void DrawTriangle(Point p1, Point p2, Point p3, WorkScene scene, Color color)
{
if (p1.y > p2.y)
{
Swap(ref p1, ref p2);
}
if (p1.y > p3.y)
{
Swap(ref p1, ref p3);
}
if (p2.y > p3.y)
{
Swap(ref p2, ref p3);
}
if (!scene.fill)
{
DrawLine(p1.x, p1.y, p2.x, p2.y, scene, color);
DrawLine(p2.x, p2.y, p3.x, p3.y, scene, color);
DrawLine(p3.x, p3.y, p1.x, p1.y, scene, color);
}
else
{
int total_height = (int)(p3.y - p1.y);
for (int i = 0; i < total_height; i++)
{
bool second_half = i > p2.y - p1.y || p2.y == p1.y;
int segment_height = second_half ? (int)(p3.y - p2.y) : (int)(p2.y - p1.y);
float alpha = (float)i / total_height;
float beta = (float)(i - (second_half ? p2.y - p1.y : 0)) / segment_height;
Point A = p1 + (p3 - p1) * alpha;
Point B = second_half ? p2 + (p3 - p2) * beta : p1 + (p2 - p1) * beta;
if (A.x > B.x)
{
Swap(ref A, ref B);
}
for (int j = (int)A.x; j <= B.x; j++)
{
double phi = B.x == A.x ? 1 : (j - A.x) / (B.x - A.x);
Point P = new Point(A) + new Point(B - A) * phi;
P.x = j; P.y = p1.y + i;
int idx = (int)(P.x + P.y * scene.bmp.Width);
if (P.x >= scene.bmp.Width || P.x < 0 || P.y >= scene.bmp.Height || P.y < 0 || new Line(scene.camera.eye, P).Length < scene.camera.near || new Line(scene.camera.eye, P).Length > scene.camera.far)
{
continue;
}
try
{
if (scene.zBuf[idx] < P.z)
{
scene.zBuf[idx] = (int)P.z;
scene.bmp.SetPixel((int)P.x, (int)P.y, color);
}
}
catch { }
}
}
}
}
void DrawLine(Point p1, Point p2, WorkScene scene, Color color)
{
double x1 = p1.x;
double y1 = p1.y;
double x2 = p2.x;
double y2 = p2.y;
bool steep = false;
if (Math.Abs(x1 - x2) < Math.Abs(y1 - y2))
{
Swap(ref x1, ref y1);
Swap(ref x2, ref y2);
steep = true;
}
if (x1 > x2)
{
Swap(ref x1, ref x2);
Swap(ref y1, ref y2);
}
int dx = (int)(x2 - x1);
int dy = (int)(y2 - y1);
int derror2 = Math.Abs(dy) * 2;
int error2 = 0;
int y = (int)y1;
for (int x = (int)x1; x <= x2; x++)
{
if (steep)
{
try
{
scene.bmp.SetPixel(y, x, color);
}
catch { }
}
else
{
try
{
scene.bmp.SetPixel(x, y, color);
}
catch { }
}
error2 += derror2;
if (error2 > dx)
{
y += (y2 > y1 ? 1 : -1);
error2 -= dx * 2;
}
}
}
void DrawTriangle(Triangle triangle, WorkScene scene)
{
DrawTriangle(triangle.Points[0], triangle.Points[1], triangle.Points[2], scene, triangle.Color);
}
public MainForm()
{
InitializeComponent();
scene = new WorkScene(PBox.Width, PBox.Height);
Redraw();
}
void DrawLine(double x1, double y1, double x2, double y2, WorkScene scene, Color color)
{
DrawLine(new Point(x1, y1, 0), new Point(x2, y2, 0), scene, color);
}