Sprite width to fit all resolutions cocos2dx - cocos2d-x

Cocos2dx beginner here. Using Cocos2dx V3.10.
I've read lots of tutorials and documentation on Multi platform support across iOS/Android etc and in the main i get it. I'm using setDesignResolutionSize in combination with setContentScaleFactor and it's working out pretty well so far.
I do have one issue which i'm not sure of the best way to approach it.
My game is portrait and i'd like a particular sprite to be the same width on iphone4s and iphone5.
They both use the same design resolution size and content scale factor but on iphone4 the sprite is smaller than that on iphone4 (and iphone5).
I've attached two images to demonstrate what i mean.
As you can see on the iphone4 the sprite isn't quite the same distance away from the edges as the iphone5 is, which i assume is down to the difference in resolution.
Do i need to create another set of assets for this resolution and how would i go about setting those? As currently iphone4 and iphone5 both use the same scale and design size, ie:
glview->setDesignResolutionSize(designResolutionSize.width, designResolutionSize.height, ResolutionPolicy::NO_BORDER);
Size frameSize = glview->getFrameSize();
// if the frame's height is larger than the height of medium size.
if (frameSize.height > mediumResolutionSize.height)
{
director->setContentScaleFactor(MIN(largeResolutionSize.height/designResolutionSize.height, largeResolutionSize.width/designResolutionSize.width));
searchPaths.push_back("hd");
FileUtils::getInstance()->setSearchPaths(searchPaths);
}
Any help much appreciated.

This can be done in a way so that the game will look same no matter what device you use.
First of all, comment out all the following code in your AppDelegate.cpp
/* if (frameSize.height > mediumResolutionSize.height)
{
director->setContentScaleFactor(MIN(largeResolutionSize.height/designResolutionSize.height, largeResolutionSize.width/designResolutionSize.width));
}
// if the frame's height is larger than the height of small size.
else if (frameSize.height > smallResolutionSize.height)
{
director->setContentScaleFactor(MIN(mediumResolutionSize.height/designResolutionSize.height, mediumResolutionSize.width/designResolutionSize.width));
}
// if the frame's height is smaller than the height of medium sxize.
else
{
director->setContentScaleFactor(MIN(smallResolutionSize.height/designResolutionSize.height, smallResolutionSize.width/designResolutionSize.width));
}
*/
Now, make sure all of your assets have been developed in reference to a canvas size which is ideally the size of your background.
Let's say that size is customWidth x customHeight.
Now edit the following lines in AppDelegate.cpp as below:
glview->setDesignResolutionSize(customWidth, customHeight, ResolutionPolicy::EXACT_FIT);
Size frameSize = glview->getFrameSize();
Your game will now look same irrespective of the device, as long as aspect ratio is maintained(which is same for all the phones, but different for tablets).

Related

Website assets 'zoomed in' on desktop version, but not mobile

I am using the following viewport meta in my html:
meta name="viewport" content="width=device-width, initial-scale=1
Which works perfectly for mobile devices. However, on the desktop version all assets, fonts and even the various elements are increased in size by 20%.
For example, see the image below. Even though the image is defined as being 300px by 300px in the devtools, if I take a screenshot and measure it in Photoshop it is in fact 360px by 360px.
The browser zoom is at 100%. What am I doing wrong?
/** EDIT **/
So, I found out that Windows sets the size of images and text to a default of 125%. That is why my website images and text were looking bigger. Now that I can see that is the case, how can I find a workaround so that even with the setting at 125% the images and text will display as intended? Is it even possible?
The problem is that a CSS px is not equal to a physical pixel. The definition is complicated, but in desktop browsers, the ratio between a CSS px and a physical pixel (A.K.A devicePixelRatio) is equal to the OS display scaling factor.
This is done in order to adapt to various screen resolutions and their distance to the observer. In my screen, the image in the codepen you sent is 600x600 physical pixels, because my screen is high PPI. I would have difficulty seeing text rendered with the default size in pixels.
If you really need to set the dimensions in physical pixels, you can just divide each dimension by `devicePixelRatio, but that creates accessibility concerns.
I worked it out in the end. In jQuery you can add the following to make your website display as intended:
$(document).ready(function(){
checkBrowserDpi();
}
function checkBrowserDpi(){
if(window.devicePixelRatio == 1.25 ) {
$("header, section, footer").removeClass("zoom100");
$("header, section, footer").addClass("zoom080");
} else {
$("header, section, footer").removeClass("zoom080");
$("header, section, footer").addClass("zoom100");
}
}
$(window).on('resize', function(){
checkBrowserDpi();
});
and then have two classes in your CSS file as follows:
.zoom100 { zoom: 100%; }
.zoom080 { zoom: 80%; }
In this particular case, it checks the device pixel ratio when the document is loaded and every time the window is resized and then sets the correct zoom to the header, section tags and footer for desktop browsers. You set the zoom to any tag you wish.
** EDIT **
As #D.Pardal points out this does create accessibility issues which I had not taken into consideration. That said, if you do want to mess with the devicePixelRatio then the method above works.

iPhone X / Samsung Galaxy S8 aspect ratio issues for cocos2dx games

I have been designing all my landscape oriented cocos2dx mobile games at 2508x1584 with a "always visible area" of 2112x1408 so there would be no black borders or scaling, just a bit of cropping which would be limited to the "maybe not visible area" as shown below.
This worked well for all mobile device aspect ratios until iPhone X and Samsung Galaxy S8 arrived. These devices have 19.5:9 and 18:9 aspect ratios respectively which takes the "always visible area" down from 1408 to 1158 which is significant enough that it looks like i have no choice but to redesign all my games as shown in the image below.
Since I designed all my previous games for a taller visible area when I run them on iPhone X and Samsung galaxy S8 the top and bottom of the game are obviously cut off.
Am I stuck re-designing these games in order to make them fit this shorter aspect ratio? Or is there another solution I am overlooking here?
Sadly I don't see any magic solution. Here are the different options:
Test the screen ratio, and for iPhone X and Galaxy S8, switch resolution policy to ResolutionPolicy::SHOW_ALL instead of ResolutionPolicy::NO_BORDER. That's a quick-and-dirty solution, which will display black borders on left and right. You can improve this solution a little bit by scaling all content so that the important area takes all screen height.
Change the width of your design resolution, offset the content, and find a way to fill all this resolution with your background textures. This requires more effort but most of the content should not change, except for the offset. It will solve the problem because a larger design resolution means that it has less to cut vertically (which is the problem in your case).
As you said, you can also redesign the important area so that it is more flexible to different ratios. This requires some effort and reduces the size of this important area, which affects the experience on the other ratios.
I would go with the second option. Hope this helps, and sorry for not having a magic solution to that problem.
Might be a bit late for you, but I think I've solved this issue.
I used ResolutionPolicy::NO_BORDER, a design resolution of 1080x1920 and this guide image
The green area is 1080x1920. You should design your app to fit within this area. Taller phones such as the S8 and iPhoneX will expand up into the orange space. Wider devices such as tablets will expand into the orange space on the left and right.
What you need to do on launch is to calculate a scale factor for the Director to use.
Do this in your AppDelegate.cpp
auto frameSize = glview->getFrameSize();
float deviceAspectRatio = frameSize.height / frameSize.width;
float designAspectRatio = designResolutionSize.height / designResolutionSize.width;
director->setContentScaleFactor(MAX(
deviceAspectRatio / designAspectRatio,
designAspectRatio / deviceAspectRatio)
);
To be honest I'm not 100% on why this works. I discovered it by trying random scale factors until I found one that worked, and then trying to work backwards to come up with some math that will work. Turns out dividing the aspect ratio of the device by the aspect ratio of your design resolution is what you want.

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.

Viewport pixel Vs Device pixel Vs CSS pixel

CSS pixel:
div.sidebar {
width: 300px;
}
css-pixel-width = device-pixel-width x 1 / Device-pixel-ratio
For example: Say, a device with 1920(w) X 960(h) device pixels and dpr = 2.
css-width = 1920 * (1 css px / 2 device px) = 960 px
Device pixel:
#media all and (max-device-width: 320px) {
....
}
Zooming factor:
When the zooming factor is exactly 100%, one CSS pixel equals one device pixel (though the upcoming intermediate layer will take the place of device pixels here.) The image below depicts that. Not much to see here, since one CSS pixel exactly overlaps one device pixel.
I should probably warn you that “zoom 100%” has little meaning in web development. Zooming level is unimportant to us; what we need to know is how many CSS pixels currently fit on the screen.The following two images illustrate what happens when the user zooms. The first shows device pixels (the dark blue background) and CSS pixels (the semi-transparent foreground) when the user has zoomed out. The CSS pixels have become smaller; one device pixel overlaps several CSS pixels. The second image shows device and CSS pixels when the user has zoomed in. One CSS pixel now overlaps several device pixels.
Question:
1) How to manage zoom levels? Does auto-scale attribute of meta tag decides the zoom level?
Viewport: It’s the area (in CSS pixels)
Wrt viewport pixel,
initial-scale sets the relation between CSS pixel and viewport pixel, as mentioned here. For example: initial-scale = 1 mean 1 CSS pixel is equal to 1 viewport pixel.
Question:
2) What is viewport pixel?
Sounds like the answerer made up that term on the spot when answering the linked question. It doesn't help that their answer (before I edited it) consisted entirely of blockquotes, giving the false impression that they cited an external source that apparently defined those terms.
CSS does not define such a term, nor does any other specification. The viewport meta tags simply change the zoom behavior of a mobile browser and don't have any meaningful effect on rendering.

How to make Sprites support different screen sizes?

I am using libgdx to work on a game but just came across that how will I implement it for various screen sizes? I figured out how to position images for different sizes and resolutions but how do we make sprites support different screen sizes ? My background on 320x480 goes fine but takes a very small place on 480 by 800, how to accomplish this that it works on all the screens?
You have various options depending on what you are happy to do,
a. You could use a set of HQ sprites scaled down to fit in each of the screens something like;
in resize()
width = arg0;
height = arg1;
then in your render()
batch.draw(textureRegion, -width/2, -height/2, width, height);
will draw a sprite across the whole screen (assuming orthographic camera centered at 0,0)
b. You could use different sets of sprites for different resolutions you would then load a set sprites based on the dimensions of the viewport.
You could use scene2d.
There you can inform the scene, that the window resized in application
#Override
public void resize(int width, int height) {
stage.setViewport(width, height, true);
...
}
Divide your screen into virtual units, for example grid 10x10.
Calculate your virtual units from actual screen size.
VIRTUAL_UNIT_WIDTH = Gdx.graphics.getWidth()/10;
VIRTUAL_UNIT_HEIGHT = Gdx.graphics.getHeight()/10;
And set your sprite size via those virtual units, and use virtual units when calling spriteBatch.draw();
Like this you will be able to keep the same aspect ratio of the game trough various screen resolutions.
Hope that this gives you an idea.
I am using below approach and it's works for almost all screen sizes with ignoble minor scaling issue.
I always uses graphics images for screen size 1920.0x1080.0
ScreenViewport screenViewport=new ScreenViewport(camera);
screenViewport.setUnitsPerPixel(Math.min(1920.0f/Gdx.graphics.getWidth(),1080.0f/Gdx.graphics.getHeight()));
stage = new Stage(screenViewport);
#Override
public void resize (int width, int height) {
ScreenViewport screenViewport= (ScreenViewport) stage.getViewport();
screenViewport.setUnitsPerPixel(Math.min(1920.0f/width,1080.0f/height));
screenViewport.update(width,height,false);
}
Here you can set your approach from Math.min() or Math.max().
It will result your camera view-port size near to 1920.0*1080.0
Device screen-size Math.max() Math.max()
800.0x480.0 1800.0x1080.0 1920.0x1152.0
1920.0x1080.0 1920.0x1080.0 1920.0x1080.0
2048.0x1440.0 1536.0x1080.0 1920.0x1350.0
Note: Always use camera.viewportWidth and camera.viewportHeight for set positions of Games UI screens.