ofxMsdfgen/libs/msdf-atlas-gen/include/msdfgen/ext/import-svg.cpp

311 lines
11 KiB
C++
Raw Normal View History

#define _USE_MATH_DEFINES
#define _CRT_SECURE_NO_WARNINGS
#include "import-svg.h"
#include <cstdio>
#include <tinyxml2.h>
#include "../core/arithmetics.hpp"
#define ARC_SEGMENTS_PER_PI 2
#define ENDPOINT_SNAP_RANGE_PROPORTION (1/16384.)
namespace msdfgen {
#if defined(_DEBUG) || !NDEBUG
#define REQUIRE(cond) { if (!(cond)) { fprintf(stderr, "SVG Parse Error (%s:%d): " #cond "\n", __FILE__, __LINE__); return false; } }
#else
#define REQUIRE(cond) { if (!(cond)) return false; }
#endif
static void skipExtraChars(const char *&pathDef) {
while (*pathDef == ',' || *pathDef == ' ' || *pathDef == '\t' || *pathDef == '\r' || *pathDef == '\n')
++pathDef;
}
static bool readNodeType(char &output, const char *&pathDef) {
skipExtraChars(pathDef);
char nodeType = *pathDef;
if (nodeType && nodeType != '+' && nodeType != '-' && nodeType != '.' && nodeType != ',' && (nodeType < '0' || nodeType > '9')) {
++pathDef;
output = nodeType;
return true;
}
return false;
}
static bool readCoord(Point2 &output, const char *&pathDef) {
skipExtraChars(pathDef);
int shift;
double x, y;
if (sscanf(pathDef, "%lf%lf%n", &x, &y, &shift) == 2 || sscanf(pathDef, "%lf , %lf%n", &x, &y, &shift) == 2) {
output.x = x;
output.y = y;
pathDef += shift;
return true;
}
return false;
}
static bool readDouble(double &output, const char *&pathDef) {
skipExtraChars(pathDef);
int shift;
double v;
if (sscanf(pathDef, "%lf%n", &v, &shift) == 1) {
pathDef += shift;
output = v;
return true;
}
return false;
}
static bool readBool(bool &output, const char *&pathDef) {
skipExtraChars(pathDef);
int shift;
int v;
if (sscanf(pathDef, "%d%n", &v, &shift) == 1) {
pathDef += shift;
output = v != 0;
return true;
}
return false;
}
static double arcAngle(Vector2 u, Vector2 v) {
return nonZeroSign(crossProduct(u, v))*acos(clamp(dotProduct(u, v)/(u.length()*v.length()), -1., +1.));
}
static Vector2 rotateVector(Vector2 v, Vector2 direction) {
return Vector2(direction.x*v.x-direction.y*v.y, direction.y*v.x+direction.x*v.y);
}
static void addArcApproximate(Contour &contour, Point2 startPoint, Point2 endPoint, Vector2 radius, double rotation, bool largeArc, bool sweep) {
if (endPoint == startPoint)
return;
if (radius.x == 0 || radius.y == 0)
return contour.addEdge(new LinearSegment(startPoint, endPoint));
radius.x = fabs(radius.x);
radius.y = fabs(radius.y);
Vector2 axis(cos(rotation), sin(rotation));
Vector2 rm = rotateVector(.5*(startPoint-endPoint), Vector2(axis.x, -axis.y));
Vector2 rm2 = rm*rm;
Vector2 radius2 = radius*radius;
double radiusGap = rm2.x/radius2.x+rm2.y/radius2.y;
if (radiusGap > 1) {
radius *= sqrt(radiusGap);
radius2 = radius*radius;
}
double dq = (radius2.x*rm2.y+radius2.y*rm2.x);
double pq = radius2.x*radius2.y/dq-1;
double q = (largeArc == sweep ? -1 : +1)*sqrt(max(pq, 0.));
Vector2 rc(q*radius.x*rm.y/radius.y, -q*radius.y*rm.x/radius.x);
Point2 center = .5*(startPoint+endPoint)+rotateVector(rc, axis);
double angleStart = arcAngle(Vector2(1, 0), (rm-rc)/radius);
double angleExtent = arcAngle((rm-rc)/radius, (-rm-rc)/radius);
if (!sweep && angleExtent > 0)
angleExtent -= 2*M_PI;
else if (sweep && angleExtent < 0)
angleExtent += 2*M_PI;
int segments = (int) ceil(ARC_SEGMENTS_PER_PI/M_PI*fabs(angleExtent));
double angleIncrement = angleExtent/segments;
double cl = 4/3.*sin(.5*angleIncrement)/(1+cos(.5*angleIncrement));
Point2 prevNode = startPoint;
double angle = angleStart;
for (int i = 0; i < segments; ++i) {
Point2 controlPoint[2];
Vector2 d(cos(angle), sin(angle));
controlPoint[0] = center+rotateVector(Vector2(d.x-cl*d.y, d.y+cl*d.x)*radius, axis);
angle += angleIncrement;
d.set(cos(angle), sin(angle));
controlPoint[1] = center+rotateVector(Vector2(d.x+cl*d.y, d.y-cl*d.x)*radius, axis);
Point2 node = i == segments-1 ? endPoint : center+rotateVector(d*radius, axis);
contour.addEdge(new CubicSegment(prevNode, controlPoint[0], controlPoint[1], node));
prevNode = node;
}
}
bool buildShapeFromSvgPath(Shape &shape, const char *pathDef, double endpointSnapRange) {
char nodeType = '\0';
char prevNodeType = '\0';
Point2 prevNode(0, 0);
bool nodeTypePreread = false;
while (nodeTypePreread || readNodeType(nodeType, pathDef)) {
nodeTypePreread = false;
Contour &contour = shape.addContour();
bool contourStart = true;
Point2 startPoint;
Point2 controlPoint[2];
Point2 node;
while (*pathDef) {
switch (nodeType) {
case 'M': case 'm':
if (!contourStart) {
nodeTypePreread = true;
goto NEXT_CONTOUR;
}
REQUIRE(readCoord(node, pathDef));
if (nodeType == 'm')
node += prevNode;
startPoint = node;
--nodeType; // to 'L' or 'l'
break;
case 'Z': case 'z':
REQUIRE(!contourStart);
goto NEXT_CONTOUR;
case 'L': case 'l':
REQUIRE(readCoord(node, pathDef));
if (nodeType == 'l')
node += prevNode;
contour.addEdge(new LinearSegment(prevNode, node));
break;
case 'H': case 'h':
REQUIRE(readDouble(node.x, pathDef));
if (nodeType == 'h')
node.x += prevNode.x;
contour.addEdge(new LinearSegment(prevNode, node));
break;
case 'V': case 'v':
REQUIRE(readDouble(node.y, pathDef));
if (nodeType == 'v')
node.y += prevNode.y;
contour.addEdge(new LinearSegment(prevNode, node));
break;
case 'Q': case 'q':
REQUIRE(readCoord(controlPoint[0], pathDef));
REQUIRE(readCoord(node, pathDef));
if (nodeType == 'q') {
controlPoint[0] += prevNode;
node += prevNode;
}
contour.addEdge(new QuadraticSegment(prevNode, controlPoint[0], node));
break;
case 'T': case 't':
if (prevNodeType == 'Q' || prevNodeType == 'q' || prevNodeType == 'T' || prevNodeType == 't')
controlPoint[0] = node+node-controlPoint[0];
else
controlPoint[0] = node;
REQUIRE(readCoord(node, pathDef));
if (nodeType == 't')
node += prevNode;
contour.addEdge(new QuadraticSegment(prevNode, controlPoint[0], node));
break;
case 'C': case 'c':
REQUIRE(readCoord(controlPoint[0], pathDef));
REQUIRE(readCoord(controlPoint[1], pathDef));
REQUIRE(readCoord(node, pathDef));
if (nodeType == 'c') {
controlPoint[0] += prevNode;
controlPoint[1] += prevNode;
node += prevNode;
}
contour.addEdge(new CubicSegment(prevNode, controlPoint[0], controlPoint[1], node));
break;
case 'S': case 's':
if (prevNodeType == 'C' || prevNodeType == 'c' || prevNodeType == 'S' || prevNodeType == 's')
controlPoint[0] = node+node-controlPoint[1];
else
controlPoint[0] = node;
REQUIRE(readCoord(controlPoint[1], pathDef));
REQUIRE(readCoord(node, pathDef));
if (nodeType == 's') {
controlPoint[1] += prevNode;
node += prevNode;
}
contour.addEdge(new CubicSegment(prevNode, controlPoint[0], controlPoint[1], node));
break;
case 'A': case 'a':
{
Vector2 radius;
double angle;
bool largeArg;
bool sweep;
REQUIRE(readCoord(radius, pathDef));
REQUIRE(readDouble(angle, pathDef));
REQUIRE(readBool(largeArg, pathDef));
REQUIRE(readBool(sweep, pathDef));
REQUIRE(readCoord(node, pathDef));
if (nodeType == 'a')
node += prevNode;
angle *= M_PI/180.0;
addArcApproximate(contour, prevNode, node, radius, angle, largeArg, sweep);
}
break;
default:
REQUIRE(!"Unknown node type");
}
contourStart &= nodeType == 'M' || nodeType == 'm';
prevNode = node;
prevNodeType = nodeType;
readNodeType(nodeType, pathDef);
}
NEXT_CONTOUR:
// Fix contour if it isn't properly closed
if (!contour.edges.empty() && prevNode != startPoint) {
if ((contour.edges.back()->point(1)-contour.edges[0]->point(0)).length() < endpointSnapRange)
contour.edges.back()->moveEndPoint(contour.edges[0]->point(0));
else
contour.addEdge(new LinearSegment(prevNode, startPoint));
}
prevNode = startPoint;
prevNodeType = '\0';
}
return true;
}
bool loadSvgShape(Shape &output, const char *filename, int pathIndex, Vector2 *dimensions) {
tinyxml2::XMLDocument doc;
if (doc.LoadFile(filename))
return false;
tinyxml2::XMLElement *root = doc.FirstChildElement("svg");
if (!root)
return false;
tinyxml2::XMLElement *path = NULL;
if (pathIndex > 0) {
path = root->FirstChildElement("path");
if (!path) {
tinyxml2::XMLElement *g = root->FirstChildElement("g");
if (g)
path = g->FirstChildElement("path");
}
while (path && --pathIndex > 0)
path = path->NextSiblingElement("path");
} else {
path = root->LastChildElement("path");
if (!path) {
tinyxml2::XMLElement *g = root->LastChildElement("g");
if (g)
path = g->LastChildElement("path");
}
while (path && ++pathIndex < 0)
path = path->PreviousSiblingElement("path");
}
if (!path)
return false;
const char *pd = path->Attribute("d");
if (!pd)
return false;
output.contours.clear();
output.inverseYAxis = true;
Vector2 dims(root->DoubleAttribute("width"), root->DoubleAttribute("height"));
if (!dims) {
double left, top;
const char *viewBox = root->Attribute("viewBox");
if (viewBox)
sscanf(viewBox, "%lf %lf %lf %lf", &left, &top, &dims.x, &dims.y);
}
if (dimensions)
*dimensions = dims;
return buildShapeFromSvgPath(output, pd, ENDPOINT_SNAP_RANGE_PROPORTION*dims.length());
}
}