squishlib optimization

TheGuardians · May 21, 2024 · 3117cd1 · 3117cd1
1 parent d1f76bb
commit 3117cd1
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Showing 5 changed files with 333 additions and 166 deletions.
diff --git a/TagTool/Bitmaps/Utils/BitmapDownsampler.cs b/TagTool/Bitmaps/Utils/BitmapDownsampler.cs
@@ -54,6 +54,49 @@ public static byte[] Downsample4x4BlockRgba(BitmapSampler sampler)
             return result;
         }
 
+        public static byte[] Downsample4x4BlockRgba(BitmapSampler sampler, int width, int height)
+        {
+            sampler.SetFilteringMode(BitmapSampler.FilteringMode.Bilinear); // must use bilinear
+
+            byte[] result = new byte[width * height * 4];
+
+            float pixelWidth = 1.0f / width;
+            float pixelHeight = 1.0f / height;
+            float halfPxWidth = pixelWidth * 0.5f;
+            float halfPxHeight = pixelHeight * 0.5f;
+
+            int rowBytes = width * 4;
+            int rowOffset = 0;
+
+            for (int i = 0; i < height; i++)
+            {
+                float yCoord = (pixelHeight * i) + halfPxHeight;
+
+                for (int j = 0; j < width; j++)
+                {
+                    float xCoord = (pixelWidth * j) + halfPxWidth;
+
+                    // 4x4 block
+                    var sample0 = sampler.Sample2dOffsetF(xCoord, yCoord, -1, -1);
+                    var sample1 = sampler.Sample2dOffsetF(xCoord, yCoord, 1, -1);
+                    var sample2 = sampler.Sample2dOffsetF(xCoord, yCoord, -1, 1);
+                    var sample3 = sampler.Sample2dOffsetF(xCoord, yCoord, 1, 1);
+                    RealVector4d sample = (sample0 + sample1 + sample2 + sample3) / 4.0f;
+                    sample *= 255; // to byte
+
+                    int streamOffset = rowOffset + j * 4;
+                    result[streamOffset] = (byte)sample.I;
+                    result[streamOffset + 1] = (byte)sample.J;
+                    result[streamOffset + 2] = (byte)sample.K;
+                    result[streamOffset + 3] = (byte)sample.W;
+                }
+
+                rowOffset += rowBytes;
+            }
+
+            return result;
+        }
+
         // try not to use this
         public static byte[] DownsampleBilinearRgba(BitmapSampler sampler)
         {

diff --git a/TagTool/Bitmaps/Utils/BitmapSampler.cs b/TagTool/Bitmaps/Utils/BitmapSampler.cs
@@ -6,6 +6,7 @@ namespace TagTool.Bitmaps.Utils
     public class BitmapSampler
     {
         private byte[] Rgba;
+        private uint StreamOffset;
         private int Width;
         private int Height;
         private FilteringMode FilterMode;
@@ -20,6 +21,18 @@ public BitmapSampler(byte[] rgba, int width, int height, FilteringMode filter =
             FilterMode = filter;
             MipmapCount = mipCount;
             CurrentLevel = 0;
+            StreamOffset = 0;
+        }
+
+        public BitmapSampler(byte[] rgba, uint streamOffset, int width, int height, FilteringMode filter = FilteringMode.Point, int mipCount = 0)
+        {
+            Rgba = rgba;
+            Width = width;
+            Height = height;
+            FilterMode = filter;
+            MipmapCount = mipCount;
+            CurrentLevel = 0;
+            StreamOffset = streamOffset;
         }
 
         public void SetData(byte[] d) => Rgba = d;
@@ -76,7 +89,7 @@ public RealVector4d Sample2dOffsetF(float x, float y, int offsetX, int offsetY)
         private float PixelWidth() => 1.0f / Width;
         private float PixelHeight() => 1.0f / Height;
         private int UvToIndex(float x, float y) => 4 * ((int)(y * Height) * Width + (int)(x * Width));
-        private RGBAColor GetColour(int index) => new RGBAColor(Rgba[index], Rgba[index + 1], Rgba[index + 2], Rgba[index + 3]);
+        private RGBAColor GetColour(int index) => new RGBAColor(Rgba[StreamOffset + index], Rgba[StreamOffset + index + 1], Rgba[StreamOffset + index + 2], Rgba[StreamOffset + index + 3]);
         private RGBAColor Sample2dPoint(int index) => GetColour(index);
         private RGBAColor Sample2dPoint(float x, float y) => Sample2dPoint(UvToIndex(x, y));
         private RGBAColor Sample2dPointBounded(float x, float y, bool hasX, bool hasY) => GetColourBounded(UvToIndex(x, y), x, y, hasX, hasY);