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#ifndef QTRIANGULATINGSTROKER_P_H
#define QTRIANGULATINGSTROKER_P_H
#include <private/qdatabuffer_p.h>
#include <private/qvectorpath_p.h>
#include <private/qbezier_p.h>
#include <private/qnumeric_p.h>
#include <private/qmath_p.h>
class QTriangulatingStroker
{
public:
void process(const QVectorPath &path, const QPen &pen);
inline int vertexCount() const { return m_vertices.size(); }
inline const float *vertices() const { return m_vertices.data(); }
inline void setInvScale(qreal invScale) { m_inv_scale = invScale; }
private:
inline void emitLineSegment(float x, float y, float nx, float ny);
inline void moveTo(const qreal *pts);
inline void lineTo(const qreal *pts);
void cubicTo(const qreal *pts);
inline void join(const qreal *pts);
inline void normalVector(float x1, float y1, float x2, float y2, float *nx, float *ny);
inline void endCap(const qreal *pts);
inline void arc(float x, float y);
void endCapOrJoinClosed(const qreal *start, const qreal *cur, bool implicitClose, bool endsAtStart);
QDataBuffer<float> m_vertices;
float m_cx, m_cy; // current points
float m_nvx, m_nvy; // normal vector...
float m_width;
qreal m_miter_limit;
int m_roundness; // Number of line segments in a round join
qreal m_sin_theta; // sin(m_roundness / 360);
qreal m_cos_theta; // cos(m_roundness / 360);
qreal m_inv_scale;
float m_curvyness_mul;
float m_curvyness_add;
Qt::PenJoinStyle m_join_style;
Qt::PenCapStyle m_cap_style;
};
class QDashedStrokeProcessor
{
public:
QDashedStrokeProcessor();
void process(const QVectorPath &path, const QPen &pen);
inline void addElement(QPainterPath::ElementType type, qreal x, qreal y) {
m_points.add(x);
m_points.add(y);
m_types.add(type);
}
inline int elementCount() const { return m_types.size(); }
inline qreal *points() const { return m_points.data(); }
inline QPainterPath::ElementType *elementTypes() const { return m_types.data(); }
inline void setInvScale(qreal invScale) { m_inv_scale = invScale; }
private:
QDataBuffer<qreal> m_points;
QDataBuffer<QPainterPath::ElementType> m_types;
QDashStroker m_dash_stroker;
qreal m_inv_scale;
};
inline void QTriangulatingStroker::normalVector(float x1, float y1, float x2, float y2,
float *nx, float *ny)
{
float dx = x2 - x1;
float dy = y2 - y1;
float pw = m_width / sqrt(dx*dx + dy*dy);
*nx = -dy * pw;
*ny = dx * pw;
}
inline void QTriangulatingStroker::emitLineSegment(float x, float y, float vx, float vy)
{
m_vertices.add(x + vx);
m_vertices.add(y + vy);
m_vertices.add(x - vx);
m_vertices.add(y - vy);
}
// We draw a full circle for any round join or round cap which is a
// bit of overkill...
inline void QTriangulatingStroker::arc(float x, float y)
{
float dx = m_width;
float dy = 0;
for (int i=0; i<=m_roundness; ++i) {
float tmpx = dx * m_cos_theta - dy * m_sin_theta;
float tmpy = dx * m_sin_theta + dy * m_cos_theta;
dx = tmpx;
dy = tmpy;
emitLineSegment(x, y, dx, dy);
}
}
inline void QTriangulatingStroker::endCap(const qreal *pts)
{
switch (m_cap_style) {
case Qt::FlatCap:
break;
case Qt::SquareCap: {
float dx = m_cx - *(pts - 2);
float dy = m_cy - *(pts - 1);
float len = m_width / sqrt(dx * dx + dy * dy);
dx = dx * len;
dy = dy * len;
emitLineSegment(m_cx + dx, m_cy + dy, m_nvx, m_nvy);
break; }
case Qt::RoundCap:
arc(m_cx, m_cy);
break;
default: break; // to shut gcc up...
}
int count = m_vertices.size();
m_vertices.add(m_vertices.at(count-2));
m_vertices.add(m_vertices.at(count-1));
}
void QTriangulatingStroker::moveTo(const qreal *pts)
{
m_cx = pts[0];
m_cy = pts[1];
float x2 = pts[2];
float y2 = pts[3];
normalVector(m_cx, m_cy, x2, y2, &m_nvx, &m_nvy);
// To acheive jumps we insert zero-area tringles. This is done by
// adding two identical points in both the end of previous strip
// and beginning of next strip
bool invisibleJump = m_vertices.size();
switch (m_cap_style) {
case Qt::FlatCap:
if (invisibleJump) {
m_vertices.add(m_cx + m_nvx);
m_vertices.add(m_cy + m_nvy);
}
break;
case Qt::SquareCap: {
float dx = x2 - m_cx;
float dy = y2 - m_cy;
float len = m_width / sqrt(dx * dx + dy * dy);
dx = dx * len;
dy = dy * len;
float sx = m_cx - dx;
float sy = m_cy - dy;
if (invisibleJump) {
m_vertices.add(sx + m_nvx);
m_vertices.add(sy + m_nvy);
}
emitLineSegment(sx, sy, m_nvx, m_nvy);
break; }
case Qt::RoundCap:
if (invisibleJump) {
m_vertices.add(m_cx + m_nvx);
m_vertices.add(m_cy + m_nvy);
}
// This emitLineSegment is not needed for the arc, but we need
// to start where we put the invisibleJump vertex, otherwise
// we'll have visible triangles between subpaths.
emitLineSegment(m_cx, m_cy, m_nvx, m_nvy);
arc(m_cx, m_cy);
break;
default: break; // ssssh gcc...
}
emitLineSegment(m_cx, m_cy, m_nvx, m_nvy);
}
void QTriangulatingStroker::lineTo(const qreal *pts)
{
emitLineSegment(pts[0], pts[1], m_nvx, m_nvy);
m_cx = pts[0];
m_cy = pts[1];
}
void QTriangulatingStroker::join(const qreal *pts)
{
// Creates a join to the next segment (m_cx, m_cy) -> (pts[0], pts[1])
normalVector(m_cx, m_cy, pts[0], pts[1], &m_nvx, &m_nvy);
switch (m_join_style) {
case Qt::BevelJoin:
break;
case Qt::MiterJoin: {
int p1 = m_vertices.size() - 6;
int p2 = m_vertices.size() - 2;
QLineF line(m_vertices.at(p1), m_vertices.at(p1+1),
m_vertices.at(p2), m_vertices.at(p2+1));
QLineF nextLine(m_cx - m_nvx, m_cy - m_nvy,
pts[0] - m_nvx, pts[1] - m_nvy);
QPointF isect;
if (line.intersect(nextLine, &isect) != QLineF::NoIntersection
&& QLineF(line.p2(), isect).length() <= m_miter_limit) {
// The intersection point mirrored over the m_cx, m_cy point
m_vertices.add(m_cx - (isect.x() - m_cx));
m_vertices.add(m_cy - (isect.y() - m_cy));
// The intersection point
m_vertices.add(isect.x());
m_vertices.add(isect.y());
}
// else
// Do a plain bevel join if the miter limit is exceeded or if
// the lines are parallel. This is not what the raster
// engine's stroker does, but it is both faster and similar to
// what some other graphics API's do.
break; }
case Qt::RoundJoin:
arc(m_cx, m_cy);
break;
default: break; // gcc warn--
}
emitLineSegment(m_cx, m_cy, m_nvx, m_nvy);
}
#endif