public void FillLine(Color32 lc, Color32 rc, int xs, int xe, int y, int debug)
{
float dx = System.Math.Abs(xe - xs);
for (var x = xs; x <= xe; x++)
{
if (x >= Width || y >= Height || x <= 0 || y <= 0)
{
continue;
}
;
var factor = System.Math.Abs((x - xs + 1) / (dx + 1));
var color = Mathx.Lerp(lc, rc, factor);
Program.main.SetPixel(x, y, color.ToDX());
}
}
public void VFillLine(Vertex left, Vertex right, int y)
{
//int y = (int)((left.point.y+right.point.y)/2);
float dx = System.Math.Abs(left.point.x - right.point.x);
for (var x = (int)left.point.x; x <= right.point.x; x++)
{
if (x >= Width || y >= Height || x <= 0 || y <= 0)
{
continue;
}
;
var factor = System.Math.Abs((x - left.point.x + 1) / (dx + 1));
var color = Mathx.Lerp(left.vcolor, right.vcolor, factor);
var lcolor = Mathx.Lerp(left.lightingColor, right.lightingColor, factor);
float u = Mathx.Lerp(left.u, right.u, factor),
v = Mathx.Lerp(left.v, right.v, factor);
var c = new Color32(ReadTexture(u, v, currentMaterial.texture));
Program.main.SetPixel(x, y, (c * lcolor).ToDX());
}
}
public void TriangleD(Vertex top, Vertex down_left, Vertex down_right)
{
if (down_left.point.x > down_right.point.x)
{
var t = down_left;
down_left = down_right;
down_right = t;
}
var dxy_left = (down_left.point.x - top.point.x) / (down_left.point.y - top.point.y);
var dxy_right = (down_right.point.x - top.point.x) / (down_right.point.y - top.point.y);
float xs = top.point.x, xe = top.point.x;
for (var y = top.point.y; y <= down_right.point.y; y++)
{
if (draw_mode == DrawMode.GouraudShading)
{
var v = (xe - xs == 0) ? 0 : (xe - xs) / (down_right.point.x - down_left.point.x);
Color32 left_color = Mathx.Lerp(top.vcolor, down_left.vcolor, v),
right_color = Mathx.Lerp(top.vcolor, down_right.vcolor, v);
FillLine(left_color, right_color, (int)xs, (int)xe, (int)y, 1);
}
else if (draw_mode == DrawMode.Texture)
{
var v = (xe - xs == 0) ? 0 : (xe - xs) / (down_right.point.x - down_left.point.x);
var left = Mathx.Lerp(top, down_left, v);
var right = Mathx.Lerp(top, down_right, v);
VFillLine(left, right, (int)y);
}
else
{
Program.main.DrawLine((int)xs, (int)xe, (int)y, currentColor);
}
xs += dxy_left;
xe += dxy_right;
}
}
public void TriangleT(Vertex down, Vertex up_left, Vertex up_right)
{
if (up_left.point.x > up_right.point.x)
{
var t = up_left;
up_left = up_right;
up_right = t;
}
var dxy_left = (down.point.x - up_left.point.x) / (down.point.y - up_left.point.y);
var dxy_right = (down.point.x - up_right.point.x) / (down.point.y - up_right.point.y);
float xs = up_left.point.x, xe = up_right.point.x;
for (var y = up_left.point.y; y <= down.point.y; y++)
{
if (draw_mode == DrawMode.GouraudShading)
{
var v = (xe - xs == 0) ? 0 : (xe - xs) / (up_right.point.x - up_left.point.x);
Color32 left_color = Mathx.Lerp(down.vcolor, up_left.vcolor, v),
right_color = Mathx.Lerp(down.vcolor, up_right.vcolor, v);
FillLine(left_color, right_color, (int)(xs + 0.5f), (int)(xe + 0.5f), (int)y, 0);
}
else if (draw_mode == DrawMode.Texture)
{
var v = (xe - xs == 0) ? 0 : (xe - xs) / (up_right.point.x - up_left.point.x);
var left = Mathx.Lerp(down, up_left, v);
var right = Mathx.Lerp(down, up_right, v);
VFillLine(left, right, (int)y);
}
else
{
Program.main.DrawLine((int)xs, (int)xe, (int)y, currentColor);
}
xs += dxy_left;
xe += dxy_right;
}
}
public void Triangle(Vertex p0, Vertex p1, Vertex p2)
{
if (draw_mode == DrawMode.Wireframe || draw_mode == DrawMode.WireframeWithoutCulling || draw_mode == DrawMode.Tex_Wire || draw_mode == DrawMode.GouraudShading)
{
Program.main.DrawLine(p0, p1);
Program.main.DrawLine(p1, p2);
Program.main.DrawLine(p2, p0);
if (draw_mode == DrawMode.Wireframe || draw_mode == DrawMode.WireframeWithoutCulling)
{
return;
}
}
if (p0.point.y == p1.point.y) // 0 1 为平
{
if (p0.point.y < p2.point.y) //平顶 2为底
{
TriangleT(p2, p0, p1);
}
else //平底 2为顶
{
TriangleD(p2, p0, p1);
}
}
else if (p0.point.y == p2.point.y) //0 2 为平
{
if (p0.point.y < p1.point.y) //平1顶
{
TriangleT(p1, p0, p2);
}
else//平1底
{
TriangleD(p1, p0, p2);
}
}
else if (p1.point.y == p2.point.y) //1,2 为平
{
if (p1.point.y < p0.point.y)
{//平0顶
TriangleT(p0, p1, p2);
}
else
{//平0底
TriangleD(p0, p1, p2);
}
}
else
{//分割三角形
Vertex top, bottom, middle;
if (p0.point.y > p1.point.y && p1.point.y > p2.point.y)
{
top = p2;
middle = p1;
bottom = p0;
}
else if (p2.point.y > p1.point.y && p1.point.y > p0.point.y)
{
top = p0;
middle = p1;
bottom = p2;
}
else if (p1.point.y > p0.point.y && p0.point.y > p2.point.y)
{
top = p2;
middle = p0;
bottom = p1;
}
else if (p2.point.y > p0.point.y && p0.point.y > p1.point.y)
{
top = p1;
middle = p0;
bottom = p2;
}
else if (p0.point.y > p2.point.y && p2.point.y > p1.point.y)
{
top = p1;
middle = p2;
bottom = p0;
}
else if (p1.point.y > p2.point.y && p2.point.y > p0.point.y)
{
top = p0;
middle = p2;
bottom = p1;
}
else
{
//三点共线
return;
}
//插值求中间点x
var middlex = (middle.point.y - top.point.y) * (bottom.point.x - top.point.x) / (bottom.point.y - top.point.y) + top.point.x;
float dy = middle.point.y - top.point.y;
float t = dy / (bottom.point.y - top.point.y);//插值生成左右顶点
Vertex newMiddle = new Vertex(new Vector3(middlex, middle.point.y, 0));
var f = (top.point.y - middle.point.y) / (top.point.y - bottom.point.y);
newMiddle = Mathx.Lerp(top, bottom, f);
Vertex left = middlex > middle.point.x ? middle : newMiddle;
Vertex right = middlex < middle.point.x ? middle : newMiddle;
////平底
TriangleD(top, left, right);
////平顶
TriangleT(bottom, left, right);
}
}
