Create sketch_2020_04_03b.pyde

2020/sketch_2020_04_03b/sketch_2020_04_03b.pyde

@@ -0,0 +1,75 @@
+"""
+Bézier Curves Cubic (Interactive)
+https://rosettacode.org/wiki/Bitmap/B%C3%A9zier_curves/Cubic#Processing
+Processing 3.4
+2020-04 Alexandre Villares
+
+Task:
+
+Using the data storage type for raster images and a draw_line function,
+draw a cubic bezier curve.
+"""
+
+# A working sketch with movable anchor and control points.
+# It can be run online :
+# https://www.openprocessing.org/sketch/846556/
+
+x = [0] * 4
+y = [0] * 4
+permitDrag = -1
+ 
+def setup() :
+    size(300, 300)
+    smooth()
+    # startpoint coordinates
+    x[0] = x[1] = 50
+    y[0] = 50
+    y[1] = y[2] = 150
+    x[2] = x[3] = 250
+    y[3] = 250
+  
+def draw() :
+    background(255)
+    noFill()
+    stroke(0, 0, 255)
+    bezier(x[1], y[1], x[0], y[0], x[3], y[3], x[2], y[2])
+    # the bezier handles
+    strokeWeight(1)
+    stroke(100)
+    line(x[0], y[0], x[1], y[1])
+    line(x[2], y[2], x[3], y[3])
+    # the anchor and control points
+    stroke(0)
+    fill(0)
+    for i in range(4):
+        if i == 0 or i == 3:
+            fill(255, 100, 10)
+            rectMode(CENTER)
+            rect(x[i], y[i], 5, 5)
+        else:
+            fill(0)
+            ellipse(x[i], y[i], 5, 5)
+    # permit dragging 
+    if permitDrag >= 0:
+            x[permitDrag] = mouseX
+            y[permitDrag] = mouseY    
+ 
+def mouseReleased():
+    global permitDrag
+    permitDrag = -1
+    
+def mousePressed () :
+    global permitDrag
+    for i in range(4):
+        if (x[i]-5 <= mouseX <= x[i]+10 and 
+            y[i]-5 <= mouseY <= y[i]+10):
+            permitDrag = i
+            break
+        
+# hand cursor when over dragging over points
+def mouseMoved () :
+    cursor(ARROW)
+    for i in range(4):
+        if (x[i]-5 <= mouseX <= x[i]+10 and 
+            y[i]-5 <= mouseY <= y[i]+10):
+            cursor(HAND)