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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 2
* 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, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
* $URL$
* $Id$
*
*/
/*
* This code is based on Broken Sword 2.5 engine
*
* Copyright (c) Malte Thiesen, Daniel Queteschiner and Michael Elsdoerfer
*
* Licensed under GNU GPL v2
*
*/
#include "sword25/gfx/image/image.h"
#include "sword25/gfx/image/pngloader.h"
#include <png.h>
namespace Sword25 {
#define BS_LOG_PREFIX "PNGLOADER"
/**
* Load a NULL-terminated string from the given stream.
*/
static Common::String loadString(Common::ReadStream &in, uint maxSize = 999) {
Common::String result;
while (!in.eos() && (result.size() < maxSize)) {
char ch = (char)in.readByte();
if (ch == '\0')
break;
result += ch;
}
return result;
}
/**
* Check if the given data is a savegame, and if so, locate the
* offset to the image data.
* @return offset to image data if fileDataPtr contains a savegame; 0 otherwise
*/
static uint findEmbeddedPNG(const byte *fileDataPtr, uint fileSize) {
if (fileSize < 100)
return 0;
if (memcmp(fileDataPtr, "BS25SAVEGAME", 12))
return 0;
// Read in the header
Common::MemoryReadStream stream(fileDataPtr, fileSize);
stream.seek(0, SEEK_SET);
// Headerinformationen der Spielstandes einlesen.
uint compressedGamedataSize;
loadString(stream); // Marker
loadString(stream); // Version
loadString(stream); // Description
Common::String gameSize = loadString(stream);
compressedGamedataSize = atoi(gameSize.c_str());
loadString(stream);
// Return the offset of where the thumbnail starts
return static_cast<uint>(stream.pos() + compressedGamedataSize);
}
static void png_user_read_data(png_structp png_ptr, png_bytep data, png_size_t length) {
const byte **ref = (const byte **)png_get_io_ptr(png_ptr);
memcpy(data, *ref, length);
*ref += length;
}
static bool doIsCorrectImageFormat(const byte *fileDataPtr, uint fileSize) {
return (fileSize > 8) && png_check_sig(const_cast<byte *>(fileDataPtr), 8);
}
bool PNGLoader::doDecodeImage(const byte *fileDataPtr, uint fileSize, byte *&uncompressedDataPtr, int &width, int &height, int &pitch) {
png_structp png_ptr = NULL;
png_infop info_ptr = NULL;
png_bytep rawDataBuffer = NULL;
png_bytep *pRowPtr = NULL;
int bitDepth;
int colorType;
int interlaceType;
int i;
// Check for valid PNG signature
if (!doIsCorrectImageFormat(fileDataPtr, fileSize)) {
error("png_check_sig failed");
}
// Die beiden PNG Strukturen erstellen
png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
if (!png_ptr) {
error("Could not create libpng read struct.");
}
info_ptr = png_create_info_struct(png_ptr);
if (!info_ptr) {
error("Could not create libpng info struct.");
}
// Alternative Lesefunktion benutzen
const byte **ref = &fileDataPtr;
png_set_read_fn(png_ptr, (void *)ref, png_user_read_data);
// PNG Header einlesen
png_read_info(png_ptr, info_ptr);
// PNG Informationen auslesen
png_get_IHDR(png_ptr, info_ptr, (png_uint_32 *)&width, (png_uint_32 *)&height, &bitDepth, &colorType, &interlaceType, NULL, NULL);
// Pitch des Ausgabebildes berechnen
pitch = GraphicEngine::calcPitch(GraphicEngine::CF_ARGB32, width);
// Speicher f�r die endg�ltigen Bilddaten reservieren
// Dieses geschieht vor dem reservieren von Speicher f�r tempor�re Bilddaten um die Fragmentierung des Speichers gering zu halten
uncompressedDataPtr = new byte[pitch * height];
if (!uncompressedDataPtr) {
error("Could not allocate memory for output image.");
}
// Bilder jeglicher Farbformate werden zun�chst in ARGB Bilder umgewandelt
if (bitDepth == 16)
png_set_strip_16(png_ptr);
if (colorType == PNG_COLOR_TYPE_PALETTE)
png_set_expand(png_ptr);
if (bitDepth < 8)
png_set_expand(png_ptr);
if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS))
png_set_expand(png_ptr);
if (colorType == PNG_COLOR_TYPE_GRAY ||
colorType == PNG_COLOR_TYPE_GRAY_ALPHA)
png_set_gray_to_rgb(png_ptr);
png_set_bgr(png_ptr);
if (colorType != PNG_COLOR_TYPE_RGB_ALPHA)
png_set_filler(png_ptr, 0xff, PNG_FILLER_AFTER);
// Nachdem die Transformationen registriert wurden, werden die Bilddaten erneut eingelesen
png_read_update_info(png_ptr, info_ptr);
png_get_IHDR(png_ptr, info_ptr, (png_uint_32 *)&width, (png_uint_32 *)&height, &bitDepth, &colorType, NULL, NULL, NULL);
// PNGs ohne Interlacing werden Zeilenweise eingelesen
if (interlaceType == PNG_INTERLACE_NONE) {
// Speicher f�r eine Bildzeile reservieren
rawDataBuffer = new png_byte[png_get_rowbytes(png_ptr, info_ptr)];
if (!rawDataBuffer) {
error("Could not allocate memory for row buffer.");
}
// Bilddaten zeilenweise einlesen und in das gew�nschte Zielformat konvertieren
for (i = 0; i < height; i++) {
// Zeile einlesen
png_read_row(png_ptr, rawDataBuffer, NULL);
// Zeile konvertieren
memcpy(&uncompressedDataPtr[i * pitch], rawDataBuffer, pitch);
}
} else {
// PNGs mit Interlacing werden an einem St�ck eingelesen
// Speicher f�r das komplette Bild reservieren
rawDataBuffer = new png_byte[png_get_rowbytes(png_ptr, info_ptr) * height];
if (!rawDataBuffer) {
error("Could not allocate memory for raw image buffer.");
}
// Speicher f�r die Rowpointer reservieren
pRowPtr = new png_bytep[height];
if (!pRowPtr) {
error("Could not allocate memory for row pointers.");
}
// Alle Rowpointer mit den richtigen Offsets initialisieren
for (i = 0; i < height; i++)
pRowPtr[i] = rawDataBuffer + i * png_get_rowbytes(png_ptr, info_ptr);
// Bild einlesen
png_read_image(png_ptr, pRowPtr);
// Bilddaten zeilenweise in das gew�nschte Ausgabeformat konvertieren
for (i = 0; i < height; i++)
memcpy(&uncompressedDataPtr[i * pitch], &rawDataBuffer[i * png_get_rowbytes(png_ptr, info_ptr)], pitch);
}
// Die zus�tzlichen Daten am Ende des Bildes lesen
png_read_end(png_ptr, NULL);
// Die Strukturen freigeben
png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
// Tempor�re Buffer freigeben
delete[] pRowPtr;
delete[] rawDataBuffer;
// Der Funktionsaufruf war erfolgreich
return true;
}
bool PNGLoader::decodeImage(const byte *fileDataPtr, uint fileSize, byte *&uncompressedDataPtr, int &width, int &height, int &pitch) {
uint pngOffset = findEmbeddedPNG(fileDataPtr, fileSize);
return doDecodeImage(fileDataPtr + pngOffset, fileSize - pngOffset, uncompressedDataPtr, width, height, pitch);
}
bool PNGLoader::doImageProperties(const byte *fileDataPtr, uint fileSize, int &width, int &height) {
// Check for valid PNG signature
if (!doIsCorrectImageFormat(fileDataPtr, fileSize))
return false;
png_structp png_ptr = NULL;
png_infop info_ptr = NULL;
// Die beiden PNG Strukturen erstellen
png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
if (!png_ptr) {
error("Could not create libpng read struct.");
}
info_ptr = png_create_info_struct(png_ptr);
if (!info_ptr) {
error("Could not create libpng info struct.");
}
// Alternative Lesefunktion benutzen
const byte **ref = &fileDataPtr;
png_set_read_fn(png_ptr, (void *)ref, png_user_read_data);
// PNG Header einlesen
png_read_info(png_ptr, info_ptr);
// PNG Informationen auslesen
int bitDepth;
int colorType;
png_get_IHDR(png_ptr, info_ptr, (png_uint_32 *)&width, (png_uint_32 *)&height, &bitDepth, &colorType, NULL, NULL, NULL);
// Die Strukturen freigeben
png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
return true;
}
bool PNGLoader::imageProperties(const byte *fileDataPtr, uint fileSize, int &width, int &height) {
uint pngOffset = findEmbeddedPNG(fileDataPtr, fileSize);
return doImageProperties(fileDataPtr + pngOffset, fileSize - pngOffset, width, height);
}
} // End of namespace Sword25
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