Hi All,
How difficult are the registration questions. never seen anything like it
anyways
Please could somebody help me with the following issue.
I control my sprite in box2d with the sneaky joystick and rotate the sprite accordingly.
However when i shoot lasers/bullets from the sprite i find that sometime the bullets go off direction .. i.e. not straight forward.
this only happens when I'm rotating the sprite and shooting at the same time. its like I'm waiting for box2d to catch up. after x amount of time it sorts itself out.
please see below the code i am using to rotate the sprite and shoot
Code:
- (void)movePlayer {
//move the player with joypad
CGPoint velocity = ccpMult(_hud->leftJoystick.velocity, 5);
if (velocity.x != 0)
{
b2Vec2 force = b2Vec2(0,0);
force = b2Vec2(velocity.x,velocity.y);
playerBody->SetLinearVelocity(force);
float bodyAngle = playerBody->GetAngle();
b2Vec2 toTarget = playerBody->GetPosition();
float desiredAngle = atan2f( -velocity.x, velocity.y );
float totalRotation = desiredAngle - bodyAngle;
while ( totalRotation < -180 * DEGTORAD ) totalRotation += 360 * DEGTORAD;
while ( totalRotation > 180 * DEGTORAD ) totalRotation -= 360 * DEGTORAD;
playerBody->SetTransform( playerBody->GetPosition(), desiredAngle );
}
if (velocity.x == 0)
{
playerBody->SetAwake(false) ;
}
}
- (void)LaserGun:(ccTime)dt {
for (b2Body* b = world->GetBodyList(); b; b = b->GetNext())
{
NSArray *players = [lh spritesWithTag:PLAYERSHIP];
for (playerShip in players) {
playerBody = [playerShip body];
b2Vec2 eyeOffset = b2Vec2(0, 0.5);
b2Vec2 eye = playerBody->GetWorldPoint(eyeOffset);
b2Vec2 target = eye - playerBody->GetWorldCenter();
target.Normalize();
target *= 20.0;
target = eye + target;
playerData * playerData = [playerShip customValueWithKey:@"data"];
playerData.eye = ccp(eye.x * [LevelHelperLoader pixelsToMeterRatio], eye.y * [LevelHelperLoader pixelsToMeterRatio]);
playerData.target = ccp(target.x * [LevelHelperLoader pixelsToMeterRatio], target.y * [LevelHelperLoader pixelsToMeterRatio]);
playerData.canSeePlayer = NO;
RaysCastCallback callback;
world->RayCast(&callback, eye, target);
if (callback.m_fixture)
{
playerData.target = ccp(callback.m_point.x * [LevelHelperLoader pixelsToMeterRatio],
callback.m_point.y * [LevelHelperLoader pixelsToMeterRatio]);
if (callback.m_fixture->GetBody() == monster1body)
{ playerData.canSeePlayer = TRUE;}
}
if(_hud->jumpButton.active)
{
if (CACurrentMediaTime() - playerData.lastShot > 0.1)
{
playerData.lastShot = CACurrentMediaTime();
// Create and position laser
b2Body *laserBody = [lh newBodyWithUniqueName:@"LaserBeam" world:world];
laserSprite = (LHSprite *)laserBody->GetUserData();
laserSprite.position = playerData.eye;
laserSprite.rotation = playerShip.rotation;
laserBody->SetTransform(b2Vec2(laserSprite.position.x/[LevelHelperLoader pixelsToMeterRatio],
laserSprite.position.y/[LevelHelperLoader pixelsToMeterRatio]),
CC_DEGREES_TO_RADIANS(-laserSprite.rotation));
// Make laser move
b2Vec2 laserVel = callback.m_point - eye;
laserVel.Normalize();
laserVel *= 20.0;
laserBody->SetLinearVelocity(laserVel);
if(!world->IsLocked())
{
b2Body* laserBody = [laserSprite body];
if(laserBody)
{
laserBody->SetLinearVelocity(laserVel);
}
}}}}}}
thanks
Thomas
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