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engines/draci/font.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 3 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, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include "common/file.h"
+
+#include "draci/draci.h"
+#include "draci/font.h"
+#include "draci/surface.h"
+
+namespace Draci {
+
+const char * const kFontSmall = "Small.fon";
+const char * const kFontBig = "Big.fon";
+
+Font::Font(const Common::Path &filename) {
+	_fontHeight = 0;
+	_maxCharWidth = 0;
+	_charWidths = nullptr;
+	_charData = nullptr;
+
+	loadFont(filename);
+}
+
+Font::~Font() {
+	 freeFont();
+}
+
+/**
+ * @brief Loads fonts from a file
+ * @param path Path to font file
+ * @return true if the font was loaded successfully, false otherwise
+ *
+ * Loads fonts from a file into a Font instance. The original game uses two
+ * fonts (located inside files "Small.fon" and "Big.fon"). The characters in the
+ * font are indexed from the space character so an appropriate offset must be
+ * added to convert them to equivalent char values, i.e. kDraciIndexOffset.
+ * Characters in the higher range are non-ASCII and vary between different
+ * language versions of the game.
+ *
+ * font format: [1 byte] maximum character width
+ *              [1 byte] font height
+ *              [138 bytes] character widths of all 138 characters in the font
+ *              [138 * fontHeight * maxWidth bytes] character data, stored row-wise
+ */
+
+bool Font::loadFont(const Common::Path &filename) {
+	// Free previously loaded font (if any)
+	freeFont();
+
+	Common::File f;
+
+	f.open(filename);
+	if (f.isOpen()) {
+		debugC(6, kDraciGeneralDebugLevel, "Opened font file %s",
+			filename.toString(Common::Path::kNativeSeparator).c_str());
+	} else {
+		debugC(6, kDraciGeneralDebugLevel, "Error opening font file %s",
+			filename.toString(Common::Path::kNativeSeparator).c_str());
+		return false;
+	}
+
+	_maxCharWidth = f.readByte();
+	_fontHeight = f.readByte();
+
+	// Read in the widths of the glyphs
+	_charWidths = new uint8[kCharNum];
+	for (uint i = 0; i < kCharNum; ++i) {
+		_charWidths[i] = f.readByte();
+	}
+
+	// Calculate size of font data
+	uint fontDataSize = kCharNum * _maxCharWidth * _fontHeight;
+
+	// Read in all glyphs
+	_charData = new byte[fontDataSize];
+	f.read(_charData, fontDataSize);
+
+	debugC(5, kDraciGeneralDebugLevel, "Font %s loaded", filename.toString(Common::Path::kNativeSeparator).c_str());
+
+	return true;
+}
+
+void Font::freeFont() {
+	delete[] _charWidths;
+	delete[] _charData;
+}
+
+uint8 Font::getCharWidth(uint8 chr) const {
+	// Safe-guard against incorrect strings containing localized characters
+	// with inaccessible codes.  These strings do not exist in the original
+	// Czech version, but they do in the (never properly reviewed) English
+	// version.
+	return chr >= kCharIndexOffset && chr < kCharIndexOffset + kCharNum
+		? _charWidths[chr - kCharIndexOffset] : 0;
+}
+
+/**
+ * @brief Draw a char to a Draci::Surface
+ *
+ * @param dst   Pointer to the destination surface
+ * @param chr   Character to draw
+ * @param tx    Horizontal offset on the surface
+ * @param ty    Vertical offset on the surface
+ */
+
+void Font::drawChar(Surface *dst, uint8 chr, int tx, int ty, int with_color) const {
+	assert(dst != nullptr);
+	assert(tx >= 0);
+	assert(ty >= 0);
+
+	byte *ptr = (byte *)dst->getBasePtr(tx, ty);
+	const uint8 currentWidth = getCharWidth(chr);
+	if (currentWidth == 0) {
+		return;
+	}
+
+	const uint8 charIndex = chr - kCharIndexOffset;
+	const int charOffset = charIndex * _fontHeight * _maxCharWidth;
+
+	// Determine how many pixels to draw horizontally (to prevent overflow)
+	int xSpaceLeft = dst->w - tx - 1;
+	int xPixelsToDraw = (currentWidth < xSpaceLeft) ? currentWidth : xSpaceLeft;
+
+	// Determine how many pixels to draw vertically
+	int ySpaceLeft = dst->h - ty - 1;
+	int yPixelsToDraw = (_fontHeight < ySpaceLeft) ? _fontHeight : ySpaceLeft;
+
+	int _transparent = dst->getTransparentColor();
+
+	for (int y = 0; y < yPixelsToDraw; ++y) {
+		for (int x = 0; x <= xPixelsToDraw; ++x) {
+
+			int curr = y * _maxCharWidth + x;
+			int color = _charData[charOffset + curr];
+
+			// If pixel is transparent, skip it
+			if (color == _transparent)
+				continue;
+
+			// Replace color with font colors
+			switch (color) {
+			case 254:
+				color = with_color;
+				break;
+
+			case 253:
+				color = kFontColor2;
+				break;
+
+			case 252:
+				color = kFontColor3;
+				break;
+
+			case 251:
+				color = kFontColor4;
+				break;
+
+			default:
+				break;
+			}
+
+			// Paint the pixel
+			ptr[x] = color;
+		}
+
+		// Advance to next row
+		ptr += dst->pitch;
+	}
+}
+
+/**
+ * @brief Draw a string to a Draci::Surface
+ *
+ * @param dst       Pointer to the destination surface
+ * @param str       Buffer containing string data
+ * @param len       Length of the data
+ * @param x         Horizontal offset on the surface
+ * @param y         Vertical offset on the surface
+ * @param spacing   Space to leave between individual characters. Defaults to 0.
+ */
+void Font::drawString(Surface *dst, const byte *str, uint len,
+	                  int x, int y, int with_color, int spacing, bool markDirty) const {
+	drawString(dst, Common::String((const char *)str, len), x, y, with_color, spacing, markDirty);
+}
+
+/**
+ * @brief Draw a string to a Draci::Surface
+ *
+ * @param dst       Pointer to the destination surface
+ * @param str       String to draw
+ * @param x         Horizontal offset on the surface
+ * @param y         Vertical offset on the surface
+ * @param spacing   Space to leave between individual characters. Defaults to 0.
+ */
+
+void Font::drawString(Surface *dst, const Common::String &str,
+	                  int x, int y, int with_color, int spacing, bool markDirty) const {
+	assert(dst != nullptr);
+	assert(x >= 0);
+	assert(y >= 0);
+
+	uint widest = getStringWidth(str, spacing);
+
+	int curx = x + (widest - getLineWidth(str, 0, spacing)) / 2;
+	int cury = y;
+
+	for (uint i = 0; i < str.size(); ++i) {
+
+		// If we encounter the '|' char (newline and end of string marker),
+		// skip it and go to the start of the next line
+		if (str[i] == '|') {
+			cury += getFontHeight();
+			curx = x + (widest - getLineWidth(str, i+1, spacing) - 1) / 2;
+			continue;
+		}
+
+		// Break early if there's no more space on the screen
+		if (curx >= dst->w - 1 || cury >= dst->h - 1) {
+			break;
+		}
+
+		drawChar(dst, str[i], curx, cury, with_color);
+		curx += getCharWidth(str[i]) + spacing;
+	}
+
+	if (markDirty) {
+		Common::Rect r(x, y, x + widest, y + getStringHeight(str));
+		dst->markDirtyRect(r);
+	}
+}
+
+/**
+ * @brief Calculate the width of a string when drawn in the current font
+ *
+ * @param str       String to draw
+ * @param spacing   Space to leave between individual characters. Defaults to 0.
+ *
+ * @return The calculated width of the string
+ */
+uint Font::getStringWidth(const Common::String &str, int spacing) const {
+	uint width = 0;
+
+	// Real length, including '|' separators
+	uint len = str.size();
+
+	for (uint i = 0, tmp = 0; i < len; ++i) {
+
+		if (str[i] != '|') {
+			tmp += getCharWidth(str[i]) + spacing;
+		}
+
+		// Newline char encountered, skip it and store the new length if it is greater.
+		// Also, all strings in the data files should end with '|' but not all do.
+		// This is why we check whether we are at the last char too.
+		if (str[i] == '|' || i == len - 1) {
+			if (tmp > width) {
+				width = tmp;
+			}
+
+			tmp = 0;
+		}
+	}
+
+	return width + 1;
+}
+
+uint Font::getLineWidth(const Common::String &str, uint startIndex, int spacing) const {
+	uint width = 0;
+
+	// If the index is greater or equal to the string size,
+	// the width of the line is 0
+	if (startIndex >= str.size())
+		return 0;
+
+	for (uint i = startIndex; i < str.size(); ++i) {
+
+		// EOL encountered
+		if (str[i] == '|')
+			break;
+
+		// Add width of the current char
+		width += getCharWidth(str[i]) + spacing;
+	}
+
+	return width;
+}
+
+/**
+ * @brief Calculate the height of a string by counting the number of '|' chars (which
+ *        are used as newline characters and end-of-string markers)
+ *
+ * @param str       String to draw
+ * @param spacing   Space to leave between individual characters. Defaults to 0.
+ *
+ * @return The calculated height of the string
+ */
+uint Font::getStringHeight(const Common::String &str) const {
+	uint len = str.size();
+	int separators = 0;
+
+	for (uint i = 0; i < len; ++i) {
+		// All strings in the data files should end with '|' but not all do.
+		// This is why we check whether we are at the last char too.
+		if (str[i] == '|' || i == len - 1) {
+			++separators;
+		}
+	}
+
+	return separators * getFontHeight();
+}
+
+} // End of namespace Draci