void generateTexCoordsSphere( VertexAttributeSetSharedPtr const& vas, const Sphere3f &sphere, unsigned int tu )
{
Buffer::ConstIterator<Vec3f>::Type vertices = vas->getVertices();
std::vector<Vec2f> texCoords( vas->getNumberOfVertices() );
Vec2f tp;
for ( unsigned int i=0 ; i<vas->getNumberOfVertices() ; i++ )
{
Vec3f p = vertices[i] - sphere.getCenter();
if ( fabsf( p[1] ) > FLT_EPSILON )
{
tp[0] = 0.5f * atan2f( p[0], -p[1] ) / (float) PI + 0.5f;
}
else
{
tp[0] = (float)( ( p[0] >= 0.0f ) ? 0.75f : 0.25f );
}
float d = sqrtf( square( p[0] ) + square( p[1] ) );
if ( d > FLT_EPSILON )
{
tp[1] = atan2f( p[2], d ) / (float) PI + 0.5f;
}
else
{
tp[1] = (float)( ( p[2] >= 0.0f ) ? 1.0f : 0.0f );
}
texCoords[i] = tp;
}
vas->setTexCoords( tu, &texCoords[0], vas->getNumberOfVertices() );
}
void generateTexCoordsPlane( VertexAttributeSetSharedPtr const& vas, const Sphere3f &sphere, unsigned int tu )
{
Buffer::ConstIterator<Vec3f>::Type vertices = vas->getVertices();
// get the bounding box of vas and determine the axes u,v to use to texture along
unsigned int u, v, w;
getSortedAxes( vertices, vas->getNumberOfVertices(), u, v, w );
// create the texture coordinates
std::vector<Vec2f> texCoords( vas->getNumberOfVertices() );
Vec2f tp;
float oneOverTwoR = 0.5f / sphere.getRadius();
Vec2f tpMin( 1.0f, 1.0f );
Vec2f tpMax( 0.0f, 0.0f );
for ( unsigned int i=0 ; i<vas->getNumberOfVertices() ; i++ )
{
Vec3f p = vertices[i] - sphere.getCenter();
tp[0] = p[u] * oneOverTwoR + 0.5f; // 0.0 <= tp[0] <= 1.0
if ( tp[0] < tpMin[0] )
{
tpMin[0] = tp[0];
}
else if ( tp[0] > tpMax[0] )
{
tpMax[0] = tp[0];
}
tp[1] = p[v] * oneOverTwoR + 0.5f; // 0.0 <= tp[1] <= 1.0
if ( tp[1] < tpMin[1] )
{
tpMin[1] = tp[1];
}
else if ( tp[1] > tpMax[1] )
{
tpMax[1] = tp[1];
}
texCoords[i] = tp;
}
// scale the texcoords to [0..1]
DP_ASSERT( ( FLT_EPSILON < ( tpMax[0] - tpMin[0] ) ) && ( FLT_EPSILON < ( tpMax[1] - tpMin[1] ) ) );
Vec2f tpScale( 1.0f / ( tpMax[0] - tpMin[0] ), 1.0f / ( tpMax[1] - tpMin[1] ) );
for ( unsigned int i=0 ; i<vas->getNumberOfVertices() ; i++ )
{
texCoords[i] = Vec2f( ( texCoords[i][0] - tpMin[0] ) * tpScale[0],
( texCoords[i][1] - tpMin[1] ) * tpScale[1] );
}
vas->setTexCoords( tu, &texCoords[0], vas->getNumberOfVertices() );
}
void generateTexCoordsCylinder( VertexAttributeSetSharedPtr const& vas, const Sphere3f &sphere, unsigned int tu )
{
Buffer::ConstIterator<Vec3f>::Type vertices = vas->getVertices();
// get the bounding box of vas and determine the axes u,v to use to texture along
unsigned int u, v, w;
getSortedAxes( vertices, vas->getNumberOfVertices(), u, v, w );
// create the texture coordinates
std::vector<Vec2f> texCoords( vas->getNumberOfVertices() );
Vec2f tp;
float oneOverTwoR = 0.5f / sphere.getRadius();
float tpuMin = 1.0f;
float tpuMax = 0.0f;
for ( unsigned int i=0 ; i<vas->getNumberOfVertices() ; i++ )
{
Vec3f p = vertices[i] - sphere.getCenter();
// largest axis as the cylinder axis
tp[0] = p[u] * oneOverTwoR + 0.5f; // 0.0 <= tp[1] <= 1.0
if ( tp[0] < tpuMin )
{
tpuMin = tp[0];
}
else if ( tpuMax < tp[0] )
{
tpuMax = tp[0];
}
if ( FLT_EPSILON < fabsf( p[v] ) )
{
tp[1] = 0.5f * atan2f( p[w], -p[v] ) / (float) PI + 0.5f;
}
else
{
tp[1] = (float)( ( 0.0f <= p[w] ) ? 0.75f : 0.25f );
}
texCoords[i] = tp;
}
// scale the texcoords to [0..1]
DP_ASSERT( FLT_EPSILON < ( tpuMax - tpuMin ) );
float tpuScale = 1.0f / ( tpuMax - tpuMin );
for ( unsigned int i=0 ; i<vas->getNumberOfVertices() ; i++ )
{
texCoords[i][0] = ( texCoords[i][0] - tpuMin ) * tpuScale;
}
vas->setTexCoords( tu, &texCoords[0], vas->getNumberOfVertices() );
}