scummvm/engines/sword25/gfx/screenshot.cpp

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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.
*
*/
/*
* 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 "common/memstream.h"
#include "common/textconsole.h"
#include "sword25/gfx/screenshot.h"
#include "sword25/kernel/filesystemutil.h"
namespace Sword25 {
#define THUMBNAIL_VERSION 1
bool Screenshot::saveToFile(Graphics::Surface *data, Common::WriteStream *stream) {
// Convert the RGBA data to RGB
const byte *pSrc = (const byte *)data->getBasePtr(0, 0);
// Write our own custom header
stream->writeUint32BE(MKTAG('S','C','R','N')); // SCRN, short for "Screenshot"
stream->writeUint16LE(data->w);
stream->writeUint16LE(data->h);
stream->writeByte(THUMBNAIL_VERSION);
for (uint y = 0; y < data->h; y++) {
for (uint x = 0; x < data->w; x++) {
// This is only called by createThumbnail below, which
// provides a fake 'surface' with LE data in it.
uint32 srcPixel = READ_LE_UINT32(pSrc);
pSrc += sizeof(uint32);
stream->writeByte((srcPixel >> 16) & 0xff); // R
stream->writeByte((srcPixel >> 8) & 0xff); // G
stream->writeByte(srcPixel & 0xff); // B
}
}
return true;
}
// -----------------------------------------------------------------------------
Common::SeekableReadStream *Screenshot::createThumbnail(Graphics::Surface *data) {
// This method takes a screen image with a dimension of 800x600, and creates a screenshot with a dimension of 200x125.
// First 50 pixels are cut off the top and bottom (the interface boards in the game). The remaining image of 800x500
// will be on a 16th of its size, reduced by being handed out in 4x4 pixel blocks and the average of each block
// generates a pixel of the target image. Finally, the result as a PNG file is stored as a file.
// The source image must be 800x600.
if (data->w != 800 || data->h != 600 || data->format.bytesPerPixel != 4) {
error("The sreenshot dimensions have to be 800x600 in order to be saved as a thumbnail.");
return false;
}
// Buffer for the output thumbnail
Graphics::Surface thumbnail;
thumbnail.create(200, 125, g_system->getScreenFormat());
// <20>ber das Zielbild iterieren und einen Pixel zur Zeit berechnen.
uint x, y;
x = y = 0;
for (byte *pDest = (byte *)thumbnail.pixels; pDest < ((byte *)thumbnail.pixels + thumbnail.pitch * thumbnail.h); ) {
// Get an average over a 4x4 pixel block in the source image
int alpha, red, green, blue;
alpha = red = green = blue = 0;
for (int j = 0; j < 4; ++j) {
const uint32 *srcP = (const uint32 *)data->getBasePtr(x * 4, y * 4 + j + 50);
for (int i = 0; i < 4; ++i) {
uint32 pixel = READ_UINT32(srcP + i);
alpha += (pixel >> 24);
red += (pixel >> 16) & 0xff;
green += (pixel >> 8) & 0xff;
blue += pixel & 0xff;
}
}
// Write target pixel
*pDest++ = blue / 16;
*pDest++ = green / 16;
*pDest++ = red / 16;
*pDest++ = alpha / 16;
// Move to next block
++x;
if (x == thumbnail.w) {
x = 0;
++y;
}
}
// Create a PNG representation of the thumbnail data
Common::MemoryWriteStreamDynamic *stream = new Common::MemoryWriteStreamDynamic();
saveToFile(&thumbnail, stream);
// Output a MemoryReadStream that encompasses the written data
Common::SeekableReadStream *result = new Common::MemoryReadStream(stream->getData(), stream->size(),
DisposeAfterUse::YES);
return result;
}
} // End of namespace Sword25