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.
Related
I've been charged with designing a demo for an isometric video game in ActionScript 3. I have the bitmap spritesheets that show the avatar I'm using standing and walking in each direction. The walking animation is made up of three frames.
My problem, though, is that I need to figure out how to make use of them. I'm not familiar with animation in Flash, and I need input on how to gotoAndPlay() the walking frames for the right direction. I don't think isolating the necessary DIRECTION is going to be a challenge, so much as starting it and keeping it going while the arrow keys are down.
My current code is basically comprised of keyboard handlers for KEY_UP and KEY_DOWN, each containing a switch-case statement that changes the Avatar.currentDirection property. The handler continues to fire while the keys are down, but I need to add animation to the game.
I've seen some examples where they simply embed the animations into an SWF, propagate an array of the various walking stages, and alternate between them using an EnterFrame event handler, but this seems really clunky. I guess in the end I'm trying to make use of Adobe Animate, but I don't know how you're supposed to do that.
Ops, fortunately i'm working with sprites (atlas animations) right now!.
if i'm right, you just needs to use them for playing some animation with functionality.
if you have a well sized sprite which is tiled with isometric slots like it:
(9 frames sized 64x128)
your work is very easy, only create new movieclip from library, inside it, create a borderless rectangle (which is our mask) in a layer (named mask) then import image to the project, and its better to disabling smooth ability from image properties,
now, inside your movieclip, you have to create new layer (under the mask layer) and add your sprite image for each frame, and change its position:
at last, enable masking for mask layer, then its time of coding,
name your animation queries (like image 3) and for loopable animations, insert gotoAndPlay('anim_name') inside last frame. i hope you are familiar with controling movieclip animations which is basic consept of any flash project.
now to extend it for 8 directions support, you just need to play and switch between dirctions according single and multi keypreses,
In libGDX, which is more efficient to position the camera on the sprite?
Move the camera for the same amount on the input that moves the sprite or set the camera's position equal to the sprite's position on update?
I can't really tell if the input handler is more consuming than a regular get/set position.
Some trivial math that you do only once a frame is not worth thinking about. Moving a camera to follow a sprite only happens once a frame, so you should only be concerned with code clarity.
If you have a large object (like SpriteBatch or a big array) to instantiate, you want to avoid doing that in the render loop because that is slow. You can instantiate it when creating something instead.
It's good practice to focus on code clarity, not premature optimization. Only optimize if you actually have a frame rate problem. If that happens, the issue is usually something that happens in a big loop, like if you're cycling through 200 enemies to update them.
In LibGDX, I'm trying to create a game where you play a character who must survive waves of zombies. The plan is, when a zombie touches the player, the player loses health, and the zombie despawns; this works well until any of the sprites are rotated. Here's a screenshot of what I can imagine to be why:
To check the collisions, I use:
if (sprite.getBoundingRectangle().overlaps(Game.pl1.sprite.getBoundingRectangle())) {}
.. this is inside the Zombie class, and Game.pl1.sprite refers to the sprite belonging to the player.
So the red box is where I'm assuming the bounding rectangle is, based on where zombies despawn around it.
This is what I want the bounding rectangle to be:
I'm not sure if I can achieve this just using sprite.getBoundingRectangle so I was thinking perhaps I would need to use Box2D or maybe convert the sprite to a texture.
You could get the dimensions for a rectangle the size of the sprite if it wasn't rotated, and then rotate that.
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.
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.