Implemented rounded clip.

2 files changed, 48 insertions, 45 deletions

diff --git a/src/canvas/qxclipnode.cpp b/src/canvas/qxclipnode.cpp
index a954b62..aded473 100644
--- a/src/canvas/qxclipnode.cpp
+++ b/src/canvas/qxclipnode.cpp
@@ -44,83 +44,80 @@
 #include "qxclipnode_p.h"
 #include "utilities.h"
 
+#include <QtGui/QVector2D>
 #include <QtCore/qmath.h>
 
 QxClipNode::QxClipNode(const QRectF &rect)
 : m_rect(rect), m_radius(0)
 {
-    updateGeometry();
+    updateGeometryDescription(Utilities::getRectGeometryDescription(), GL_UNSIGNED_SHORT);
+    Utilities::setupRectGeometry(geometry(), m_rect);
     setFlag(ClipIsRectangular, true);
 }
 
 void QxClipNode::setRect(const QRectF &rect)
 {
     m_rect = rect;
-    updateGeometry();
+    setUpdateFlag(UpdateGeometry);
 }
 
 void QxClipNode::setRadius(qreal radius)
 {
     m_radius = radius;
-    updateGeometry();
+    setUpdateFlag(UpdateGeometry);
     setFlag(ClipIsRectangular, radius == 0);
 }
 
+void QxClipNode::update(uint updateFlags)
+{
+    if (updateFlags & UpdateGeometry)
+        updateGeometry();
+}
+
 void QxClipNode::updateGeometry()
 {
     if (qFuzzyIsNull(m_radius)) {
         updateGeometryDescription(Utilities::getRectGeometryDescription(), GL_UNSIGNED_SHORT);
         Utilities::setupRectGeometry(geometry(), m_rect);
     } else {
-        // ### Fix.
-        updateGeometryDescription(Utilities::getRectGeometryDescription(), GL_UNSIGNED_SHORT);
-        Utilities::setupRectGeometry(geometry(), m_rect);
-        /*
-        //XXX copy of what is in QxRectangle (we should reuse the geometry generated there if possible)
+        struct Vertex
+        {
+            QVector2D position;
+        };
+
+        Geometry *g = geometry();
+        int vertexCount = 0;
+
         QRectF rect = m_rect;
-        qreal radius = m_radius;
-
-        QArray<QVector2D> vertices;
-        QGLVertexBuffer v;
-
-        qreal zero = 0. * M_PI/180.;
-        qreal ninety = 90. * M_PI/180.;
-        qreal oneeighty = 180. * M_PI/180.;
-        qreal twoseventy = 270. * M_PI/180.;
-        qreal nninety = -90. * M_PI/180.;
-        qreal step = -1.5708/radius;
-
-        //upper left
-        QPointF cp(rect.x() + radius, rect.y() + radius);
-        for (qreal angle = twoseventy; angle >= oneeighty; angle += step) {
-            vertices.append(QVector2D(cp.x() + qFastSin(angle) * radius, cp.y() + qFastCos(angle) * radius));
-        }
+        rect.adjust(m_radius, m_radius, -m_radius, -m_radius);
 
-        //upper right
-        cp = QPointF(rect.x() + rect.width() - radius, rect.y() + radius);
-        for (qreal angle = oneeighty; angle >= ninety; angle += step) {
-            vertices.append(QVector2D(cp.x() + qFastSin(angle) * radius, cp.y() + qFastCos(angle) * radius));
-        }
+        int segments = qMin(15, qCeil(m_radius)); // Number of segments per corner.
 
-        //lower right
-        cp = QPointF(rect.x() + rect.width() - radius, rect.y() + rect.height() - radius);
-        for (qreal angle = ninety; angle >= zero; angle += step) {
-            vertices.append(QVector2D(cp.x() + qFastSin(angle) * radius, cp.y() + qFastCos(angle) * radius));
-        }
+        // Overestimate the number of vertices and indices, reduce afterwards when the actual numbers are known.
+        g->setVertexCount((segments + 1) * 4);
+        g->setIndexCount(0);
+
+        Vertex *vertices = (Vertex *)g->vertexData();
+
+        for (int part = 0; part < 2; ++part) {
+            for (int i = 0; i <= segments; ++i) {
+                //### Should change to calculate sin/cos only once.
+                qreal angle = qreal(0.5 * M_PI) * (part + i / qreal(segments));
+                qreal s = qFastSin(angle);
+                qreal c = qFastCos(angle);
+                qreal y = (part ? rect.bottom() : rect.top()) - m_radius * c; // current inner y-coordinate.
+                qreal lx = rect.left() - m_radius * s; // current inner left x-coordinate.
+                qreal rx = rect.right() + m_radius * s; // current inner right x-coordinate.
 
-        //lower left
-        cp = QPointF(rect.x() + radius, rect.y() + rect.height() - radius);
-        for (qreal angle = zero; angle >= nninety; angle += step) {
-            vertices.append(QVector2D(cp.x() + qFastSin(angle) * radius, cp.y() + qFastCos(angle) * radius));
+                vertices[vertexCount++].position = QVector2D(rx, y);
+                vertices[vertexCount++].position = QVector2D(lx, y);
+            }
         }
 
-        vertices.append(QVector2D(rect.x(), rect.y() + radius));
-        v.addAttribute(QGL::Position, vertices);
+        g->setDrawingMode(QGL::TriangleStrip);
+        g->setVertexCount(vertexCount);
 
-        setDrawingMode(QGL::TriangleFan);
-        setVertexBuffer(v);
-        setIndexBuffer(Utilities::createIndexBuffer(vertices.count()));
-        */
+        markDirty(DirtyGeometry);
     }
     setBoundingRect(m_rect);
 }
diff --git a/src/canvas/qxclipnode_p.h b/src/canvas/qxclipnode_p.h
index 76d7bbf..0754897 100644
--- a/src/canvas/qxclipnode_p.h
+++ b/src/canvas/qxclipnode_p.h
@@ -49,6 +49,10 @@
 class QxClipNode : public ClipNode
 {
 public:
+    enum UpdateFlag {
+        UpdateGeometry = 1
+    };
+
     QxClipNode(const QRectF &);
 
     void setRect(const QRectF &);
@@ -57,6 +61,8 @@ public:
     void setRadius(qreal radius);
     qreal radius() const { return m_radius; }
 
+    virtual void update(uint updateFlags);
+
 private:
     void updateGeometry();
     QRectF m_rect;