gamesalad problems

PROBLEM SOLVING IN GAMESALAD A major issue we had during this project was making the parallax scrolling background. At ﬁrst, we thought we had it covered. It seemed simple: we’d drag in 20 odd instances of the same background , line them up in an equal alignment horizontally leading off towards the left side of the screen and add a move behavior to that one background actor a the 180 degree direction and watch as all the instances moved, in sync, at the same speed. Perfect. It was just like our paper prototype, the background would be rolled through the screen the old fashioned way. There we were sitting there ready to add to our fantastic idea, naively assuming that it was entirely possibly just to loop the occurrence of the background instances, when it occurred to us that our background wasn’t rolling too smoothly and it lagged the simply yellow rectangle, that at the timed we called Chad. This was because all the instances of the background and later, the buildings over the top were causing an overload of data and we realised that if we added anymore assets in, the game would be more and more likely to crash frequently. There had to be a way to decrease the number of instances. We understood that the problem was that too many instances of the background were present at once; as the instances that had passed through the screen made an exit off the left side, they just carried on going, meaning that they were inevitably still in the game. We needed to destroy them so that once they were gone, they were gone. We came to the conclusion that creating an actor purely just to destroy those instances and creating a spawning actor to renew these expulsions. Creating these actors seemed simple and I swiftly created a spawner and a destroyer and proceeded to add in the rules of when the destroyer destroys the background upon overlap, the spawner spawns a new background. The cycle and correspondence between the time that the background’s spawned and destroyed was not equal and the backgrounds and buildings were being destroyed and spawned over each other, on screen, in a big mess. The spawner needed further indication of when the backgrounds were meeting the destroyer. A well placed attribute was required here and I later began to understand whilst creating future assets for the game that attributes are a great communicator for behaviors in GameSalad. I created an attribute exclusive to the background actor called “overlap”. When a background was to be destroyed this attribute’s value would be set to 1. A rule was then created in the spawner to show it that when the overlap attribute’s value was 1, a new instance should be spawned. This proved to be very effective and actors began to spawn and disappear better. However, once I added the buildings in over the top and made them move at a slower speed, I noticed that too many were spawning at one time and that they were overlapping each other. To ﬁx this, I created a simple debugging system with two integer attributes that added a point to themselves whenever an actor was spawned and destroyed and displayed them on screen so that I could count them and notice the difference.

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PROBLEM SOLVING IN GAMESALAD

A major issue we had during this project was making the parallax scrolling background. At first, we thought we had it covered. It seemed simple: we’d drag in 20 odd instances of the same background , line them up in an equal alignment horizontally leading off towards the left side of the screen and add a move behavior to that one background actor a the 180 degree direction and watch as all the instances moved, in sync, at the same speed. Perfect. It was just like our paper prototype, the background would be rolled through the screen the old fashioned way. There we were sitting there ready to add to our fantastic idea, naively assuming that it was entirely possibly just to loop the occurrence of the background instances, when it occurred to us that our background wasn’t rolling too smoothly and it lagged the simply yellow rectangle, that at the timed we called Chad.

This was because all the instances of the background and

later, the buildings over the top were causing an overload of data and we realised that if we added anymore assets in, the game would be more and more likely to crash frequently. There had to be a way to decrease the number of instances. We understood that the problem was that too many instances of the background were present at once; as the instances that had passed through the screen made an exit off the left side, they just carried on going, meaning that they were inevitably still in the game. We needed to destroy them so that once they were gone, they were gone. We came to the conclusion that creating an actor purely just to destroy those instances and creating a spawning actor to renew these expulsions.

Creating these actors seemed simple and I swiftly created a spawner and a destroyer and proceeded to add in the rules of when the destroyer destroys the background upon overlap, the spawner spawns a new background. The cycle and correspondence between the time that the background’s spawned and destroyed was not equal and the backgrounds and buildings were being destroyed and spawned over each other, on screen, in a big mess. The spawner needed further indication of when the backgrounds were meeting the destroyer. A well placed attribute was required here and I later began to understand whilst creating future assets for the game that attributes are a great communicator for behaviors in GameSalad. I created an attribute exclusive to the background actor called “overlap”. When a background was to be destroyed this attribute’s value would be set to 1. A rule was then created in the spawner to show it that when the overlap attribute’s value was 1, a new instance should be spawned.

This proved to be very effective and actors began to spawn and disappear better. However, once I added the buildings in over the top and made them move at a slower speed, I noticed that too many were spawning at one time and that they were overlapping each other. To fix this, I created a simple debugging system with two integer attributes that added a point to themselves whenever an actor was spawned and destroyed and displayed them on screen so that I could count them and notice the difference.

The only further issue we had with this scrolling technique was firstly, shrinking the buildings to the correct size so that they spawned correctly in the game, an issue that arose from the fact that we saved the PNGs from Photoshop in the wrong sizes. Secondly, there was a gap between the spawned buildings on screen and the newly spawned buildings coming on to the screen but this was simply fixed by altering their position on the x axis.