private void DrawSpansBetweenEdges(Edge e1, Edge e2)
{
// calculate difference between the y coordinates
// of the first edge and return if 0
float e1ydiff = (float)(e1.Y2 - e1.Y1);
if(e1ydiff == 0.0f)
return;
// calculate difference between the y coordinates
// of the second edge and return if 0
float e2ydiff = (float)(e2.Y2 - e2.Y1);
if(e2ydiff == 0.0f)
return;
// calculate differences between the x coordinates
// and colors of the points of the edges
float e1xdiff = (float)(e1.X2 - e1.X1);
float e2xdiff = (float)(e2.X2 - e2.X1);
MyColor e1colordiff = e1.Color2 - e1.Color1;
MyColor e2colordiff = e2.Color2 - e2.Color1;
// calculate factors to use for interpolation
// with the edges and the step values to increase
// them by after drawing each span
float factor1 = (float)(e2.Y1 - e1.Y1) / e1ydiff;
float factorStep1 = 1.0f / e1ydiff;
float factor2 = 0.0f;
float factorStep2 = 1.0f / e2ydiff;
// loop through the lines between the edges and draw spans
for(int y = e2.Y1; y < e2.Y2; y++)
{
// create and draw span
Span span = new Span(e1.Color1 + (e1colordiff * factor1),
e1.X1 + (int)(e1xdiff * factor1),
e2.Color1 + (e2colordiff * factor2),
e2.X1 + (int)(e2xdiff * factor2)
);
DrawSpan(span, y);
// increase factors
factor1 += factorStep1;
factor2 += factorStep2;
}
}
private void RemoveSpansBetweenEdges(Edge e1, Edge e2)
{
float e1ydiff = (float)(e1.Y2 - e1.Y1);
if (e1ydiff == 0.0f)
return;
float e2ydiff = (float)(e2.Y2 - e2.Y1);
if (e2ydiff == 0.0f)
return;
float e1xdiff = (float)(e1.X2 - e1.X1);
float e2xdiff = (float)(e2.X2 - e2.X1);
float factor1 = (float)(e2.Y1 - e1.Y1) / e1ydiff;
float factorStep1 = 1.0f / e1ydiff;
float factor2 = 0.0f;
float factorStep2 = 1.0f / e2ydiff;
// loop through the lines between the edges and draw spans
for (int y = e2.Y1; y < e2.Y2; y++)
{
// create and draw span
Span span = new Span(e1.X1 + (int)(e1xdiff * factor1),
e2.X1 + (int)(e2xdiff * factor2)
);
RemoveSpan(span, y);
// increase factors
factor1 += factorStep1;
factor2 += factorStep2;
}
}
private void DrawSpan(Span span, int y)
{
int xdiff = span.X2 - span.X1;
if (xdiff == 0)
return;
MyColor colordiff = span.Color2 - span.Color1;
float factor = 0.0f;
float factorStep = 1.0f / (float)xdiff;
// draw each pixel in the span
for (int x = span.X1; x < span.X2; x++)
{
SetPixel(x, y, span.Color1 + (colordiff * factor));
factor += factorStep;
}
}
private void RemoveSpan(Span span, int y)
{
int xdiff = span.X2 - span.X1;
if (xdiff == 0)
return;
float factor = 0.0f;
float factorStep = 1.0f / (float)xdiff;
// draw each pixel in the span
for (int x = span.X1; x < span.X2; x++)
{
Cl3DModel model = Map[x, y].GetManagedModel();
model.RemovePointFromModel(Map[x, y]);
Map[x, y] = null;
factor += factorStep;
}
}
