vertexBufferGenerator/vertexBufferGenerator.cpp

vertexBufferGenerator/vertexBufferGenerator.cpp
//-
// ==========================================================================
// Copyright 2011 Autodesk, Inc. All rights reserved.
//
// Use of this software is subject to the terms of the Autodesk
// license agreement provided at the time of installation or download,
// or which otherwise accompanies this software in either electronic
// or hard copy form.
// ==========================================================================
//+
// Example plugin: vertexBufferGenerator.cpp
//
// This plug-in is an example of a custom MPxVertexBufferGenerator.
// It provides custom vertex streams based on shader requirements coming from
// an MPxShaderOverride. The semanticName() in the MVertexBufferDescriptor is used
// to signify a unique identifier for a custom stream.
// This plugin is meant to be used in conjunction with the dx11Shader, cgfxShader and glslShader plugins.
// The vertexBufferGeneratorGL.cgfx (cgfxShader), vertexBufferGeneratorDX11.fx (dx11Shader) and
// vertexBufferGenerator.ogsfx (glslShader) files accompanying this sample
// can be loaded using the appropriate shader plugin.
// The Names of the streams and the stream data generated by this plugin match what is
// expected from the included effects files.
// This sample use the MyCustomBufferGenerator to create a custom made streams.
// The vertexBufferGenerator2GL.cgfx (cgfxShader), vertexBufferGenerator2DX11.fx (dx11Shader) and
// vertexBufferGenerator2.ogsfx (glslShader) files accompanying this sample
// can be loaded using the appropriate shader plugin.
// The Names of the streams and the stream data generated by this plugin match what is
// expected from the included effects files.
// This sample use the MyCustomBufferGenerator2 to create a custom made streams
// by combining the Position and Normal streams in a single one.
#include <maya/MStatus.h>
#include <maya/MFnPlugin.h>
#include <maya/MFnMesh.h>
#include <maya/MDrawRegistry.h>
#include <maya/MPxVertexBufferGenerator.h>
#include <maya/MHWGeometry.h>
using namespace MHWRender;
class MyCustomBufferGenerator : public MHWRender::MPxVertexBufferGenerator
{
public:
MyCustomBufferGenerator() {}
virtual ~MyCustomBufferGenerator() {}
virtual bool getSourceIndexing(const MObject& object,
MComponentDataIndexing& sourceIndexing) const
{
// get the mesh from the current path
// if it is not a mesh we do nothing.
MStatus status;
MFnMesh mesh(object, &status);
if (!status) return false; // failed
MUintArray& vertToFaceVertIDs = sourceIndexing.indices();
int faceNum = 0;
int numPolys = mesh.numPolygons();
// if it is an empty mesh we do nothing.
if (numPolys <= 0)
return false;
// for each face
for(int i = 0; i < numPolys; ++i)
{
// assign a color ID to all vertices in this face.
int faceColorID = faceNum%3;
int vertexCount = mesh.polygonVertexCount(i);
for (int x = 0; x < vertexCount; ++x)
{
// set each face vertex to the face color
vertToFaceVertIDs.append(faceColorID);
}
faceNum++;
}
// assign the source indexing
sourceIndexing.setComponentType(MComponentDataIndexing::kFaceVertex);
return true;
}
virtual bool getSourceStreams(const MObject& object,
MStringArray &sourceStreams) const
{
// No source stream needed
return false;
}
virtual void createVertexStream(const MObject& object,
MVertexBuffer& vertexBuffer, const MComponentDataIndexing& targetIndexing, const MComponentDataIndexing& /*sharedIndexing*/, const MVertexBufferArray& /*sourceStreams*/) const
{
// get the descriptor from the vertex buffer.
// It describes the format and layout of the stream.
const MVertexBufferDescriptor& descriptor = vertexBuffer.descriptor();
// we are expecting a float stream.
if (descriptor.dataType() != MGeometry::kFloat)
return;
// we are expecting a float2
if (descriptor.dimension() != 2)
return;
// we are expecting a texture channel
if (descriptor.semantic() != MGeometry::kTexture)
return;
// get the mesh from the current path
// if it is not a mesh we do nothing.
MStatus status;
MFnMesh mesh(object, &status);
if (!status) return; // failed
const MUintArray& indices = targetIndexing.indices();
unsigned int vertexCount = indices.length();
if (vertexCount <= 0)
return;
// acquire the buffer to fill with data.
float* buffer = (float*)vertexBuffer.acquire(vertexCount, true /*writeOnly - we don't need the current buffer values*/);
float* start = buffer;
for(unsigned int i = 0; i < vertexCount; ++i)
{
// Here we are embedding some custom data into the stream.
// The included effects (vertexBufferGeneratorGL.cgfx and
// vertexBufferGeneratorDX11.fx) will alternate
// red, green, and blue vertex colored triangles based on this input.
*(buffer++) = 1.0f;
*(buffer++) = (float)indices[i]; // color index
}
// commit the buffer to signal completion.
vertexBuffer.commit(start);
}
};
class MyCustomBufferGenerator2 : public MHWRender::MPxVertexBufferGenerator
{
public:
MyCustomBufferGenerator2() {}
virtual ~MyCustomBufferGenerator2() {}
virtual bool getSourceIndexing(const MObject& object,
MComponentDataIndexing& sourceIndexing) const
{
// get the mesh from the current path
// if it is not a mesh we do nothing.
MStatus status;
MFnMesh mesh(object, &status);
if (!status) return false; // failed
MIntArray vertexCount, vertexList;
mesh.getVertices(vertexCount, vertexList);
MUintArray& vertices = sourceIndexing.indices();
for(unsigned int i = 0; i < vertexList.length(); ++i)
vertices.append( (unsigned int)vertexList[i] );
return true;
}
virtual bool getSourceStreams(const MObject& object,
MStringArray &sourceStreams) const
{
sourceStreams.append( "Position" );
sourceStreams.append( "Normal" );
return true;
}
virtual void createVertexStream(const MObject& object,
MVertexBuffer& vertexBuffer, const MComponentDataIndexing& targetIndexing, const MComponentDataIndexing& /*sourceIndexing*/, const MVertexBufferArray& sourceStreams) const
{
// get the descriptor from the vertex buffer.
// It describes the format and layout of the stream.
const MVertexBufferDescriptor& descriptor = vertexBuffer.descriptor();
// we are expecting a float or int stream.
MGeometry::DataType dataType = descriptor.dataType();
if (dataType != MGeometry::kFloat && dataType != MGeometry::kInt32)
return;
// we are expecting a dimension of 3 or 4
int dimension = descriptor.dimension();
if (dimension != 4 && dimension != 3)
return;
// we are expecting a texture channel
if (descriptor.semantic() != MGeometry::kTexture)
return;
// get the mesh from the current path
// if it is not a mesh we do nothing.
MStatus status;
MFnMesh mesh(object, &status);
if (!status) return; // failed
const MUintArray& indices = targetIndexing.indices();
unsigned int vertexCount = indices.length();
if (vertexCount <= 0)
return;
MVertexBuffer *positionStream = sourceStreams.getBuffer( "Position" );
if(positionStream == NULL || positionStream->descriptor().dataType() != MGeometry::kFloat)
return;
int positionDimension = positionStream->descriptor().dimension();
if(positionDimension != 3 && positionDimension != 4)
return;
MVertexBuffer *normalStream = sourceStreams.getBuffer( "Normal" );
if(normalStream == NULL || normalStream->descriptor().dataType() != MGeometry::kFloat)
return;
int normalDimension = normalStream->descriptor().dimension();
if(normalDimension != 3 && normalDimension != 4)
return;
float* positionBuffer = (float*)positionStream->map();
if(positionBuffer)
{
float* normalBuffer = (float*)normalStream->map();
if(normalBuffer)
{
void* compositeBuffer = vertexBuffer.acquire(vertexCount, true /*writeOnly - we don't need the current buffer values*/);
if(compositeBuffer)
{
void* compositeBufferStart = compositeBuffer;
float* compositeBufferAsFloat = (float*)compositeBuffer;
int* compositeBufferAsInt = (int*)compositeBuffer;
for(unsigned int i = 0; i < vertexCount; ++i)
{
if(dataType == MGeometry::kFloat)
{
*(compositeBufferAsFloat++) = *(positionBuffer + 1); // store position.y
*(compositeBufferAsFloat++) = *(positionBuffer + 2); // store position.z
*(compositeBufferAsFloat++) = *(normalBuffer); // store normal.x
if(dimension == 4)
*(compositeBufferAsFloat++) = *(normalBuffer + 2); // store normal.z
}
else if(dataType == MGeometry::kInt32)
{
*(compositeBufferAsInt++) = (int)(*(positionBuffer + 1) * 255); // store position.y
*(compositeBufferAsInt++) = (int)(*(positionBuffer + 2) * 255); // store position.z
*(compositeBufferAsInt++) = (int)(*(normalBuffer) * 255); // store normal.x
if(dimension == 4)
*(compositeBufferAsInt++) = (int)(*(normalBuffer + 2) * 255); // store normal.z
}
positionBuffer += positionDimension;
normalBuffer += normalDimension;
}
vertexBuffer.commit(compositeBufferStart);
}
normalStream->unmap();
}
positionStream->unmap();
}
}
};
// This is the buffer generator creation function registered with the DrawRegistry.
// Used to initialize the generator.
static MPxVertexBufferGenerator* createMyCustomBufferGenerator()
{
return new MyCustomBufferGenerator();
}
static MPxVertexBufferGenerator* createMyCustomBufferGenerator2()
{
return new MyCustomBufferGenerator2();
}
static void getCustomSemantics(MString& customSemantic, MString& customSemantic2)
{
if( renderer ) {
if( renderer->drawAPI() == MHWRender::kDirectX11 ) {
// register a generator based on a custom semantic for DX11.
// You can use any name in DX11.
customSemantic = "myCustomStream";
customSemantic2 = "myCustomStreamB";
}
else if( renderer->drawAPI() == MHWRender::kOpenGLCoreProfile ) {
// register a generator based on a custom semantic for OGSFX.
// Pretty limited in OGSFX since it only allows standard semantics.
// But thanks to the annotations a custom value can be set afterward from glslShader plugin
customSemantic = "myCustomStream";
customSemantic2 = "myCustomStreamB";
}
else if( renderer->drawAPI() == MHWRender::kOpenGL ) {
// register a generator based on a custom semantic for cg.
// Pretty limited in cg so we hook onto the "ATTR" semantics.
customSemantic = "ATTR8";
customSemantic2 = "ATTR7";
}
}
}
// The following routines are used to register/unregister
// the vertex generators with Maya
//
MStatus initializePlugin( MObject obj )
{
MString customSemantic, customSemantic2;
getCustomSemantics(customSemantic, customSemantic2);
MDrawRegistry::registerVertexBufferGenerator(customSemantic, createMyCustomBufferGenerator);
MDrawRegistry::registerVertexBufferGenerator(customSemantic2, createMyCustomBufferGenerator2);
return MS::kSuccess;
}
MStatus uninitializePlugin( MObject obj)
{
MString customSemantic, customSemantic2;
getCustomSemantics(customSemantic, customSemantic2);
return MS::kSuccess;
}