Axiom.Overlays.Elements.Panel.UpdateTextureGeometry C# (CSharp) Method

		protected override void UpdateTextureGeometry()
		{
			if ( material != null && isInitialized )
			{
				int numLayers = material.GetTechnique( 0 ).GetPass( 0 ).TextureUnitStageCount;

				VertexDeclaration decl = renderOperation.vertexData.vertexDeclaration;

				// if the required layers is less than the current amount of tex coord buffers, remove
				// the extraneous buffers
				if ( numTexCoordsInBuffer > numLayers )
				{
					for ( int i = numTexCoordsInBuffer; i > numLayers; --i )
					{
						decl.RemoveElement( VertexElementSemantic.TexCoords, i );
					}
				}
				else if ( numTexCoordsInBuffer < numLayers )
				{
					// we need to add more buffers
					int offset = VertexElement.GetTypeSize( VertexElementType.Float2 ) * numTexCoordsInBuffer;

					for ( int i = numTexCoordsInBuffer; i < numLayers; ++i )
					{
						decl.AddElement( TEXTURE_COORDS, offset, VertexElementType.Float2, VertexElementSemantic.TexCoords, i );
						offset += VertexElement.GetTypeSize( VertexElementType.Float2 );
					} // for
				} // if

				// if the number of layers changed at all, we'll need to reallocate buffer
				if ( numTexCoordsInBuffer != numLayers )
				{
					HardwareVertexBuffer newBuffer =
						HardwareBufferManager.Instance.CreateVertexBuffer( decl.Clone( TEXTURE_COORDS ), renderOperation.vertexData.vertexCount, BufferUsage.StaticWriteOnly );

					// Bind buffer, note this will unbind the old one and destroy the buffer it had
					renderOperation.vertexData.vertexBufferBinding.SetBinding( TEXTURE_COORDS, newBuffer );

					// record the current number of tex layers now
					numTexCoordsInBuffer = numLayers;
				} // if

				if ( numTexCoordsInBuffer != 0 )
				{
					// get the tex coord buffer
					HardwareVertexBuffer buffer = renderOperation.vertexData.vertexBufferBinding.GetBuffer( TEXTURE_COORDS );
					IntPtr data = buffer.Lock( BufferLocking.Discard );

					unsafe
					{

						float* texPtr = (float*)data.ToPointer();
						int texIndex = 0;

						int uvSize = VertexElement.GetTypeSize( VertexElementType.Float2 ) / sizeof( float );
						int vertexSize = decl.GetVertexSize( TEXTURE_COORDS ) / sizeof( float );

						for ( int i = 0; i < numLayers; i++ )
						{
							// Calc upper tex coords
							float upperX = bottomRight.x * tileX[ i ];
							float upperY = bottomRight.y * tileY[ i ];

							/*
								0-----2
								|    /|
								|  /  |
								|/    |
								1-----3
							*/
							// Find start offset for this set
							texIndex = ( i * uvSize );

							texPtr[ texIndex ] = topLeft.x;
							texPtr[ texIndex + 1 ] = topLeft.y;

							texIndex += vertexSize; // jump by 1 vertex stride
							texPtr[ texIndex ] = topLeft.x;
							texPtr[ texIndex + 1 ] = upperY;

							texIndex += vertexSize;
							texPtr[ texIndex ] = upperX;
							texPtr[ texIndex + 1 ] = topLeft.y;

							texIndex += vertexSize;
							texPtr[ texIndex ] = upperX;
							texPtr[ texIndex + 1 ] = upperY;
						} // for
					} // unsafev

					// unlock the buffer
					buffer.Unlock();
				}
			} // if material != null
		}