1 files changed, 89 insertions, 0 deletions
diff --git a/src/styles/TraceUtils.js b/src/styles/TraceUtils.js
new file mode 100644
index 00000000..f2dd9bbb
--- /dev/null
+++ b/src/styles/TraceUtils.js
@@ -0,0 +1,89 @@
+/****************************************************************************
+**
+** Copyright (C) 2016 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the Qt Virtual Keyboard module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:GPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3 or (at your option) any later version
+** approved by the KDE Free Qt Foundation. The licenses are as published by
+** the Free Software Foundation and appearing in the file LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+.pragma library
+
+function renderSmoothedLine(ctx, trace, renderPos) {
+
+    if (!trace)
+        return renderPos
+
+    if (renderPos >= trace.length)
+        return renderPos
+
+    // Fetch points and draw the initial "dot"
+    var points, tp
+    if (renderPos === 0) {
+        points = trace.points()
+        tp = points[renderPos++]
+        ctx.beginPath()
+        ctx.moveTo(tp.x, tp.y)
+        ctx.lineTo(tp.x, tp.y + 0.000001)
+        ctx.stroke()
+    } else {
+        points = trace.points(renderPos - 1)
+    }
+
+    // Draw smoothed line using quadratic curve
+    var i = 1
+    if (i + 1 < points.length) {
+        var pt1, pt2
+        if (renderPos === 1) {
+            tp = points[i - 1]
+        } else {
+            pt1 = points[i - 1]
+            pt2 = points[i]
+            tp = Qt.point((pt1.x + pt2.x) / 2, (pt1.y + pt2.y) / 2)
+        }
+        ctx.beginPath()
+        ctx.moveTo(tp.x, tp.y)
+        while (i + 1 < points.length) {
+            pt1 = points[i++]
+            pt2 = points[i]
+            tp = Qt.point((pt1.x + pt2.x) / 2, (pt1.y + pt2.y) / 2)
+            ctx.quadraticCurveTo(pt1.x, pt1.y, tp.x, tp.y)
+            ctx.moveTo(tp.x, tp.y)
+        }
+        ctx.stroke()
+    }
+
+    // Draw the remainder of the line
+    if (trace.isFinal) {
+        if (i < points.length) {
+            tp = points[i - 1]
+            ctx.beginPath()
+            ctx.moveTo(tp.x, tp.y)
+            tp = points[i++]
+            ctx.lineTo(tp.x, tp.y)
+            ctx.stroke()
+        }
+    }
+
+    return renderPos + i - 1
+}