1 files changed, 119 insertions, 0 deletions
diff --git a/Plugins/MonoGame.Extended/source/MonoGame.Extended.Graphics/Geometry/GeometryBuilder2D.cs b/Plugins/MonoGame.Extended/source/MonoGame.Extended.Graphics/Geometry/GeometryBuilder2D.cs
new file mode 100644
index 0000000..c113fbe
--- /dev/null
+++ b/Plugins/MonoGame.Extended/source/MonoGame.Extended.Graphics/Geometry/GeometryBuilder2D.cs
@@ -0,0 +1,119 @@
+using System;
+using System.Runtime.CompilerServices;
+using Microsoft.Xna.Framework;
+using Microsoft.Xna.Framework.Graphics;
+
+namespace MonoGame.Extended.Graphics.Geometry
+{
+    public class GeometryBuilder2D : GeometryBuilder<VertexPositionColorTexture, ushort>
+    {
+        public GeometryBuilder2D(int maximumVerticesCount, int maximumIndicesCount)
+            : base(maximumVerticesCount, maximumIndicesCount)
+        {
+        }
+
+        public void BuildSprite(int indexOffset, ref Matrix2 transformMatrix, Texture2D texture,
+            ref Rectangle sourceRectangle,
+            Color? color = null, FlipFlags flags = FlipFlags.None, float depth = 0)
+        {
+            if (texture == null)
+                throw new ArgumentNullException(nameof(texture));
+
+            var texelLeft = 0f;
+            var texelTop = 0f;
+            var texelRight = 1f;
+            var texelBottom = 1f;
+
+            if (sourceRectangle.Width > 0)
+            {
+                texelLeft = (float)sourceRectangle.X / texture.Width;
+                texelTop = (float)sourceRectangle.Y / texture.Height;
+                texelRight = (sourceRectangle.X + sourceRectangle.Width) / (float)texture.Width;
+                texelBottom = (sourceRectangle.Y + sourceRectangle.Height) / (float)texture.Height;
+            }
+            else
+            {
+                sourceRectangle.Width = texture.Width;
+                sourceRectangle.Height = texture.Height;
+            }
+
+            var color1 = color ?? Color.White;
+
+            var vertices = Vertices;
+
+            transformMatrix.Transform(0, 0, ref vertices[0].Position);
+            vertices[0].Position.Z = depth;
+            vertices[0].Color = color1;
+            vertices[0].TextureCoordinate.X = texelLeft;
+            vertices[0].TextureCoordinate.Y = texelTop;
+
+            transformMatrix.Transform(sourceRectangle.Width, 0, ref vertices[1].Position);
+            vertices[1].Position.Z = depth;
+            vertices[1].Color = color1;
+            vertices[1].TextureCoordinate.X = texelRight;
+            vertices[1].TextureCoordinate.Y = texelTop;
+
+            transformMatrix.Transform(0, sourceRectangle.Height, ref vertices[2].Position);
+            vertices[2].Position.Z = depth;
+            vertices[2].Color = color1;
+            vertices[2].TextureCoordinate.X = texelLeft;
+            vertices[2].TextureCoordinate.Y = texelBottom;
+
+            transformMatrix.Transform(sourceRectangle.Width, sourceRectangle.Height, ref vertices[3].Position);
+            vertices[3].Position.Z = depth;
+            vertices[3].Color = color1;
+            vertices[3].TextureCoordinate.X = texelRight;
+            vertices[3].TextureCoordinate.Y = texelBottom;
+
+            var flipDiagonally = (flags & FlipFlags.FlipDiagonally) != 0;
+            var flipHorizontally = (flags & FlipFlags.FlipHorizontally) != 0;
+            var flipVertically = (flags & FlipFlags.FlipVertically) != 0;
+
+            if (flipDiagonally)
+            {
+                FloatHelper.Swap(ref vertices[1].TextureCoordinate.X, ref vertices[2].TextureCoordinate.X);
+                FloatHelper.Swap(ref vertices[1].TextureCoordinate.Y, ref vertices[2].TextureCoordinate.Y);
+            }
+
+            if (flipHorizontally)
+                if (flipDiagonally)
+                {
+                    FloatHelper.Swap(ref vertices[0].TextureCoordinate.Y, ref vertices[1].TextureCoordinate.Y);
+                    FloatHelper.Swap(ref vertices[2].TextureCoordinate.Y, ref vertices[3].TextureCoordinate.Y);
+                }
+                else
+                {
+                    FloatHelper.Swap(ref vertices[0].TextureCoordinate.X, ref vertices[1].TextureCoordinate.X);
+                    FloatHelper.Swap(ref vertices[2].TextureCoordinate.X, ref vertices[3].TextureCoordinate.X);
+                }
+
+            if (flipVertically)
+                if (flipDiagonally)
+                {
+                    FloatHelper.Swap(ref vertices[0].TextureCoordinate.X, ref vertices[2].TextureCoordinate.X);
+                    FloatHelper.Swap(ref vertices[1].TextureCoordinate.X, ref vertices[3].TextureCoordinate.X);
+                }
+                else
+                {
+                    FloatHelper.Swap(ref vertices[0].TextureCoordinate.Y, ref vertices[2].TextureCoordinate.Y);
+                    FloatHelper.Swap(ref vertices[1].TextureCoordinate.Y, ref vertices[3].TextureCoordinate.Y);
+                }
+
+            VertexCount = 4;
+            AddQuadrilateralIndices(indexOffset);
+            IndexCount = 6;
+            PrimitivesCount = 2;
+        }
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        private void AddQuadrilateralIndices(int indexOffset)
+        {
+            Indices[0] = (ushort)(0 + indexOffset);
+            Indices[1] = (ushort)(1 + indexOffset);
+            Indices[2] = (ushort)(2 + indexOffset);
+            Indices[3] = (ushort)(1 + indexOffset);
+            Indices[4] = (ushort)(3 + indexOffset);
+            Indices[5] = (ushort)(2 + indexOffset);
+        }
+    }
+}