// lesson3
public static void Triangle(Image image, Vec3f [] coordinates, Image texture, Vec2f [] uv, float intensivity, float [] zbuffer)
{
Vec3f t0 = coordinates [0];
Vec3f t1 = coordinates [1];
Vec3f t2 = coordinates [2];
var pMax = new Vec2i {
x = (int)Math.Max(0, Math.Max(t0.x, Math.Max(t1.x, t2.x))),
y = (int)Math.Max(0, Math.Max(t0.y, Math.Max(t1.y, t2.y)))
};
var pMin = new Vec2i {
x = (int)Math.Min(image.Width, Math.Min(t0.x, Math.Min(t1.x, t2.x))),
y = (int)Math.Min(image.Height, Math.Min(t0.y, Math.Min(t1.y, t2.y)))
};
for (int x = pMin.x; x <= pMax.x; x++)
{
for (int y = pMin.y; y <= pMax.y; y++)
{
var pixelCenter = new Vec2f {
x = x + 0.5f,
y = y + 0.5f
};
var bc = Barycentric(Project2D(t0), Project2D(t1), Project2D(t2), pixelCenter);
if (bc.x < 0 || bc.y < 0 || bc.z < 0)
{
continue;
}
var z = t0.z * bc.x + t1.z * bc.y + t2.z * bc.z;
var u = (int)(uv [0].x * bc.x + uv [1].x * bc.y + uv [2].x * bc.z);
var v = (int)(uv [0].y * bc.x + uv [1].y * bc.y + uv [2].y * bc.z);
var idx = x + y * image.Width;
if (zbuffer [idx] < z)
{
zbuffer [idx] = z;
var color = texture [u, v];
image [x, y] = color * intensivity;
}
}
}
}
// lesson4
public static Matrix4 LookAt(Vec3f eye, Vec3f center, Vec3f up)
{
var z = (eye - center).Normalize();
var x = Cross(up, z).Normalize();
var y = Cross(z, x).Normalize();
var Minv = Matrix4.Identity();
Minv [0, 0] = x.x; Minv [0, 1] = x.y; Minv [0, 2] = x.z;
Minv [1, 0] = y.x; Minv [1, 1] = y.y; Minv [1, 2] = y.z;
Minv [2, 0] = z.x; Minv [2, 1] = z.y; Minv [2, 2] = z.z;
var Tr = Matrix4.Identity();
Tr [0, 3] = -center.x;
Tr [1, 3] = -center.y;
Tr [2, 3] = -center.y;
return(Minv * Tr);
}
public static void Execute(Model model, Image texture)
{
var image = new Image(width, height, Format.BGR);
Func <Vec3f, Vec3f> map = v => new Vec3f {
x = (int)Math.Round((v.x + 1) * (image.Width - 1) / 2, MidpointRounding.AwayFromZero),
y = (int)Math.Round((v.y + 1) * (image.Height - 1) / 2, MidpointRounding.AwayFromZero),
z = v.z
};
Func <Vec3f, Vec2f> uvMap = v => new Vec2f {
x = v.x * (texture.Width - 1),
y = v.y * (texture.Height - 1)
};
var zbuffer = InitZBuffer(image);
var uv = new Vec2f [3];
foreach (var face in model.Faces)
{
for (int i = 0; i < 3; i++)
{
var vIndex = face.Vertices [i];
world [i] = model.Vertices [vIndex];
screen [i] = map(world [i]);
var tIndex = face.Textures [i];
uv [i] = uvMap(model.Textures [tIndex]);
}
Vec3f n = Cross(world [2] - world [0], world [1] - world [0]).Normalize();
var intensivity = Dot(n, light_dir);
if (intensivity > 0)
{
Triangle(image, screen, texture, uv, intensivity, zbuffer);
}
}
image.VerticalFlip();
image.WriteToFile("texture-head.tga");
}
public bool Fragment(Vec3f fragment, Vec3f bar, out Color color)
{
var uv = CalcUV(varyingU, varyingV, bar);
var n = Transform(uniformMIT, Normal(normalMap, uv)).Normalize();
var l = Transform(uniformM, lightDir).Normalize();
var r = (n * (2 * Dot(n, l)) - l).Normalize();
var diff = Math.Max(0f, Dot(n, l));
var specular = Math.Pow(Math.Max(0f, r.z), Specular(specularMap, uv) + 15);
color = GetColor(texture, uv);
int v = 0;
for (int i = 0; i < 4; i++)
{
v = (v << 8) | (byte)Math.Min(255, (int)(5 + color [i] * (diff + 1.3f * specular)));
}
color = new Color(v, color.format);
return(false);
}
static void ProjectionListing()
{
var image = new Image(width, height, Format.BGR);
var camera = new Vec3f {
z = 3
};
var projection = Projection(-1 / camera.z);
var viewPort = Viewport(width / 8, height / 8, width * 3 / 4, height * 3 / 4);
var zbuffer = InitZBuffer(image);
foreach (var face in headModel.Faces)
{
for (int i = 0; i < 3; i++)
{
var vIndex = face.Vertices [i];
world [i] = headModel.Vertices [vIndex];
screen [i] = map(world [i]);
var tIndex = face.Textures [i];
uv [i] = uvMap(headModel.Textures [tIndex]);
}
var n = Cross(world [2] - world [0], world [1] - world [0]).Normalize();
var intensivity = Dot(n, light_dir);
if (intensivity > 0)
{
Triangle(image, screen, headTexture, uv, intensivity, zbuffer);
}
}
image.VerticalFlip();
image.WriteToFile("project-head.tga");
}
public bool Fragment(Vec3f fragment, Vec3f bar, out Color color)
{
color = Color.White * (fragment.z / depth);
return(false);
}
public ShadowShader(Model model, Matrix4 viewport, Matrix4 projection, Matrix4 modelView, Matrix4 uniformShadow, Vec3f lightDir, Image texture, Image normalMap, Image specularMap, float[] shadowbuffer, int width)
{
this.model = model;
this.lightDir = lightDir.Normalize();
this.texture = texture;
this.normalMap = normalMap;
this.specularMap = specularMap;
this.shadowbuffer = shadowbuffer;
this.width = width;
uniformM = projection * modelView;
uniformMIT = TransposeInverse(uniformM);
transformation = viewport * uniformM;
this.uniformShadow = uniformShadow;
}
// use this commit for 6bis lesson:
// https://github.com/xamarin/private-samples/commit/ddad38f7787d5e9c065afc91547730ad38e51fd1#diff-8603c43660c04f4d430053b29c80ed15R253
public TangentShader(Model model, Matrix4 viewport, Matrix4 projection, Matrix4 modelView, Vec3f lightDir, Image texture, Image normalMap)
{
this.model = model;
this.lightDir = lightDir.Normalize();
this.texture = texture;
// do not need for starting poing
this.normalMap = normalMap;
// this.specularMap = specularMap;
uniformM = projection * modelView;
uniformMIT = TransposeInverse(uniformM);
transformation = viewport * uniformM;
}
public GouraudShader(Model model, Matrix4 viewPort, Matrix4 projection, Matrix4 modelView, Vec3f lightDir)
{
this.model = model;
transformation = viewPort * projection * modelView;
this.lightDir = lightDir.Normalize();
}
public NormalMapShader(Model model, Matrix4 viewport, Matrix4 projection, Matrix4 modelView, Vec3f lightDir, Image texture, Image normalMap)
{
this.model = model;
this.lightDir = lightDir.Normalize();
this.texture = texture;
this.normalMap = normalMap;
uniformM = projection * modelView;
uniformMIT = TransposeInverse(uniformM);
transformation = viewport * uniformM;
}
// lesson6
public static void UpdateVarayingUV(Model model, Face face, int nthvert, ref Vec3f varyingU, ref Vec3f varyingV)
{
var vt = model.GetUV(face, nthvert);
varyingU [nthvert] = vt.x;
varyingV [nthvert] = vt.y;
}
public GouraudShader6(Model model, Matrix4 viewPort, Matrix4 projection, Matrix4 modelView, Vec3f lightDir)
: base(model, viewPort, projection, modelView, lightDir)
{
}
public void SetRow(int row, Vec3f v)
{
this [row, 0] = v.x;
this [row, 1] = v.y;
this [row, 2] = v.z;
}
public void SetColumn(int col, Vec3f v)
{
this [0, col] = v.x;
this [1, col] = v.y;
this [2, col] = v.z;
}
public static Vec2f Project2D(Vec3f v)
{
return(new Vec2f {
x = v.x, y = v.y
});
}
public static Vec4f Embed4D(Vec3f v, float fill = 1)
{
return(new Vec4f {
x = v.x, y = v.y, z = v.z, h = fill
});
}
public static float Dot(Vec3f l, Vec3f r)
{
return(l.x * r.x + l.y * r.y + l.z * r.z);
}
public bool Fragment(Vec3f fragment, Vec3f bar, out Color color)
{
color = Color.Black;
return(false);
}
public TextureShader(Model model, Matrix4 viewPort, Matrix4 projection, Matrix4 modelView, Vec3f lightDir, Image texture)
{
this.model = model;
transformation = viewPort * projection * modelView;
this.lightDir = lightDir.Normalize();
this.texture = texture;
}
public static Vec3f Transform(Matrix4 t, Vec3f v)
{
var v4d = Mult(t, Embed4D(v));
return(Project3D(v4d));
}
static void AmbientListing()
{
var rnd = new Random();
var screen_coords = new Vec4f [3];
var frame = new Image(width, height, Format.BGR);
var shadowbuffer = InitZBuffer(frame);
var zbuffer = InitZBuffer(frame);
var total = new Image(1024, 1024, Format.BGR);
var occl = new Image(1024, 1024, Format.BGR);
const int nrenders = 1;
for (int iter = 1; iter <= nrenders; iter++)
{
for (int i = 0; i < shadowbuffer.Length; i++)
{
shadowbuffer [i] = 0;
zbuffer [i] = 0;
}
var vUp = new Vec3f {
x = (float)rnd.NextDouble(),
y = (float)rnd.NextDouble(),
z = (float)rnd.NextDouble()
};
var spLocation = RandPointOnUnitSphere();
spLocation.y = Math.Abs(spLocation.y);
frame.Clear();
var mvM = LookAt(spLocation, center, vUp);
var pM = Projection(0);
var zshader = new ZShader(diabloModel, viewPort, pM, mvM);
foreach (var face in diabloModel.Faces)
{
for (int i = 0; i < 3; i++)
{
screen_coords [i] = zshader.Vertex(face, i);
}
Triangle(frame, screen_coords, zshader, shadowbuffer);
}
//frame.VerticalFlip ();
//frame.WriteToFile ("framebuffer.tga");
occl.Clear();
var shader = new OcclusionShader(diabloModel, viewPort, pM, mvM, occl, shadowbuffer, frame.Width);
foreach (var face in diabloModel.Faces)
{
for (int i = 0; i < 3; i++)
{
screen_coords [i] = shader.Vertex(face, i);
}
Triangle(frame, screen_coords, shader, zbuffer);
}
for (int i = 0; i < total.Width; i++)
{
for (int j = 0; j < total.Height; j++)
{
float prev = total [i, j] [0];
float curr = occl [i, j] [0];
var val = (byte)((prev * (iter - 1) + curr) / iter + 0.5f);
total [i, j] = new Color(val, val, val);
}
}
}
total.VerticalFlip();
total.WriteToFile("total-occlusion.tga");
}