I am using as3 and try to drag the background within the screen. What am I doing wrong?
Here is my code:
bg.startDrag(false, new Rectangle(-bg.width + stage.stageWidth, stage.stageHeight, bg.width - stage.stageWidth, bg.height - stage.stageHeight));
It seems that it didn’t work properly when the background was with a transparent background like this. That is, the flash had green rectangles without a common rectangular background.
Related
I just started working on as3. I want to create a Rectangle but without color fill, so I can see what is behind it on stage. I love to draw on that Rectangle, but it never works without color fill.
var Canvas_sp:Sprite = new Sprite();
this.addChild(Canvas_sp);
//here i love Rectangle be without collor fill not whit(FFFFFF)e color
//i love see what behind the Rectangle and draw over it
Canvas_sp.graphics.beginFill(0xFFFFFF);
Canvas_sp.graphics.drawRect(0,0,550,400);
thx for all
If you don't want a fill, don't begin one.
Omit this line:
Canvas_sp.graphics.beginFill(0xFFFFFF);
To achieve the goal you want, you need to set the alpha parameter to 0, and maybe, to draw just a border of a Rectangle. You can see an example here: example
In your case, you can try something like this:
Canvas_sp.graphics.beginFill(0xffffff, 0);
Canvas_sp.graphics.lineStyle(0x000000, 0.1);
Canvas_sp.graphics.drawRect(0, 0, 550, 400);
Canvas_sp.graphics.endFill();
I'm having difficulty with transforming colour in Flash. It should be easy I think, but for some reason my code isn't working as expected.
I have a bitmap graphic consisting of a colour spectrum from red to yellow to green (you know, like you see in an audio level meter).
I simply want to sample a colour from that bitmap and then tint a movie clip on stage that sampled colour. (the effect I'll be going for is coloured progress - the closer you get to 100% green is displayed, the closer you are to 0% it's red - I haven't implemented that part yet, but I'm not worried about that).
Anyhow, I sample the colour just fine, and tint my clip, but no matter what I tint the clip it comes up a different colour than what I've sampled (the trace is a different colour than what I see on the clip). I can't see where I'm going wrong - I'm hoping it's a stupid mistake and someone can spot it easily.
import flash.display.BitmapData;
var bmd:BitmapData = new BitmapData(mc_colourbar.width, mc_colourbar.height);
bmd.draw(mc_colourbar);
var pixelvalue:uint = bmd.getPixel(0, 1);
trace(pixelvalue.toString(16));
var colourtransform:ColorTransform = mc_box.transform.colorTransform;
colourtransform.color = uint("0xff" + pixelvalue);
mc_box.transform.colorTransform = colourtransform ;
mc_box is the clip on stage I'm trying to tint - it's simply a white square.
Any help is appreciated, thanks in advance!
ColorTransform.color expects an RGB value, and it appears as though you're attempting to give it an ARGB value*.
Change the line:
colourtransform.color = uint("0xff" + pixelvalue);
to just:
colourtransform.color = pixelvalue;
and your code should work as expected.
*Though I don't think the way you're trying to do it here is correct.
I want to fill no color to canvas i.e. I want the background div color should keep on displaying in the div. I have googled it but didn't find any solution to keep fillStyle as no color.
Also I tried omitting the fillStyle but it leave me with black color.
Any options available?
Thanks
You need to use this to clear the canvas:
context.clearRect(0, 0, canvas.width, canvas.height);
(or the rectangle you need).
Also make sure you have no CSS rules set for the canvas element's background (which might be the case if your canvas is not transparent on init as canvas is transparent as default).
If you need to clear a non-regular shape you can use composite mode:
context.globalCompositeOperation = 'destination-out';
(xor and source-out can also be used too to a certain degree too to remove existing pixels but with some variations).
This will clear the canvas in the form of the next shape (Path) you draw (or use an image which solid pixels will clear the canvas).
I don't know what you're trying to do, but it seems you want to make your canvas transparent. You could do that in JavaScript:
context.fillStyle = "rgba(0, 0, 200, 0)";
Or in CSS, where foo would be the id of the canvas element. Note that this would make the element per se transparent, not just it's contents.
#foo {
opacity: 0;
}
You need to clear your canvas, not draw transparency... just think about that. You can't clean a glass, by using clear paint, the same is applied to the <canvas> element.
http://jsfiddle.net/Z6XTg/1/
this canvas demo does a very simple
ctx.clearRect(0,0,canvas.width,canvas.height);
before it draws anything, thus maintaining the canvas transparency.
How can I make a canvas transparent? I need to because I want to put two canvases on top of one another.
Canvases are transparent by default.
Try setting a page background image, and then put a canvas over it. If nothing is drawn on the canvas, you can fully see the page background.
Think of a canvas as like painting on a glass plate.
To clear a canvas after having drawn on it, just use clearRect:
const context = canvas.getContext('2d');
context.clearRect(0, 0, canvas.width, canvas.height);
I believe you are trying to do exactly what I just tried to do:
I want two stacked canvases... the bottom one has a static image and the top one contains animated sprites. Because of the animation, you need to clear the background of the top layer to transparent at the start of rendering every new frame. I finally found the answer: it's not using globalAlpha, and it's not using a rgba() color. The simple, effective answer is:
context.clearRect(0,0,width,height);
Iif you want a particular <canvas id="canvasID"> to be always transparent you just have to set
#canvasID{
opacity:0.5;
}
Instead, if you want some particular elements inside the canvas area to be transparent, you have to set transparency when you draw, i.e.
context.fillStyle = "rgba(0, 0, 200, 0.5)";
Just set the background of the canvas to transparent.
#canvasID{
background:transparent;
}
Paint your two canvases onto a third canvas.
I had this same problem and none of the solutions here solved my problem. I had one opaque canvas with another transparent canvas above it. The opaque canvas was completely invisible but the background of the page body was visible. The drawings from the transparent canvas on top were visible while the opaque canvas below it was not.
fillStyle might not be what you are looking for because it can't really clear the canvas; it will either paint it with a solid color or with a transparent color which doesn't paint anything.
The trick that did for me relies on an implementation detail about the <canvas></canvas>. They "reset" when resized (tested on Chrome and Firefox):
canvas.width = canvas.width
This phenomenon initially struck me as a very annoying behavior, but it also became the only way I know to hard reset the canvas.
If you're exporting your canvas, remember to export as png!!
Been there, failed at that xD
Here's a minimal proof of concept of the default transparency of canvases, and using position: absolute to stack them on top of each other:
const canvases = [...Array(4)]
.map(() => document.createElement("canvas"));
canvases.forEach((canvas, i) => {
document.body.appendChild(canvas);
const ctx = canvas.getContext("2d");
const saturation = 100 / canvases.length * (i + 1);
ctx.strokeStyle = `hsl(160, ${saturation}%, 60%)`;
ctx.lineWidth = 10;
ctx.strokeRect(i * 50 + 10, i * 15 + 10, 100, 80);
});
canvas {
position: absolute;
border: 1px solid black;
}
Can't comment the last answer but the fix is relatively easy. Just set the background color of your opaque canvas:
#canvas1 { background-color: black; } //opaque canvas
#canvas2 { ... } //transparent canvas
I'm not sure but it looks like that the background-color is inherited as transparent from the body.
Okay so basically I want to draw a circle in as3 that has a 'hole' in it (like a donut). Something like this, but without the outlines:
http://www.steel.ie/DugganSteel/Pictures/Hollow-circle.gif
This doesn't work:
SPRITE.graphics.beginFill(0xFFFFFF);
SPRITE.graphics.drawCircle(0,0,10);
SPRITE.graphics.endFill();
SPRITE.graphics.drawCircle(0,0,5);
I mean this seems like it'd be simple but I can't find any information on it. I should also mention that I'm trying to only draw 3/4 of the circle, like 3/4 of donut. So I was planning on drawing a transparent circle and square over the original circle, I know this seems kinda of weird since you'd expect something transparent to show whats underneath it.
Its actually really simple. See the following code:
var p:Point = new Point(100, 100);
graphics.beginFill(0xFF0000);
graphics.drawCircle(p.x, p.y, 100);
graphics.drawCircle(p.x, p.y, 50);
Intersections cancel each other out until you call endFill
Goodluck!
You can just make the line thickness the desired donut width and avoid using beginFill
set graphics.lineStyle
To make it only go 3/4 of the way around you could use curveTo to draw the 3 quarters.
The above method by Tyler works, however if an easier way to do it is to simply begin drawing the inner circle first. Basically Flash doesn't actually fill in the color until you call endFill() (again as mentioned by Tyler), so you start drawing on the inner circle, then the outer circle then on endFill() Flash fills in the gap.
SPRITE.graphics.beginFill(0xFFFFFF);
SPRITE.graphics.drawCircle(0,0,5);
SPRITE.graphics.drawCircle(0,0,10);
SPRITE.graphics.endFill();
Hope this clears things up for you.
Introduction to Flash drawing API, will help you understand a bit more :
http://www.senocular.com/flash/tutorials/flash10drawingapi/