flappy bird bouncing effect

ira_ira

Hi!! I want to achieve behaviour of my ball like in flappy bird game and here what I have

            float xpos = 200;
            float ypos = 50;
            float vy = 0;
            float gravity = 0.98;
            float bounce = -1;

            void setup() 
            {
              size(400,600);
              smooth();
              noStroke();
            }
            void draw() 
            {
              background(0);
              ellipse(xpos, ypos, 30, 30);
              vy += gravity;
              ypos += vy;
              if(ypos > height - 15)
              {
               ypos = height - 15;
              }
            }

            void keyPressed() {
              vy *= bounce;
            }

But behaviour is strange and its going down anyway. What is my mistake?

TfGuy44

Your code's fine. It behaves just like the bird would. What's the problem?

ira_ira

@TfCuy Try to do it longer and you will see that it's impossible to move ellipse higher than it was

TfGuy44

Ah! Ok. When you "bounce" your velocity suddenly changes direction. When you "flap", you actually gain some upward force - some to stop your decent, and some to make you go up. Instead of simply reversing the direction of the velocity when a key is pressed, try setting it to a fixed constant (-12 seems good).

ira_ira

@TfGuy44 that helped me! thank you very much!