update core.imagelib

core/imagelib/sd/draw.py

@@ -0,0 +1,40 @@
+"""
+Signed distance drawing functions using numpy.
+"""
+
+import numpy as np
+from numpy import linalg as npla
+
+def circle_faded( hw, center, fade_dists ):
+    """
+    returns drawn circle in [h,w,1] output range [0..1.0] float32
+    
+    hw         = [h,w]                      resolution
+    center     = [y,x]                      center of circle
+    fade_dists = [fade_start, fade_end]     fade values
+    """
+    h,w = hw      
+    
+    pts = np.empty( (h,w,2), dtype=np.float32 )
+    pts[...,1] = np.arange(h)[None,:]
+    pts[...,0] = np.arange(w)[:,None]
+    pts = pts.reshape ( (h*w, -1) )
+
+    pts_dists = np.abs ( npla.norm(pts-center, axis=-1) )
+    
+    pts_dists = ( pts_dists - fade_dists[0] ) / fade_dists[1]
+    pts_dists = np.clip( 1-pts_dists, 0, 1)
+    
+    return pts_dists.reshape ( (h,w,1) ).astype(np.float32)
+    
+def random_circle_faded ( hw, rnd_state=None ):
+    if rnd_state is None:
+        rnd_state = np.random
+        
+    h,w = hw
+    hw_max = max(h,w)
+    fade_start = rnd_state.randint(hw_max)
+    fade_end = fade_start + rnd_state.randint(hw_max- fade_start)
+    
+    return circle_faded (hw, [ rnd_state.randint(h), rnd_state.randint(w) ], 
+                             [fade_start, fade_end] )