Leaked source code of windows server 2003
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 
 
 
 

397 lines
14 KiB

///////////////////////////////////////////////////////////////////////////////
// Copyright (C) Microsoft Corporation, 1998.
//
// scancnv.cpp
//
// Direct3D Reference Rasterizer - Primitive Scan Conversion
//
///////////////////////////////////////////////////////////////////////////////
#include "pch.cpp"
#pragma hdrstop
///////////////////////////////////////////////////////////////////////////////
// //
// Scan Conversion Utilities //
// //
///////////////////////////////////////////////////////////////////////////////
//-----------------------------------------------------------------------------
//
// ComputePixelAttrib(Clamp/Tex) - Evaluates given linear function at current
// scan conversion position (m_SCCS.iX,iY). Return is FLOAT value.
//
// Clamp version clamps result to 0. to 1. range.
//
// Tex version does texture coordinate function (unclamped).
//
//-----------------------------------------------------------------------------
FLOAT
ReferenceRasterizer::ComputePixelAttrib( int iAttrib )
{
return m_pSCS->AttribFuncs[iAttrib].Eval();
}
FLOAT
ReferenceRasterizer::ComputePixelAttribClamp( int iAttrib )
{
FLOAT fValue = ComputePixelAttrib( iAttrib );
fValue = MAX( MIN( fValue, 1. ), 0. );
return fValue;
}
//
// iStage specifies set of transformed texture coordinates
// iCrd specifies which value within coord
FLOAT
ReferenceRasterizer::ComputePixelAttribTex( int iStage, int iCrd )
{
return m_pSCS->TextureFuncs[iStage][iCrd].Eval(iStage);
}
//-----------------------------------------------------------------------------
//
// ComputeFogIntensity - Computes scalar fog intensity value and writes it to
// the RRPixel.FogIntensity value.
//
//-----------------------------------------------------------------------------
void
ReferenceRasterizer::ComputeFogIntensity( RRPixel& Pixel )
{
FLOAT fFogDensity, fPow;
FLOAT fFogStart, fFogEnd;
// select fog index - this is either Z or W depending on the W range
//
// use Z if projection matrix is set to an affine projection, else use W
// (both for perspective projection and an unset projection matrix - the
// latter is preferred for legacy content which uses TLVERTEX)
//
FLOAT fFogIndex =
( ( 1.f == m_pRenderTarget->m_fWRange[0] ) &&
( 1.f == m_pRenderTarget->m_fWRange[1] ) )
? ( MAX( MIN( ComputePixelAttribClamp( ATTRFUNC_Z ),
m_pSCS->fDepthMax ), m_pSCS->fDepthMin ) ) // use clamped Z for affine projection
: ( Pixel.fW ); // use W for non-affine projection
// compute fog intensity
if ( m_dwRenderState[D3DRENDERSTATE_FOGENABLE] )
{
// select between vertex and table fog - vertex fog is selected if
// fog is enabled but the renderstate fog table mode is disabled
switch ( m_dwRenderState[D3DRENDERSTATE_FOGTABLEMODE] )
{
default:
case D3DFOG_NONE:
// table fog disabled, so use interpolated vertex fog value for fog intensity
Pixel.FogIntensity = ComputePixelAttribClamp( ATTRFUNC_F );
break;
case D3DFOG_EXP:
fFogDensity = m_fRenderState[D3DRENDERSTATE_FOGTABLEDENSITY];
fPow = fFogDensity * fFogIndex;
// note that exp(-x) returns a result in the range (0.0, 1.0]
// for x >= 0
Pixel.FogIntensity = (float)exp( -fPow );
break;
case D3DFOG_EXP2:
fFogDensity = m_fRenderState[D3DRENDERSTATE_FOGTABLEDENSITY];
fPow = fFogDensity * fFogIndex;
Pixel.FogIntensity = (float)exp( -(fPow*fPow) );
break;
case D3DFOG_LINEAR:
fFogStart = m_fRenderState[D3DRENDERSTATE_FOGTABLESTART];
fFogEnd = m_fRenderState[D3DRENDERSTATE_FOGTABLEEND];
if (fFogIndex >= fFogEnd)
{
Pixel.FogIntensity = 0.0f;
}
else if (fFogIndex <= fFogStart)
{
Pixel.FogIntensity = 1.0f;
}
else
{
Pixel.FogIntensity = ( fFogEnd - fFogIndex ) / ( fFogEnd - fFogStart );
}
break;
}
}
}
//-----------------------------------------------------------------------------
//
// DoScanCnvGenPixel - This is called for each generated pixel, and extracts and
// processes attributes from the interpolator state, and passes the pixels on to
// the pixel processing module.
//
//-----------------------------------------------------------------------------
void
ReferenceRasterizer::DoScanCnvGenPixel( RRCvgMask CvgMask, BOOL bTri )
{
// set per-pixel state for attribute evaluators
m_pSCS->AttribFuncStatic.SetPerPixelData( m_pSCS->iX, m_pSCS->iY );
// instantiate and fill out pixel struct
RRPixel Pixel;
memset(&Pixel, 0, sizeof(Pixel));
Pixel.iX = m_pSCS->iX;
Pixel.iY = m_pSCS->iY;
Pixel.fW = m_pSCS->AttribFuncStatic.GetPixelW();
Pixel.CvgMask = CvgMask;
Pixel.Depth.SetSType(m_pRenderTarget->m_DepthSType);
// get depth from clamp interpolator and clamp
if ( m_dwRenderState[D3DRENDERSTATE_ZENABLE] ||
m_dwRenderState[D3DRENDERSTATE_FOGENABLE])
{
if ( D3DZB_USEW == m_dwRenderState[D3DRENDERSTATE_ZENABLE] )
{
// depth buffering with W value
FLOAT fW = Pixel.fW;
// clamp to primitive range (due to sampling outside primitive for antialiasing)
// (triangles only)
if ( bTri )
{
fW = MAX( MIN( fW, m_pSCS->fDepthMax ), m_pSCS->fDepthMin );
}
// apply normalization to get to 0. to 1. range
fW = (fW - m_fWBufferNorm[0]) * m_fWBufferNorm[1];
Pixel.Depth = fW;
}
else
{
// depth buffering with Z value
FLOAT fZ = ComputePixelAttribClamp( ATTRFUNC_Z );
// clamp to primitive range (due to sampling outside primitive for antialiasing)
// (triangles only)
if ( bTri )
{
fZ = MAX( MIN( fZ, m_pSCS->fDepthMax ), m_pSCS->fDepthMin );
}
Pixel.Depth = fZ;
}
// snap off extra bits by converting to/from buffer format
//
// this is mainly because of storing RRDepth values in the fragment buffer
// and then comparing these (higher resolution) values to the buffer value
// when forming the fragment lists at each pixel - cleanly snapping off the
// extra bits here solves this problem
//
switch ( m_pRenderTarget->m_DepthSType)
{
case RR_STYPE_Z16S0: Pixel.Depth = UINT16( Pixel.Depth ); break;
case RR_STYPE_Z24S4:
case RR_STYPE_Z24S8: Pixel.Depth = UINT32( Pixel.Depth ); break;
case RR_STYPE_Z15S1: Pixel.Depth = UINT16( Pixel.Depth ); break;
case RR_STYPE_Z32S0: Pixel.Depth = UINT32( Pixel.Depth ); break;
case RR_STYPE_S1Z15: Pixel.Depth = UINT16( Pixel.Depth ); break;
case RR_STYPE_S4Z24:
case RR_STYPE_S8Z24: Pixel.Depth = UINT32( Pixel.Depth ); break;
}
}
// set pixel diffuse color from clamped interpolator values
Pixel.Color.A = ComputePixelAttribClamp( ATTRFUNC_A );
Pixel.Color.R = ComputePixelAttribClamp( ATTRFUNC_R );
Pixel.Color.G = ComputePixelAttribClamp( ATTRFUNC_G );
Pixel.Color.B = ComputePixelAttribClamp( ATTRFUNC_B );
// set pixel specular color from clamped interpolator values
if ( m_qwFVFControl & D3DFVF_SPECULAR )
{
Pixel.Specular.A = ComputePixelAttribClamp( ATTRFUNC_SA );
Pixel.Specular.R = ComputePixelAttribClamp( ATTRFUNC_SR );
Pixel.Specular.G = ComputePixelAttribClamp( ATTRFUNC_SG );
Pixel.Specular.B = ComputePixelAttribClamp( ATTRFUNC_SB );
}
// compute fog intensity
ComputeFogIntensity( Pixel );
// send to pixel processor
DoPixel( Pixel );
}
///////////////////////////////////////////////////////////////////////////////
// //
// Triangle Scan Conversion //
// //
///////////////////////////////////////////////////////////////////////////////
//-----------------------------------------------------------------------------
//
// DoScanCnvTri - Scans the bounding box of the triangle and generates pixels.
//
//-----------------------------------------------------------------------------
void
ReferenceRasterizer::DoScanCnvTri( int iEdgeCount )
{
DPFM(3,RAST,("DoScanCnvTri:\n"))
//
// do simple scan of surface-intersected triangle bounding box
//
for ( m_pSCS->iY = m_pSCS->iYMin;
m_pSCS->iY <= m_pSCS->iYMax;
m_pSCS->iY++ )
{
for ( m_pSCS->iX = m_pSCS->iXMin;
m_pSCS->iX <= m_pSCS->iXMax;
m_pSCS->iX++ )
{
RRCvgMask CvgMask = 0xFFFF; // assume pixel is inside all edges
for ( int iEdge=0; iEdge<iEdgeCount; iEdge++ )
{
if ( m_bFragmentProcessingEnabled )
{
CvgMask &= m_pSCS->EdgeFuncs[iEdge].AATest( m_pSCS->iX, m_pSCS->iY) ;
}
else
{
CvgMask &= m_pSCS->EdgeFuncs[iEdge].PSTest( m_pSCS->iX, m_pSCS->iY) ;
}
}
if ( CvgMask != 0x0000 )
{
// pixel is not out, so process it
DoScanCnvGenPixel( CvgMask, TRUE );
}
}
}
}
///////////////////////////////////////////////////////////////////////////////
// //
// Line Scan Conversion //
// //
///////////////////////////////////////////////////////////////////////////////
//----------------------------------------------------------------------------
//
// LinePatternStateMachine
//
// Runs the line pattern state machine and returns TRUE if the pixel is to be
// drawn, false otherwise. Always returns true if wRepeatFactor is 0, which
// means pattern is disabled.
//
//----------------------------------------------------------------------------
static BOOL LinePatternStateMachine(DWORD dwLinePattern, WORD& wRepeati, WORD& wPatterni)
{
union
{
D3DLINEPATTERN LPat;
DWORD dwLPat;
} LinePat;
LinePat.dwLPat = dwLinePattern;
if (LinePat.LPat.wRepeatFactor)
{
WORD wBit = (LinePat.LPat.wLinePattern >> wPatterni) & 1;
if (++wRepeati >= LinePat.LPat.wRepeatFactor)
{
wRepeati = 0;
wPatterni = (wPatterni+1) & 0xf;
}
return (BOOL)wBit;
}
else
{
return TRUE;
}
}
//-----------------------------------------------------------------------------
//
// DivRoundDown(A,B) = ceiling(A/B - 1/2)
//
// ceiling(A/B - 1/2) == floor(A/B + 1/2 - epsilon)
// == floor( (A + (B/2 - epsilon))/B )
//
// Does correct thing for all sign combinations of A and B.
//
//-----------------------------------------------------------------------------
INT64 DivRoundDown(INT64 iA, INT32 iB)
{
INT32 i = 0;
static const INT32 iEps[3] =
{
1, // iA > 0, iB > 0
0, // iA < 0, iB > 0 OR iA > 0, iB < 0
1 // iA < 0, iB < 0
};
if (iA < 0)
{
i++;
iA = -iA;
}
if (iB < 0)
{
i++;
iB = -iB;
}
iA += (iB-iEps[i]) >> 1;
iA /= iB;
if (iEps[i] == 0)
iA = -iA;
return(iA);
}
//-----------------------------------------------------------------------------
//
// DoScanCnvLine - Walks the line major axis, computes the appropriate minor
// axis coordinate, and generates pixels.
//
//-----------------------------------------------------------------------------
void
ReferenceRasterizer::DoScanCnvLine( void )
{
DPFM(3,RAST,("DoScanCnvLine:\n"))
// step in major axis
INT16 iMajorCoord = m_pSCS->iLineMin;
int cSteps = abs( m_pSCS->iLineMax - m_pSCS->iLineMin );
// state for line pattern state machine
WORD wRepeati = 0;
WORD wPatterni = 0;
for ( int cStep = 0; cStep <= cSteps; cStep++ )
{
// evaluate line function to compute minor coord for this major
INT64 iMinorCoord =
( ( m_pSCS->iLineEdgeFunc[0] * (INT64)(iMajorCoord<<4) ) + m_pSCS->iLineEdgeFunc[1] );
iMinorCoord = DivRoundDown(iMinorCoord, m_pSCS->iLineEdgeFunc[2]<<4);
m_pSCS->iX = m_pSCS->bXMajor ? iMajorCoord : iMinorCoord;
m_pSCS->iY = m_pSCS->bXMajor ? iMinorCoord : iMajorCoord;
// check if the point is inside the viewport
if ( ( m_pSCS->iX >= m_pRenderTarget->m_Clip.left ) &&
( m_pSCS->iX <= m_pRenderTarget->m_Clip.right ) &&
( m_pSCS->iY >= m_pRenderTarget->m_Clip.top ) &&
( m_pSCS->iY <= m_pRenderTarget->m_Clip.bottom ) )
{
// The line pattern should have been walked in from its origin, which may have been
// offscreen, to be completely correct.
if (LinePatternStateMachine(m_dwRenderState[D3DRENDERSTATE_LINEPATTERN], wRepeati, wPatterni))
{
DoScanCnvGenPixel( 0xFFFF, FALSE );
}
}
iMajorCoord += m_pSCS->iLineStep;
}
}
///////////////////////////////////////////////////////////////////////////////
// end