aboutsummaryrefslogtreecommitdiff
path: root/graphics/font.cpp
blob: 4f53dfe8580ac13a4b61816524b84282280d2d54 (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
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
/* 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.
 *
 */

#include "graphics/font.h"
#include "graphics/managed_surface.h"

#include "common/array.h"
#include "common/util.h"

namespace Graphics {

int Font::getKerningOffset(uint32 left, uint32 right) const {
	return 0;
}

Common::Rect Font::getBoundingBox(uint32 chr) const {
	return Common::Rect(getCharWidth(chr), getFontHeight());
}

namespace {

template<class StringType>
Common::Rect getBoundingBoxImpl(const Font &font, const StringType &str, int x, int y, int w, TextAlign align, int deltax) {
	// We follow the logic of drawStringImpl here. The only exception is
	// that we do allow an empty width to be specified here. This allows us
	// to obtain the complete bounding box of a string.
	const int leftX = x, rightX = w ? (x + w) : 0x7FFFFFFF;
	int width = font.getStringWidth(str);

	if (align == kTextAlignCenter)
		x = x + (w - width)/2;
	else if (align == kTextAlignRight)
		x = x + w - width;
	x += deltax;

	bool first = true;
	Common::Rect bbox;

	typename StringType::unsigned_type last = 0;
	for (typename StringType::const_iterator i = str.begin(), end = str.end(); i != end; ++i) {
		const typename StringType::unsigned_type cur = *i;
		x += font.getKerningOffset(last, cur);
		last = cur;
		w = font.getCharWidth(cur);
		if (x+w > rightX)
			break;
		if (x+w >= leftX) {
			Common::Rect charBox = font.getBoundingBox(cur);
			charBox.translate(x, y);
			if (first) {
				bbox = charBox;
				first = false;
			} else {
				bbox.extend(charBox);
			}
		}
		x += w;
	}

	return bbox;
}

template<class StringType>
int getStringWidthImpl(const Font &font, const StringType &str) {
	int space = 0;
	typename StringType::unsigned_type last = 0;

	for (uint i = 0; i < str.size(); ++i) {
		const typename StringType::unsigned_type cur = str[i];
		space += font.getCharWidth(cur) + font.getKerningOffset(last, cur);
		last = cur;
	}

	return space;
}

template<class StringType>
void drawStringImpl(const Font &font, Surface *dst, const StringType &str, int x, int y, int w, uint32 color, TextAlign align, int deltax) {
	// The logic in getBoundingImpl is the same as we use here. In case we
	// ever change something here we will need to change it there too.
	assert(dst != 0);

	const int leftX = x, rightX = x + w;
	int width = font.getStringWidth(str);

	if (align == kTextAlignCenter)
		x = x + (w - width)/2;
	else if (align == kTextAlignRight)
		x = x + w - width;
	x += deltax;

	typename StringType::unsigned_type last = 0;
	for (typename StringType::const_iterator i = str.begin(), end = str.end(); i != end; ++i) {
		const typename StringType::unsigned_type cur = *i;
		x += font.getKerningOffset(last, cur);
		last = cur;
		w = font.getCharWidth(cur);
		if (x+w > rightX)
			break;
		if (x+w >= leftX)
			font.drawChar(dst, cur, x, y, color);
		x += w;
	}
}

template<class StringType>
struct WordWrapper {
	Common::Array<StringType> &lines;
	int actualMaxLineWidth;

	WordWrapper(Common::Array<StringType> &l) : lines(l), actualMaxLineWidth(0) {
	}

	void add(StringType &line, int &w) {
		if (actualMaxLineWidth < w)
			actualMaxLineWidth = w;

		lines.push_back(line);

		line.clear();
		w = 0;
	}
};

template<class StringType>
int wordWrapTextImpl(const Font &font, const StringType &str, int maxWidth, Common::Array<StringType> &lines) {
	WordWrapper<StringType> wrapper(lines);
	StringType line;
	StringType tmpStr;
	int lineWidth = 0;
	int tmpWidth = 0;

	// The rough idea behind this algorithm is as follows:
	// We accumulate characters into the string tmpStr. Whenever a full word
	// has been gathered together this way, we 'commit' it to the line buffer
	// 'line', i.e. we add tmpStr to the end of line, then clear it. Before
	// we do that, we check whether it would cause 'line' to exceed maxWidth;
	// in that case, we first add line to lines, then reset it.
	//
	// If a newline character is read, then we also add line to lines and clear it.
	//
	// Special care has to be taken to account for 'words' that exceed the width
	// of a line. If we encounter such a word, we have to wrap it over multiple
	// lines.

	typename StringType::unsigned_type last = 0;
	for (typename StringType::const_iterator x = str.begin(); x != str.end(); ++x) {
		typename StringType::unsigned_type c = *x;

		// Convert Windows and Mac line breaks into plain \n
		if (c == '\r') {
			if (x != str.end() && *(x + 1) == '\n') {
				++x;
			}
			c = '\n';
		}

		const int w = font.getCharWidth(c) + font.getKerningOffset(last, c);
		last = c;
		const bool wouldExceedWidth = (lineWidth + tmpWidth + w > maxWidth);

		// If this char is a whitespace, then it represents a potential
		// 'wrap point' where wrapping could take place. Everything that
		// came before it can now safely be added to the line, as we know
		// that it will not have to be wrapped.
		if (Common::isSpace(c)) {
			line += tmpStr;
			lineWidth += tmpWidth;

			tmpStr.clear();
			tmpWidth = 0;

			// If we encounter a line break (\n), or if the new space would
			// cause the line to overflow: start a new line
			if (c == '\n' || wouldExceedWidth) {
				wrapper.add(line, lineWidth);
				continue;
			}
		}

		// If the max line width would be exceeded by adding this char,
		// insert a line break.
		if (wouldExceedWidth) {
			// Commit what we have so far, *if* we have anything.
			// If line is empty, then we are looking at a word
			// which exceeds the maximum line width.
			if (lineWidth > 0) {
				wrapper.add(line, lineWidth);
				// Trim left side
				while (tmpStr.size() && Common::isSpace(tmpStr[0])) {
					tmpStr.deleteChar(0);
					// This is not very fast, but it is the simplest way to
					// assure we do not mess something up because of kerning.
					tmpWidth = font.getStringWidth(tmpStr);
				}
			} else {
				wrapper.add(tmpStr, tmpWidth);
			}
		}

		tmpWidth += w;
		tmpStr += c;
	}

	// If some text is left over, add it as the final line
	line += tmpStr;
	lineWidth += tmpWidth;
	if (lineWidth > 0) {
		wrapper.add(line, lineWidth);
	}
	return MAX(wrapper.actualMaxLineWidth, maxWidth);
}

} // End of anonymous namespace

Common::Rect Font::getBoundingBox(const Common::String &input, int x, int y, const int w, TextAlign align, int deltax, bool useEllipsis) const {
	// In case no width was given we cannot use ellipsis or any alignment
	// apart from left alignment.
	if (w == 0) {
		if (useEllipsis) {
			warning("Font::getBoundingBox: Requested ellipsis when no width was specified");
		}

		if (align != kTextAlignLeft) {
			warning("Font::getBoundingBox: Requested text alignment when no width was specified");
		}

		useEllipsis = false;
		align = kTextAlignLeft;
	}

	const Common::String str = useEllipsis ? handleEllipsis(input, w) : input;
	return getBoundingBoxImpl(*this, str, x, y, w, align, deltax);
}

Common::Rect Font::getBoundingBox(const Common::U32String &str, int x, int y, const int w, TextAlign align) const {
	// In case no width was given we cannot any alignment apart from left
	// alignment.
	if (w == 0) {
		if (align != kTextAlignLeft) {
			warning("Font::getBoundingBox: Requested text alignment when no width was specified");
		}

		align = kTextAlignLeft;
	}

	return getBoundingBoxImpl(*this, str, x, y, w, align, 0);
}

int Font::getStringWidth(const Common::String &str) const {
	return getStringWidthImpl(*this, str);
}

int Font::getStringWidth(const Common::U32String &str) const {
	return getStringWidthImpl(*this, str);
}

void Font::drawChar(ManagedSurface *dst, uint32 chr, int x, int y, uint32 color) const {
	drawChar(&dst->_innerSurface, chr, x, y, color);

	Common::Rect charBox = getBoundingBox(chr);
	charBox.translate(x, y);
	dst->addDirtyRect(charBox);
}

void Font::drawString(Surface *dst, const Common::String &str, int x, int y, int w, uint32 color, TextAlign align, int deltax, bool useEllipsis) const {
	Common::String renderStr = useEllipsis ? handleEllipsis(str, w) : str;
	drawStringImpl(*this, dst, renderStr, x, y, w, color, align, deltax);
}

void Font::drawString(Surface *dst, const Common::U32String &str, int x, int y, int w, uint32 color, TextAlign align) const {
	drawStringImpl(*this, dst, str, x, y, w, color, align, 0);
}

void Font::drawString(ManagedSurface *dst, const Common::String &str, int x, int y, int w, uint32 color, TextAlign align, int deltax, bool useEllipsis) const {
	drawString(&dst->_innerSurface, str, x, y, w, color, align, deltax, useEllipsis);
	if (w != 0) {
		dst->addDirtyRect(getBoundingBox(str, x, y, w, align, deltax, useEllipsis));
	}
}

void Font::drawString(ManagedSurface *dst, const Common::U32String &str, int x, int y, int w, uint32 color, TextAlign align) const {
	drawString(&dst->_innerSurface, str, x, y, w, color, align);
	if (w != 0) {
		dst->addDirtyRect(getBoundingBox(str, x, y, w, align));
	}
}

int Font::wordWrapText(const Common::String &str, int maxWidth, Common::Array<Common::String> &lines) const {
	return wordWrapTextImpl(*this, str, maxWidth, lines);
}

int Font::wordWrapText(const Common::U32String &str, int maxWidth, Common::Array<Common::U32String> &lines) const {
	return wordWrapTextImpl(*this, str, maxWidth, lines);
}

Common::String Font::handleEllipsis(const Common::String &input, int w) const {
	Common::String s = input;
	int width = getStringWidth(s);

	if (width > w && s.hasSuffix("...")) {
		// String is too wide. Check whether it ends in an ellipsis
		// ("..."). If so, remove that and try again!
		s.deleteLastChar();
		s.deleteLastChar();
		s.deleteLastChar();
		width = getStringWidth(s);
	}

	if (width > w) {
		Common::String str;

		// String is too wide. So we shorten it "intelligently" by
		// replacing parts of the string by an ellipsis. There are
		// three possibilities for this: replace the start, the end, or
		// the middle of the string. What is best really depends on the
		// context; but unless we want to make this configurable,
		// replacing the middle seems to be a good compromise.

		const int ellipsisWidth = getStringWidth("...");

		// SLOW algorithm to remove enough of the middle. But it is good enough
		// for now.
		const int halfWidth = (w - ellipsisWidth) / 2;
		int w2 = 0;
		Common::String::unsigned_type last = 0;
		uint i = 0;

		for (; i < s.size(); ++i) {
			const Common::String::unsigned_type cur = s[i];
			int charWidth = getCharWidth(cur) + getKerningOffset(last, cur);
			if (w2 + charWidth > halfWidth)
				break;
			last = cur;
			w2 += charWidth;
			str += cur;
		}

		// At this point we know that the first 'i' chars are together 'w2'
		// pixels wide. We took the first i-1, and add "..." to them.
		str += "...";
		last = '.';

		// The original string is width wide. Of those we already skipped past
		// w2 pixels, which means (width - w2) remain.
		// The new str is (w2+ellipsisWidth) wide, so we can accommodate about
		// (w - (w2+ellipsisWidth)) more pixels.
		// Thus we skip ((width - w2) - (w - (w2+ellipsisWidth))) =
		// (width + ellipsisWidth - w)
		int skip = width + ellipsisWidth - w;
		for (; i < s.size() && skip > 0; ++i) {
			const Common::String::unsigned_type cur = s[i];
			skip -= getCharWidth(cur) + getKerningOffset(last, cur);
			last = cur;
		}

		// Append the remaining chars, if any
		for (; i < s.size(); ++i) {
			str += s[i];
		}

		return str;
	} else {
		return s;
	}
}

} // End of namespace Graphics