Update privacy_policy.md

privacy_policy.md

@@ -1,25 +1,113 @@
-# Privacy Policy for Hydrangea VolumeVibe
+# For every boid . . .
+for each boid (boid):
 
-This Privacy Policy describes how I, Acan Xie, handle information collected from users of my iOS mobile application (the "App").
+    # Zero all accumulator variables (can't do this in one line in C)
+​    xpos_avg, ypos_avg, xvel_avg, yvel_avg, neighboring_boids, close_dx, close_dy = 0
 
-**Information I Do Not Collect**
+    # For every other boid in the flock . . .
+​    for each other boid (otherboid):
 
-I do not collect any personal information or user data through the App. This includes but is not limited to:
+        # Compute differences in x and y coordinates
+​        dx = boid.x - otherboid.x
+​        dy = boid.y - otherboid.y
 
-- Name
-- Email address
-- Phone number
-- Device information
-- Usage data
+        # Are both those differences less than the visual range?
+​        if (abs(dx)<visual_range and abs(dy)<visual_range):  
 
-**Third-Party Services**
+            # If so, calculate the squared distance
+​            squared_distance = dx*dx + dy*dy
 
-I do not integrate any third-party services that collect user data or personal information within my App.
+            # Is squared distance less than the protected range?
+​            if (squared_distance < protected_range_squared):
 
-**Changes to This Privacy Policy**
+                # If so, calculate difference in x/y-coordinates to nearfield boid
+​                close_dx += boid.x - otherboid.x 
+​                close_dy += boid.y - otherboid.y
 
-I may update this Privacy Policy from time to time. Any changes will be reflected in the App's updated Privacy Policy.
+            # If not in protected range, is the boid in the visual range?
+​            else if (squared_distance < visual_range_squared):
 
-**Contact Me**
+                # Add other boid's x/y-coord and x/y vel to accumulator variables
+​                xpos_avg += otherboid.x 
+​                ypos_avg += otherboid.y 
+​                xvel_avg += otherboid.vx
+​                yvel_avg += otherboid.vy
 
-If you have any questions about this Privacy Policy, please contact me at [email protected].
+                # Increment number of boids within visual range
+​                neighboring_boids += 1 
+
+
+    # If there were any boids in the visual range . . .            
+​    if (neighboring_boids > 0): 
+
+        # Divide accumulator variables by number of boids in visual range
+​        xpos_avg = xpos_avg/neighboring_boids 
+​        ypos_avg = ypos_avg/neighboring_boids
+​        xvel_avg = xvel_avg/neighboring_boids
+​        yvel_avg = yvel_avg/neighboring_boids
+
+        # Add the centering/matching contributions to velocity
+​        boid.vx = (boid.vx + 
+​                   (xpos_avg - boid.x)*centering_factor + 
+​                   (xvel_avg - boid.vx)*matching_factor)
+
+​        boid.vy = (boid.vy + 
+​                   (ypos_avg - boid.y)*centering_factor + 
+​                   (yvel_avg - boid.vy)*matching_factor)
+
+    # Add the avoidance contribution to velocity
+​    boid.vx = boid.vx + (close_dx*avoidfactor)
+​    boid.vy = boid.vy + (close_dy*avoidfactor)
+
+
+    # If the boid is near an edge, make it turn by turnfactor
+    # (this describes a box, will vary based on boundary conditions)
+​    if outside top margin:
+​        boid.vy = boid.vy + turnfactor
+​    if outside right margin:
+​        boid.vx = boid.vx - turnfactor
+​    if outside left margin:
+​        boid.vx = boid.vx + turnfactor
+​    if outside bottom margin:
+​        boid.vy = boid.vy - turnfactor
+
+​    ##############################################################
+    ### ECE 5730 students only - dynamically update bias value ###
+​    ##############################################################
+    # biased to right of screen
+​    if (boid in scout group 1): 
+​        if (boid.vx > 0):
+​            boid.biasval = min(maxbias, boid.biasval + bias_increment)
+​        else:
+​            boid.biasval = max(bias_increment, boid.biasval - bias_increment)
+    # biased to left of screen
+​    else if (boid in scout group 2): # biased to left of screen
+​        if (boid.vx < 0):
+​            boid.biasval = min(maxbias, boid.biasval + bias_increment)
+​        else:
+​            boid.biasval = max(bias_increment, boid.biasval - bias_increment)
+​    ##############################################################
+
+    # If the boid has a bias, bias it!
+    # biased to right of screen
+​    if (boid in scout group 1):
+​        boid.vx = (1 - boid.biasval)*boid.vx + (boid.biasval * 1)
+    # biased to left of screen
+​    else if (boid in scout group 2):
+​        boid.vx = (1 - boid.biasval)*boid.vx + (boid.biasval * (-1))
+
+    # Calculate the boid's speed
+    # Slow step! Lookup the "alpha max plus beta min" algorithm
+​    speed = sqrt(boid.vx*boid.vx + boid.vy*boid.vy)
+
+    # Enforce min and max speeds
+​    if speed < minspeed:
+​        boid.vx = (boid.vx/speed)*minspeed
+​        boid.vy = (boid.vy/speed)*minspeed
+​    if speed > maxspeed:
+​        boid.vx = (boid.vx/speed)*maxspeed
+​        boid.vy = (boid.vy/speed)*maxspeed
+
+    # Update boid's position
+​    boid.x = boid.x + boid.vx
+​    boid.y = boid.y + boid.vy