svgparserutilities.cpp

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                if (process) {
                    curx = curx + tox;
                    svgLineTo(narrowPrecisionToFloat(curx), narrowPrecisionToFloat(cury));
                }
                else
                    svgLineToHorizontal(narrowPrecisionToFloat(tox), false);
                break;
            }
            case 'H':
            {
                if (!parseNumber(ptr, end, tox))
                    return false;
                if (process) {
                    curx = tox;
                    svgLineTo(narrowPrecisionToFloat(curx), narrowPrecisionToFloat(cury));
                }
                else
                    svgLineToHorizontal(narrowPrecisionToFloat(tox));
                break;
            }
            case 'v':
            {
                if (!parseNumber(ptr, end, toy))
                    return false;
                if (process) {
                    cury = cury + toy;
                    svgLineTo(narrowPrecisionToFloat(curx), narrowPrecisionToFloat(cury));
                }
                else
                    svgLineToVertical(narrowPrecisionToFloat(toy), false);
                break;
            }
            case 'V':
            {
                if (!parseNumber(ptr, end, toy))
                    return false;
                if (process) {
                    cury = toy;
                    svgLineTo(narrowPrecisionToFloat(curx), narrowPrecisionToFloat(cury));
                }
                else
                    svgLineToVertical(narrowPrecisionToFloat(toy));
                break;
            }
            case 'z':
            case 'Z':
            {
                // reset curx, cury for next path
                if (process) {
                    curx = subpathx;
                    cury = subpathy;
                }
                closed = true;
                svgClosePath();
                break;
            }
            case 'c':
                relative = true;
            case 'C':
            {
                if (!parseNumber(ptr, end, x1)  || !parseNumber(ptr, end, y1) ||
                    !parseNumber(ptr, end, x2)  || !parseNumber(ptr, end, y2) ||
                    !parseNumber(ptr, end, tox) || !parseNumber(ptr, end, toy))
                    return false;

                if (process) {
                    px1 = relative ? curx + x1 : x1;
                    py1 = relative ? cury + y1 : y1;
                    px2 = relative ? curx + x2 : x2;
                    py2 = relative ? cury + y2 : y2;
                    px3 = relative ? curx + tox : tox;
                    py3 = relative ? cury + toy : toy;

                    svgCurveToCubic(narrowPrecisionToFloat(px1), narrowPrecisionToFloat(py1), narrowPrecisionToFloat(px2), 
                                    narrowPrecisionToFloat(py2), narrowPrecisionToFloat(px3), narrowPrecisionToFloat(py3));

                    contrlx = relative ? curx + x2 : x2;
                    contrly = relative ? cury + y2 : y2;
                    curx = relative ? curx + tox : tox;
                    cury = relative ? cury + toy : toy;
                }
                else
                    svgCurveToCubic(narrowPrecisionToFloat(x1), narrowPrecisionToFloat(y1), narrowPrecisionToFloat(x2),
                                    narrowPrecisionToFloat(y2), narrowPrecisionToFloat(tox), narrowPrecisionToFloat(toy), !relative);

                break;
            }
            case 's':
                relative = true;
            case 'S':
            {
                if (!parseNumber(ptr, end, x2)  || !parseNumber(ptr, end, y2) ||
                    !parseNumber(ptr, end, tox) || !parseNumber(ptr, end, toy))
                    return false;

                if (!(lastCommand == 'c' || lastCommand == 'C' ||
                     lastCommand == 's' || lastCommand == 'S')) {
                    contrlx = curx;
                    contrly = cury;
                }

                if (process) {
                    px1 = 2 * curx - contrlx;
                    py1 = 2 * cury - contrly;
                    px2 = relative ? curx + x2 : x2;
                    py2 = relative ? cury + y2 : y2;
                    px3 = relative ? curx + tox : tox;
                    py3 = relative ? cury + toy : toy;

                    svgCurveToCubic(narrowPrecisionToFloat(px1), narrowPrecisionToFloat(py1), narrowPrecisionToFloat(px2),
                                    narrowPrecisionToFloat(py2), narrowPrecisionToFloat(px3), narrowPrecisionToFloat(py3));

                    contrlx = relative ? curx + x2 : x2;
                    contrly = relative ? cury + y2 : y2;
                    curx = relative ? curx + tox : tox;
                    cury = relative ? cury + toy : toy;
                }
                else
                    svgCurveToCubicSmooth(narrowPrecisionToFloat(x2), narrowPrecisionToFloat(y2), 
                                          narrowPrecisionToFloat(tox), narrowPrecisionToFloat(toy), !relative);
                break;
            }
            case 'q':
                relative = true;
            case 'Q':
            {
                if (!parseNumber(ptr, end, x1)  || !parseNumber(ptr, end, y1) ||
                    !parseNumber(ptr, end, tox) || !parseNumber(ptr, end, toy))
                    return false;

                if (process) {
                    px1 = relative ? (curx + 2 * (x1 + curx)) * (1.0 / 3.0) : (curx + 2 * x1) * (1.0 / 3.0);
                    py1 = relative ? (cury + 2 * (y1 + cury)) * (1.0 / 3.0) : (cury + 2 * y1) * (1.0 / 3.0);
                    px2 = relative ? ((curx + tox) + 2 * (x1 + curx)) * (1.0 / 3.0) : (tox + 2 * x1) * (1.0 / 3.0);
                    py2 = relative ? ((cury + toy) + 2 * (y1 + cury)) * (1.0 / 3.0) : (toy + 2 * y1) * (1.0 / 3.0);
                    px3 = relative ? curx + tox : tox;
                    py3 = relative ? cury + toy : toy;

                    svgCurveToCubic(narrowPrecisionToFloat(px1), narrowPrecisionToFloat(py1), narrowPrecisionToFloat(px2),
                                    narrowPrecisionToFloat(py2), narrowPrecisionToFloat(px3), narrowPrecisionToFloat(py3));

                    contrlx = relative ? curx + x1 : x1;
                    contrly = relative ? cury + y1 : y1;
                    curx = relative ? curx + tox : tox;
                    cury = relative ? cury + toy : toy;
                }
                else
                    svgCurveToQuadratic(narrowPrecisionToFloat(x1), narrowPrecisionToFloat(y1),
                                        narrowPrecisionToFloat(tox), narrowPrecisionToFloat(toy), !relative);
                break;
            }
            case 't':
                relative = true;
            case 'T':
            {
                if (!parseNumber(ptr, end, tox) || !parseNumber(ptr, end, toy))
                    return false;
                if (!(lastCommand == 'q' || lastCommand == 'Q' ||
                     lastCommand == 't' || lastCommand == 'T')) {
                    contrlx = curx;
                    contrly = cury;
                }

                if (process) {
                    xc = 2 * curx - contrlx;
                    yc = 2 * cury - contrly;

                    px1 = relative ? (curx + 2 * xc) * (1.0 / 3.0) : (curx + 2 * xc) * (1.0 / 3.0);
                    py1 = relative ? (cury + 2 * yc) * (1.0 / 3.0) : (cury + 2 * yc) * (1.0 / 3.0);
                    px2 = relative ? ((curx + tox) + 2 * xc) * (1.0 / 3.0) : (tox + 2 * xc) * (1.0 / 3.0);
                    py2 = relative ? ((cury + toy) + 2 * yc) * (1.0 / 3.0) : (toy + 2 * yc) * (1.0 / 3.0);
                    px3 = relative ? curx + tox : tox;
                    py3 = relative ? cury + toy : toy;

                    svgCurveToCubic(narrowPrecisionToFloat(px1), narrowPrecisionToFloat(py1), narrowPrecisionToFloat(px2),
                                    narrowPrecisionToFloat(py2), narrowPrecisionToFloat(px3), narrowPrecisionToFloat(py3));

                    contrlx = xc;
                    contrly = yc;
                    curx = relative ? curx + tox : tox;
                    cury = relative ? cury + toy : toy;
                }
                else
                    svgCurveToQuadraticSmooth(narrowPrecisionToFloat(tox), narrowPrecisionToFloat(toy), !relative);
                break;
            }
            case 'a':
                relative = true;
            case 'A':
            {
                bool largeArc, sweep;
                double angle, rx, ry;
                if (!parseNumber(ptr, end, rx)    || !parseNumber(ptr, end, ry) ||
                    !parseNumber(ptr, end, angle) || !parseNumber(ptr, end, tox))
                    return false;
                largeArc = tox == 1;
                if (!parseNumber(ptr, end, tox))
                    return false;
                sweep = tox == 1;
                if (!parseNumber(ptr, end, tox) || !parseNumber(ptr, end, toy))
                    return false;

                // Spec: radii are nonnegative numbers
                rx = fabs(rx);
                ry = fabs(ry);

                if (process)
                    calculateArc(relative, curx, cury, angle, tox, toy, rx, ry, largeArc, sweep);
                else
                    svgArcTo(narrowPrecisionToFloat(tox), narrowPrecisionToFloat(toy), narrowPrecisionToFloat(rx), narrowPrecisionToFloat(ry),
                             narrowPrecisionToFloat(angle), largeArc, sweep, !relative);
                break;
            }
            default:
                // FIXME: An error should go to the JavaScript console, or the like.
                return false;
        }
        lastCommand = command;

        if (ptr >= end)
            return true;

        // Check for remaining coordinates in the current command.
        if ((*ptr == '+' || *ptr == '-' || (*ptr >= '0' && *ptr <= '9')) &&
            (command != 'z' && command != 'Z')) {
            if (command == 'M')
                command = 'L';
            else if (command == 'm')
                command = 'l';
        } else
            command = *(ptr++);

        if (lastCommand != 'C' && lastCommand != 'c' &&
            lastCommand != 'S' && lastCommand != 's' &&
            lastCommand != 'Q' && lastCommand != 'q' &&
            lastCommand != 'T' && lastCommand != 't') {
            contrlx = curx;
            contrly = cury;
        }
    }

    return false;
}

// This works by converting the SVG arc to "simple" beziers.
// For each bezier found a svgToCurve call is done.
// Adapted from Niko's code in kdelibs/kdecore/svgicons.
// Maybe this can serve in some shared lib? (Rob)
void SVGPathParser::calculateArc(bool relative, double& curx, double& cury, double angle, double x, double y, double r1, double r2, bool largeArcFlag, bool sweepFlag)
{
    double sin_th, cos_th;
    double a00, a01, a10, a11;
    double x0, y0, x1, y1, xc, yc;
    double d, sfactor, sfactor_sq;
    double th0, th1, th_arc;
    int i, n_segs;

    sin_th = sin(angle * (piDouble / 180.0));
    cos_th = cos(angle * (piDouble / 180.0));

    double dx;

    if (!relative)
        dx = (curx - x) / 2.0;
    else
        dx = -x / 2.0;

    double dy;
        
    if (!relative)
        dy = (cury - y) / 2.0;
    else
        dy = -y / 2.0;
        
    double _x1 =  cos_th * dx + sin_th * dy;
    double _y1 = -sin_th * dx + cos_th * dy;
    double Pr1 = r1 * r1;
    double Pr2 = r2 * r2;
    double Px = _x1 * _x1;
    double Py = _y1 * _y1;

    // Spec : check if radii are large enough
    double check = Px / Pr1 + Py / Pr2;
    if (check > 1) {
        r1 = r1 * sqrt(check);
        r2 = r2 * sqrt(check);
    }