1 files changed, 122 insertions, 0 deletions
diff --git a/src/main/java/com/jsyn/scope/swing/WaveTraceView.java b/src/main/java/com/jsyn/scope/swing/WaveTraceView.java
new file mode 100644
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--- /dev/null
+++ b/src/main/java/com/jsyn/scope/swing/WaveTraceView.java
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+/*
+ * Copyright 2009 Phil Burk, Mobileer Inc
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.jsyn.scope.swing;
+
+import java.awt.Color;
+import java.awt.Graphics;
+
+import javax.swing.JToggleButton.ToggleButtonModel;
+
+import com.jsyn.scope.WaveTraceModel;
+import com.jsyn.swing.ExponentialRangeModel;
+
+public class WaveTraceView {
+    private static final double AUTO_DECAY = 0.95;
+    private WaveTraceModel waveTraceModel;
+    private Color color;
+    private ExponentialRangeModel verticalScaleModel;
+    private ToggleButtonModel autoScaleButtonModel;
+
+    private double xScaler;
+    private double yScalar;
+    private int centerY;
+
+    public WaveTraceView(ToggleButtonModel autoButtonModel, ExponentialRangeModel verticalRangeModel) {
+        this.verticalScaleModel = verticalRangeModel;
+        this.autoScaleButtonModel = autoButtonModel;
+    }
+
+    public Color getColor() {
+        return color;
+    }
+
+    public void setColor(Color color) {
+        this.color = color;
+    }
+
+    public ExponentialRangeModel getVerticalRangeModel() {
+        return verticalScaleModel;
+    }
+
+    public ToggleButtonModel getAutoButtonModel() {
+        return autoScaleButtonModel;
+    }
+
+    public void setModel(WaveTraceModel waveTraceModel) {
+        this.waveTraceModel = waveTraceModel;
+    }
+
+    public int convertRealToY(double r) {
+        return centerY - (int) (yScalar * r);
+    }
+
+    public void drawWave(Graphics g, int width, int height) {
+        double sampleMax = 0.0;
+        double sampleMin = 0.0;
+        g.setColor(color);
+        int numSamples = waveTraceModel.getVisibleSize();
+        if (numSamples > 0) {
+            xScaler = (double) width / numSamples;
+            // Scale by 0.5 because it is bipolar.
+            yScalar = 0.5 * height / verticalScaleModel.getDoubleValue();
+            centerY = height / 2;
+
+            // Calculate position of first point.
+            int x1 = 0;
+            int offset = waveTraceModel.getStartIndex();
+            double value = waveTraceModel.getSample(offset);
+            int y1 = convertRealToY(value);
+
+            // Draw lines to remaining points.
+            for (int i = 1; i < numSamples; i++) {
+                int x2 = (int) (i * xScaler);
+                value = waveTraceModel.getSample(offset + i);
+                int y2 = convertRealToY(value);
+                g.drawLine(x1, y1, x2, y2);
+                x1 = x2;
+                y1 = y2;
+                // measure min and max for auto
+                if (value > sampleMax) {
+                    sampleMax = value;
+                } else if (value < sampleMin) {
+                    sampleMin = value;
+                }
+            }
+
+            autoScaleRange(sampleMax);
+        }
+    }
+
+    // Autoscale the vertical range.
+    private void autoScaleRange(double sampleMax) {
+        if (autoScaleButtonModel.isSelected()) {
+            double scaledMax = sampleMax * 1.1;
+            double current = verticalScaleModel.getDoubleValue();
+            if (scaledMax > current) {
+                verticalScaleModel.setDoubleValue(scaledMax);
+            } else {
+                double decayed = current * AUTO_DECAY;
+                if (decayed > verticalScaleModel.getMinimum()) {
+                    if (scaledMax < decayed) {
+                        verticalScaleModel.setDoubleValue(decayed);
+                    }
+                }
+            }
+        }
+    }
+
+}