public static GradVertex SolidVert(Vector2 position, Color color, EllipseDesc ellipse)
{
return(new GradVertex()
{
Color1 = color,
Coord = position,
Params = new Vector4(0, 0, ellipse.pos.X, ellipse.pos.Y),
EllipseDat = ellipse.dimensions
});
}
public static Tuple <GradVertex[], int[]> GenerateShadows(IEnumerable <Vector2[]> volumes, LightData light, List <Vector3> ctrWidths, List <Rectangle> rectGeom)
{
DistanceMult = 5000f;
var pointLight = light.LightPos;
var mat_cw = Matrix.CreateRotationZ(WallPenumbra);
var mat_ccw = Matrix.CreateRotationZ(-WallPenumbra);
var vertices = new List <GradVertex>();
var indices = new List <int>();
var j = 0;
var basicDesc = new EllipseDesc();
var hc = Color.White * 0.5f;
var p = WallPenumbra * 2;
foreach (var pts in volumes)
{
//find sides closest to point
float distM;
if (light.LightType == LightType.OUTDOORS && ctrWidths == null)
{
distM = 32f * light.FalloffMultiplier;
}
else
{
distM = DistanceMult;
}
var baseIdx = vertices.Count;
//var pts = ClockwiseLine(wall, pointLight);
//var pts = ClosestPtsClockwise(wall, pointLight);
//through project the points on each side with angle offsets.
var mid = (pts[0] + pts[2]) / 2;
Vector2 leftNorm, midNorm, rightNorm, leftFac, midFac, rightFac;
if (light.LightType == LightType.OUTDOORS)
{
leftNorm = midNorm = rightNorm = light.LightDir;
}
else
{
leftNorm = pts[0] - pointLight; leftNorm.Normalize();
midNorm = mid - pointLight; midNorm.Normalize();
rightNorm = pts[2] - pointLight; rightNorm.Normalize();
}
leftFac = leftNorm * distM; rightFac = rightNorm * distM; midFac = midNorm * distM;
EllipseDesc ellipse;
if (ctrWidths != null)
{
//distance * obj2height / (lightheight - obj2height)
var ctW = ctrWidths[j++];
var mid2 = new Vector2(ctW.X, ctW.Y);
float height;
if (light.LightType == LightType.OUTDOORS)
{
height = 16 * light.FalloffMultiplier;
}
else
{
height = (mid2 - pointLight).Length() * 16 / ((16 * 3) - 16);
}
var midNorm2 = mid2 - pointLight; midNorm2.Normalize();
var largeDim = (ctW.Z + height) * midNorm2;
var smallDim = new Vector2(largeDim.Y, -largeDim.X);
smallDim.Normalize();
smallDim *= ctW.Z;
ellipse = new EllipseDesc {
pos = mid2, dimensions = new Vector4(smallDim, largeDim.X, largeDim.Y)
};
}
else if (light.LightType == LightType.OUTDOORS)
{
//wall linear falloff
var perp = (pts[2] - pts[0]);
var px = perp.Y;
perp.Y = -perp.X;
perp.X = px;
perp.Normalize();
var midN2 = light.LightDir;
var dot = Vector2.Dot(perp, midN2);
//if (Math.Abs(dot) < 0.35) continue;
var length = distM * (dot);
var spos = pts[0];// - ((dot>0)?perp:(-perp))*2;
perp *= length;
ellipse = new EllipseDesc {
pos = spos, dimensions = new Vector4(length * length, 0, perp.X, perp.Y)
};
}
else
{
ellipse = basicDesc;
}
//rotate the left and right norms to make the new penumbras
var leftpen1 = pts[0] + Vector2.Transform(leftFac, mat_ccw);
var leftpen2 = pts[0] + Vector2.Transform(leftFac, mat_cw);
var rightpen1 = pts[2] + Vector2.Transform(rightFac, mat_ccw);
var rightpen2 = pts[2] + Vector2.Transform(rightFac, mat_cw);
//------ filled points ------
//three cases. left and right penubras intersect at some point, in which case we make 2 triangles.
//if they diverge, make 4 triangles.
//penumbras contain each other. use one and center at half the target color.
//y = mx + c
var dist1 = (pts[0] - pointLight).LengthSquared();
var dist2 = (pts[2] - pointLight).LengthSquared();
if (dist1 > dist2)
{
//is penumbra 1 inside 2?
if (Vector2.Dot(Vector2.Normalize(pts[0] - pts[2]), rightNorm) > PenCos)
{
//yes
//continue;
var conectr = pts[2] + rightNorm;
vertices.Add(GradVertex.ConeVert(pts[2], pts[2], conectr, Color.TransparentBlack, hc, p / 2, ellipse));
vertices.Add(GradVertex.ConeVert(rightpen1, pts[2], conectr, Color.TransparentBlack, hc, p / 2, ellipse));
vertices.Add(GradVertex.ConeVert(rightpen2, pts[2], conectr, Color.TransparentBlack, hc, p / 2, ellipse));
for (int i = 0; i < 3; i++)
{
indices.Add(baseIdx + i);
}
continue;
}
}
else
{
//is penumbra 2 inside 1?
if (Vector2.Dot(Vector2.Normalize(pts[2] - pts[0]), leftNorm) > PenCos)
{
//yes
//continue;
var conectr = pts[0] + leftNorm;
vertices.Add(GradVertex.ConeVert(pts[0], pts[0], conectr, Color.TransparentBlack, hc, p, ellipse));
vertices.Add(GradVertex.ConeVert(leftpen1, pts[0], conectr, Color.TransparentBlack, hc, p, ellipse));
vertices.Add(GradVertex.ConeVert(leftpen2, pts[0], conectr, Color.TransparentBlack, hc, p, ellipse));
for (int i = 0; i < 3; i++)
{
indices.Add(baseIdx + i);
}
continue;
}
}
var midBack = pts[1] + midFac;
//continue;
var a = leftpen2 - pts[0];
var b = (rightpen1 - pts[2]);
var negX = -b.X;
b.X = b.Y;
b.Y = negX;
var c = pts[2] - pts[0];
var t = Vector2.Dot(c, b) / Vector2.Dot(a, b);
if (t < 0)
{
vertices.Add(GradVertex.SolidVert(pts[0], Color.White, ellipse));
vertices.Add(GradVertex.SolidVert(pts[1], Color.White, ellipse));
vertices.Add(GradVertex.SolidVert(pts[2], Color.White, ellipse));
vertices.Add(GradVertex.SolidVert(leftpen2, Color.White, ellipse));
vertices.Add(GradVertex.SolidVert(midBack, Color.White, ellipse));
vertices.Add(GradVertex.SolidVert(rightpen1, Color.White, ellipse));
indices.Add(baseIdx); indices.Add(baseIdx + 2); indices.Add(baseIdx + 1); //half of rectangle
indices.Add(baseIdx); indices.Add(baseIdx + 3); indices.Add(baseIdx + 2); //extension 1
indices.Add(baseIdx + 3); indices.Add(baseIdx + 4); indices.Add(baseIdx + 2); //extension 2
indices.Add(baseIdx + 4); indices.Add(baseIdx + 5); indices.Add(baseIdx + 2); //extension 3
baseIdx += 6;
//penumbras
vertices.Add(GradVertex.ConeVert(pts[0], pts[0], leftpen2, Color.TransparentBlack, Color.White, p, ellipse));
vertices.Add(GradVertex.ConeVert(leftpen1, pts[0], leftpen2, Color.TransparentBlack, Color.White, p, ellipse));
vertices.Add(GradVertex.ConeVert(leftpen2, pts[0], leftpen2, Color.TransparentBlack, Color.White, p, ellipse));
vertices.Add(GradVertex.ConeVert(pts[2], pts[2], rightpen1, Color.TransparentBlack, Color.White, p, ellipse));
vertices.Add(GradVertex.ConeVert(rightpen1, pts[2], rightpen1, Color.TransparentBlack, Color.White, p, ellipse));
vertices.Add(GradVertex.ConeVert(rightpen2, pts[2], rightpen1, Color.TransparentBlack, Color.White, p, ellipse));
for (int i = 0; i < 6; i++)
{
indices.Add(baseIdx + i);
}
}
else
{
var inter = pts[0] + a * t;
var distant = mid + Vector2.Normalize(inter - pointLight) * distM;
vertices.Add(GradVertex.SolidVert(pts[0], Color.White, ellipse));
vertices.Add(GradVertex.SolidVert(pts[0] + a * t, Color.White, ellipse));
vertices.Add(GradVertex.SolidVert(pts[2], Color.White, ellipse));
vertices.Add(GradVertex.SolidVert(pts[1], Color.White, ellipse));
indices.Add(baseIdx); indices.Add(baseIdx + 1); indices.Add(baseIdx + 2);
indices.Add(baseIdx); indices.Add(baseIdx + 2); indices.Add(baseIdx + 3); //half of rectangle
baseIdx += 4;
//penumbras: each penumbra becomes two tris as they intersect
vertices.Add(GradVertex.ConeVert(pts[0], pts[0], leftpen2, Color.TransparentBlack, Color.White, p, ellipse));
vertices.Add(GradVertex.ConeVert(leftpen1, pts[0], leftpen2, Color.TransparentBlack, Color.White, p, ellipse));
vertices.Add(GradVertex.ConeVert(inter, pts[0], leftpen2, Color.TransparentBlack, Color.White, p, ellipse));
vertices.Add(GradVertex.ConeVert(distant, pts[0], leftpen2, Color.TransparentBlack, Color.White, p, ellipse));
vertices.Add(GradVertex.ConeVert(pts[2], pts[2], rightpen1, Color.TransparentBlack, Color.White, p, ellipse));
vertices.Add(GradVertex.ConeVert(rightpen2, pts[2], rightpen1, Color.TransparentBlack, Color.White, p, ellipse));
vertices.Add(GradVertex.ConeVert(inter, pts[2], rightpen1, Color.TransparentBlack, Color.White, p, ellipse));
vertices.Add(GradVertex.ConeVert(distant, pts[2], rightpen1, Color.TransparentBlack, Color.White, p, ellipse));
indices.Add(baseIdx); indices.Add(baseIdx + 1); indices.Add(baseIdx + 2);
indices.Add(baseIdx + 1); indices.Add(baseIdx + 3); indices.Add(baseIdx + 2);
baseIdx += 4;
indices.Add(baseIdx); indices.Add(baseIdx + 1); indices.Add(baseIdx + 2);
indices.Add(baseIdx + 1); indices.Add(baseIdx + 3); indices.Add(baseIdx + 2);
}
}
return(new Tuple <GradVertex[], int[]>(vertices.ToArray(), indices.ToArray()));
}
public static GradVertex ConeVert(Vector2 position, Vector2 coneCtr, Vector2 coneOuter, Color color1, Color color2, float penumbra, EllipseDesc ellipse)
{
return(new GradVertex()
{
Color1 = color1,
Color2 = color2,
Coord = position,
StartPosition = coneCtr,
EndPosition = coneOuter,
Params = new Vector4(2, penumbra, ellipse.pos.X, ellipse.pos.Y),
EllipseDat = ellipse.dimensions
});
}