I have the following scenario: player is in the middle of the screen and never moves from those coordinates. If I click with the mouse on the far right of the screen, the A* script kicks in and moves the background the player is on according with its own walkable/not walkable criteria, so for example if there is an obstacle in between the center of the screen where the player always is in the far right of the screen, the background correctly moves in the opposite direction And when needed moves around the obstacle, so you have the illusion of player walking, but instead only the background moves.
my problem is that I don't know how to rotate my player to simulate that he is following the path that the actual background is making. For example, in the beginning, the player is facing down. If I click on the right side of the screen, the player should face right. When an obstacle is present, the player should face the direction of the path around the obstacle and so on
but again technically my player never moves, so I don't know what coordinates should I have the atan2 use. In my mind I thought that the player should rotate toward the center of the next best hop in the array of best path created during the A* script, but for some reason I can't figure out the correct coordinates y and x for the atan2 command
I bet this is a simple thing I overlooked, but apparently my mind is in shutdown mode, so I can use a new fresh perspective :-)
thanks!
First, do not code in brain shutdown mode, this can save you lots of brainhurt time.
You don't need atan2() in this scenario, since your player is technically on a grid instead of on the screen. Give the player internal coordinates on the grid that will be updated as the player walks around the world, and use them in your A* script. The A* script generates a sequence of tiles the player should walk, thus you derive player's facing from current and next tile, for example, if the next tile to walk is adjacent upwards, you make the player face up and continue moving.
Related
i am creating an endless runner game and the player as to jump over an obstacle, and if he touches it he looses health. The current collision code is this:
if (man_mc.hitTestObject(crate_mc)) {
health--;
health_txt.text=health.toString();
which is inside a loop. But the problem is that my obstacles are triangles, so when you jump over them if you touch the 'hit box' or dimensions of the triangle you loose health. So how do i make it so the collision is only true if my player is touching the triangle. (and the triangle is a png with transparent background)
EDIT: I found that i could use hitTestPoint instead of hitTestObject but how do i know what co ordinates to put into the parameters?
I would abandon the use of hitTestObject() (or even hitTestPoint()) for collision detection. Instead, I'd use another algorithm for collision detection in your game
I'll assume your player is a (pretty) skinny box and you said that your obstacles are triangles. I'd first try using a basic method of checking if any of the triangle's points are within the player's bounding box. If it is, then you have a collision.
You could also go the other way and check if a player's points in the bounding box are within any triangle, but you may end up with an odd case where a triangle is poking in to the player, but none of the player's points are within the triangle (which can happen if a player gets a triangle right up between the legs >.> ). Also, by going triangle first, there are less points to check per player and triangle pair.
Note that using this simple method won't tell you how much intersection there is, but I'm guessing you may not need that, since you were using the hitTestObject() method before.
Following my comment
I won't write the code for you line by line, but it's pretty easy to figure it out. So I'll describe one method:
Let's say your player is a rectangle that is 50px wide by 100px tall and the center of the player rectangle is set as the player's position. Half the width of the player is 25px and half the height is 50px.
So if the player is at say 240, 370 (a random spot I made up on screen), then to check if a point falls within you'd check if the x point is within 215 to 265 (240 +/- 25px) and if it is, then you'd check if the y point is within 320 and 420 (370 +/- 50px). If both these conditions are true, then the point is either touching or within the player box (so there is a collision). If any of them are false then the point is not (you could stop checking if the first condition is false, saving you a extra check operation).
Once you have that working (a point vs box test), then you'd just run a triangle's points through it to see if the triangle is intersecting the player box. How you get your triangle's points would vary based on your triangles.
I've seen in flash sidescrollers they mostly use sidescroller by making the background move.
But if I had a background and I wanted the player to move and the camera to follow, how would I do it?
There are several ways to accomplish this. The first is to put all of the background objects into a container MovieClip and move that instead of the player. This also makes other aspects of having a camera, such as zoom and rotation, relatively simple, since you can just scale and rotate the container MovieClip.
Another method is putting all background objects into an array. Every time there is movement, you loop through the array and move the objects. This requires more math and separate x/ y variables for each object, so it's not as convenient.
One thing to note is that if you're going to rotate the camera, you might experience vibration issues as your camera gets further away from the origin. To prevent this, you'll have to shift all of the objects in your container MovieClip closer to the origin when they get too far away.
If you want the camera to ease towards the player's position, you just move 1/10 (or some other fraction) of the distance to the camera's target position each frame.
I've just started using actionscript 3 and I am currently trying to make a scrolling runner game in Flash CS5, similar to the Flood Runner games from Tremor games. The difference is, however, that my game is not an endless runner game and the character has a destination that she must reach before time runs out. Alot of the tutorials I've read on the subject use the player character's x and y positions to scroll, but in my game the background scrolls independent of the character. The tutorials I've read about this do not address my problems specifically.
TL;DR: I do not want to loop my background but have a series of multiple background images.
I am trying to figure out the best way to patch together multiple background images seamlessly. Currently, I have one background movie clip object at the maximum pixel width. The background object scrolls to the left independently of the position of the player character, who can only jump.
What I am thinking about doing is this:
Every time a point at the far right edge of one background image reaches the far right stage boundary, I have my actionscript call an addChild command for the next background object and instantiate it at the far right stage boundary. It will scroll at the same speed as the preceding background object.
I also need to figure out how to remove the background objects once they have completely exited the stage for memory purposes.
So, what would be the best way to tackle this?
Your basic concept will work, and to remove you just need to evaluate when the background image is off the screen :
if (backgroundImage.x < -backgroundImage.width)
{
// image is no longer on the screen.
removeChild(backgroundImage);
}
I am building a survival horror like game and am hoping to make a very nice camera system to compliment the mechanics. Part of this is the fact that you will be able to crouch down and cover your face. The camera work I want to do with this is to zoom in to the character in order to constrain the view for the player as well.
The current MC structure that I have is:
GameMaster
>
Spawner (this is for the player and all enemies)
>
Player
The issue I'm having is that scaling the GameMaster (which is where side scrolling and other global game effects are happening) causes the centering of the camera to offset based on how far away the player is from 0,0.
You can see the issue clearly in this video. The red arrows point to the 0,0.
On this stackoverflow question the answer says to make a container for everything and center the containers 0,0 over the target that you want to zoom around. This poses a challenge for me because I would then have to get proper coordinates for an object nested 4 MC's in. I'm also unsure what that will then do for my current side scrolling camera.
Is there a way that I could mathematically figure out the offset when the character ducks? It seems like a viable option because you can't move until you let go of crouch and the camera zooms out.
If not, is the container MC a good option or is it just one of those "you gotta do what you gotta do." type situations?
[Added]
I also see something about Transform Matrices or something. Is that something that would work? I know NOTHING about them but I assume they are CPU heavy and wouldn't be a good option for a mechanic prevalent throughout the whole game.
[Added 2]
ALSO, I want to do a rotation camera effect that suffers from the same 0,0 issue. Blatantly showing up as the player and level rotating around some far off pivot point.
If a Transform Matrix can swiftly and functionally offset the 0,0 to the players location so that I can do all the camera effects and alterations. I think that may be the best way to go.
----Close to Conclusion----
In regards to Vespers answer. Would I then be able to tween the resulting transform?
If so then that completely answers my entire problem. If not, I have no clue how to get the result I want.
I think the container is the cleanest solution. Since it'll be centered on the player, rotations and scaling will work normally. You mention getting the coordinates for the nested MC is hard, but there is a built-in function to do exactly that: localToGlobal()
To get the player position in global coordinates, just do player.localToGlobal(new Point(0, 0)). This should return the Player's center in global coordinates. If your main container is not in global coordinates (because it's nested inside another transformed MC, for example), you can use the opposite function on the container to convert from global to local:
container.globalToLocal(player.localToGlobal(new Point(0, 0)))
Now you just need to center the container. That could also be used to simulate the camera movement. If you update the container position at every frame, it'll give the effect of the camera following the player.
I'm not sure if this question fits properly, but I'm wondering in tile-based games, does the tiles 'shift' when the player is moving (and the player stays in the same place) or does the player move instead (and instead the tiles stay in the same place)?
Visually or in the model?
Visually, there’s usually some code that keeps the player fixed in the middle of the screen while the tiles scroll under him, with the tiles stopping and the player moving to the edge of the screen when the end of the map is reached. Typically this implies some sort of camera that knows how to follow the player, and perhaps changes its behavior depending on which direction the player is facing, and can also be locked for special effects and cutscenes.
In the model, it makes no sense to update the positions of all the tiles and every single object relative to the player, when you could instead just move the player.
Well, the specifics of how you want to draw it are up to you. Some tile-based games show the player fixed in the center of the screen -- in that case, your function to draw the character sprite always centers the character, while the function to draw the background would take an offset.
Others might give the player a pixel offset as well, either to show movement or to give "edges" to a map, not allowing the player to see what lies beyond.
How you implement it in your game is really up to you -- there's no "right" way to draw your sprites.
The tiles do. Unless there's no more to scroll in a certain direction, then the character moves. It's better to have as much as possible that's static cached together rather than move all the tiles individually.
The player moves, and the camera moves. The tiles are drawn shifted by the camera's position so that the world appears to scroll while the player stays roughly centered on screen. The camera follows the player, but usually a little loosely. (For example, you'll notice that you can walk a bit towards the edge of the screen before it starts scrolling in Super Mario Brothers.)