AS3: mask does not work if maskee is over certain pixel size? - actionscript-3

I have a mask i'm using for a continuous scroll type thingy, and notice that when my masked sprite gets past a certain pixel size in height (2878) the mask does not mask. Has anyone experienced this? is this a bug?
to reproduce:
create a sprite over 2878 px in height and apply mask, mask breaks
create a sprite 2877 px in height and apply mask, mask works

I can't verify if that is a hard limit, but there are a bunch of similar size limits for bitmaps in Flash that crop up in various areas. One potential solution would be to use the scrollRect property of your content display object. When you set scrollRect you are essentially creating a rectangular mask and I'm almost positive I've done it with 5000+ pixel wide sprites in the past.

Related

Interface gets extra pixel

I made an interface for a game, using extended viewport and when i resize the screen the aspect ratio changes and every element in scene is scales, but when this happens this is what i get :
This is the most annoying issue i dealt with, any advice ? I tried making the tower n times bigger and then just setting bigger world size for the viewport but same thing happens, idk what is this extra pixels on images..
I'm loading image from atlas
new TextureRegion(skin.getAtlas().findRegion("tower0"));
the atlas looks like this:
skin.png
size: 1024,1024
format: RGBA8888
filter: Nearest,Nearest
repeat: none
tower0
rotate: false
xy: 657, 855
size: 43, 45
orig: 43, 45
offset: 0, 0
index: -1
In the third picture, you are drawing your source image just slightly bigger than it's actual size in screen pixels. So there are some boundaries where extra pixels have to be filled in to make it fill its full on-screen size. Here are some ways to fix this.
Use linear filtering. For the best appearance, use MipMapLinearLinear for the min filter. This is a quick and dirty fix. The results might look slightly blurry.
Draw your game to a FrameBuffer that is sized to the same aspect ratio as you screen, but shrunk down to a size where your sprites will be drawn pixel perfect to their original scale. Then draw that FrameBuffer to the screen using an upsampling shader. There are some good ones you can find by searching for pixel upscale shaders.
The best looking option is to write a custom Viewport class that sizes your world width and height such that you will be always be drawing the sprites pixel perfect or at a whole number multiple. The downside here is that your world size will be inconsistent across devices. Some devices will see more of the scene at once. I've used this method in a game where the player is always traveling in the same direction, so I position the camera to show the same amount of space in front of the character regardless of world size, which keeps it fair.
Edit:
I looked up my code where I did option 3. As a shortcut, rather than writing a custom Viewport class, I used a StretchViewport, and simply changed its world width and height right before updating it in the game's resize() method. Like this:
int pixelScale = Math.min(
height / MIN_WORLD_HEIGHT,
width / MIN_WORLD_WIDTH);
int worldWidth = width / pixelScale;
int worldHeight = height / pixelScale;
stretchViewport.setWorldWidth(worldWidth);
stretchViewport.setWorldHeight(worldHeight);
stretchViewport.update(width, height, true);
Now you may still have rounding artifacts if your pixel scale becomes something that isn't cleanly divisible for both the screen width and height. You might want to do a bit more in your calculations, like round pixelScale off to the nearest common integer factor between screen width and height. The tricky part is picking a value that won't result in a huge variation in amounts of "zoom" between different phone dimensions, but you can quickly test this by experimenting with resizing a desktop window.
In my case, I merged options 2 and 3. I rounded worldWidth and worldHeight up to the nearest even number and used that size for my FrameBuffer. Then I draw the FrameBuffer to the screen at just the right size to crop off any extra from the rounding. This eliminates the possibility of variations in common factors. Quite a bit more complicated, though. Maybe someday I'll clean up that code and publish it.

Solid lines become dotted - flash 3d transform

I am trying to 3d transform a floor tile pattern in flash, But when i do so the tile lines become dotted (dashed) here is the screenshot
The best solution is as LDMS said, thickening your lines (even if it is an image), or if you can, enable Anti Aliasing (which i think is what smoothing does)
As for why this happens, this is due to texture sampling. You will probably see that if you move your camera around the gaps/dots in the lines move. Now without going into too many details these are the basics:
Close to your camera the amount of pixel from your image that fit into a pixel on your screen will be less then 1, meaning that one pixel from your image is bigger then an actual pixel on your screen, so it will just display that color from the image. But what happens, if your image is so far away that multiple pixels from your image are so small that they combined fit into one pixel on your screen? With smoothing and Anti Aliasing you run an algorithm to combine colors and get en estimated result. But if you do not do this it will have to pick a color, say we have 2 pixels of black (your line) and 2 of the red background for the same pixel on screen, it will (randomly or based on some variable) pick a color and display it without regard of the other colors.
This is why you sometimes see your line and sometimes the background.

scaling canvas directly VS scaling the CSS in HiDPI

Sorry, I am a beginner, sometimes i find people saying that I have to scale only the CSS, and the other examples i find that they multiply the size directly with the new scale, in other words canvas.width VS canvas.style.width
What is the difference?
Does latest Chrome behave like Safari (now in March 2014)?
Canvas consists of two parts: the element canvas which is what you see on screen. Then sort of "behind" the scenes there is the image bitmap which you draw onto.
Setting element.style will only affect the element itself, but not the behind the scene (internal) bitmap. This bitmap is simply stretched to fit the element size (like an image). If the size isn't specified it will default to 300 x 150 pixels.
The width and height properties (or attributes for the tag) are the ones setting the size of the internal bitmap.
An element without CSS will typically adopt to the size of the internal bitmap (there is pixel aspect ratio involved here as wel but normally the relationship is 1:1).
You can however override this by setting the element's CSS size. Again, it doesn't affect the internal bitmap but simply stretches it to fit the element.
All browsers should behave the same.

Away3D: How to resize an ObjectContainer3D instance

my question is: how can I resize an ObjectContainer3D instance (as it doesn't have "width", "height" and "depth" properties)?
Maybe you can use 'scaleX', 'scaleY', 'scaleZ', or 'scale'.
Note that this will chance the size of the objects in the ObjectContainer3D within the 3D space. Not sure if that's what you're trying to do, given that 3D objects have width, height & depth.
In 3D space there is no concept of pixels. Usually the size is in "units". What you are looking for is a way to render pixel perfect textures. So a pixel mapped onto the 3D object renders as a pixel on screen. This is usually achieved by moving the object at a specific distance from the camera.
Here's a link to a blog post I found on the subject that should point you in the right direction.
In the end the size of the actual 3D object doesn't matter. What matter is the scale and mainly the aspect ratio to render texture as needed. To render a 400px by 200px texture on screen, the 3D plane can be 4 units by 2 units. After that positioning it correctly in front of the camera will produce a 400px by 200px image on screen.
hth.
J.

scaling logo in html5 <canvas>?

Having trouble scaling with . It seems to make sense to code up a drawing in canvas to a fixed size (ie 800x600) then scale it for specific locations - but sizing occurs in 4 places: 1) in the context definition (ie ctx.width = 800 2) with ctx.scale; 3) in html with
I can scale it with ctx.scale(0.25,0.25) and use but this doesn't appear right - it seems to want the scale to be proportional.
css sizing simply makes it fuzzy so not a good way to go. Any ideas?
Actually, you can resize a canvas using stylesheets. The results may vary across browsers as HTML5 is still in the process of being finalized.
There is no width or height property for a drawing context, only for canvas. A context's scale is used to resize the unit step size in x or y dimensions and it doesn't have to be proportional. For example,
context.scale(5, 1);
changes the x unit size to 5, and y's to 1. If we draw a 30x30 square now, it will actually come out to be 150x30 as x has been scaled 5 times while y remains the same. If you want the logo to be larger, increase the context scale before drawing your logo.
Mozilla has a good tutorial on scaling and transformations in general.
Edit: In response to your comment, the logo's size and canvas dimensions will determine what should be the scaling factor for enlarging the image. If the logo is 100x100 px in size and the canvas is 800x600, then you are limited by canvas height (600) as its smaller. So the maximum scaling that you can do without clipping part of the logo outside canvas will be 600/100 = 6
context.scale(6, 6)
These numbers will vary and you can do your own calculations to find the optimal size.
You could convert the logo to svg and let the browser do the scaling for you, with or without adding css mediaqueries.
Check out Andreas Bovens' presentation and examples.
You can resize the image when you draw it
imageobject=new Image();
imageobject.src="imagefile";
imageobject.onload=function(){
context.drawImage(imageobject,0,0,imageobject.width,imageobject.height,0,0,800,600);
}
The last 2 arguments are the width an height to resize the image
http://www.w3.org/TR/html5/the-canvas-element.html#dom-context-2d-drawimage
If you set the element.style.width and element.style.height attributes (assuming element is a canvas element) you are stretching the contents of the canvas. If you set the element.width and element.height you are resizing the canvas itself not the content. The ctx.scale is for dynamic resizing whenever you drawing something with javascript and gives you the same stretching effect as element.style.