public ShaderState(int size, World world)
{
_world = world;
_face = new FaceShaderState(world);
_vertex = new VertexShaderState(size, world);
_fragment = new FragmentShaderState(size, world);
}
public override void Face(FaceShaderState state, int face)
{
var v0 = _geometry.GetVertex(face, 0);
var v1 = _geometry.GetVertex(face, 1);
var v2 = _geometry.GetVertex(face, 2);
var foo1 = Vector3.Subtract(v1, v0);
var foo2 = Vector3.Subtract(v2, v1);
var normal = Vector3.Cross(foo1, foo2);
normal = Vector3.Normalize(normal);
var intensity = Vector3.Dot(normal, _light);
if (intensity < 0)
{
intensity = 0;
}
state.Intensity = intensity;
}
public override void Face(FaceShaderState state, int face)
{
}
private void DrawFilling(WritableTexture screen, int startY, int endY, Vector3 v0, Vector3 v1, Vector3 v2,
FragmentShaderState fragmentState, FaceShaderState faceState, VertexShaderState vertexState, Shader shader)
{
var x0 = (int)Math.Round(v0.X);
var y0 = (int)Math.Round(v0.Y);
var x1 = (int)Math.Round(v1.X);
var y1 = (int)Math.Round(v1.Y);
var x2 = (int)Math.Round(v2.X);
var y2 = (int)Math.Round(v2.Y);
int minX = ClipX(Math3(x0, x1, x2, Math.Min));
int minY = ClipY(Math3(y0, y1, y2, Math.Min), startY, endY);
int maxX = ClipX(Math3(x0, x1, x2, Math.Max));
int maxY = ClipY(Math3(y0, y1, y2, Math.Max), startY, endY);
float midX = (v0.X + v1.X + v2.X) / 3;
float midY = (v0.Y + v1.Y + v2.Y) / 3;
var dirV0 = new Vector3(v0.X - midX, v0.Y - midY, 0);
var dirV1 = new Vector3(v1.X - midX, v1.Y - midY, 0);
var direction = Vector3.Cross(dirV0, dirV1).Z;
if (direction < 0)
{
Vector3 tbuf;
tbuf = v1;
v1 = v2;
v2 = tbuf;
}
var line1 = new Line(v0.X, v0.Y, v1.X, v1.Y, minX, minY);
var line2 = new Line(v1.X, v1.Y, v2.X, v2.Y, minX, minY);
var line3 = new Line(v2.X, v2.Y, v0.X, v0.Y, minX, minY);
var converter = new BarycentricCoordinatesConverter(v0.X, v0.Y, v1.X, v1.Y, v2.X, v2.Y);
var writer = screen.GetWriter(minY);
for (int y = minY; y <= maxY; y++)
{
for (int x = minX; x <= maxX; x++)
{
var curr1 = line1.Value;
var curr2 = line2.Value;
var curr3 = line3.Value;
if (curr1 >= 0 && curr2 >= 0 && curr3 >= 0)
{
var p = converter.Convert(x, y);
if (p.A < 0 || p.B < 0 || p.C < 0)
{
continue;
}
var z = v0.Z * p.A + v1.Z * p.B + v2.Z * p.C;
if (z < _zBuffer[x, y])
{
continue;
}
fragmentState.Clear();
fragmentState.Intensity = faceState.Intensity;
for (var i = 0; i < vertexState.Varying[0].Count; i++)
{
var fragmentValue = vertexState.Varying[0][i] * p.A + vertexState.Varying[1][i] * p.B +
vertexState.Varying[2][i] * p.C;
fragmentState.Varying.Add(fragmentValue);
}
var resColor = shader.Fragment(fragmentState);
if (resColor != null)
{
_zBuffer[x, y] = z;
writer.Write(x, resColor.Value);
}
}
line1.StepX();
line2.StepX();
line3.StepX();
}
line1.StepY();
line2.StepY();
line3.StepY();
writer.NextLine();
}
}
