I am trying to create a side scroller and I am having trouble setting the Y coordinates of my objects to random values.
I call my objects platforms. I want each of the platform to appear at different Y coordinates, and believe that my approach was the right way of doing this. But it isn't working so well.
All the Y coordinates log out the same number and I am not entirely sure why? I mean I am clearly adding spacing when I am instantiating them.
Also one thing I noticed was, if i don't add the timer and call the moving method they do show up in the right place. so it may be something inbetween calling the function.
Also another problem I found was when I call in the platforms again , only one of the platforms follows what the slide functions asks it to do, the other 2 follows the points, however does not react to anything else.
Any help is super appreciated!
//
// C4WorkSpace.m
// TheGame
//
//
#import "C4Workspace.h"
@implementation C4WorkSpace {
C4Shape *player ; // player
CGPoint p, move; // CG point for moving platforms && Players
int speed; // Speed of the platforms
C4Timer *timer; // Timer
NSMutableArray *platforms; // Platform Array
}
-(void)setup {
speed = 5; // Speed Limit
p = CGPointMake(self.canvas.width, 400); // Making 2 coordinates for the platform shape to follow
move = CGPointMake(0, 0); // Making 2 coordinates for the user shape to follow
platforms = [NSMutableArray array]; // Pointer of Array for platforms
// Generating shapes
for ( int i = 0; i < 3; i++)
{
C4Shape * s = [C4Shape rect:CGRectMake(0, 400, 50, [C4Math randomInt:50])]; // Making the platform
p.x = self.canvas.width; // x - coordinate for the platforms
p.y += 100; // y - coordinate of the platforms
s.center = p; // The Center of the Circle is P
[platforms addObject:s]; // Adding platforms to the platforms array
[self.canvas addShape:platforms[i]]; // Adding an instance of it
timer = [C4Timer automaticTimerWithInterval:1.0f/30 target:self method:@"slide" repeats:YES]; // Timer to shoot it off ever frame
}
player = [C4Shape ellipse:CGRectMake(0, 0, 50, 50)]; // The shape of the player
[self.canvas addSubview:player]; // Adding an instance of the player
}
//Moving the platform
-(void) slide {
//Calling the platforms again to add movement
for (C4Shape *s in platforms){
// Adding boundries
if (p.x <= 0 ) {
p.x = self.canvas.width; // if it's smaller than the width of the cavas auto transport
p.y = [C4Math randomInt:self.canvas.height]; // choose a different y coordinate for each
}
p.x-= speed; // Adding accelaration
C4Log(@"The Y is .%2f", p.y); // Logging the problem
s.center = p; // making the shape follow the point
}
}
-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch *place = [[event allTouches] anyObject]; // Get touches
move = [place locationInView:place.view]; // Gets the location of the current mouse point
player.center = move; // folllowing the move point
[self collisionCheck]; // collision check
}
-(void) collisionCheck {
//currently empty!
}
@end
Ben's answer about updating only the p variable is right. What you want to do is check the center point of each individual shape and manipulate that.
The reason for the error is this logic:
for(every shape in platforms) {
check to see if a point p is off the screen
if it is, then change its value to a random number
then update the speed of p
set the centerpoint of the current shape to p
}
The above logic is what you've coded here:
for (C4Shape *s in platforms) {
if (p.x <= 0 ) {
p.x = self.canvas.width;
p.y = [C4Math randomInt:self.canvas.height];
}
p.x-= speed; // Adding accelaration
s.center = p; // making the shape follow the point
}
The problem with this is the line that says:
s.center = p; // making the shape follow the point
Because is sets ALL the centre points of the shapes to the same point. But, it is only the LAST point that makes a difference.
Your method should look like the following:
-(void) slide {
//Calling the platforms again to add movement
for (C4Shape *currentShape in platforms) {
CGPoint currentCenterPoint = currentShape.center;
if (currentCenterPoint.x <= 0 ) {
// if it's smaller than the width of the cavas auto transport
currentCenterPoint.x = self.canvas.width;
// choose a different y coordinate for each
currentCenterPoint.y = [C4Math randomInt:self.canvas.height];
}
currentCenterPoint.x-= speed; //Adding accelaration
currentShape.center = currentCenterPoint;
}
}
Also, notice that this method renames the variables so the code is more readable. This is a good practice for helping to remember what's going on, and for other people to be able to read your code more easily.
NOTE: you're really close to being able to add this kind of functionality to a class of its own to make things simpler for yourself, good work!