exercises.py

import cv2
import numpy as np
import mediapipe as mp

# draw landmarks & connections to screen
mp_drawing = mp.solutions.drawing_utils
# import Pose model
mp_pose = mp.solutions.pose

# Function to calculate the angle between three points
def calc_angle(x, y, z):
    x = np.array(x)
    y = np.array(y)
    z = np.array(z)

    radians = np.arctan2(z[1]-y[1], z[0]-y[0]) - np.arctan2(x[1]-y[1], x[0]-y[0])
    angle = np.abs(radians * 180.0 / np.pi)

    if angle > 180.0:
        angle = 360 - angle

    return angle

# Recognize curl function
def recognise_curl(detection):
    global counter
    global state
    global feedback
    global range_flag
    
    try:
        landmarks = detection.pose_landmarks.landmark
        
        # left arm
        left_wrist = [landmarks[mp_pose.PoseLandmark.LEFT_WRIST.value].x, landmarks[mp_pose.PoseLandmark.LEFT_WRIST.value].y]
        left_shoulder = [landmarks[mp_pose.PoseLandmark.LEFT_SHOULDER.value].x, landmarks[mp_pose.PoseLandmark.LEFT_SHOULDER.value].y]
        left_elbow = [landmarks[mp_pose.PoseLandmark.LEFT_ELBOW.value].x, landmarks[mp_pose.PoseLandmark.LEFT_ELBOW.value].y] 

        # right arm
        right_wrist = [landmarks[mp_pose.PoseLandmark.RIGHT_WRIST.value].x, landmarks[mp_pose.PoseLandmark.RIGHT_WRIST.value].y]
        right_shoulder = [landmarks[mp_pose.PoseLandmark.RIGHT_SHOULDER.value].x, landmarks[mp_pose.PoseLandmark.RIGHT_SHOULDER.value].y]
        right_elbow = [landmarks[mp_pose.PoseLandmark.RIGHT_ELBOW.value].x, landmarks[mp_pose.PoseLandmark.RIGHT_ELBOW.value].y]
        
        left_elbow_angle = calc_angle(left_shoulder, left_elbow, left_wrist)
        right_elbow_angle = calc_angle(right_shoulder, right_elbow, right_wrist)
        
        # down state
        if left_elbow_angle > 160 and right_elbow_angle > 160:
            if not range_flag:
                feedback = 'Did not curl completely.'
            else:
                feedback = 'Good rep!'
            state = 'Down'
            
        # not fully curled
        elif (left_elbow_angle > 50 and right_elbow_angle > 50) and state == 'Down':
            range_flag = False
            feedback = ''
            
        # up state
        elif (left_elbow_angle < 30 and right_elbow_angle < 30) and state == 'Down':
            state = 'Up'
            feedback = ''
            range_flag = True
            counter += 1
    
    except:
        pass

# Recognize squat function
def recognise_squat(detection):
    global counter
    global state
    global feedback

    try:
        landmarks = detection.pose_landmarks.landmark
        
        # GET COORDINATES
        left_hip = [landmarks[mp_pose.PoseLandmark.LEFT_HIP.value].x, landmarks[mp_pose.PoseLandmark.LEFT_HIP.value].y]
        left_knee = [landmarks[mp_pose.PoseLandmark.LEFT_KNEE.value].x, landmarks[mp_pose.PoseLandmark.LEFT_KNEE.value].y]
        left_heel = [landmarks[mp_pose.PoseLandmark.LEFT_HEEL.value].x, landmarks[mp_pose.PoseLandmark.LEFT_HEEL.value].y]
        
        right_hip = [landmarks[mp_pose.PoseLandmark.RIGHT_HIP.value].x, landmarks[mp_pose.PoseLandmark.RIGHT_HIP.value].y]
        right_knee = [landmarks[mp_pose.PoseLandmark.RIGHT_KNEE.value].x, landmarks[mp_pose.PoseLandmark.RIGHT_KNEE.value].y]
        right_heel = [landmarks[mp_pose.PoseLandmark.RIGHT_HEEL.value].x, landmarks[mp_pose.PoseLandmark.RIGHT_HEEL.value].y]
        
        left_shoulder = [landmarks[mp_pose.PoseLandmark.LEFT_SHOULDER.value].x, landmarks[mp_pose.PoseLandmark.LEFT_SHOULDER.value].y]
        right_shoulder = [landmarks[mp_pose.PoseLandmark.RIGHT_SHOULDER.value].x, landmarks[mp_pose.PoseLandmark.RIGHT_SHOULDER.value].y]

        left = calc_angle(left_hip, left_knee, left_heel)
        right = calc_angle(right_hip, right_knee, right_heel)
        
        #POSE CHECKING 1: Knees bending inwards    
        shoulder_dist = left_shoulder[0] - right_shoulder[0]
        knee_dist = left_knee[0] - right_knee[0]

        if shoulder_dist - knee_dist > 0.04:
            feedback = 'Open up your knees further apart to shoulder width!'
        else:
            feedback = ''

        # standing up
        if left > 170 and right > 170:
            state = "Up"
            
        if left < 165 and right < 165:
            feedback = 'Almost there... lower until height of hips!'
            
        if left < 140 and right < 140 and state == "Up":
            state = "Down"
            counter += 1
            
        if state == "Down":
            feedback = 'Good rep!'
    
    except:
        pass


# Recognize situp function
def recognise_situp(detection):
    global counter
    global state
    global feedback
    global range_flag
    global halfway

    try: 
        landmarks = detection.pose_landmarks.landmark
        
        left_hip = [landmarks[mp_pose.PoseLandmark.LEFT_HIP.value].x, landmarks[mp_pose.PoseLandmark.LEFT_HIP.value].y]
        left_knee = [landmarks[mp_pose.PoseLandmark.LEFT_KNEE.value].x, landmarks[mp_pose.PoseLandmark.LEFT_KNEE.value].y]
        left_heel = [landmarks[mp_pose.PoseLandmark.LEFT_HEEL.value].x, landmarks[mp_pose.PoseLandmark.LEFT_HEEL.value].y]
        left_shoulder = [landmarks[mp_pose.PoseLandmark.LEFT_SHOULDER.value].x, landmarks[mp_pose.PoseLandmark.LEFT_SHOULDER.value].y]

        # CALCULATE ANGLES 
        angle_knee = calc_angle(left_hip, left_knee, left_heel)
        angle_body = calc_angle(left_shoulder, left_hip, left_knee)

        if (angle_body < 80 and angle_body > 50) and state == "Down": #Half-way there (Used for checking bad situps)
            halfway = True

        if angle_body < 40 and state == "Down": #Complete situp
            state = "Up"
            range_flag = True
            
        if angle_body > 90 and angle_knee < 60: #Resting position;to check if situp was done properly
            state = "Down"
            
            if halfway: #Check if a rep was attempted
                if range_flag: #Check if a proper rep was performed
                    counter += 1
                    feedback = "Good repetition!"
                else:
                    feedback = "Did not perform sit up completely."
                range_flag = False #Reset vars
                halfway = False
                
        if angle_knee > 70: #Triggers anytime the legs are not tucked in
            feedback = "Keep legs tucked in closer"

    except: 
        pass

#Recognize pushup function
def recognize_pushup(detection):
    global counter
    global state
    global feedback
    global range_flag

    try:
        landmarks = detection.pose_landmarks.landmark

        #Get coordinates
        left_shoulder = [landmarks[mp_pose.PoseLandmark.LEFT_SHOULDER.value].x, landmarks[mp_pose.PoseLandmark.LEFT_SHOULDER.value].y]
        left_elbow = [landmarks[mp_pose.PoseLandmark.LEFT_ELBOW.value].x, landmarks[mp_pose.PoseLandmark.LEFT_ELBOW.value].y]
        left_wrist = [landmarks[mp_pose.PoseLandmark.LEFT_WRIST.value].x, landmarks[mp_pose.PoseLandmark.LEFT_WRIST.value].y]

        right_shoulder = [landmarks[mp_pose.PoseLandmark.RIGHT_SHOULDER.value].x, landmarks[mp_pose.PoseLandmark.RIGHT_SHOULDER.value].y]
        right_elbow = [landmarks[mp_pose.PoseLandmark.RIGHT_ELBOW.value].x, landmarks[mp_pose.PoseLandmark.RIGHT_ELBOW.value].y]
        right_wrist = [landmarks[mp_pose.PoseLandmark.RIGHT_WRIST.value].x, landmarks[mp_pose.PoseLandmark.RIGHT_WRIST.value].y]

        left_elbow_angle = calc_angle(left_shoulder, left_elbow, left_wrist)
        right_elbow_angle = calc_angle(right_shoulder, right_elbow, right_wrist)

        #Down state
        if left_elbow_angle < 90 and right_elbow_angle < 90:
            range_flag = True
            state = "Down"
            feedback = "Push upwards!"

        elif left_elbow_angle >= 100 and right_elbow_angle >= 100 and state == "Down":
            range_flag = False
            feedback = "Go Lower!."


        #Up state
        elif left_elbow_angle > 160 and right_elbow_angle > 160 and state == "Down":
            if range_flag:  
                state = "Up"
                counter += 1
                feedback = "Good push-up!"
            else:
                feedback = "Did not push up completely."

        else:
            feedback = "keep going!"
    except:
        pass


def reset_exercise_state():
    global counter
    global state
    global feedback
    global range_flag
    global halfway
    counter = 0
    state = 'Down'
    feedback = ''
    range_flag = True



# initialise variables
counter = 0
state = 'Down'
range_flag = True
halfway = False
feedback = ''

# Start video capture
def generate_frames(user_choice):
    cap = cv2.VideoCapture(0, cv2.CAP_DSHOW)  

    # Mediapipe Pose model instance
    with mp_pose.Pose(min_detection_confidence=0.5, min_tracking_confidence=0.5) as pose:
        while cap.isOpened():
            success, frame = cap.read()
            if not success:
                break

            # Mirror frame
            frame = cv2.flip(frame, 1)
            # Recolor image from BGR to RGB
            image = cv2.cvtColor(frame, cv2.COLOR_BGR2RGB)
            image.flags.writeable = False
            
            # Pose detection
            detection = pose.process(image)
            # Recolor image from RGB back to BGR
            image = cv2.cvtColor(image, cv2.COLOR_RGB2BGR)
            image.flags.writeable = True

            # Render detections
            mp_drawing.draw_landmarks(image, detection.pose_landmarks, mp_pose.POSE_CONNECTIONS,
                                      mp_drawing.DrawingSpec(color=(245,117,66), thickness=2, circle_radius=2), 
                                      mp_drawing.DrawingSpec(color=(245,66,230), thickness=2, circle_radius=2))
            
            # Recognise particular exercise based on user input
            if user_choice == 1:
                recognise_squat(detection)
            elif user_choice == 2:
                recognise_curl(detection)
            elif user_choice == 3:
                recognise_situp(detection)
            elif user_choice == 4:
                recognize_pushup(detection)
            
            # Status box setup
            cv2.rectangle(image, (0,0), (int(cap.get(3)), 60), (0,0,0), -1)
            cv2.putText(image, "REPS:", (10, 20), 
                        cv2.FONT_HERSHEY_SIMPLEX, 0.4, (255,255,255), 1, cv2.LINE_AA) # font, size, color, line width, line type
            
            cv2.putText(image, "STATE:", (150, 20), 
                        cv2.FONT_HERSHEY_SIMPLEX, 0.4, (255,255,255), 1, cv2.LINE_AA)
            
            cv2.putText(image, "FEEDBACK:", (300, 20), 
                        cv2.FONT_HERSHEY_SIMPLEX, 0.4, (255,255,255), 1, cv2.LINE_AA)
            
            cv2.putText(image, str(counter), (10, 50), 
                        cv2.FONT_HERSHEY_SIMPLEX, 0.4, (255,255,255), 1, cv2.LINE_AA)
            
            cv2.putText(image, state, (150, 50), 
                        cv2.FONT_HERSHEY_SIMPLEX, 0.4, (255,255,255), 1, cv2.LINE_AA)
            
            cv2.putText(image, feedback, (300, 50), 
                        cv2.FONT_HERSHEY_SIMPLEX, 0.45, (255,255,255), 1, cv2.LINE_AA)
            
            ret, buffer = cv2.imencode('.jpg', image)
            frame = buffer.tobytes()
            yield (b'--frame\r\n'
                   b'Content-Type: image/jpeg\r\n\r\n' + frame + b'\r\n')

    cap.release()
    cv2.destroyAllWindows()