From 2bcaf5d46bb46ecc824db581d81942a3125450ab Mon Sep 17 00:00:00 2001
From: UnknownShadow200 <unknownshadow200@gmail.com>
Date: Fri, 10 Apr 2015 19:53:11 +1000
Subject: [PATCH] Add clipping in homogenous coordinates.

---
 SoftwareEngine/Engine/SoftwareEngine.cs | 22 ++++++++++++++++++++++
 SoftwareEngine/MainForm.cs              |  8 ++++----
 2 files changed, 26 insertions(+), 4 deletions(-)

diff --git a/SoftwareEngine/Engine/SoftwareEngine.cs b/SoftwareEngine/Engine/SoftwareEngine.cs
index fa3f1b653..6d92cd69d 100644
--- a/SoftwareEngine/Engine/SoftwareEngine.cs
+++ b/SoftwareEngine/Engine/SoftwareEngine.cs
@@ -122,6 +122,28 @@ namespace SoftwareRasterizer.Engine {
 			v.Y = -point.Y * height + height / 2.0f;
 			v.Z = point.Z;
 		}
+		
+		bool ProjectClipped( ref Vector3 coord, out Vector3 v ) {
+			v = Vector3.Zero;
+			Vector4 point = Vector4.Zero;
+			Vector4 wCoord = new Vector4( coord.X, coord.Y, coord.Z, 1 );
+			Vector4.Transform( ref wCoord, ref worldViewProj, out point );
+			
+			if( Math.Abs( point.X ) > Math.Abs( point.W ) && 
+			   Math.Abs( point.Y ) > Math.Abs( point.W ) ) {
+				return true;
+			}
+			point.X /= point.W;
+			point.Y /= point.W;
+			point.Z /= point.W;
+			
+			//x = ( point.X * 0.5f + 0.5f ) * width;
+			//y = ( point.Y * 0.5f + 0.5f ) * height;
+			v.X = point.X * width + width / 2.0f;
+			v.Y = -point.Y * height + height / 2.0f;
+			v.Z = point.Z;
+			return false;
+		}
 
 		void SetPixelClipped( ref Vector3 p, ref FastColour col ) {
 			if( p.X >= 0 && p.Y >= 0 && p.X < width && p.Y < height )  {
diff --git a/SoftwareEngine/MainForm.cs b/SoftwareEngine/MainForm.cs
index d615662ba..755ba1469 100644
--- a/SoftwareEngine/MainForm.cs
+++ b/SoftwareEngine/MainForm.cs
@@ -67,16 +67,16 @@ namespace SoftwareRasterizer {
 				};
 				
 				rot.X += 0.01f;
-				Matrix4 world = Matrix4.RotateX( rot.X ) * Matrix4.RotateY( rot.X );
+				Matrix4 world = Matrix4.RotateX( rot.X ) * Matrix4.RotateZ( rot.X );
 				device.SetAllMatrices( ref proj, ref view, ref world );
-				device.Filled_DrawIndexedTriangles( vertices, indices );
-				/*for( int i = 0; i < 1000; i++ ) {
+				//device.Filled_DrawIndexedTriangles( vertices, indices );
+				for( int i = 0; i < 1000; i++ ) {
 					float offset = (float)rnd.NextDouble() - 0.5f;
 					for( int j = 0; j < vertices.Length; j++ ) {
 						vertices[j] += new Vector3( offset, offset, offset );
 					}
 					device.Line_DrawIndexedTriangles( vertices, indices );
-				}*/
+				}
 				
 				device.Present( e.Graphics );
 				base.OnPaint( e );