3 files changed, 77 insertions, 8 deletions

diff --git a/UVtools.Core/Extensions/DrawingExtensions.cs b/UVtools.Core/Extensions/DrawingExtensions.cs
new file mode 100644
index 0000000..8a60ee4
--- /dev/null
+++ b/UVtools.Core/Extensions/DrawingExtensions.cs
@@ -0,0 +1,34 @@
+using System;
+using System.Drawing;
+
+namespace UVtools.Core.Extensions
+{
+    public static class DrawingExtensions
+    {
+        public static Color FactorColor(this Color color, byte pixelColor, byte min = 0, byte max = byte.MaxValue) =>
+            FactorColor(color, pixelColor / 255f, min, max);
+
+        public static Color FactorColor(this Color color, float factor, byte min = 0, byte max = byte.MaxValue)
+        {
+            byte r = (byte)(color.R == 0 ? 0 :
+                Math.Min(Math.Max(min, color.R * factor), max));
+
+            byte g = (byte)(color.G == 0 ? 0 :
+                Math.Min(Math.Max(min, color.G * factor), max));
+
+            byte b = (byte)(color.B == 0 ? 0 :
+                Math.Min(Math.Max(min, color.B * factor), max));
+            return Color.FromArgb(r, g, b);
+        }
+
+        public static int GetArea(this Rectangle rect)
+        {
+            return rect.Width * rect.Height;
+        }
+
+        public static int GetArea(this Size size)
+        {
+            return size.Width * size.Height;
+        }
+    }
+}
diff --git a/UVtools.Core/Extensions/EmguExtensions.cs b/UVtools.Core/Extensions/EmguExtensions.cs
index a96a50f..735c41a 100644
--- a/UVtools.Core/Extensions/EmguExtensions.cs
+++ b/UVtools.Core/Extensions/EmguExtensions.cs
@@ -27,11 +27,10 @@ namespace UVtools.Core.Extensions
             return new Span<T>(mat.DataPointer.ToPointer(), mat.GetLength());
         }
 
-        public static Span<T> GetPixelRowSpan<T>(this Mat mat, int y)
+        public static unsafe Span<T> GetPixelRowSpan<T>(this Mat mat, int y)
         {
-            int offset = y * mat.Step;
-            //IntPtr ptr = IntPtr.Add(mat.DataPointer, offset);
-            return mat.GetPixelSpan<T>().Slice(offset, mat.Step);
+            return new Span<T>(IntPtr.Add(mat.DataPointer, y * mat.Step).ToPointer(), mat.Step);
+            //return mat.GetPixelSpan<T>().Slice(offset, mat.Step);
         }
 
         /// <summary>
@@ -44,17 +43,19 @@ namespace UVtools.Core.Extensions
         /// <param name="xTrans">X translation</param>
         /// <param name="yTrans">Y translation</param>
         /// <param name="interpolation">Interpolation mode</param>
-        public static void ScaleFromCenter(this Mat src, double xScale, double yScale, double xTrans = 0, double yTrans = 0, Inter interpolation = Inter.Linear)
+        public static void TransformFromCenter(this Mat src, double xScale, double yScale, double xTrans = 0, double yTrans = 0, Inter interpolation = Inter.Linear)
         {
             //var dst = new Mat(src.Size, src.Depth, src.NumberOfChannels);
-            var translateTransform = new Matrix<double>(2, 3)
+            using (var translateTransform = new Matrix<double>(2, 3)
             {
                 [0, 0] = xScale, // xScale
                 [1, 1] = yScale, // yScale
                 [0, 2] = xTrans + (src.Width - src.Width * xScale) / 2.0, //x translation + compensation of  x scaling
                 [1, 2] = yTrans + (src.Height - src.Height * yScale) / 2.0 // y translation + compensation of y scaling
-            };
-            CvInvoke.WarpAffine(src, src, translateTransform, src.Size, interpolation);
+            })
+            {
+                CvInvoke.WarpAffine(src, src, translateTransform, src.Size, interpolation);
+            }
         }
 
         /// <summary>
diff --git a/UVtools.Core/Extensions/SpanExtensions.cs b/UVtools.Core/Extensions/SpanExtensions.cs
new file mode 100644
index 0000000..0a9ffeb
--- /dev/null
+++ b/UVtools.Core/Extensions/SpanExtensions.cs
@@ -0,0 +1,34 @@
+using System;
+using System.Runtime.CompilerServices;
+using System.Threading.Tasks;
+
+namespace UVtools.Core.Extensions
+{
+    public static class SpanExtensions
+    {
+        public static unsafe void Fill<T>(this Span<T> span, Func<T> provider) where T : struct
+        {
+            int
+                cores = Environment.ProcessorCount,
+                batch = span.Length / cores,
+                mod = span.Length % cores,
+                size = Unsafe.SizeOf<T>();
+            ref T r0 = ref span.GetPinnableReference();
+            fixed (byte* p0 = &Unsafe.As<T, byte>(ref r0))
+            {
+                byte* p = p0;
+                Parallel.For(0, cores, i =>
+                {
+                    byte* pi = p + i * batch * size;
+                    for (int j = 0; j < batch; j++, pi += size)
+                        Unsafe.Write(pi, provider());
+                });
+
+                // Remaining values
+                if (mod < 1) return;
+                for (int i = span.Length - mod; i < span.Length; i++)
+                    Unsafe.Write(p + i * size, provider());
+            }
+        }
+    }
+}