep paletted images paletted, even when the image has transparency
+	bool _keepTransparencyPaletted;
+	bool _hasTransparentColor;
+	uint32 _transparentColor;
+
+	Graphics::Surface *_outputSurface;
+};
+
+/**
+ * Outputs a compressed PNG stream of the given input surface.
+ *
+ *  @param out  Stream to which to write the PNG image.
+ *  @param input The surface to save as a PNG image..
+ *  @param palette    The palette (in RGB888), if the source format has a bpp of 1.
+ *  @param paletteCount Number of colors in the palette (default: 256).
+ */
+bool writePNG(Common::WriteStream &out, const Graphics::Surface &input, const byte *palette = nullptr, uint paletteCount = 256);
+
+/**
+ * Outputs a compressed PNG stream of the given input surface.
+ *
+ *  @param out  Stream to which to write the PNG image.
+ *  @param input The surface to save as a PNG image..
+ *  @param palette    The palette if the source format has a bpp of 1.
+ */
+bool writePNG(Common::WriteStream &out, const Graphics::Surface &input, const Graphics::Palette &palette);
+/** @} */
+} // End of namespace Image
+
+#endif