From d42b2f45e5f4e5c02f417592bc68a5a27dcb4da9 Mon Sep 17 00:00:00 2001
From: chrisf <chrisf@993157c7-ee19-0410-b2c4-bb4e9862e678>
Date: Tue, 10 Jul 2007 06:08:38 +0000
Subject: [PATCH] git-svn-id: svn://svn.ijw.co.nz/svn/OpenRa@1156
 993157c7-ee19-0410-b2c4-bb4e9862e678

---
 BluntDx/GraphicsDevice.h  | 21 +++++++++++++++++++++
 OpenRa.Game/MainWindow.cs | 28 ++++++++++++++++++++++++----
 2 files changed, 45 insertions(+), 4 deletions(-)

diff --git a/BluntDx/GraphicsDevice.h b/BluntDx/GraphicsDevice.h
index 63041a026a..7f31456588 100644
--- a/BluntDx/GraphicsDevice.h
+++ b/BluntDx/GraphicsDevice.h
@@ -2,6 +2,20 @@
 
 namespace BluntDirectX { namespace Direct3D
 {	
+	generic< typename T >
+	public value class Range
+	{
+		T start, end;
+	public:
+		Range( T start, T end )
+			: start( start ), end( end )
+		{
+		}
+
+		property T Start { T get() { return start; } }
+		property T End { T get() { return end; } }
+	};
+
 	public ref class GraphicsDevice
 	{
 	private:
@@ -164,5 +178,12 @@ namespace BluntDirectX { namespace Direct3D
 		{
 			device->DrawIndexedPrimitive( (D3DPRIMITIVETYPE)primtype, 0, 0, vertexPoolSize, 0, numPrimitives );
 		}
+
+		void DrawIndexedPrimitives(PrimitiveType primType, Range<int> vertices, Range<int> indices)
+		{
+			device->DrawIndexedPrimitive( (D3DPRIMITIVETYPE)primType,
+				0, vertices.Start, vertices.End - vertices.Start, 
+				indices.Start, (indices.End - indices.Start) / 3 );
+		}
 	};
 }}
diff --git a/OpenRa.Game/MainWindow.cs b/OpenRa.Game/MainWindow.cs
index fd183b035e..3e7a9a9183 100644
--- a/OpenRa.Game/MainWindow.cs
+++ b/OpenRa.Game/MainWindow.cs
@@ -87,7 +87,7 @@ namespace OpenRa.Game
 		void LoadVertexBuffer()
 		{
 			Dictionary<Sheet, List<ushort>> indexMap = new Dictionary<Sheet, List<ushort>>();
-			List<Vertex> vertices = new List<Vertex>();// Vertex[] vertices = new Vertex[4 * 128 * 128];
+			List<Vertex> vertices = new List<Vertex>();
 
 			for (int j = 0; j < map.Height; j++)
 				for (int i = 0; i < map.Width; i++)
@@ -127,7 +127,7 @@ namespace OpenRa.Game
 
 		public MainWindow()
 		{
-			ClientSize = new Size(640, 480);
+			ClientSize = new Size(1280, 800);
 
 			Visible = true;
 
@@ -216,8 +216,28 @@ namespace OpenRa.Game
 
 				batch.Value.Bind();
 
-				device.DrawIndexedPrimitives(PrimitiveType.TriangleList, 
-					vertexBuffer.Size, batch.Value.Size / 3);
+				int indicesPerRow = map.Width * 6;
+				int verticesPerRow = map.Width * 4;
+
+				int visibleRows = (int)Math.Ceiling(800.0f / 24.0f) + 2;
+
+				int firstRow = (int)((scrollPos.Y - 1) * 16.0f);
+				int lastRow = firstRow + visibleRows;
+
+				if (firstRow < 0)
+					firstRow = 0;
+
+				if (lastRow < 0)
+					lastRow = 0;
+
+				if (lastRow > map.Height)
+					lastRow = map.Height;
+
+				Range<int> indexRange = new Range<int>(indicesPerRow * firstRow, indicesPerRow * lastRow);
+				Range<int> vertexRange = new Range<int>(verticesPerRow * firstRow, verticesPerRow * lastRow);
+
+				device.DrawIndexedPrimitives(PrimitiveType.TriangleList,
+					vertexRange, indexRange);
 			}
 
 			effect.EndPass();