eroder.py 文件源码

def _sort(self, expfact):
        # keep unique vertices only by creating a set and sort first on x then on y coordinate
        # using rather slow python sort but couldn;t wrap my head around np.lexsort
        verts = sorted(list({ tuple(t) for t in self.center[::] }))
        x = set(c[0] for c in verts)
        y = set(c[1] for c in verts)
        nx = len(x)
        ny = len(y)
        self.minx = min(x)
        self.maxx = max(x)
        self.miny = min(y)
        self.maxy = max(y)
        xscale = (self.maxx-self.minx)/(nx-1)
        yscale = (self.maxy-self.miny)/(ny-1)
        # note: a purely flat plane cannot be scaled 
        if (yscale != 0.0) and (abs(xscale/yscale) - 1.0 > 1e-3):
            raise ValueError("Mesh spacing not square %d x %d  %.4f x %4.f"%(nx,ny,xscale,yscale))
        self.zscale = 1.0
        if abs(yscale) > 1e-6 :
            self.zscale = 1.0/yscale

        # keep just the z-values and null any ofsset
        # we might catch a reshape error that will occur if nx*ny != # of vertices (if we are not dealing with a heightfield but with a mesh with duplicate x,y coords, like an axis aligned cube
        self.center = np.array([c[2] for c in verts],dtype=np.single).reshape(nx,ny)
        self.center = (self.center-np.amin(self.center))*self.zscale
        if self.rainmap is not None:
            rmscale = np.max(self.center)
            self.rainmap = expfact + (1-expfact)*(self.center/rmscale)