path: root/mayaPlug/shaveBrushManip.cpp

// Shave and a Haircut
// (c) 2019 Epic Games
// US Patent 6720962

//Qt headers must be included before any others !!!
#if (defined LINUX) || (defined OSMac_)
#include <QtOpenGL/QGLContext>
#include <QtOpenGL/QGLWidget>

#if QT_VERSION < 0x050000
#  include <QtGui/QWidget>
#else
#  include <QtWidgets/QWidget>
#endif
#endif

#include <maya/M3dView.h>
#include <maya/MDagPath.h>
#include <maya/MFnDependencyNode.h>
#include <maya/MFnNumericAttribute.h>
#include <maya/MFnTransform.h>
#include <maya/MHWGeometry.h>
#include <maya/MGlobal.h>
#include <maya/MPoint.h>
#include <maya/MShaderManager.h>
#include <maya/MString.h>
#include <maya/MVector.h>

#if defined(_WIN32) && (MAYA_API_VERSION >= 201600)
#include <Windows.h>
#endif

#ifdef OSMac_MachO_
# include <OpenGL/gl.h>
# include <OpenGL/glu.h>
//#   include <AppKit/NSOpenGL.h>
#else
//#define GL_GLEXT_PROTOTYPES
# include <GL/gl.h>
# include <GL/glu.h>
#endif

#include "shaveBrushManip.h"

MTypeId	shaveBrushManip::id(0x001029B8);
MString shaveBrushManip::nodeTypeName = "shaveBrushManip";


//	The 'fast brush' does an XOR draw on top of the view, meaning that it
//	can be drawn and erased without having Maya redraw the entire view.
//
//	The standard brush is drawn normally during a refresh, which is
//	triggered either by moving a proxy transform within the scene to match
//	the mouse movement, or by forcing a refresh.
//
//	The fast brush is enabled by default in shaveGlobals, but on some
//	graphics cards it can cause visual anomalies, in which case the user
//	can switch to the standard brush.

shaveBrushManip::shaveBrushManip()
:	mBrushSize(0.0f)
,	mClearOld(false)
,	mCX(-1)
,	mCY(-1)
,	mFastBrush(true)
,	mIsActive(false)
,	mViewHeight(0)
,	mViewWidth(0)
,	mWindow(0)
{
	aWidget = NULL;
}


shaveBrushManip::~shaveBrushManip()
{
	mProxy = MObject::kNullObj;
}


MStatus shaveBrushManip::connectToDependNode(const MObject& node)
{
	//thisObj = thisMObject();

	finishAddingManips();
	MPxManipContainer::connectToDependNode(node);

	if (!mFastBrush)
	{
		MFnDependencyNode nodeFn(node);
		mProxy = node;
	}

	return MS::kSuccess;
}


MStatus shaveBrushManip::createChildren()
{
	//
	// We don't want any manips because their handles, even though not
	// drawn, can still capture mouse clicks.
	//
    return MS::kSuccess;
}


void shaveBrushManip::draw(
		M3dView&				view,
		const MDagPath&			path,
		M3dView::DisplayStyle	dStyle,
		M3dView::DisplayStatus	dStatus
)
{
	if (mFastBrush)
	{
		//
		// If Maya is asking us to redraw in the same view where we last did a
		// draw, then it must have already cleared the old image, so we should
		// not try to clear it ourselves.
		//
		if (mClearOld && isSameView(view)) mClearOld = false;
	}
	else
	{
		M3dView	activeView = M3dView::active3dView();

		if ((view.window() == activeView.window())
		&&	(mCX >= 0) && (mCY >= 0)
		&&	(mCX < view.portWidth()) && (mCY < view.portHeight()))
		{
			prepareView(activeView);
			drawBrush();
			restoreView(activeView);
		}
	}
}


void shaveBrushManip::getBrushRadii(int& rx, int& ry) const
{
	rx = mRX;
	ry = mRY;
}


void shaveBrushManip::leaveView()
{
	//MGlobal::displayInfo("leaveView");

	///////////////////////////
	//return;
	///////////////////////////

	if (mIsActive)
	{
		M3dView	activeView = M3dView::active3dView();

		if (mFastBrush)
			eraseBrush(activeView);
		else
		{
			if(mCX != -1 || mCY != -1) //to avoid exra redraws
			{
				//	This will let us know not to draw the brush.
				mCX = mCY = -1;

				//	Force Maya to redraw the view so that the brush will be
				//	erased.
				activeView.refresh(false, true);
			}
		}
	}
}


void shaveBrushManip::setActive(bool active)
{
	///////////////////////////
	//return;
	///////////////////////////

	if (mIsActive != active)
	{
		//
		// If we're being made active then clear out the old view
		// information.
		//
		// If we're being made inactive then erase the current brush image.
		//
		if (active)
		{
			mWindow = 0;
			mViewHeight = 0;
			mViewWidth = 0;
		}
		else
		{
			M3dView	activeView = M3dView::active3dView();
			eraseBrush(activeView, false);
		}

		mIsActive = active;
	}
}


void shaveBrushManip::setBrushPos(
		int cx, int cy, bool forceRedraw, bool isMayaDraw
)
{
	///////////////////////////
	//return;
	///////////////////////////

	//printf("set pos %i %i\n",cx,cx);fflush(stdout);

	M3dView	activeView = M3dView::active3dView();
	bool	isNewView = !isSameView(activeView);

	// If someone is giving us brush positions, then we must be active.
	setActive(true);

	if (mFastBrush)
	{
		// If we were previously inactive or the view has changed, then we
		// will need to redraw the brush even if its position is unchanged.
		if (isNewView || !mIsActive) 
			forceRedraw = true;

		// If the brush has moved, or this is a forced redraw, then do the
		// draw.
		if (forceRedraw || (mCX != cx) || (mCY != cy))
		{
			bool	activeViewPrepared = eraseBrush(activeView, true);

			if (!activeViewPrepared) prepareView(activeView);

			// If we've changed views, or the view has changed size, then
			// we need to recalculate the radii.
			if (isNewView)
			{
				saveView(activeView);
				calculateRadii();
			}

			mCX = cx;
			mCY = cy;

			if ((mCX >= 0) && (mCY >= 0))
			{
				drawBrush();
				mClearOld = true;
			}

			if (!isMayaDraw) 
				swapGLBuffers(activeView);

			restoreView(activeView);
		}
	}
	else
	{
		//	If the brush has moved, move the proxy transform
		//	correspondingly.
		if ((mCX != cx) || (mCY != cy))
		{
			// If we've changed views, or the view has changed size, then
			// we need to recalculate the radii.
			if (isNewView)
			{
				saveView(activeView);
				calculateRadii();
			}

			MPoint	nearPlane;
			MPoint	farPlane;
			activeView.viewToWorld(cx, cy, nearPlane, farPlane);

			MVector	translation(
						(nearPlane.x + farPlane.x) / 2.0,
						(nearPlane.y + farPlane.y) / 2.0,
						(nearPlane.z + farPlane.z) / 2.0
					);
			MFnTransform	transformFn(mProxy);
			transformFn.setTranslation(translation, MSpace::kObject);

			mCX = cx;
			mCY = cy;
		}
	}

	MHWRender::MRenderer::setGeometryDrawDirty(thisObj);
}


void shaveBrushManip::setBrushSize(float brushSize)
{
	///////////////////////////
	//return;
	///////////////////////////

	if (brushSize != mBrushSize)
	{
		M3dView	view;
		bool	viewPrepared = false;
		bool	foundView = findOldView(view);

		if (foundView) 
			viewPrepared = eraseBrush(view, true);

		mBrushSize = brushSize;

		if (foundView)
		{
			calculateRadii();

			if (!viewPrepared) 
				prepareView(view);

			if ((mCX >= 0) && (mCY >= 0))
			{
				drawBrush();
				mClearOld = true;
			}

			swapGLBuffers(view);
			restoreView(view);
		}
	}
}


//----------------------------------------------------------------------
//
//		Internal Methods
//
//----------------------------------------------------------------------

void shaveBrushManip::calculateRadii()
{
	unsigned	radius;

	if (mViewHeight < mViewWidth)
		radius = (unsigned)((float)mViewHeight * mBrushSize / 2.0f + 0.5);
	else
		radius = (unsigned)((float)mViewWidth * mBrushSize / 2.0f + 0.5);

	if (radius < 4) radius = 4;

	//
	// %%%	We eventually need to compensate for non-square pixels by
	//		assigning X and Y different radii.
	//
	mRX = radius;
	mRY = radius;
}


void shaveBrushManip::drawBrush() const
{
	//printf("draw pos %i %i\n",mCX,mCY);fflush(stdout);
	//
	// Draw the outer circle.  We use an ellipse drawing method because
	// eventually we want to support displays with non-square pixels, which
	// will require different X and Y radii.
	//
	drawEllipse(mCX, mCY, mRX, mRY);

#if 0
	//
	// Draw a small crosshair in the center.
	//
	glBegin(GL_LINES);
	glVertex2i(mCX-4, mCY);
	glVertex2i(mCX+4, mCY);

	glVertex2i(mCX, mCY-4);
	glVertex2i(mCX, mCY+4);
	glEnd();
#endif
}


//
// This method uses a DDA to draw an ellipse with the given radii into the
// bitmap.
//
// The algorithm is taken almost verbatim from Tim Kientzle's 'Algorithm
// Alley' column in the July, 1994 issue of Dr. Dobb's Journal.
//
void shaveBrushManip::drawEllipse(int cx, int cy, unsigned rx, unsigned ry)
{
	const unsigned	rxSquared = rx * rx;
	const unsigned	rySquared = ry * ry;
	const unsigned	twoRXSquared = 2 * rxSquared;
	const unsigned	twoRYSquared = 2 * rySquared;

	glBegin(GL_POINTS);

	//
	// Plot the octant from the top of the ellipse to the top-right
	// and reflect it in the other four quadrants.
	//
	int	x = 0;
	int	y = ry;

	int	twoXTimesRYSquared = 0;
	int	twoYTimesRXSquared = (int)(y * twoRXSquared);
	int	error = -(int)(y * rxSquared);

	while (twoXTimesRYSquared <= twoYTimesRXSquared)
	{
		drawMirroredVert(cx, cy, x, y);

		x += 1;
		twoXTimesRYSquared += (int)twoRYSquared;
		error += twoXTimesRYSquared - (int)rySquared;

		if (error >= 0)
		{
			y -= 1;
			twoYTimesRXSquared -= (int)twoRXSquared;
			error -= twoYTimesRXSquared;
		}
	}

	//
	// Plot the octant from the right of the ellipse to the top-right
	// and reflect it in the other four quadrants.
	//
	x = rx;
	y = 0;
	twoXTimesRYSquared = (int)(x * twoRYSquared);
	twoYTimesRXSquared = 0;
	error  = -(int)(x * rySquared);

	while (twoXTimesRYSquared > twoYTimesRXSquared)
	{
		drawMirroredVert(cx, cy, x, y);

		y += 1;
		twoYTimesRXSquared += (int)twoRXSquared;
		error += twoYTimesRXSquared - (int)rxSquared;

		if (error >= 0)
		{
			x -= 1;
			twoXTimesRYSquared -= (int)twoRYSquared;
			error -= twoXTimesRYSquared;
		}
	}

	glEnd();
}


void shaveBrushManip::drawMirroredVert(int cx, int cy, int x, int y)
{
	//
	// Mirror the vert in the four quadrants around the center point.
	//
	// Because we are drawing in XOR mode, we don't want to plot the same
	// point an even number of times as that will be as if we hadn't
	// plotted it at all.  So we have special cases for x==0 and y==0 to
	// prevent that.
	//
	if (x == 0)
	{
		glVertex2i(cx, cy + y);
		glVertex2i(cx, cy - y);
	}
	else if (y == 0)
	{
		glVertex2i(cx + x, cy);
		glVertex2i(cx - x, cy);
	}
	else
	{
		glVertex2i(cx + x, cy + y);
		glVertex2i(cx + x, cy - y);
		glVertex2i(cx - x, cy + y);
		glVertex2i(cx - x, cy - y);
	}
}


bool shaveBrushManip::eraseBrush(
		M3dView& currentView, bool dontRestoreCurrentView
)
{
	bool	currentViewIsPrepared = false;


	if (mFastBrush && mClearOld)
	{
		//
		// If the previous brush image was drawn in a different view from
		// the one passed to us by the caller, then we must find that view.
		//
		if (!isSameView(currentView))
		{
			M3dView		oldView;

			if (findOldView(oldView))
			{
				prepareView(oldView);
				drawBrush();
				swapGLBuffers(oldView);
				restoreView(oldView);
			}
		}
		else
		{
			prepareView(currentView);
			drawBrush();

			if (dontRestoreCurrentView)
				currentViewIsPrepared = true;
			else
			{
				swapGLBuffers(currentView);
				restoreView(currentView);
			}
		}

		mClearOld = false;
	}

	return currentViewIsPrepared;
}


bool shaveBrushManip::findOldView(M3dView& view) const
{
	if (mIsActive)
	{
		unsigned	numViews = M3dView::numberOf3dViews();
		unsigned	i;

		for (i = 0; i < numViews; i++)
		{
			M3dView::get3dView(i, view);

			if (isSameView(view)) return true;
		}
	}

	return false;
}


bool shaveBrushManip::isSameView(M3dView& view) const
{
	if ((view.window() != mWindow)
	||	(view.portHeight() != mViewHeight)
	||	(view.portWidth() != mViewWidth))
	{
		return false;

	}

	
#if OSMac_
	QWidget* wgt = view.widget();
	return (wgt == aWidget);
#endif

	return true;
}

void shaveBrushManip::prepareView(M3dView& view)
{
	view.beginGL();

	glPushAttrib(GL_TRANSFORM_BIT | GL_ENABLE_BIT | GL_COLOR_BUFFER_BIT);
	glMatrixMode(GL_PROJECTION);
	glPushMatrix();
	glLoadIdentity();
	gluOrtho2D(
		0.0, (GLdouble)view.portWidth(),
		0.0, (GLdouble)view.portHeight()
	);

	glMatrixMode(GL_MODELVIEW);
	glPushMatrix();
	glLoadIdentity();

	// This bit of magic is from marqueeTool.cpp in the devkit.
	glTranslatef(0.375, 0.375, 0.0);

	glDisable(GL_DEPTH_TEST);
	glDisable(GL_CULL_FACE);

	if (mFastBrush)
	{
		glEnable(GL_COLOR_LOGIC_OP);
		glLogicOp(GL_XOR);

		//	Because we're doing XOR, if we set the draw color to 12 (red)
		//	it won't appear red when over the default grey background of
		//	Maya's views. By choosing light green XOR will give us
		//	reddish-orange against a grey background, which is at least
		//	close to red.
		view.setDrawColor(18, M3dView::kActiveColors);
	}
	else
		view.setDrawColor(12, M3dView::kActiveColors);	// red
}


void shaveBrushManip::restoreView(M3dView& view)
{
	glPopMatrix();
	glMatrixMode(GL_PROJECTION);
	glPopMatrix();
	glPopAttrib();

	view.endGL();
}


void shaveBrushManip::saveView(M3dView& view)
{
	mWindow = view.window();
	mViewHeight = view.portHeight();
	mViewWidth = view.portWidth();

#ifdef OSMac_
	//
	//	On OSX the views do not have their own windows but are merely
	//	regions within the main window.  So to know if we have the correct
	//	view we must compare not just the window but the position of the
	//	region.
	//
	aWidget = view.widget();
#endif
}


void shaveBrushManip::swapGLBuffers(M3dView& view)
{
#if defined(LINUX)
	glXSwapBuffers(view.display(), view.window());
#elif defined(OSMac_)
	//there is no good way to swap buffers now
	//so we grey out 'fast brush' checkbox for 2011

	//const QGLContext* qgl = QGLContext::currentContext();
	//if(qgl)
	//	qgl->swapBuffers();
	//else
	//	MGlobal::displayInfo("null QGLContext");

	//NSOpenGLContext* nsgl = view.display();
	//[nsgl flushBuffer]; //cocoa
	//nsgl->flushBuffer(); 
	//CGLContextObj* cgl = nsgl->CGLContextObj();
#elif defined(_WIN32)
	SwapBuffers(view.deviceContext());
#else
	#error	Unsupported OS type.
#endif
}

MString   shaveBrushManip::drawDbClassification("drawdb/geometry/shaveBrushManip");
MString   shaveBrushManip::drawRegistrantId("shave_and_haircut_brush");

MObject shaveBrushManip::trigger;

MStatus	shaveBrushManip::initialize()
{
	MStatus stat;
	MFnNumericAttribute na;

	trigger  = na.create("atrigger", "tr", MFnNumericData::kInt,0,&stat);
	if(stat != MStatus::kSuccess)
	{
		MGlobal::displayError("shaveBrushManip: can't create attribute");
	}
	na.setStorable(false);
    na.setHidden(true);

	stat = addAttribute(trigger);
	if(stat != MStatus::kSuccess)
	{
		MGlobal::displayError("shaveBrushManip: can't add attribute");
	}

	return MStatus::kSuccess;
	//return MPxManipContainer::initialize();
}


// pre-draw callback
static void shaveBrushPreDrawCallback(
	MHWRender::MDrawContext& context,
	const MHWRender::MRenderItemList& renderItemList,
	MHWRender::MShaderInstance *shaderInstance
	)
{
	//printf("Pre-draw callback triggered for render item with name '%s'\n", renderItem->name().asChar());
}
// post-draw callback
static void shaveBrushPostDrawCallback(
	MHWRender::MDrawContext& context,
	const MHWRender::MRenderItemList& renderItemList,
	MHWRender::MShaderInstance *shaderInstance
	)
{
	//printf("Post-draw callback triggered for render item with name '%s'\n", renderItem->name().asChar());
}

shaveBrushOverride::shaveBrushOverride(const MObject& obj)
: MPxGeometryOverride(obj)
, brush(NULL)
{
	MStatus status;
	MFnDependencyNode node(obj, &status);
	if (status)
	{
		brush = dynamic_cast<shaveBrushManip*>(node.userNode());
	}
}

shaveBrushOverride::~shaveBrushOverride()
{
}

MHWRender::DrawAPI shaveBrushOverride::supportedDrawAPIs() const
{
	//return MHWRender::kAllDevices;
	return MHWRender::kOpenGL;
}

void shaveBrushOverride::updateDG()
{
	if (brush)
	{
		//nothing to do at the moment
	}
}

//#define BRUSH_BY_SHADER //geom shaders are 

static const bool debugShader = false;//true;

void shaveBrushOverride::updateRenderItems(const MDagPath& path,
											  MHWRender::MRenderItemList& list)
{
	MHWRender::MRenderer* renderer = MHWRender::MRenderer::theRenderer();
	if (!renderer) return;
	
	const MHWRender::MShaderManager* shaderMgr = renderer->getShaderManager();
	if (!shaderMgr) return;


	MHWRender::MRenderItem* item = NULL;
	int index = list.indexOf(
		"shaveBrush",
//#ifdef BRUSH_BY_SHADER
//		MHWRender::MGeometry::kPoints,
//#else
		MHWRender::MGeometry::kLines,
//#endif
		MHWRender::MGeometry::kAll);

	if (index < 0)
	{
		item = MHWRender::MRenderItem::Create
		(	"shaveBrush",
//#ifdef BRUSH_BY_SHADER
//			MHWRender::MGeometry::kPoints,
//#else
			MHWRender::MGeometry::kLines,
//#endif
			MHWRender::MGeometry::kAll,
			false);
		list.append(item);

		//MHWRender::MShaderInstance* shader = shaderMgr->getStockShader(
		//	MHWRender::MShaderManager::k3dSolidShader,
		//	debugShader ? shaveBrushPreDrawCallback : NULL,
		//	debugShader ? shaveBrushPostDrawCallback : NULL);
		MHWRender::MShaderInstance* shader = shaderMgr->getEffectsFileShader("shaveHair.cgfx","Brush");
		if (shader)
		{
			//static const float theColor[] = {0.0f, 0.01f, 0.27f, 1.0f};
			//shader->setParameter("solidColor", theColor);

			// assign shader
			item->setShader(shader);

			// sample debug code
			if (debugShader)
			{
				MStringArray params;
				shader->parameterList(params);
				unsigned int numParams = params.length();
				printf("DEBUGGING SHADER, BEGIN PARAM LIST OF LENGTH %d\n", numParams);
				for (unsigned int i=0; i<numParams; i++)
				{
					printf("ParamName='%s', ParamType=", params[i].asChar());
					switch (shader->parameterType(params[i]))
					{
						case MHWRender::MShaderInstance::kInvalid:
							printf("'Invalid', ");
						break;
						case MHWRender::MShaderInstance::kBoolean:
							printf("'Boolean', ");
						break;
						case MHWRender::MShaderInstance::kInteger:
							printf("'Integer', ");
						break;
						case MHWRender::MShaderInstance::kFloat:
							printf("'Float', ");
						break;
						case MHWRender::MShaderInstance::kFloat2:
							printf("'Float2', ");
						break;
						case MHWRender::MShaderInstance::kFloat3:
							printf("'Float3', ");
						break;
						case MHWRender::MShaderInstance::kFloat4:
							printf("'Float4', ");
						break;
						case MHWRender::MShaderInstance::kFloat4x4Row:
							printf("'Float4x4Row', ");
						break;
						case MHWRender::MShaderInstance::kFloat4x4Col:
							printf("'Float4x4Col', ");
						break;
						case MHWRender::MShaderInstance::kTexture1:
							printf("'1D Texture', ");
						break;
						case MHWRender::MShaderInstance::kTexture2:
							printf("'2D Texture', ");
						break;
						case MHWRender::MShaderInstance::kTexture3:
							printf("'3D Texture', ");
						break;
						case MHWRender::MShaderInstance::kTextureCube:
							printf("'Cube Texture', ");
						break;
						case MHWRender::MShaderInstance::kSampler:
							printf("'Sampler', ");
						break;
						default:
							printf("'Unknown', ");
						break;
					}
					printf("IsArrayParameter='%s'\n", shader->isArrayParameter(params[i]) ? "YES" : "NO");
				}
				printf("END PARAM LIST\n");
				fflush(stdout);
			}
		}
	}
}



void shaveBrushOverride::populateGeometry(
	const MHWRender::MGeometryRequirements& requirements,
	const MHWRender::MRenderItemList& itemList,
		MHWRender::MGeometry& data
		)
{
	MHWRender::MVertexBuffer* positionBuffer = NULL;
	float* positions = NULL;

	const MHWRender::MVertexBufferDescriptorList& descList = requirements.vertexRequirements();
	int numVertexReqs = descList.length();
	MHWRender::MVertexBufferDescriptor desc;

#ifndef BRUSH_BY_SHADER
	int nsegs = 24;
	int nverts = nsegs*2;
#endif	

	for (int reqNum=0; reqNum<numVertexReqs; reqNum++)
	{
		if (!descList.getDescriptor(reqNum, desc))
		{
			continue;
		}

		switch (desc.semantic())
		{
			case MHWRender::MGeometry::kPosition:
			{
				positionBuffer = data.createVertexBuffer(desc);
				if (positionBuffer)
#ifdef BRUSH_BY_SHADER
						positions = (float*)positionBuffer->acquire(2);
#else
						positions = (float*)positionBuffer->acquire(nverts);
#endif
			}
			break;

			case MHWRender::MGeometry::kColor:
			case MHWRender::MGeometry::kTexture:
			case MHWRender::MGeometry::kNormal:
			case MHWRender::MGeometry::kTangent:
			case MHWRender::MGeometry::kBitangent:
			default:
			break;
		}
	}
	

	if (positions)
	{
#ifdef BRUSH_BY_SHADER
		
		M3dView	activeView = M3dView::active3dView();
		float H = (float)activeView.portHeight();
		float W = (float)activeView.portWidth();

		float x = (brush->mCX - 0.5f*W)/(0.5f*W);
		float y = (brush->mCY - 0.5f*H)/(0.5f*H);

		//MVector C(0.0f, 0.0f, 0.0f);
		MVector C(x, y, 0.0f);
		//MVector C(brush->mCX, brush->mCY, 0.0f);

		positions[0] = C.x;
		positions[1] = C.y;
		positions[2] = 0.0f;

		
		float w = brush->mRX/(0.5f*W);
		float h = brush->mRY/(0.5f*H);
		
		MVector P(w, h, 0.0f);
		//MVector P(brush->mRX, brush->mRY, 0.0f);

		positions[3] = P.x;
		positions[4] = P.y;
		positions[5] = 0.0f;
#else
		float R = 0.3f;

		M3dView	activeView = M3dView::active3dView();
		float H = (float)activeView.portHeight();
		float W = (float)activeView.portWidth();

		float x = (brush->mCX - 0.5f*W)/(0.5f*W);
		float y = (brush->mCY - 0.5f*H)/(0.5f*H);
		MVector C(x, y, 0.0f);

		float _w = brush->mRX/(0.5f*W);
		float _h = brush->mRY/(0.5f*H);
		MVector P(_w, _h, 0.0f);

		const float pi = 3.14159f;
		float dstep = 360.0f/nsegs;
		float rstep = dstep*pi/(180.0f);
		int pid = 0;
		for (int h = 0; h < nsegs; h++)
		{
			int hh = (h+1)%nsegs;
			float a1 = rstep*(float)h;
			float a2 = rstep*(float)hh;

			//float x1 = C.x + R*sin(a1);
			//float y1 = C.y + R*cos(a1);

			//float x2 = C.x + R*sin(a2);
			//float y2 = C.y + R*cos(a2);

			float x1 = (float)(C.x + P.x*sin(a1));
			float y1 = (float)(C.y + P.y*cos(a1));

			float x2 = (float)(C.x + P.x*sin(a2));
			float y2 = (float)(C.y + P.y*cos(a2));

			positions[pid++] = x1;
			positions[pid++] = y1;
			positions[pid++] = 0.0f;

			positions[pid++] = x2;
			positions[pid++] = y2;
			positions[pid++] = 0.0f;
		}
#endif
		positionBuffer->commit(positions);
	}

	// index data
	MHWRender::MIndexBuffer* indexBuffer = NULL; 
	int numItems = itemList.length();
	for (int i=0; i<numItems; i++)
	{
		const MHWRender::MRenderItem* item = itemList.itemAt(i);
		if (!item) continue;

		// Enable to debug vertex buffers that are associated with each render item.
		// Can also use to generate indexing better, but we don't need that here.
		// Also debugs custom data on the render item.
		static const bool debugStuff = false;
		if (debugShader)
		{
			const MHWRender::MVertexBufferDescriptorList& itemBuffers =item->requiredVertexBuffers();
			int numBufs = itemBuffers.length();
			MHWRender::MVertexBufferDescriptor desc;
			for (int bufNum=0; bufNum<numBufs; bufNum++)
			{
				if (itemBuffers.getDescriptor(bufNum, desc))
				{
					printf("Buffer Required for Item #%d ('%s'):\n", i, item->name().asChar());
					printf("\tBufferName: %s\n", desc.name().asChar());
					printf("\tDataType: %s (dimension %d)\n", MHWRender::MGeometry::dataTypeString(desc.dataType()).asChar(), desc.dimension());
					printf("\tSemantic: %s\n", MHWRender::MGeometry::semanticString(desc.semantic()).asChar());
					printf("\n");
				}
			}
			fflush(stdout);
		}

		//same indexing for all 
		if (item->name() == "shaveBrush")
		{
			if (!indexBuffer)
			{
				indexBuffer = data.createIndexBuffer(MHWRender::MGeometry::kUnsignedInt32);
				if (indexBuffer)
				{
#ifdef BRUSH_BY_SHADER
					unsigned int* buffer = (unsigned int*)indexBuffer->acquire(2);
					if (buffer)
					{
						buffer[0] = 0;
						buffer[1] = 1;
						indexBuffer->commit(buffer);
					}
#else
					unsigned int* buffer = (unsigned int*)indexBuffer->acquire(nsegs*2);
					if (buffer)
					{
						int idx = 0;
						for (int h = 0; h < nsegs; h++)
						{
							buffer[idx] = idx;
							buffer[idx+1] = idx+1;
							idx += 2;
						}
						indexBuffer->commit(buffer);
					}
#endif
				}
			}

			// Associate same index buffer with either render item
			if (indexBuffer)
			{
				item->associateWithIndexBuffer(indexBuffer);

			}
		}
	}

}

void shaveBrushOverride::cleanUp()
{

}