How do I position a Sprite and Text entities relative to the position of a Body on the screen. I tried body.getPosition().x and this gives weird results.I think it may be a bounds issue, as I want only the area of the screen that is shown to be used in the calculations and not the entire map space that's available.
You will get the body position in PIXELTOMETER(PTM) ratio w.r.t physics world.So you have to multiply PTM ratio to the body to get the pixel values as follows
body.getPosition().x*PTM
Related
I'm trying to achieve an effect on single 2D sprites that is similar to those used on animes when characters are moving fast.
My start point was using the Tilling and Offset node on URP shader graphs to distort the sprite, i could change the tilling based on variables such as time but that didn't achieve the desired effect, the main problem with that node is that it distorts the whole sprite on the same amount, while the desired effect would be a distortion that varies along the height of the sprite.
Anyone got any insights on this?
Here's my reference point,
base sprite:
distorted (i would like a more detailed - less distorted effect but i hope you get the idea):
Edit 1: My current progress
Is it possible to check whether a point is within viewport using Leaflet?
I have center of viewport and zoom level. Is it possible to calculate boundaries having only those values?
I think you can use getBounds function of map and contains to check if marker is within viewport or not.
if(m.getBounds().contains(marker.getLatLng()))
//within viewport
I have center of viewport and zoom level. Is it possible to calculate boundaries having those values?
No.
One needs the size of the map (e.g. in pixels) in order to calculate the visible bounds of the map viewport.
Think about the edge cases: a map 0 pixels high and 0 pixels wide will never contain a marker within its bounds, whereas a map of infinite size on an infinitely large screen will always contain any marker.
I write a custom content fitter that is required for my custom layout. So, I need to control RectTransform.sizeDelta property when anchors aren't same but I can't get that shows this value.
I don't need Unity3D API reference, I read it and got a nothing cuz it says only:
The size of this RectTransform relative to the distances between the
anchors. If the anchors are together, sizeDelta is the same as size.
If the anchors are in each of the four corners of the parent, the
sizeDelta is how much bigger or smaller the rectangle is compared to
its parent.
Can anyone explain in normal language what does it mean? And how can I calculate it manually when anchors aren't same?
The definition is somewhat confusing, indeed.
sizeDelta, basically, returns the difference between the actual rectangle of the UI element and the rectangle defined by the anchors.
For example, given a rectangle of 300x200:
Anchors in the same place as the corners of the rectangle: sizeDelta is (0,0)
Left or right anchors at half width of the rectangle: sizeDelta is (150,0)
All four anchors in a point: sizeDelta is (300,200) (i.e.: same size as the rectangle)
As you can see, it doesn't matter at all where the center of the rectangle defined by the anchors is, the only thing that matters is the difference between the width and height of the element rectangle and the anchors rectangle.
In pseudo-code, it's like this:
sizeDelta.x = UIElementRectangle.width - AnchorsRectangle.width;
sizeDelta.y = UIElementRectangle.height - AnchorsRectangle.height;
So, if the UI Rectangle has a dimension bigger than the anchors' one, sizeDelta is positive, if it's smaller, sizeDelta is negative.
sizeDelta: If you made a search, and end up here for an explanation of what sizeDelta means, like GetComponent().sizeDelta.y, then clear your mind.
Visualize a small PANEL, resting on top of a big CANVAS, it's Parent object.
In the PANEL's Rect Transform component, there are 2 rectangles defined:
(a) The rectangle defined by its Anchors. Those triangles. Normally related to the Parent Object location and dimensions, in this case the CANVAS.
(b) The rectangle defined by its own size, the PANEL's own dimension.
sizeDelta = (b) - (a)
That's it. Because normally an interactive component like a Button, smaller in size compared to the object where it rests, like a Panel, and because of that, normally sizeDelta is a negative value. Button size - Panel size = a negative value, normally.
You know the term Negative Space, used in general Design theory?
Think of it, as the space NOT used by a Button resting on a Panel.
Example:
How to find the height of a Panel, that is a Child of a Canvas that is a Camera overlay, thus screen sized. The Anchors of the Panel are related to the Canvas dimensions. Script is on the Panel object:
panelHeight = Screen.height + this.GetComponent().sizeDelta.y;
Remember, sizeDelta is normally negative so it reads more like this pseudo code:
panelHeight = Screen.height - this.sizeDelta.y
Hope this helps you, drove me crazy for a while. Cheers!
References:
https://www.youtube.com/watch?v=VhGxKDIKRvc
https://www.youtube.com/watch?v=FeheZqu85WI
public Vector2 ActualSize(RectTransform trans, Canvas can)
{
var v = new Vector3[4];
trans.GetWorldCorners(v);
//method one
//return new Vector2(v[3].x - v[0].x, v[1].y - v[0].y);
//method two
return RectTransformUtility.PixelAdjustRect(trans, canvas).size;
}
this function works in start
I have an image like below
then I want to rotate it, but I don't want its position to be changed.
For example the output should look like below
If I do imrotate, it will change its position. Is there any other way to rotate this without changing its position?
The imrotate function rotates the entire image around the specified angle. What you want is to rotate only a part of the image. For that you'll have to specify which part you want to rotate. Formally speaking, this is the rectangle in which this symbol is located.
The coordinates of this rectangle can be found by selecting all rows and columns, where any pixel is black. This can be done by taking the sum over all rows, finding the first and last non-zero entries there, and doing the same over all columns.
sx=find(sum(im==0,1),1,'first');
ex=find(sum(im==0,1),1,'last');
sy=find(sum(im==0,2),1,'first');
ey=find(sum(im==0,2),1,'last');
The relevant part of the image is then
im(sy:ey,sx:ex)
Now you can rotate only this part of the image and save it to the same location within the whole image:
im(sy:ey,sx:ex) = imrotate(im(sy:ey,sx:ex),180);
with the desired result:
Note: this will only work for 180° angles, such as the example you provided. If you rotate by any other angle, e.g. 90° or even arbitrary angles, such as 23°, the output of imrotate will not have the same size as the input, so the assignment im(sy:ey,sx:ex) = ... will always throw an error.
I use the glTranslate command to shift the position of a sprite which I load from a texture in my iPhone OpenGL App. My problem is after I apply glTranslatef, the image appears a little blurred. When I comment that line of code, the image is crystal clear. How can i resolve this issue???
You're probably not hitting the screen pixel grid exactly. This will cause texture filtering to blur it. The issue is a bit complicated: Instead of seeing the screen an texture as a array of points, see it as sheets of grid ruled paper (the texture sheet can be stretched, sheared, scaled). To make things look crisp the grids must align perfectly. The texture coordinates (0,0) and (1,1) don't hit the center of the texels but the outer edges of the texture sheet. Thus you need a little bit to offset and scale to address the texel centers. And the same goes for placing the target quads on the screen, where the vertex position must be aligned with the edges of the screen, not the pixel centers. If your projection and modelview matrix are not setup in a way that one unit in modelview space is one pixel wide and the projection fills the whole screen (or window viewport) it's difficult to get this right.
One normally starts with
glViewport(0,0, width, height);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glOrtho(0, width, 0, height, -1, 1);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
// modelview XY range 0..width x 0..height now covers the whole viewport
// (0,0) don't address the lower left pixel but the lower left edge of this
// (width,height) similarily addresses the upper right corner
// drawing a 0..width x 0..height quad with texture coordinates 0..1 x 0..1
// will cover it perfectly
This will work as long as the quad as exactly the same dimensions (i.e. it's vertex positions match) the texture coordinates and the vertex positions are integers.
Now the interesting part is: What if they don't meet those conditions. Then aliasing occours. In GL_NEAREST filtering mode things still look crisp, but some lines/rows are simply missing. In GL_LINEAR filtering mode neighbouring pixels are interpolated with the interpolation factor beding determined how far off grid they are (in laymans terms, the actual implementation looks slightly different).
So how to solve your issue: Draw sprites in a projection/modelview that matches with the viewport, use only integer coordinates for the vertex coordinates and make your texture cover the whole picture. If you're using only a part of the texture coordinate range, things get even more interesting, since one addressed the texture grid, not the texel centers.
I would recommend looking at your modelview matrix declaration and be sure that glLoadIdentity() is being called to ensure that the matrix stack is clean before applying the transform.