/// <summary>
///
/// </summary>
/// <param name="model"></param>
/// <returns></returns>
public IPickableRenderMethod ToRenderMethod(IBufferSource model)
{
// init shader program.
ShaderProgram pickProgram = this.programProvider.GetShaderProgram();
// init vertex attribute buffer objects.
VertexBuffer positionBuffer = model.GetVertexAttributeBuffer(this.positionNameInIBufferSource);
// RULE: 由于picking.vert/frag只支持vec3的position buffer，所以有此硬性规定。
if (positionBuffer == null || positionBuffer.Config != VBOConfig.Vec3)
{
throw new Exception(string.Format("Position buffer must use a type composed of 3 float as PropertyBuffer<T>'s T!"));
}
// init index buffer.
IndexBuffer indexBuffer = model.GetIndexBuffer();
// init VAO.
var pickingVAO = new VertexArrayObject(indexBuffer, pickProgram, new VertexShaderAttribute(positionBuffer, PickingShaderHelper.in_Position));
var renderUnit = new IPickableRenderMethod(pickProgram, pickingVAO, positionBuffer, this.states);
// RULE: Renderer takes uint.MaxValue, ushort.MaxValue or byte.MaxValue as PrimitiveRestartIndex. So take care this rule when designing a model's index buffer.
var ptr = indexBuffer as OneIndexBuffer;
if (ptr != null)
{
GLState glState = new PrimitiveRestartState(ptr.ElementType);
renderUnit.StateList.Add(glState);
}
return(renderUnit);
}
/// <summary>
///
/// </summary>
protected override void DoInitialize()
{
base.DoInitialize();
IPickableRenderMethod renderUnit = this.pickingRenderUnitBuilder.ToRenderMethod(this.RenderUnit.Model);
var pickerList = new List <PickerBase>();
foreach (var vao in renderUnit.VertexArrayObjects)
{
IDrawCommand cmd = vao.DrawCommand;
if (cmd is DrawArraysCmd)
//|| cmd is MultiDrawArraysCmd)
{
//I don't know what will happen during picking if 'overlap' exists in glMultiDrawArrays(..). I don't care either, because that is a problem that should be solved in modeling stage.
VertexBuffer positionBuffer = vao.VertexAttributes[0].Buffer; // according to base.DoInitialize(), this is the position buffer of the only vertex attribute.
pickerList.Add(new DrawArraysPicker(this, positionBuffer, cmd as DrawArraysCmd));
}
else if (cmd is DrawElementsCmd)
//|| cmd is MultiDrawElementsCmd)
{
//I don't know what will happen during picking if 'overlap' exists in glMultiDrawElements(..). I don't care either, because that is a problem that should be solved in modeling stage.
VertexBuffer positionBuffer = vao.VertexAttributes[0].Buffer; // according to base.DoInitialize(), this is the position buffer of the only vertex attribute.
pickerList.Add(new DrawElementsPicker(this, positionBuffer, cmd as DrawElementsCmd));
}
else
{
throw new NotImplementedException(string.Format("`{0}` is a IDrawCommand type that has not been supported for `IPickable`.", cmd.GetType()));
}
}
this.picker = pickerList.ToArray();
this.PickingRenderUnit = renderUnit;
}
/// <summary>
/// This method should only be invoked once.
/// </summary>
private void DoInitialize()
{
IBufferSource model = this.Model;
for (int i = 0; i < this.builders.Length; i++)
{
IPickableRenderMethod method = this.builders[i].ToRenderMethod(model);
this.Methods[i] = method;
}
}
/// <summary>
///
/// </summary>
protected override void DoInitialize()
{
base.DoInitialize();
{
IPickableRenderMethod renderUnit = this.pickingRenderUnitBuilder.ToRenderMethod(this.RenderUnit.Model);
if (renderUnit.VertexArrayObject.IndexBuffer is ZeroIndexBuffer)
{
this.picker = new ZeroIndexPicker(this);
}
else if (renderUnit.VertexArrayObject.IndexBuffer is OneIndexBuffer)
{
this.picker = new OneIndexPicker(this);
}
this.PickingRenderUnit = renderUnit;
}
}
/// <summary>
///
/// </summary>
/// <param name="model"></param>
/// <returns></returns>
public IPickableRenderMethod ToRenderMethod(IBufferSource model)
{
// init shader program.
ShaderProgram pickProgram = this.programProvider.GetShaderProgram();
// init vertex attribute buffer objects.
var positionBuffers = new List <VertexBuffer>(); // position attribute is divided into blocks.
// we only care about the position attribute.
foreach (var buffer in model.GetVertexAttributeBuffer(this.positionNameInIBufferSource))
{
if (buffer == null)
{
throw new Exception(string.Format("[{0}] returns null buffer pointer!", model));
}
positionBuffers.Add(buffer);
}
int blockCount = positionBuffers.Count;
// RULE: 由于picking.vert/frag只支持vec3的position buffer，所以有此硬性规定。
foreach (var buffer in positionBuffers)
{
if (buffer == null || buffer.Config != VBOConfig.Vec3)
{
throw new Exception(string.Format("Position buffer must use a type composed of 3 float as PropertyBuffer<T>'s T!"));
}
}
// init draw command.
var allDrawCommands = (from item in model.GetDrawCommand()
where (item != null)
select item).ToArray();
int cmdCount = allDrawCommands.Length;
if (cmdCount != blockCount)
{
throw new Exception("Draw Commands count != vertex buffer block count.");
}
// init VAO.
var pickingVAOs = new VertexArrayObject[cmdCount];
for (int b = 0; b < cmdCount; b++)
{
var vertexAttributeBuffers = new VertexShaderAttribute(positionBuffers[b], PickingShaderHelper.in_Position);
pickingVAOs[b] = new VertexArrayObject(allDrawCommands[b], pickProgram, vertexAttributeBuffers);
}
var renderUnit = new IPickableRenderMethod(pickProgram, pickingVAOs, positionBuffers.ToArray(), this.states);
// RULE: Renderer takes uint.MaxValue, ushort.MaxValue or byte.MaxValue as PrimitiveRestartIndex. So take care this rule when designing a model's index buffer.
foreach (var cmd in allDrawCommands)
{
var ptr = cmd as IHasIndexBuffer;
if (ptr != null)
{
GLState glState = new PrimitiveRestartState(ptr.IndexBufferObject.ElementType);
renderUnit.StateList.Add(glState);
break;
}
}
return(renderUnit);
}
