protected void DrawScreenSpaceTriangleInterpolated(PreparedTriangle triangle)
{
WriteableBitmap rt = _renderWindow.Framebuffer;
if (triangle.GetScreenSpaceDirection() != VisibleTriangleDirection)
{
return;
}
var triangleArea = CalculateTriangleArea(
triangle.Vertices[0].X, triangle.Vertices[0].Y,
triangle.Vertices[1].X, triangle.Vertices[1].Y,
triangle.Vertices[2].X, triangle.Vertices[2].Y);
var vertexX = new double[] { triangle.Vertices[0].X, triangle.Vertices[1].X, triangle.Vertices[2].X };
var vertexY = new double[] { triangle.Vertices[0].Y, triangle.Vertices[1].Y, triangle.Vertices[2].Y };
var scanEdges = new List <ScanEdge>();
for (int current = 0; current < 3; ++current)
{
int next = (current + 1) % 3;
double higherx, highery;
double lowerx, lowery;
if (vertexY[current] < vertexY[next])
{
higherx = vertexX[current];
highery = vertexY[current];
lowerx = vertexX[next];
lowery = vertexY[next];
}
else
{
higherx = vertexX[next];
highery = vertexY[next];
lowerx = vertexX[current];
lowery = vertexY[current];
}
int minY = (int)highery;
int maxY = (int)lowery;
//int startX = (int)higherx;
//int endX = (int)lowerx;
if (minY == maxY)
{
continue;
}
var scanEdge = new ScanEdge();
scanEdge.MinimalY = (int)Math.Ceiling(highery);
scanEdge.MaximalY = (int)Math.Ceiling(lowery);
scanEdge.X = higherx;
scanEdge.XSlope = (lowerx - higherx) / ((double)(lowery - highery));
scanEdges.Add(scanEdge);
}
if (scanEdges.Count == 0)
{
return;
}
scanEdges = scanEdges.OrderBy(t => t.MinimalY).ToList();
int scanEdgesActivated = 0;
var startY = Math.Max(scanEdges.Min(t => t.MinimalY), 0);
var endY = Math.Min(scanEdges.Max(t => t.MaximalY), rt.PixelHeight - 1);
var activeEdges = new List <ScanEdge>();
for (var y = startY; y <= endY; ++y)
{
activeEdges = activeEdges.Where(t => y < t.MaximalY).ToList();
while (scanEdgesActivated < scanEdges.Count)
{
if (y < scanEdges[scanEdgesActivated].MinimalY)
{
break;
}
activeEdges.Add(scanEdges[scanEdgesActivated]);
++scanEdgesActivated;
}
activeEdges = activeEdges.OrderBy(t => t.X).ToList();
for (int i = 0; i < activeEdges.Count - 1; i += 2)
{
int startX = (int)Math.Ceiling(Math.Max(activeEdges[i].X, 0));
int endX = (int)Math.Floor(Math.Min(activeEdges[i + 1].X, rt.PixelWidth - 1));
for (int x = startX; x <= endX; ++x)
{
var aArea = CalculateTriangleArea(
x, y,
triangle.Vertices[1].X, triangle.Vertices[1].Y,
triangle.Vertices[2].X, triangle.Vertices[2].Y);
var bArea = CalculateTriangleArea(
triangle.Vertices[0].X, triangle.Vertices[0].Y,
x, y,
triangle.Vertices[2].X, triangle.Vertices[2].Y);
var cArea = CalculateTriangleArea(
triangle.Vertices[0].X, triangle.Vertices[0].Y,
triangle.Vertices[1].X, triangle.Vertices[1].Y,
x, y);
var fa = Math.Min(aArea / triangleArea, 1.0);
var fb = Math.Min(bArea / triangleArea, 1.0);
var fc = Math.Min(cArea / triangleArea, 1.0);
if (fa + fb + fc > 1.0)
{
int lowestAreaIndex = 0;
double lowestArea = fa;
if (lowestArea > fb)
{
lowestAreaIndex = 1;
lowestArea = fb;
}
if (lowestArea > fc)
{
lowestAreaIndex = 2;
lowestArea = fc;
}
switch (lowestAreaIndex)
{
case 0:
fa = 1.0 - fb - fc;
break;
case 1:
fb = 1.0 - fa - fc;
break;
case 2:
fc = 1.0 - fa - fb;
break;
}
}
var z = fa * triangle.Vertices[0].Z
+ fb * triangle.Vertices[1].Z
+ fc * triangle.Vertices[2].Z;
if (z <= 1.0)
{
continue;
}
if (_zBuffer[x, y] > z)
{
continue;
}
_zBuffer[x, y] = z;
// Pixel Shader
Color outputColor = InterpolateColor(
fa, triangle.Vertices[0].VertexColor,
fb, triangle.Vertices[1].VertexColor,
fc, triangle.Vertices[2].VertexColor);
if (TexturingEnabled && Material.DiffuseTexture != null)
{
var u = fa * triangle.Vertices[0].U + fb * triangle.Vertices[1].U + fc * triangle.Vertices[2].U;
var v = fa * triangle.Vertices[0].V + fb * triangle.Vertices[1].V + fc * triangle.Vertices[2].V;
u = Math.Min(Math.Max(u, 0.0), 1.0);
v = Math.Min(Math.Max(v, 0.0), 1.0);
Color texColor = Material.DiffuseTexture.GetPixel((int)(u * Material.DiffuseTexture.PixelWidth),
(int)(v * Material.DiffuseTexture.PixelHeight));
outputColor = MultiplyColors(outputColor, texColor);
}
// End of pixel shader
rt.SetPixel(x, y, outputColor);
}
}
activeEdges.ForEach(t => t.X += t.XSlope);
}
}
public void RenderObjMesh(ObjData meshToRender, Matrix <double> transformation, Matrix <double> normalTransformation)
{
if (Material == null)
{
Material = new Material();
}
if (TexturingEnabled)
{
if (Material.DiffuseTexture != null)
{
Material.DiffuseTexture.Lock();
}
}
var hw = _renderWindow.Framebuffer.PixelWidth * 0.5;
var hh = _renderWindow.Framebuffer.PixelHeight * 0.5;
foreach (var triangle in meshToRender.Triangles)
{
var tri = new PreparedTriangle();
for (int i = 0; i < 3; ++i)
{
Vector <double> modelSpacePosition = meshToRender.Vertices[triangle.Vertices[i]];
Vector <double> modelSpaceNormal = meshToRender.Normals[triangle.Normals[i]];
Vector <double> screenSpacePosition = (transformation * modelSpacePosition.ExtendVector())
.ToCartesian()
.Add(VectorHelpers.Create(1.0, 1.0, 0.0))
.PointwiseMultiply(VectorHelpers.Create(hw, hh, 1.0));
Vector <double> worldSpacePosition = (normalTransformation * modelSpacePosition.ExtendVector())
.ToCartesian();
Vector <double> worldSpaceNormal = (normalTransformation * modelSpaceNormal.ExtendVector(0.0))
.DiscardLastCoordinate().Normalize(2);
// Vertex shader
tri.Vertices[i].SetCoordinates(screenSpacePosition);
tri.Vertices[i].SetTextureCoordinates(meshToRender.TexCoords[triangle.TexCoords[i]]);
var vR = 0;
var vG = 0;
var vB = 0;
if (AmbientLightingEnabled)
{
vR += Material.AmbientColor.R;
vG += Material.AmbientColor.G;
vB += Material.AmbientColor.B;
}
if (DiffuseLightingEnabled || SpecularLightingEnabled)
{
foreach (var light in Lights)
{
var lightDirection = (light.Position - worldSpacePosition).Normalize(2);
if (DiffuseLightingEnabled)
{
var diffuseLightFactor = Math.Max(lightDirection.DotProduct(worldSpaceNormal), 0);
var fullSaturationDiffuseColor = MultiplyColors(light.Color, Material.DiffuseColor);
vR += (byte)(fullSaturationDiffuseColor.R * diffuseLightFactor);
vG += (byte)(fullSaturationDiffuseColor.G * diffuseLightFactor);
vB += (byte)(fullSaturationDiffuseColor.B * diffuseLightFactor);
}
if (SpecularLightingEnabled)
{
var eyeDirection = (WorldPositionEye - worldSpacePosition).Normalize(2);
var reflected = (2 * worldSpaceNormal.DotProduct(lightDirection) * worldSpaceNormal - lightDirection).Normalize(2);
var specularLightFactor = Math.Pow(Math.Max(eyeDirection.DotProduct(reflected), 0), Material.ShineFactor);
var fullSaturationSpecularColor = MultiplyColors(light.Color, Material.SpecularColor);
vR += (byte)(fullSaturationSpecularColor.R * specularLightFactor);
vG += (byte)(fullSaturationSpecularColor.G * specularLightFactor);
vB += (byte)(fullSaturationSpecularColor.B * specularLightFactor);
}
}
}
tri.Vertices[i].VertexColor = Color.FromRgb(
(byte)Math.Min(vR, 255),
(byte)Math.Min(vG, 255),
(byte)Math.Min(vB, 255));
// End of vertex shader
}
DrawScreenSpaceTriangleInterpolated(tri);
}
if (TexturingEnabled && Material.DiffuseTexture != null)
{
Material.DiffuseTexture.Unlock();
}
}