#region LGPL License
/*
Axiom Game Engine Library
Copyright (C) 2003 Axiom Project Team
The overall design, and a majority of the core engine and rendering code
contained within this library is a derivative of the open source Object Oriented
Graphics Engine OGRE, which can be found at http://ogre.sourceforge.net.
Many thanks to the OGRE team for maintaining such a high quality project.
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#endregion
using System;
using System.Collections;
using System.Diagnostics;
using System.Runtime.InteropServices;
using Axiom.Core;
namespace Axiom.Graphics{
/// <summary>
/// Summary class collecting together vertex source information.
/// </summary>
public class VertexData {
#region Fields
/// <summary>
/// Declaration of the vertex to be used in this operation.
/// </summary>
public VertexDeclaration vertexDeclaration;
/// <summary>
/// The vertex buffer bindings to be used.
/// </summary>
public VertexBufferBinding vertexBufferBinding;
/// <summary>
/// The base vertex index to start from, if using unindexed geometry.
/// </summary>
public int vertexStart;
/// <summary>
/// The number of vertices used in this operation.
/// </summary>
public int vertexCount;
/// <summary>
/// Additional shadow volume vertex buffer storage.
/// </summary>
/// <remarks>
/// This additional buffer is only used where we have prepared this VertexData for
/// use in shadow volume contruction, and where the current render system supports
/// vertex programs. This buffer contains the 'w' vertex position component which will
/// be used by that program to differentiate between extruded and non-extruded vertices.
/// This 'w' component cannot be included in the original position buffer because
/// DirectX does not allow 4-component positions in the fixed-function pipeline, and the original
/// position buffer must still be usable for fixed-function rendering.
/// <p/>
/// Note that we don't store any vertex declaration or vertex buffer binding here becuase this
/// can be reused in the shadow algorithm.
/// </remarks>
public HardwareVertexBuffer hardwareShadowVolWBuffer;
#endregion Fields
#region Constructor
/// <summary>
/// Default constructor. Calls on the current buffer manager to initialize the bindings and declarations.
/// </summary>
public VertexData() {
vertexDeclaration = HardwareBufferManager.Instance.CreateVertexDeclaration();
vertexBufferBinding = HardwareBufferManager.Instance.CreateVertexBufferBinding();
}
#endregion Constructor
#region Methods
/// <summary>
/// Clones this vertex data, potentially including replicating any vertex buffers.
/// </summary>
/// <returns>A cloned vertex data object.</returns>
public VertexData Clone() {
return Clone(false);
}
/// <summary>
/// Clones this vertex data, potentially including replicating any vertex buffers.
/// </summary>
/// <param name="copyData">
/// If true, makes a copy the vertex buffer in addition to the definition.
/// If false, the clone will refer to the same vertex buffer this object refers to.
/// </param>
/// <returns>A cloned vertex data object.</returns>
public VertexData Clone(bool copyData) {
VertexData dest = new VertexData();
// Copy vertex buffers in turn
IEnumerator bindings = vertexBufferBinding.Bindings;
while(bindings.MoveNext()) {
DictionaryEntry entry = (DictionaryEntry)bindings.Current;
short source = (short)entry.Key;
HardwareVertexBuffer srcbuf = (HardwareVertexBuffer)entry.Value;
HardwareVertexBuffer dstBuf;
if (copyData) {
// create new buffer with the same settings
dstBuf =
HardwareBufferManager.Instance.CreateVertexBuffer(
srcbuf.VertexSize, srcbuf.VertexCount, srcbuf.Usage,
srcbuf.HasShadowBuffer);
// copy data
dstBuf.CopyData(srcbuf, 0, 0, srcbuf.Size, true);
}
else {
// don't copy, point at existing buffer
dstBuf = srcbuf;
}
// Copy binding
dest.vertexBufferBinding.SetBinding(source, dstBuf);
}
// Basic vertex info
dest.vertexStart = this.vertexStart;
dest.vertexCount = this.vertexCount;
// Copy elements
for (int i = 0; i < vertexDeclaration.ElementCount; i++) {
VertexElement element = vertexDeclaration.GetElement(i);
dest.vertexDeclaration.AddElement(
element.Source,
element.Offset,
element.Type,
element.Semantic,
element.Index);
}
return dest;
}
/// <summary>
/// Modifies the vertex data to be suitable for use for rendering shadow geometry.
/// </summary>
/// <remarks>
/// <para>
/// Preparing vertex data to generate a shadow volume involves firstly ensuring that the
/// vertex buffer containing the positions is a standalone vertex buffer,
/// with no other components in it. This method will therefore break apart any existing
/// vertex buffers if position is sharing a vertex buffer.
/// Secondly, it will double the size of this vertex buffer so that there are 2 copies of
/// the position data for the mesh. The first half is used for the original, and the second
/// half is used for the 'extruded' version. The vertex count used to render will remain
/// the same though, so as not to add any overhead to regular rendering of the object.
/// Both copies of the position are required in one buffer because shadow volumes stretch
/// from the original mesh to the extruded version.
/// </para>
/// <para>
/// It's important to appreciate that this method can fundamentally change the structure of your
/// vertex buffers, although in reality they will be new buffers. As it happens, if other
/// objects are using the original buffers then they will be unaffected because the reference
/// counting will keep them intact. However, if you have made any assumptions about the
/// structure of the vertex data in the buffers of this object, you may have to rethink them.
/// </para>
/// </remarks>
// TODO: Step through and test
public void PrepareForShadowVolume() {
/* NOTE
Sinbad would dearly, dearly love to just use a 4D position buffer in order to
store the extra 'w' value I need to differentiate between extruded and
non-extruded sections of the buffer, so that vertex programs could use that.
Hey, it works fine for GL. However, D3D9 in it's infinite stupidity, does not
support 4d position vertices in the fixed-function pipeline. If you use them,
you just see nothing. Since we can't know whether the application is going to use
fixed function or vertex programs, we have to stick to 3d position vertices and
store the 'w' in a separate 1D texture coordinate buffer, which is only used
when rendering the shadow.
*/
// Upfront, lets check whether we have vertex program capability
RenderSystem renderSystem = Root.Instance.RenderSystem;
bool useVertexPrograms = false;
if (renderSystem != null && renderSystem.Caps.CheckCap(Capabilities.VertexPrograms)) {
useVertexPrograms = true;
}
// Look for a position element
VertexElement posElem =
vertexDeclaration.FindElementBySemantic(VertexElementSemantic.Position);
if(posElem != null) {
short posOldSource = posElem.Source;
HardwareVertexBuffer vbuf = vertexBufferBinding.GetBuffer(posOldSource);
bool wasSharedBuffer = false;
// Are there other elements in the buffer except for the position?
if (vbuf.VertexSize > posElem.Size) {
// We need to create another buffer to contain the remaining elements
// Most drivers don't like gaps in the declaration, and in any case it's waste
wasSharedBuffer = true;
}
HardwareVertexBuffer newPosBuffer = null, newRemainderBuffer = null;
if (wasSharedBuffer) {
newRemainderBuffer = HardwareBufferManager.Instance.CreateVertexBuffer(
vbuf.VertexSize - posElem.Size, vbuf.VertexCount, vbuf.Usage,
vbuf.HasShadowBuffer);
}
// Allocate new position buffer, will be FLOAT3 and 2x the size
int oldVertexCount = vbuf.VertexCount;
int newVertexCount = oldVertexCount * 2;
newPosBuffer = HardwareBufferManager.Instance.CreateVertexBuffer(
VertexElement.GetTypeSize(VertexElementType.Float3),
newVertexCount, vbuf.Usage, vbuf.HasShadowBuffer);
// Iterate over the old buffer, copying the appropriate elements and initializing the rest
IntPtr baseSrcPtr = vbuf.Lock(BufferLocking.ReadOnly);
// Point first destination pointer at the start of the new position buffer,
// the other one half way along
IntPtr destPtr = newPosBuffer.Lock(BufferLocking.Discard);
// oldVertexCount * 3 * 4, since we are dealing with byte offsets here
IntPtr dest2Ptr = new IntPtr(destPtr.ToInt32() + (oldVertexCount * 12));
int prePosVertexSize = 0;
int postPosVertexSize = 0;
int postPosVertexOffset = 0;
if(wasSharedBuffer) {
// Precalculate any dimensions of vertex areas outside the position
prePosVertexSize = posElem.Offset;
postPosVertexOffset = prePosVertexSize + posElem.Size;
postPosVertexSize = vbuf.VertexSize - postPosVertexOffset;
// the 2 separate bits together should be the same size as the remainder buffer vertex
Debug.Assert(newRemainderBuffer.VertexSize == (prePosVertexSize + postPosVertexSize));
IntPtr baseDestRemPtr = newRemainderBuffer.Lock(BufferLocking.Discard);
int baseSrcOffset = 0;
int baseDestRemOffset = 0;
unsafe {
float* pDest = (float*)destPtr.ToPointer();
float* pDest2 = (float*)dest2Ptr.ToPointer();
int destCount = 0, dest2Count = 0;
// Iterate over the vertices
for (int v = 0; v < oldVertexCount; v++) {
float* pSrc = (float*)((byte*)baseSrcPtr.ToPointer() + posElem.Offset + baseSrcOffset);
// Copy position, into both buffers
pDest[destCount++] = pDest2[dest2Count++] = pSrc[0];
pDest[destCount++] = pDest2[dest2Count++] = pSrc[1];
pDest[destCount++] = pDest2[dest2Count++] = pSrc[2];
// now deal with any other elements
// Basically we just memcpy the vertex excluding the position
if (prePosVertexSize > 0) {
Memory.Copy(
baseSrcPtr, baseDestRemPtr,
baseSrcOffset, baseDestRemOffset,
prePosVertexSize);
}
if (postPosVertexSize > 0) {
Memory.Copy(
baseSrcPtr, baseDestRemPtr,
baseSrcOffset + postPosVertexOffset,
baseDestRemOffset + prePosVertexSize,
postPosVertexSize);
}
// increment the pointer offsets
baseDestRemOffset += newRemainderBuffer.VertexSize;
baseSrcOffset += vbuf.VertexSize;
} // next vertex
} // unsafe
}
else {
// copy the data directly
Memory.Copy(baseSrcPtr, destPtr, vbuf.Size);
Memory.Copy(baseSrcPtr, dest2Ptr, vbuf.Size);
}
vbuf.Unlock();
newPosBuffer.Unlock();
if(wasSharedBuffer) {
newRemainderBuffer.Unlock();
}
// At this stage, he original vertex buffer is going to be destroyed
// So we should force the deallocation of any temporary copies
HardwareBufferManager.Instance.ForceReleaseBufferCopies(vbuf);
if (useVertexPrograms) {
unsafe {
// Now it's time to set up the w buffer
hardwareShadowVolWBuffer =
HardwareBufferManager.Instance.CreateVertexBuffer(
sizeof(float),
newVertexCount,
BufferUsage.StaticWriteOnly,
false);
// Fill the first half with 1.0, second half with 0.0
IntPtr wPtr = hardwareShadowVolWBuffer.Lock(BufferLocking.Discard);
float* pDest = (float*)wPtr.ToPointer();
int destCount = 0;
for(int v = 0; v < oldVertexCount; v++) {
pDest[destCount++] = 1.0f;
}
for(int v = 0; v < oldVertexCount; v++) {
pDest[destCount++] = 0.0f;
}
} // unsafe
hardwareShadowVolWBuffer.Unlock();
} // if vertexPrograms
short newPosBufferSource = 0;
if (wasSharedBuffer) {
// Get the a new buffer binding index
newPosBufferSource = vertexBufferBinding.NextIndex;
// Re-bind the old index to the remainder buffer
vertexBufferBinding.SetBinding(posOldSource, newRemainderBuffer);
}
else {
// We can just re-use the same source idex for the new position buffer
newPosBufferSource = posOldSource;
}
// Bind the new position buffer
vertexBufferBinding.SetBinding(newPosBufferSource, newPosBuffer);
// Now, alter the vertex declaration to change the position source
// and the offsets of elements using the same buffer
for(int i = 0; i < vertexDeclaration.ElementCount; i++) {
VertexElement element = vertexDeclaration.GetElement(i);
if(element.Semantic == VertexElementSemantic.Position) {
// Modify position to point at new position buffer
vertexDeclaration.ModifyElement(
i,
newPosBufferSource, // new source buffer
0, // no offset now
VertexElementType.Float3,
VertexElementSemantic.Position);
}
else if(wasSharedBuffer &&
element.Source == posOldSource &&
element.Offset > prePosVertexSize) {
// This element came after position, remove the position's
// size
vertexDeclaration.ModifyElement(
i,
posOldSource, // same old source
element.Offset - posElem.Size, // less offset now
element.Type,
element.Semantic,
element.Index);
}
}
} // if posElem != null
}
#endregion Methods
}
/// <summary>
/// Summary class collecting together index data source information.
/// </summary>
public class IndexData {
#region Fields
/// <summary>
/// Reference to the <see cref="HardwareIndexBuffer"/> to use, must be specified if useIndexes = true
/// </summary>
public HardwareIndexBuffer indexBuffer;
/// <summary>
/// Index in the buffer to start from for this operation.
/// </summary>
public int indexStart;
/// <summary>
/// The number of indexes to use from the buffer.
/// </summary>
public int indexCount;
#endregion
#region Methods
/// <summary>
/// Creates a copy of the index data object, without a copy of the buffer data.
/// </summary>
/// <returns>A copy of this IndexData object without the data.</returns>
public IndexData Clone() {
return Clone(false);
}
/// <summary>
/// Clones this vertex data, potentially including replicating any index buffers.
/// </summary>
/// <param name="copyData">
/// If true, makes a copy the index buffer in addition to the definition.
/// If false, the clone will refer to the same index buffer this object refers to.
/// </param>
/// <returns>A copy of this IndexData object.</returns>
public IndexData Clone(bool copyData) {
IndexData clone = new IndexData();
if(indexBuffer != null) {
if(copyData) {
clone.indexBuffer =
HardwareBufferManager.Instance.CreateIndexBuffer(
indexBuffer.Type,
indexBuffer.IndexCount,
indexBuffer.Usage,
indexBuffer.HasShadowBuffer);
// copy all the existing buffer data
clone.indexBuffer.CopyData(indexBuffer, 0, 0, indexBuffer.Size, true);
}
else {
clone.indexBuffer = indexBuffer;
}
}
clone.indexStart = indexStart;
clone.indexCount = indexCount;
return clone;
}
#endregion Methods
}
}
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