/// <summary>
/// 初始化控制点集合：1.把所有的控制点读到缓存Hashtable中去,并设置GCP的高宽.2.计算每个GCP的包围范围
/// </summary>
/// <param name="drawArgs"></param>
public override void Initialize(DrawArgs drawArgs)
{
//判断是否显示此图层，若不显示，则返回
if (!isOn)
{
return;
}
//判断绘制GCP的对象，是否存在，若不存在，则创建，若存在，则先释放
if (m_sprite != null)
{
m_sprite.Dispose();
m_sprite = null;
}
m_sprite = new Sprite(drawArgs.device);
System.TimeSpan smallestRefreshInterval = System.TimeSpan.MaxValue;
// 添加所有的GCP对象的纹理到缓存中去，并设置GCP的宽与高
foreach (RenderableObject ro in m_children)
{
GCP gcp = ro as GCP;
if (gcp == null)
{
// 判断当前GCP是否显示，若不显示，则Continue下一个
if (ro.IsOn)
{
ro.Initialize(drawArgs);
}
continue;
}
if (gcp.RefreshInterval.TotalMilliseconds != 0 && gcp.RefreshInterval != TimeSpan.MaxValue && gcp.RefreshInterval < smallestRefreshInterval)
{
smallestRefreshInterval = gcp.RefreshInterval;
}
// 子GCP初始化
gcp.Initialize(drawArgs);
object key = null;
//创建一个GCPeTexture对象
GCPTexture gcpTexture = null;
//从文件中读取当前GCP纹理
if (gcp.TextureFileName != null && gcp.TextureFileName.Length > 0)
{
// 从缓存中读取GCP纹理对象
gcpTexture = (GCPTexture)m_textures[gcp.TextureFileName];
//若缓存中不存在，则从文件中读取GCP对象
if (gcpTexture == null)
{
key = gcp.TextureFileName;
gcpTexture = new GCPTexture(drawArgs.device, gcp.TextureFileName);
}
}
//从Bitmap对象中读取GCP对象
else
{
if (gcp.Image != null)
{
gcpTexture = (GCPTexture)m_textures[gcp.Image];
if (gcpTexture == null)
{
key = gcp.Image;
gcpTexture = new GCPTexture(drawArgs.device, gcp.Image);
}
}
}
//若仍然没有纹理，则循环下一个
if (gcpTexture == null)
{
continue;
}
//若有纹理的话
if (key != null)
{
//把纹理放到缓存中去
m_textures.Add(key, gcpTexture);
// 设置GCP的宽度
if (gcp.Width == 0)
{
gcp.Width = gcpTexture.Width;
}
// 设置GCP的高度
if (gcp.Height == 0)
{
gcp.Height = gcpTexture.Height;
}
}
}
// 计算GCP的包围盒
foreach (RenderableObject ro in m_children)
{
GCP GCP = ro as GCP;
if (GCP == null)
{
continue;
}
if (GetTexture(GCP) == null)
{
//计算文字的范围
GCP.SelectionRectangle = drawArgs.DefaultDrawingFont.MeasureString(null, GCP.Name, DrawTextFormat.None, 0);
}
else
{
//计算控制点的范围
GCP.SelectionRectangle = new Rectangle(0, 0, GCP.Width, GCP.Height);
}
// Center the box at (0,0)
GCP.SelectionRectangle.Offset(-GCP.SelectionRectangle.Width / 2, -GCP.SelectionRectangle.Height / 2);
}
if (refreshTimer == null && smallestRefreshInterval != TimeSpan.MaxValue)
{
refreshTimer = new System.Timers.Timer(smallestRefreshInterval.TotalMilliseconds);
refreshTimer.Elapsed += new System.Timers.ElapsedEventHandler(refreshTimer_Elapsed);
refreshTimer.Start();
}
IsInitialized = true;
}
/// <summary>
/// 渲染控制点
/// </summary>
protected virtual void Render(DrawArgs drawArgs, GCP gcp, Vector3 projectedPoint)
{
//判断当前GCP是否被初始化了，比如，若重新定义了控制点的位置，则它的isInitialized就是false
if (!gcp.IsInitialized)
{
gcp.Initialize(drawArgs);
}
//判断当前控制点是否在视地范围内，若不在，则不进行绘制
if (!drawArgs.WorldCamera.ViewFrustum.ContainsPoint(gcp.Position))
{
return;
}
// 判断控制点是否在最大，最小可见的范围内，若不在，则不进行绘制
double distanceToGCP = Vector3.Length(gcp.Position - drawArgs.WorldCamera.Position);
if (distanceToGCP > gcp.MaximumDisplayDistance)
{
return;
}
if (distanceToGCP < gcp.MinimumDisplayDistance)
{
return;
}
//获得当前图层的纹理对象
GCPTexture gcpTexture = GetTexture(gcp);
//判断是否是MouseOver对象
bool isMouseOver = gcp == mouseOverGCP;
//若是MouseOver对象，则绘制Description里的内容
if (isMouseOver)
{
//若是MouseOver对象
isMouseOver = true;
//若当前图层可以操作，则设置当前的鼠标是Hand
if (gcp.IsSelectable)
{
DrawArgs.MouseCursor = DrawArgs.MouseCursor == CursorType.SizeAll ? CursorType.SizeAll : CursorType.Hand;
}
//显示文字描述信息,暂时不需要
string description = string.Format("纬度：{0:f6}°\n经度：{1:f6}°\n", gcp.Latitude, gcp.Longitude);
//绘制文字信息
if (description != null)
{
//设置文字的绘制区域
DrawTextFormat format = DrawTextFormat.NoClip | DrawTextFormat.WordBreak | DrawTextFormat.Bottom;
Rectangle rect = Rectangle.FromLTRB(DrawArgs.CurrentMousePosition.X,
DrawArgs.CurrentMousePosition.Y,
DrawArgs.CurrentMousePosition.X + 200, DrawArgs.CurrentMousePosition.Y + 60);
//绘制边框
drawArgs.DefaultDrawingFont.DrawText(
m_sprite, description,
rect,
format, 0xb0 << 24);
rect.Offset(2, 0);
drawArgs.DefaultDrawingFont.DrawText(
m_sprite, description,
rect,
format, 0xb0 << 24);
rect.Offset(0, 2);
drawArgs.DefaultDrawingFont.DrawText(
m_sprite, description,
rect,
format, 0xb0 << 24);
rect.Offset(-2, 0);
drawArgs.DefaultDrawingFont.DrawText(
m_sprite, description,
rect,
format, 0xb0 << 24);
// 绘制文字信息
rect.Offset(1, -1);
drawArgs.DefaultDrawingFont.DrawText(
m_sprite, description,
rect,
format, descriptionColor);
}
}
//获取颜色
int color = isMouseOver ? hotColor : normalColor;
if (gcpTexture == null || isMouseOver || gcp.NameAlwaysVisible)
{
// 绘制控制点的名称
if (gcp.Name != null)
{
// Render name field
const int labelWidth = 1000; // Dummy value needed for centering the text
if (gcpTexture == null)
{
// Center over target as we have no bitmap
Rectangle rect = new Rectangle(
(int)projectedPoint.X - (labelWidth >> 1),
(int)(projectedPoint.Y - (drawArgs.GCPNameFont.Description.Height >> 1)),
labelWidth,
drawArgs.ScreenHeight);
drawArgs.GCPNameFont.DrawText(m_sprite, gcp.Name, rect, DrawTextFormat.Center, color);
}
else
{
// Adjust text to make room for GCP
int spacing = (int)(gcp.Width * 0.3f);
if (spacing > 10)
{
spacing = 10;
}
int offsetForGCP = (gcp.Width >> 1) + spacing;
Rectangle rect = new Rectangle(
(int)projectedPoint.X + offsetForGCP,
(int)(projectedPoint.Y - (drawArgs.GCPNameFont.Description.Height >> 1)),
labelWidth,
drawArgs.ScreenHeight);
drawArgs.GCPNameFont.DrawText(m_sprite, gcp.Name, rect, DrawTextFormat.WordBreak, color);
}
}
}
//绘制控制点
if (gcpTexture != null)
{
// Render GCP
float xscale = (float)gcp.Width / gcpTexture.Width;
float yscale = (float)gcp.Height / gcpTexture.Height;
m_sprite.Transform = Matrix.Scaling(xscale, yscale, 0);
if (gcp.IsRotated)
{
m_sprite.Transform *= Matrix.RotationZ((float)gcp.Rotation.Radians - (float)drawArgs.WorldCamera.Heading.Radians);
}
m_sprite.Transform *= Matrix.Translation(projectedPoint.X, projectedPoint.Y, 0);
m_sprite.Draw(gcpTexture.Texture,
new Vector3(gcpTexture.Width >> 1, gcpTexture.Height >> 1, 0),
Vector3.Empty,
color);
// Reset transform to prepare for text rendering later
m_sprite.Transform = Matrix.Identity;
}
}
