private static void GetSortedPoints(ref Vertex vertexA,
ref Vertex vertexB,
ref Vertex vertexC,
ref TextureCoordinate textureA,
ref TextureCoordinate textureB,
ref TextureCoordinate textureC)
{
var point1 = vertexA;
var point2 = vertexB;
var point3 = vertexC;
if (point2.TranslatedScreenCoordinates.Y < point1.TranslatedScreenCoordinates.Y)
{
var p = point1;
point1 = point2;
point2 = p;
var t = textureA;
textureA = textureB;
textureB = t;
}
if (point3.TranslatedScreenCoordinates.Y < point2.TranslatedScreenCoordinates.Y)
{
var p = point2;
point2 = point3;
point3 = p;
var t = textureB;
textureB = textureC;
textureC = t;
}
if (point2.TranslatedScreenCoordinates.Y < point1.TranslatedScreenCoordinates.Y)
{
var p = point1;
point1 = point2;
point2 = p;
var t = textureA;
textureA = textureB;
textureB = t;
}
vertexA = point1;
vertexB = point2;
vertexC = point3;
}
public void SetVertex(int index, Vertex vertex)
{
this.Vertices[index] = vertex;
}
public void AllocateVertices(int count)
{
Vertices = new Vertex[count];
}
public static void Draw(IBuffers buffers, ISpanRenderer renderer, TriangleShade shade, Face face, Vertex[] vertices, TextureCoordinate[] textureCoordinates)
{
var vertexA = vertices[face.A];
var vertexB = vertices[face.B];
var vertexC = vertices[face.C];
var textureA = ZeroTextureCoordinate;
var textureB = ZeroTextureCoordinate;
var textureC = ZeroTextureCoordinate;
Image image = null;
ImageContext texture = null;
var useTexture = false;
if( null != face.Material && null != face.Material.DiffuseMap)
{
useTexture = true;
image = face.Material.DiffuseMap;
texture = face.Material.DiffuseMap.ImageContext as ImageContext;
textureA = textureCoordinates[face.DiffuseA];
textureB = textureCoordinates[face.DiffuseB];
textureC = textureCoordinates[face.DiffuseC];
}
/*
SetSphericalEnvironmentMapTextureCoordinate(ref vertexA, ref textureA);
SetSphericalEnvironmentMapTextureCoordinate(ref vertexB, ref textureB);
SetSphericalEnvironmentMapTextureCoordinate(ref vertexC, ref textureC);
*/
GetSortedPoints(ref vertexA, ref vertexB, ref vertexC, ref textureA, ref textureB, ref textureC);
var interpolator = GetInterpolatorForFace(face, shade);
var secondaryStartY = (int)(vertexB.TranslatedScreenCoordinates.Y - vertexA.TranslatedScreenCoordinates.Y);
var spreadCount = ((int)(vertexC.TranslatedScreenCoordinates.Y - vertexA.TranslatedScreenCoordinates.Y)) + 1;
interpolator.SetPoint(0, (int)vertexA.TranslatedScreenCoordinates.X, (int)vertexC.TranslatedScreenCoordinates.X);
interpolator.SetPoint(1, (int)vertexA.TranslatedScreenCoordinates.X, (int)vertexB.TranslatedScreenCoordinates.X, (int)vertexB.TranslatedScreenCoordinates.X, (int)vertexC.TranslatedScreenCoordinates.X, secondaryStartY);
interpolator.SetPoint(2, vertexA.DepthBufferAdjustedZ, vertexC.DepthBufferAdjustedZ);
interpolator.SetPoint(3, vertexA.DepthBufferAdjustedZ, vertexB.DepthBufferAdjustedZ, vertexB.DepthBufferAdjustedZ, vertexC.DepthBufferAdjustedZ, secondaryStartY);
if (useTexture)
{
interpolator.SetPoint(4, textureA.U, textureC.U);
interpolator.SetPoint(5, textureA.U, textureB.U, textureB.U, textureC.U, secondaryStartY);
interpolator.SetPoint(6, textureA.V, textureC.V);
interpolator.SetPoint(7, textureA.V, textureB.V, textureB.V, textureC.V, secondaryStartY);
}
var color = Color.FromArgb(0xff, 0xff, 0xff, 0xff);
if (shade == TriangleShade.Gouraud && !useTexture)
{
var vertexAColor = vertexA.Color.ToVector();
var vertexBColor = vertexB.Color.ToVector();
var vertexCColor = vertexC.Color.ToVector();
interpolator.SetPoint(4, vertexAColor.Red, vertexCColor.Red);
interpolator.SetPoint(5, vertexAColor.Red, vertexBColor.Red, vertexBColor.Red, vertexCColor.Red, secondaryStartY);
interpolator.SetPoint(6, vertexAColor.Green, vertexCColor.Green);
interpolator.SetPoint(7, vertexAColor.Green, vertexBColor.Green, vertexBColor.Green, vertexCColor.Green, secondaryStartY);
interpolator.SetPoint(8, vertexAColor.Blue, vertexCColor.Blue);
interpolator.SetPoint(9, vertexAColor.Blue, vertexBColor.Blue, vertexBColor.Blue, vertexCColor.Blue, secondaryStartY);
interpolator.SetPoint(10, vertexAColor.Alpha, vertexCColor.Alpha);
interpolator.SetPoint(11, vertexAColor.Alpha, vertexBColor.Alpha, vertexBColor.Alpha, vertexCColor.Alpha, secondaryStartY);
}
else
{
color = face.Color;
}
interpolator.Interpolate(spreadCount);
var yPosition = vertexA.TranslatedScreenCoordinates.Y;
var clip = false;
if( null == buffers )
{
return;
}
for (var index = 0; index < spreadCount; index++)
{
if( yPosition < 0 || yPosition >= buffers.Height )
{
clip = true;
} else
{
clip = false;
}
var span = GetSpan(index, interpolator, vertexA, useTexture);
if (null != span && !clip )
{
var actualSpan = (Span)span;
var swapIndex = ((Span)span).Swap ? 1 : 0;
actualSpan.ZStart = interpolator.Points[2 + swapIndex].InterpolatedValues[index];
actualSpan.ZEnd = interpolator.Points[3 - swapIndex].InterpolatedValues[index];
switch (shade)
{
case TriangleShade.Flat:
{
if (useTexture)
{
renderer.Texture(buffers, actualSpan, image, texture);
}
else
{
renderer.Flat(buffers, actualSpan, color);
}
}
break;
case TriangleShade.Gouraud:
{
if (useTexture)
{
renderer.Texture(buffers, actualSpan, image, texture);
}
else
{
actualSpan.ColorStart.Red = interpolator.Points[4 + swapIndex].InterpolatedValues[index];
actualSpan.ColorEnd.Red = interpolator.Points[5 - swapIndex].InterpolatedValues[index];
actualSpan.ColorStart.Green = interpolator.Points[6 + swapIndex].InterpolatedValues[index];
actualSpan.ColorEnd.Green = interpolator.Points[7 - swapIndex].InterpolatedValues[index];
actualSpan.ColorStart.Blue = interpolator.Points[8 + swapIndex].InterpolatedValues[index];
actualSpan.ColorEnd.Blue = interpolator.Points[9 - swapIndex].InterpolatedValues[index];
actualSpan.ColorStart.Alpha = interpolator.Points[10 + swapIndex].InterpolatedValues[index];
actualSpan.ColorEnd.Alpha = interpolator.Points[11 - swapIndex].InterpolatedValues[index];
renderer.Gouraud(buffers, actualSpan);
}
}
break;
}
}
yPosition++;
}
}
private static void SetSphericalEnvironmentMapTextureCoordinate(ref Vertex vertex, ref TextureCoordinate textureCoordinate)
{
var u = vertex.TransformedVectorNormalized;
var n = vertex.TransformedNormal;
var r = Vector.Reflect(n, u);
var m = Math.Core.Sqrt((r.X * r.X) + (r.Y * r.Y) +
((r.Z + 1f) * (r.Z + 1f)));
var s = (r.X / m) + 0.5f;
var t = (r.Y / m) + 0.5f;
textureCoordinate.U = s;
textureCoordinate.V = t;
}
private static Span? GetSpan(int interpolationIndex, Interpolator interpolator, Vertex vertexA, bool useTexture)
{
var y = ((int)vertexA.TranslatedScreenCoordinates.Y) + interpolationIndex;
var xstart = interpolator.Points[0].InterpolatedValues[interpolationIndex];
var xend = interpolator.Points[1].InterpolatedValues[interpolationIndex];
var ustart = 0f;
var vstart = 0f;
var uend = 0f;
var vend = 0f;
if (useTexture)
{
ustart = interpolator.Points[4].InterpolatedValues[interpolationIndex];
uend = interpolator.Points[5].InterpolatedValues[interpolationIndex];
vstart = interpolator.Points[6].InterpolatedValues[interpolationIndex];
vend = interpolator.Points[7].InterpolatedValues[interpolationIndex];
}
var swap = false;
if (xstart > xend)
{
var temp = xstart;
xstart = xend;
xend = temp;
swap = true;
temp = ustart;
ustart = uend;
uend = temp;
temp = vstart;
vstart = vend;
vend = temp;
}
xend += 0.5f;
var length = xend - xstart;
var absLength = (int)System.Math.Round((double)length + 0.5);
if (absLength >= 1)
{
var span = new Span
{
Y = y,
XStart = (int)xstart,
XEnd = (int)xend,
UStart = ustart,
UEnd = uend,
VStart = vstart,
VEnd = vend,
Length = absLength,
Swap = swap
};
return span;
}
return null;
}
