/// <summary> /// /// </summary> /// <param name="arg"></param> /// <param name="lastVertexId"></param> /// <param name="picker"></param> /// <returns></returns> internal override uint[] Search(PickingEventArgs arg, uint lastVertexId, DrawArraysPicker picker) { IndexBuffer buffer = GLBuffer.Create(IndexBufferElementType.UInt, 6, BufferUsage.StaticDraw); unsafe { var array = (uint *)buffer.MapBuffer(MapBufferAccess.WriteOnly); array[0] = lastVertexId - 2; array[1] = lastVertexId - 0; array[2] = lastVertexId - 4; array[3] = lastVertexId - 2; array[4] = lastVertexId - 0; array[5] = lastVertexId - 4; buffer.UnmapBuffer(); } var cmd = new DrawElementsCmd(buffer, DrawMode.Lines); picker.Node.Render4InnerPicking(arg, ControlMode.ByFrame, cmd); uint id = ColorCodedPicking.ReadStageVertexId(arg.X, arg.Y); buffer.Dispose(); if (id + 4 == lastVertexId) { return(new uint[] { id + 4, id, }); } else { return(new uint[] { id - 2, id, }); } }
/// <summary> /// 在三角形图元中拾取指定位置的Line /// </summary> /// <param name="arg"></param> /// <param name="flatColorVertexId">三角形图元的最后一个顶点</param> /// <param name="picker"></param> /// <returns></returns> internal override uint[] Search(PickingEventArgs arg, uint flatColorVertexId, DrawArraysPicker picker) { // 创建临时索引 IndexBuffer buffer = GLBuffer.Create(IndexBufferElementType.UInt, 6, BufferUsage.StaticDraw); unsafe { var array = (uint *)buffer.MapBuffer(MapBufferAccess.WriteOnly); array[0] = flatColorVertexId - 1; array[1] = flatColorVertexId - 0; array[2] = flatColorVertexId - 2; array[3] = flatColorVertexId - 1; array[4] = flatColorVertexId - 0; array[5] = flatColorVertexId - 2; buffer.UnmapBuffer(); } var cmd = new DrawElementsCmd(buffer, DrawMode.Lines); // 用临时索引渲染此三角形图元(仅渲染此三角形图元) picker.Node.Render4InnerPicking(arg, cmd); // id是拾取到的Line的Last Vertex Id uint id = ColorCodedPicking.ReadStageVertexId(arg.X, arg.Y); buffer.Dispose(); // 对比临时索引,找到那个Line if (id + 2 == flatColorVertexId) { return(new uint[] { id + 2, id, }); } else { return(new uint[] { id - 1, id, }); } }
/// <summary> /// /// </summary> /// <param name="arg"></param> /// <param name="lastVertexId"></param> /// <param name="picker"></param> /// <returns></returns> internal override uint[] Search(PickingEventArgs arg, uint lastVertexId, 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, ControlMode.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, }); } }
/// <summary> /// /// </summary> /// <param name="arg"></param> /// <param name="lastVertexId"></param> /// <param name="picker"></param> /// <returns></returns> internal abstract uint[] Search(PickingEventArgs arg, uint lastVertexId, DrawArraysPicker picker);
/// <summary> /// /// </summary> /// <param name="arg"></param> /// <param name="singleNodeVertexId">identify location inside this node.</param> /// <param name="stageVertexId">identify location when rendering multiple nodes.</param> /// <param name="picker"></param> /// <returns></returns> internal abstract uint Search(PickingEventArgs arg, uint singleNodeVertexId, uint stageVertexId, DrawArraysPicker picker);
/// <summary> /// /// </summary> /// <param name="arg"></param> /// <param name="flatColorVertexId"></param> /// <param name="picker"></param> /// <returns></returns> internal abstract uint Search(PickingEventArgs arg, uint flatColorVertexId, DrawArraysPicker picker);