Question

Getting this error in Xcode 4. I am reading a book which uses 0.99.5 I think and I am using the 1.0.0 framework for cocos2d.

error: Semantic Issue: Assigning to ‘CGPoint’ (aka ‘struct CGPoint’) from incompatible type ‘double’

on this line

playerVelocity = playerVelocity.x * dec + acceleration.x * sens;

Any ideas.

Full code

float dec = 0.4f; //lower = quicker to change direction;
float sens = 6.0f; //higher more sensitive;
float maxVel = 100;

playerVelocity = playerVelocity.x * dec + acceleration.x * sens;

if(playerVelocity.x > maxVel)
{

}
else if(playerVelocity.x < - maxVel)
{
    playerVelocity.x = - maxVel;
}

Answer 1

playerVelocity is a vector, so you should assign a value to it like this:

playerVelocity = ccp(playerVelocity.x * dec + acceleration.x * sens, 0);

ccp macro will build a vector for you with the two component you specify. I gave 0 as y component, feel free to change this value as you need.