solvespace/tools/lff2c.cpp

397 lines
12 KiB
C++

#define _USE_MATH_DEFINES
#include <zlib.h>
#include <cmath>
#include <cctype>
#include <algorithm>
#include <vector>
#include <string>
#include <map>
#include <iostream>
#include <fstream>
#include <sstream>
#define TOLERANCE 1e-6
double correctAngle(double a) {
return M_PI + remainder(a - M_PI, 2 * M_PI);
}
struct Point {
double x;
double y;
Point operator+(const Point &o) const { return { x + o.x, y + o.y }; }
Point operator-(const Point &o) const { return { x - o.x, y - o.y }; }
Point operator*(const Point &o) const { return { x * o.x, y * o.y }; }
Point operator/(const Point &o) const { return { x / o.x, y / o.y }; }
Point operator*(double k) const { return { x * k, y * k }; }
Point operator/(double k) const { return { x / k, y / k }; }
double length() const{
return sqrt(x * x + y * y);
}
double angle() const {
return correctAngle(atan2(y, x));
}
double distanceTo(const Point &v) const {
return (*this - v).length();
}
double angleTo(const Point &v) const {
return (v - *this).angle();
}
static Point polar(double radius, double angle) {
return { radius * cos(angle), radius * sin(angle) };
}
bool operator==(const Point &o) const { return x == o.x && y == o.y; }
bool operator!=(const Point &o) const { return x != o.x || y != o.y; }
};
struct Curve {
std::vector<Point> points;
};
struct Glyph {
char32_t character;
char32_t baseCharacter;
std::vector<Curve> curves;
void getBoundWidth(double *rminw, double *rmaxw) const {
if(curves.empty()) {
*rminw = 0.0;
*rmaxw = 0.0;
return;
}
double minw = curves[0].points[0].x;
double maxw = minw;
for(const Curve &c : curves) {
for(const Point &p : c.points) {
maxw = std::max(maxw, p.x);
minw = std::min(minw, p.x);
}
}
*rminw = minw;
*rmaxw = maxw;
}
void getBoundHeight(double *rminh, double *rmaxh) const {
if(curves.empty()) {
*rminh = 0.0;
*rmaxh = 0.0;
return;
}
double minh = curves[0].points[0].y;
double maxh = minh;
for(const Curve &c : curves) {
for(const Point &p : c.points) {
maxh = std::max(maxh, p.y);
minh = std::min(minh, p.y);
}
}
*rminh = minh;
*rmaxh = maxh;
}
double getWidth() const {
double maxw;
double minw;
getBoundWidth(&minw, &maxw);
return maxw - minw;
}
double getHeight() const {
double maxh;
double minh;
getBoundHeight(&minh, &maxh);
return maxh - minh;
}
bool operator<(const Glyph &o) const { return character < o.character; }
};
struct Font {
double letterSpacing;
double wordSpacing;
std::vector<Glyph> glyphs;
void getGlyphBound(double *rminw, double *rminh, double *rmaxw, double *rmaxh) {
if(glyphs.empty()) {
*rminw = 0.0;
*rmaxw = 0.0;
*rminh = 0.0;
*rmaxh = 0.0;
return;
}
glyphs[0].getBoundWidth(rminw, rmaxw);
glyphs[0].getBoundHeight(rminh, rmaxh);
for(const Glyph &g : glyphs) {
double minw, minh, maxw, maxh;
g.getBoundWidth(&minw, &maxw);
g.getBoundHeight(&minh, &maxh);
*rminw = std::min(*rminw, minw);
*rminh = std::min(*rminh, minh);
*rmaxw = std::max(*rmaxw, maxw);
*rmaxh = std::max(*rmaxh, maxh);
}
}
void createArc(Curve &curve, const Point &cp, double radius,
double a1, double a2, bool reversed) {
if (radius < 1e-6) return;
double aSign = 1.0;
if(reversed) {
if(a1 <= a2 + TOLERANCE) a1 += 2.0 * M_PI;
aSign = -1.0;
} else {
if(a2 <= a1 + TOLERANCE) a2 += 2.0 * M_PI;
}
// Angle Step (rad)
double da = fabs(a2 - a1);
int numPoints = 8;
double aStep = aSign * da / double(numPoints);
for(int i = 0; i <= numPoints; i++) {
curve.points.push_back(cp + Point::polar(radius, a1 + aStep * i));
}
}
void createBulge(const Point &v, double bulge, Curve &curve) {
bool reversed = bulge < 0.0;
double alpha = atan(bulge) * 4.0;
Point &point = curve.points.back();
Point middle = (point + v) / 2.0;
double dist = point.distanceTo(v) / 2.0;
double angle = point.angleTo(v);
// alpha can't be 0.0 at this point
double radius = fabs(dist / sin(alpha / 2.0));
double wu = fabs(radius*radius - dist*dist);
double h = sqrt(wu);
if(bulge > 0.0) {
angle += M_PI_2;
} else {
angle -= M_PI_2;
}
if (fabs(alpha) > M_PI) {
h *= -1.0;
}
Point center = Point::polar(h, angle);
center = center + middle;
double a1 = center.angleTo(point);
double a2 = center.angleTo(v);
createArc(curve, center, radius, a1, a2, reversed);
}
void readLff(const std::string &path) {
gzFile lfffont = gzopen(path.c_str(), "rb");
if(!lfffont) {
std::cerr << path << ": gzopen failed" << std::endl;
std::exit(1);
}
// Read line by line until we find a new letter:
Glyph *currentGlyph = NULL;
while(!gzeof(lfffont)) {
std::string line;
do {
char buf[128] = {0};
if(!gzgets(lfffont, buf, sizeof(buf)))
break;
line += buf;
} while(line.back() != '\n');
if(line.empty() || line[0] == '\n') {
continue;
} else if(line[0] == '#') {
// This is comment or metadata.
std::istringstream ss(line.substr(1));
std::vector<std::string> tokens;
while(!ss.eof()) {
std::string token;
std::getline(ss, token, ':');
std::istringstream(token) >> token; // trim
if(!token.empty())
tokens.push_back(token);
}
// If not in form of "a:b" then it's not metadata, just a comment.
if (tokens.size() != 2)
continue;
std::string &identifier = tokens[0];
std::string &value = tokens[1];
std::transform(identifier.begin(), identifier.end(), identifier.begin(),
::tolower);
if (identifier == "letterspacing") {
std::istringstream(value) >> letterSpacing;
} else if (identifier == "wordspacing") {
std::istringstream(value) >> wordSpacing;
} else if (identifier == "linespacingfactor") {
/* don't care */
} else if (identifier == "author") {
/* don't care */
} else if (identifier == "name") {
/* don't care */
} else if (identifier == "license") {
/* don't care */
} else if (identifier == "encoding") {
/* don't care */
} else if (identifier == "created") {
/* don't care */
}
} else if(line[0] == '[') {
// This is a glyph.
size_t closingPos;
char32_t chr = std::stoi(line.substr(1), &closingPos, 16);;
if(line[closingPos + 1] != ']') {
std::cerr << "unrecognized character number: " << line << std::endl;
currentGlyph = NULL;
continue;
}
glyphs.emplace_back();
currentGlyph = &glyphs.back();
currentGlyph->character = chr;
currentGlyph->baseCharacter = 0;
} else if(currentGlyph != NULL) {
if (line[0] == 'C') {
// This is a reference to another glyph.
currentGlyph->baseCharacter = std::stoi(line.substr(1), NULL, 16);
} else {
// This is a series of curves.
currentGlyph->curves.emplace_back();
Curve &curve = currentGlyph->curves.back();
std::stringstream ss(line);
while (!ss.eof()) {
std::string vertex;
std::getline(ss, vertex, ';');
std::stringstream ssv(vertex);
std::string coord;
Point p;
if(!std::getline(ssv, coord, ',')) continue;
p.x = std::stod(coord);
if(!std::getline(ssv, coord, ',')) continue;
p.y = std::stod(coord);
if(!std::getline(ssv, coord, ',') || coord[0] != 'A') {
// This is just a point.
curve.points.push_back(p);
} else {
// This is a point with a bulge.
double bulge = std::stod(coord.substr(1));
createBulge(p, bulge, curve);
}
}
}
} else {
std::cerr << "unrecognized line: " << line << std::endl;
}
}
gzclose(lfffont);
}
void writeCppHeader(const std::string &hName) {
std::sort(glyphs.begin(), glyphs.end());
std::ofstream ts(hName, std::ios::out);
double minX, minY, maxX, maxY;
getGlyphBound(&minX, &minY, &maxX, &maxY);
double size = 32766.0;
double scale = size / std::max({ fabs(maxX), fabs(minX), fabs(maxY), fabs(minY) });
// We use tabs for indentation here to make compilation slightly faster
ts <<
"/**** This is a generated file - do not edit ****/\n\n"
"#ifndef __VECTORFONT_TABLE_H\n"
"#define __VECTORFONT_TABLE_H\n"
"\n"
"#define PEN_UP 32767\n"
"#define UP PEN_UP\n"
"\n"
"struct VectorGlyph {\n"
"\tchar32_t character;\n"
"\tchar32_t baseCharacter;\n"
"\tint width;\n"
"\tconst int16_t *data;\n"
"};\n"
"\n"
"const int16_t VectorFontData[] = {\n"
"\tUP, UP,\n";
std::map<char32_t, size_t> glyphIndexes;
size_t index = 2;
for(const Glyph &g : glyphs) {
ts << "\t// U+" << std::hex << g.character << std::dec << "\n";
glyphIndexes[g.character] = index;
for(const Curve &c : g.curves) {
for(const Point &p : c.points) {
ts << "\t" << int(floor(p.x * scale)) << ", " <<
int(floor(p.y * scale)) << ",\n";
index += 2;
}
ts << "\tUP, UP,\n";
index += 2;
}
ts << "\tUP, UP,\n"; // end-of-glyph marker
index += 2;
}
ts <<
"};\n"
"\n"
"const VectorGlyph VectorFont[] = {\n"
"\t// U+20\n"
"\t{ 32, 0, " << int(floor(wordSpacing * scale)) << ", &VectorFontData[0] },\n";
for(const Glyph &g : glyphs) {
ts << "\t// U+" << std::hex << g.character << std::dec << "\n";
ts << "\t{ " << g.character << ", "
<< g.baseCharacter << ", "
<< int(floor((g.getWidth() + letterSpacing) * scale)) << ", ";
ts << "&VectorFontData[" << glyphIndexes[g.character] << "] },\n";
}
ts <<
"};\n"
"\n"
"#undef UP\n"
"\n"
"#endif\n";
}
};
int main(int argc, char** argv) {
if(argc != 3) {
std::cerr << "Usage: " << argv[0] << " <header out> <lff in>\n" << std::endl;
return 1;
}
Font font;
font.readLff(argv[2]);
font.writeCppHeader(argv[1]);
return 0;
}