Histogram texture now has maximum 1024 samples (=> less memory usage + fixed error or large datasets)

Author: mlavik1

Assets/Scripts/Importing/RawDatasetImporter.cs

@@ -50,6 +50,8 @@ public override VolumeDataset Import()
             if (fs.Length < expectedFileSize)
             {
                 Debug.LogError($"The dimension({dimX}, {dimY}, {dimZ}) exceeds the file size. Expected file size is {expectedFileSize} bytes, while the actual file size is {fs.Length} bytes");
+                reader.Close();
+                fs.Close();
                 return null;
             }
 
@@ -94,6 +96,8 @@ public override VolumeDataset Import()
             }
             Debug.Log("Loaded dataset in range: " + dataset.GetMinDataValue() + "  -  " + dataset.GetMaxDataValue());
 
+            reader.Close();
+            fs.Close();
             return dataset;
         }
 

Assets/Scripts/Utils/HistogramTextureGenerator.cs

@@ -8,18 +8,21 @@ public static Texture2D GenerateHistogramTexture(VolumeDataset dataset)
         {
             int minValue = dataset.GetMinDataValue();
             int maxValue = dataset.GetMaxDataValue();
+            int numValues = maxValue - minValue + 1;
 
-            int numSamples = maxValue - minValue + 1;
+            int numSamples = System.Math.Min(numValues, 1024);
             int[] values = new int[numSamples];
             Color[] cols = new Color[numSamples];
             Texture2D texture = new Texture2D(numSamples, 1, TextureFormat.RGBAFloat, false);
 
             int maxFreq = 0;
             for (int iData = 0; iData < dataset.data.Length; iData++)
             {
-                int dataValue = dataset.data[iData] - minValue;
-                values[dataValue] += 1;
-                maxFreq = System.Math.Max(values[dataValue], maxFreq);
+                int dataValue = dataset.data[iData];
+                float tValue = Mathf.InverseLerp(minValue, maxValue, dataValue);
+                int valueIndex = Mathf.RoundToInt((numSamples - 1) * tValue);
+                values[valueIndex] += 1;
+                maxFreq = System.Math.Max(values[valueIndex], maxFreq);
             }
 
             for (int iSample = 0; iSample < numSamples; iSample++)