//-----------------------------------------------------------------------------
// Return intersection point of ray with screen in barycentric coords
//-----------------------------------------------------------------------------
bool C_VGuiScreen::IntersectWithRay( const Ray_t &ray, float *u, float *v, float *t )
{
// Perform a raycast to see where in barycentric coordinates the ray hits
// the viewscreen; if it doesn't hit it, you're not in the mode
Vector origin, upt, vpt;
ComputeEdges( &origin, &upt, &vpt );
return ComputeIntersectionBarycentricCoordinates( ray, origin, upt, vpt, *u, *v, t );
}
bool C_Shield::TestCollision( const Ray_t& ray, unsigned int mask, trace_t& trace )
{
// Can't block anything if we're EMPed, or we've got no power left to block
if ( m_bIsEMPed )
return false;
if ( m_flPowerLevel <= 0 )
return false;
// Here, we're gonna test for collision.
// If we don't stop this kind of bullet, we'll generate an effect here
// but we won't change the trace to indicate a collision.
// It's just polygon soup...
int hitgroup;
bool firstTri;
int v1[2], v2[2], v3[2];
float ihit, jhit;
float mint = FLT_MAX;
float t;
int h = Height();
int w = Width();
for (int i = 0; i < h - 1; ++i)
{
for (int j = 0; j < w - 1; ++j)
{
// Don't test if this panel ain't active...
if (!IsPanelActive( j, i ))
continue;
// NOTE: Structure order of points so that our barycentric
// axes for each triangle are along the (u,v) directions of the mesh
// The barycentric coords we'll need below
// Two triangles per quad...
t = IntersectRayWithTriangle( ray,
GetPoint( j, i + 1 ),
GetPoint( j + 1, i + 1 ),
GetPoint( j, i ), true );
if ((t >= 0.0f) && (t < mint))
{
mint = t;
v1[0] = j; v1[1] = i + 1;
v2[0] = j + 1; v2[1] = i + 1;
v3[0] = j; v3[1] = i;
ihit = i; jhit = j;
firstTri = true;
}
t = IntersectRayWithTriangle( ray,
GetPoint( j + 1, i ),
GetPoint( j, i ),
GetPoint( j + 1, i + 1 ), true );
if ((t >= 0.0f) && (t < mint))
{
mint = t;
v1[0] = j + 1; v1[1] = i;
v2[0] = j; v2[1] = i;
v3[0] = j + 1; v3[1] = i + 1;
ihit = i; jhit = j;
firstTri = false;
}
}
}
if (mint == FLT_MAX)
return false;
// Stuff the barycentric coordinates of the triangle hit into the hit group
// For the first triangle, the first edge goes along u, the second edge goes
// along -v. For the second triangle, the first edge goes along -u,
// the second edge goes along v.
const Vector& v1vec = GetPoint(v1[0], v1[1]);
const Vector& v2vec = GetPoint(v2[0], v2[1]);
const Vector& v3vec = GetPoint(v3[0], v3[1]);
float u, v;
bool ok = ComputeIntersectionBarycentricCoordinates( ray,
v1vec, v2vec, v3vec, u, v );
Assert( ok );
if ( !ok )
{
return false;
}
if (firstTri)
v = 1.0 - v;
else
u = 1.0 - u;
v += ihit; u += jhit;
v /= (h - 1);
u /= (w - 1);
// Compress (u,v) into 1 dot 15, v in top bits
hitgroup = (((int)(v * (1 << 15))) << 16) + (int)(u * (1 << 15));
Vector normal;
float intercept;
ComputeTrianglePlane( v1vec, v2vec, v3vec, normal, intercept );
UTIL_SetTrace( trace, ray, this, mint, hitgroup, CONTENTS_SOLID, normal, intercept );
return true;
}
