tge/engine/dgl/splineUtil.cc
2017-04-17 06:17:10 -06:00

163 lines
4.1 KiB
C++
Executable File

//-----------------------------------------------------------------------------
// Torque Game Engine
// Copyright (C) GarageGames.com, Inc.
//-----------------------------------------------------------------------------
#include "dgl/splineUtil.h"
#include "platform/platformGL.h"
namespace SplineUtil{
//------------------------------------------------------------------------------
// Draws strip of specified width along spline. Polys on strip segments are
// front-facing (billboarded)
//------------------------------------------------------------------------------
void drawSplineBeam( const Point3F& camPos, U32 numSegments,
F32 width, SplinePatch &spline, F32 uvOffset, F32 numTexRep )
{
Point3F beginPoint, endPoint;
spline.calc( 0.0, beginPoint );
spline.calc( 1.0, endPoint );
F32 approxBeamLength = (beginPoint - endPoint).len();
F32 texRepFactor = approxBeamLength * numTexRep;
glBegin(GL_TRIANGLE_STRIP);
for( int i=0; i<numSegments; i++ )
{
F32 t = ((F32)i) / ((F32)(numSegments - 1));
Point3F curPoint;
spline.calc( t, curPoint );
Point3F segmentDir;
// handle last segment case
Point3F nextPoint;
if( i == (numSegments - 1) )
{
F32 modT = ((F32)(numSegments - 1)) / ((F32)numSegments);
spline.calc( modT, nextPoint );
segmentDir = curPoint - nextPoint;
}
else
{
F32 modT = t + (1.0 / numSegments);
spline.calc( modT, nextPoint );
segmentDir = nextPoint - curPoint;
}
if( segmentDir.isZero() ) continue;
segmentDir.normalize();
Point3F dirFromCam = curPoint - camPos;
Point3F crossVec;
mCross(dirFromCam, segmentDir, &crossVec);
crossVec.normalize();
crossVec *= width * 0.5;
F32 u = uvOffset + texRepFactor * t;
glTexCoord2f( u, 0.0 );
glVertex3fv( curPoint + crossVec );
glTexCoord2f( u, 1.0 );
glVertex3fv( curPoint - crossVec );
}
glEnd();
}
//------------------------------------------------------------------------------
// Draws strip of specified width along spline. Polys on strip segments are
// front-facing (billboarded)
//------------------------------------------------------------------------------
void drawSplineBeam( SplineBeamInfo &sbi )
{
if( !sbi.camPos || !sbi.spline ) return;
Point3F beginPoint, endPoint;
sbi.spline->calc( 0.0, beginPoint );
sbi.spline->calc( 1.0, endPoint );
F32 approxBeamLength = (beginPoint - endPoint).len();
F32 texRepFactor = approxBeamLength * sbi.numTexRep;
glBegin(GL_TRIANGLE_STRIP);
for( int i=0; i<sbi.numSegments; i++ )
{
F32 t = ((F32)i) / ((F32)(sbi.numSegments - 1));
Point3F curPoint;
sbi.spline->calc( t, curPoint );
Point3F segmentDir;
// handle last segment case
Point3F nextPoint;
if( i == (sbi.numSegments - 1) )
{
F32 modT = ((F32)(sbi.numSegments - 1)) / ((F32)sbi.numSegments);
sbi.spline->calc( modT, nextPoint );
segmentDir = curPoint - nextPoint;
}
else
{
F32 modT = t + (1.0 / sbi.numSegments);
sbi.spline->calc( modT, nextPoint );
segmentDir = nextPoint - curPoint;
}
if( segmentDir.isZero() ) continue;
segmentDir.normalize();
Point3F dirFromCam = curPoint - *sbi.camPos;
Point3F crossVec;
mCross(dirFromCam, segmentDir, &crossVec);
crossVec.normalize();
crossVec *= sbi.width * 0.5;
F32 u = sbi.uvOffset + texRepFactor * t;
if( i== 0 && sbi.zeroAlphaStart )
{
glColor4f( sbi.color.red, sbi.color.green, sbi.color.blue, 0.0 );
}
else
{
glColor4fv( sbi.color );
}
glTexCoord2f( u, 0.0 );
glVertex3fv( curPoint + crossVec );
glTexCoord2f( u, 1.0 );
glVertex3fv( curPoint - crossVec );
}
glEnd();
}
} // end SplineUtil namespace