// 平底三角绘制
private static void DrawTriangleFlatBottom(DrawContext left, DrawContext right, DrawContext middle, Renderer renderer)
{
if (left.winPos.x < right.winPos.x)
{
// noops
}
else
{
var t = left;
left = right;
right = t;
}
var dy = (int)(left.winPos.y - (int)middle.winPos.y);
for (int i = 0; i < dy; i++)
{
var t = (float)i / dy;
var line_left = Lerp(left, middle, t);
var line_right = Lerp(right, middle, t);
ScanLine(line_left, line_right, (int)line_left.winPos.y, renderer);
}
}
// 片段上下文的Y左边排序 private static int compareDc(DrawContext a, DrawContext b) => (a.winPos.y < b.winPos.y ? -1 : 1);
public void ComputeDepth(DrawContext dc)
{ // 计算[0.0~1.0]范围的深度
dc.depth = dc.clipPos.w / Cam.far;
}
