aboutsummaryrefslogtreecommitdiff
path: root/engines/sword25/gfx/screenshot.cpp
blob: 35e94976eb20e4f2e47498ba0e064b112eee49ca (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
/* 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
 *
 */

// Disable symbol overrides so that we can use png.h
#define FORBIDDEN_SYMBOL_ALLOW_ALL

#include "common/memstream.h"
#include "sword25/gfx/screenshot.h"
#include "sword25/kernel/filesystemutil.h"
#include <png.h>

namespace Sword25 {

#include "common/pack-start.h"
struct RGB_PIXEL {
	byte red;
	byte green;
	byte blue;
} PACKED_STRUCT;
#include "common/pack-end.h"

void userWriteFn(png_structp png_ptr, png_bytep data, png_size_t length) {
	static_cast<Common::WriteStream *>(png_get_io_ptr(png_ptr))->write(data, length);
}

void userFlushFn(png_structp png_ptr) {
}

bool Screenshot::saveToFile(Graphics::Surface *data, Common::WriteStream *stream) {
	// Reserve buffer space
	RGB_PIXEL *pixelBuffer = new RGB_PIXEL[data->w * data->h];

	// Convert the RGBA data to RGB
	const byte *pSrc = (const byte *)data->getBasePtr(0, 0);
	RGB_PIXEL *pDest = pixelBuffer;

	for (uint y = 0; y < data->h; y++) {
		for (uint x = 0; x < data->w; x++) {
			uint32 srcPixel = READ_LE_UINT32(pSrc);
			pSrc += sizeof(uint32);
			pDest->red = (srcPixel >> 16) & 0xff;
			pDest->green = (srcPixel >> 8) & 0xff;
			pDest->blue = srcPixel & 0xff;
			++pDest;
		}
	}

	png_structp png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
	if (!png_ptr)
		error("Could not create PNG write-struct.");

	png_infop info_ptr = png_create_info_struct(png_ptr);
	if (!info_ptr)
		error("Could not create PNG info-struct.");

	// The compression buffer must be large enough to the entire image.
	// This ensures that only an IDAT chunk is created.
	// When buffer size is used 110% of the raw data size to be sure.
	png_set_compression_buffer_size(png_ptr, (data->w * data->h * 3 * 110) / 100);

	// Initialise PNG-Info structure
	png_set_IHDR(png_ptr, info_ptr,
	             data->w,                        // Width
	             data->h,                        // Height
	             8,                              // Bits depth
	             PNG_COLOR_TYPE_RGB,             // Color type
	             PNG_INTERLACE_NONE,             // No interlacing
	             PNG_COMPRESSION_TYPE_DEFAULT,   // Compression type
	             PNG_FILTER_TYPE_DEFAULT);       // Filter Type

	// Rowpointer erstellen
	png_bytep *rowPointers = new png_bytep[data->h];
	for (uint i = 0; i < data->h; i++) {
		rowPointers[i] = (png_bytep)&pixelBuffer[data->w * i];
	}
	png_set_rows(png_ptr, info_ptr, &rowPointers[0]);

	// Write out the png data to the file
	png_set_write_fn(png_ptr, (void *)stream, userWriteFn, userFlushFn);
	png_write_png(png_ptr, info_ptr, PNG_TRANSFORM_IDENTITY, NULL);

	png_destroy_write_struct(&png_ptr, &info_ptr);

	delete[] pixelBuffer;
	delete[] rowPointers;

	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->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, 4);

	// �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_LE_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