public TransformFeedbackCalculator(int maxItemCount)
{
this.MaxItemCount = maxItemCount;
var program = new ShaderProgram();
//program.Initialize(varyings, ShaderProgram.BufferMode.InterLeaved, vertexShader);
var varyings = new string[] { "outValue" };
glTransformFeedbackVaryings(program.ProgramId, varyings.Length, varyings, GL.GL_INTERLEAVED_ATTRIBS);
var vertexShader = new VertexShader(vertexCode);
vertexShader.Initialize();
glAttachShader(program.ProgramId, vertexShader.ShaderId);
glLinkProgram(program.ProgramId);
program.CheckLinkStatus();
VertexBuffer vbo = VertexBuffer.Create(typeof(float), maxItemCount, VBOConfig.Float, BufferUsage.StaticDraw);
var drawCmd = new DrawArraysCmd(DrawMode.Points, maxItemCount);
var vao = new VertexArrayObject(drawCmd, program, new VertexShaderAttribute[] { new VertexShaderAttribute(vbo, "inValue") });
uint index = 0;
VertexBuffer tbo = VertexBuffer.Create(typeof(float), maxItemCount, VBOConfig.Float, BufferUsage.StaticRead);
glBindBufferBase(GL.GL_TRANSFORM_FEEDBACK_BUFFER, index, tbo.BufferId);
{
this.program = program;
this.inputBuffer = vbo;
this.outputBuffer = tbo;
this.vao = vao;
this.drawCommand = drawCmd;
}
}
protected override void DoInitialize()
{
base.DoInitialize();
{
this.positionBuffer = this.RenderUnit.Methods[0].VertexArrayObjects[0].VertexAttributes[0].Buffer;
this.drawCommand = this.RenderUnit.Methods[0].VertexArrayObjects[0].DrawCommand as DrawArraysCmd;
}
}
/// <summary>
///
/// </summary>
/// <returns></returns>
public IEnumerable <IDrawCommand> GetDrawCommand()
{
if (this.drawCmd == null)
{
var buffer = new DrawArraysCmd(this.Mode, this.FirstVertex, this.VertexCount, this.PrimCount);
this.drawCmd = buffer;
}
yield return(this.drawCmd);
}
/// <summary>
///
/// </summary>
/// <returns></returns>
public IEnumerable <IDrawCommand> GetDrawCommand()
{
if (this.drawCmd == null)
{
var drawCmd = new DrawArraysCmd(DrawMode.Quads, this.Capacity * 4);
drawCmd.VertexCount = 0;
this.drawCmd = drawCmd;
}
yield return(this.drawCmd);
}
public IEnumerable <IDrawCommand> GetDrawCommand()
{
if (this.drawCmd == null)
{
if (faceList != null)
{
Face[] faces = faceList.ToArray();
IndexBuffer buffer = faces.GenIndexBuffer(IndexBufferElementType.UInt, BufferUsage.StaticDraw);//改为int以增大显示数量
this.drawCmd = new DrawElementsCmd(buffer, DrawMode.Triangles);
}
else
{
DrawArraysCmd buffer = new DrawArraysCmd(DrawMode.Points, VertexCount());
this.drawCmd = buffer;
}
}
yield return(this.drawCmd);
}
/// <summary>
///
/// </summary>
/// <param name="arg"></param>
/// <param name="flatColorVertexId"></param>
/// <param name="picker"></param>
/// <returns></returns>
internal override uint[] Search(PickingEventArgs arg, uint flatColorVertexId, DrawArraysPicker picker)
{
var cmd = picker.DrawCommand as DrawArraysCmd;
// when the temp index buffer could be long, it's no longer needed.
// what a great OpenGL API design!
DrawArraysCmd drawCmd = new DrawArraysCmd(DrawMode.LineLoop, cmd.FirstVertex, cmd.RenderingVertexCount, cmd.InstanceCount, cmd.FrameCount);
picker.Node.Render4InnerPicking(arg, IndexAccessMode.ByFrame, drawCmd);
uint id = ColorCodedPicking.ReadStageVertexId(arg.X, arg.Y);
if (id == cmd.FirstVertex)
{
return(new uint[] { (uint)(cmd.FirstVertex + cmd.RenderingVertexCount - 1), id, });
}
else
{
return(new uint[] { id - 1, id, });
}
}
