public static IVertex lerp(IVertex start, IVertex end, float delta)
{
return new IVertex()
{
position = Int3.lerp(start.position, end.position, delta),
normal = Float3.lerp(start.normal, end.normal, delta),
color = start.color.lerpTo(end.color, delta),
uv = Float2.lerp(start.uv, end.uv, delta),
};
}
private void RenderTriangle2(Vertex _v1, Vertex _v2, Vertex _v3, Material material, Float3 lightDirection)
{
IVertex v1 = new IVertex(_v1);
IVertex v2 = new IVertex(_v2);
IVertex v3 = new IVertex(_v3);
if (v1.y > v2.y) Utils.swap(ref v1, ref v2);
if (v1.y > v3.y) Utils.swap(ref v1, ref v3);
if (v2.y > v3.y) Utils.swap(ref v2, ref v3);
int triangleYHeight = v3.y - v1.y + 1;
int firstSegmentHeight = v2.y - v1.y + 1;
int secondSegmentHeight = v3.y - v2.y + 1;
for (int y = v1.y; y <= v3.y; y++)
{
bool isFirstSegment = y < v2.y;
int segmentStartY = isFirstSegment ? v1.y : v2.y;
float alpha = (float)(y - v1.y) / (float)triangleYHeight;
IVertex A = IVertex.lerp(v1, v3, alpha);
float beta = (float)(y - segmentStartY) / (float)(isFirstSegment ? firstSegmentHeight : secondSegmentHeight);
IVertex B = IVertex.lerp(isFirstSegment ? v1 : v2, isFirstSegment ? v2 : v3, beta);
if (A.x > B.x)
Utils.swap(ref A, ref B);
for (int x = A.x; x <= B.x; x++)
{
// check extremes
float delta = (A.x == B.x) ? 1.0f : (float)(x - A.x) / (float)(B.x - A.x);
IVertex C = IVertex.lerp(A, B, delta);
float lc = getLamberComponent(C.normal, lightDirection);
int intLambert = (int)(lc * 255);
Color c = Color.FromArgb(intLambert, intLambert, intLambert);
c = tex2D(material.diffuseTexture, C.u, C.v);
DrawPointToFrameBuffer(x, y, C.z, c);
}
}
}