scummvm/graphics/font.cpp

/* ScummVM - Scumm Interpreter
 * Copyright (C) 2002-2004 The ScummVM project
 *
 * 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., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 *
 * $Header$
 */

#include "common/stdafx.h"
#include "graphics/font.h"

namespace Graphics {

int NewFont::getCharWidth(byte chr) const {
	// If no width table is specified, return the maximum width
	if (!desc.width)
		return desc.maxwidth;
	// If this character is not included in the font, use the default char.
	if (chr < desc.firstchar || desc.firstchar + desc.size < chr) {
		if (chr == ' ')
			return desc.maxwidth / 2;
		chr = desc.defaultchar;
	}
	return desc.width[chr - desc.firstchar];
}

void NewFont::drawChar(const Surface *dst, byte chr, int x, int y, uint32 color) const {
	assert(dst != 0);
	byte *ptr = (byte *)dst->pixels + x * dst->bytesPerPixel + y * dst->pitch;

	assert(desc.bits != 0 && desc.maxwidth <= 16);
	assert(dst->bytesPerPixel == 1 || dst->bytesPerPixel == 2);

	// If this character is not included in the font, use the default char.
	if (chr < desc.firstchar || chr >= desc.firstchar + desc.size) {
		if (chr == ' ')
			return;
		chr = desc.defaultchar;
	}

	const int w = getCharWidth(chr);
	chr -= desc.firstchar;
	const bitmap_t *tmp = desc.bits + (desc.offset ? desc.offset[chr] : (chr * desc.height));

	for (y = 0; y < desc.height; y++) {
		const bitmap_t buffer = *tmp++;
		bitmap_t mask = 0x8000;
		for (x = 0; x < w; x++) {
			if ((buffer & mask) != 0) {
				if (dst->bytesPerPixel == 1)
					ptr[x] = color;
				else if (dst->bytesPerPixel == 2)
					((uint16 *)ptr)[x] = color;
			}
			mask >>= 1;
		}
		ptr += dst->pitch;
	}
}


#pragma mark -


int Font::getStringWidth(const Common::String &str) const {
	int space = 0;

	for (uint i = 0; i < str.size(); ++i)
		space += getCharWidth(str[i]);
	return space;
}

void Font::drawString(const Surface *dst, const Common::String &s, int x, int y, int w, uint32 color, TextAlignment align, int deltax, bool useEllipsis) const {
	assert(dst != 0);
	const int leftX = x, rightX = x + w;
	uint i;
	int width = getStringWidth(s);
	Common::String str;
	
	if (useEllipsis && width > w) {
		// String is too wide. So we shorten it "intellegently", by replacing
		// parts of it 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 probably is 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;
		
		for (i = 0; i < s.size(); ++i) {
			int charWidth = getCharWidth(s[i]);
			if (w2 + charWidth > halfWidth)
				break;
			w2 += charWidth;
			str += s[i];
		}
		// 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 += "...";
		
		// 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 accomodate 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) {
			skip -= getCharWidth(s[i]);
		}

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

		width = getStringWidth(str);

	} else {
		str = s;
	}

	if (align == kTextAlignCenter)
		x = x + (w - width - 1)/2;
	else if (align == kTextAlignRight)
		x = x + w - width;
	x += deltax;

	for (i = 0; i < str.size(); ++i) {
		w = getCharWidth(str[i]);
		if (x+w > rightX)
			break;
		if (x >= leftX)
			drawChar(dst, str[i], x, y, color);
		x += w;
	}
}


} // End of namespace Graphics