So i have this image of a green ball in png format(103x104px is the size), and im trying to resize it before i draw it on the screen. Im trying this code, which i found in many threads and also in the android documentation this function is specified as exactly what i should need, but it doesnt work.
Bitmap a=BitmapFactory.decodeResource(getResources(), R.drawable.example);
Bitmap b=Bitmap.createScaledBitmap(a,30,30,false);
and then i draw it with
canvas.drawBitmap(b, x, y ,paint);
But no matter which numbers i give into the createScaledBitmap() the image is still the same on the screen.
Ok, so the solution was in the end pretty simple :D i overlooked one line in the code that i forget to erase when i decided to resize it and that line always backed it up, so this code indeed works. My fault, should have searched my code longer before posting.
Related
So I am doing small game in android studio - java. And I was using 400x400 .png image as a ship. It worked well.
Bitmap.createScaledBitmap(BitmapFactory.decodeResource(context.getResources(),R.drawable.playermove),(int)(length),(int)(height),false);
I am using drawBitmap to draw image on screen.
Now I want to use different ship. Only thing that I changed is that instead of this image I use another one that is 150x150 also .png and game becomes so laggy and sloopy.
Length and Height are 1/10 size of the screen. I have 8 ship pictures with similair dimensions and every one make game sloppy.
Any idea why those pictures make everything sloppy and first one doesn't?
You are doing that on the UI thread. You shouldn't!
I'd recommend not to scale Bitmap dynamically, as bitmap scaling is bit expensive, and if you are doing that in onDraw() which would be triggered every ~17ms, doing redundant/expensive work is bad. I'd suggest you to preprocess the image and keep a scaled version of it and just use it to draw every time.
you are not optimizing your images and this is a background work. try to do this in background.
also this post may help you.
Background
I am creating an application where I manually lay out a texture atlas. The whole point is that the image itself isn’t supposed to be transparent—it has a consistent background color that is then supposed to be removed in the code.
The problem I’m having is that I can’t seem to be able to remove pixels—make them transparent—from the Pixmap I’m working on. I’ve made sure to use RGBA_8888 for my Pixmap’s Format, which is sure to support transparency.
Problem
Here’s the piece of code I’m having trouble with:
pixmap.drawPixel(x, y, 0x00000000);
Quite obviously, 0x00000000 would be zero—even if converted from hex to base ten—seriously, it’s the same number!
From my observations, I’ve noticed that the drawPixel method draws a pixel onto the current one. What I want is for it to become transparent. Using the aforementioned piece of code, it draws transparency onto something that isn’t transparent—ending up changing nothing. As if you add nothing to something, the something remains.
Research
As usual, I’ve done some research on my own. Here on Stackoverflow I haven’t managed to find anything of use. The only things I know is the things mentioned above that I’ve managed to find out by observing the Pixmap and its drawPixel method.
Moreover
Perhaps someone can point me in the right direction as to how you’d make a pixel of a Pixmap transparent?
As you already discovered, you can't draw a blended transparent pixel over the existing pixel, because you can't see anything. So first you need to disable Pixmap blending.
Pixmap.setBlending(Pixmap.Blending.None); // before you start drawing pixels.
pixmap.drawPixel(x, y, 0x00000000);
// And all pixels you want to draw
Pixmap.setBlending(Pixmap.Blending.SourceOver); // if you want to go back to blending
If you want to maintain the RGB of the existing pixel, you have to get the current pixel color and manually black out the alpha component only:
pixmap.drawPixel(x, y, pixmap.getPixel(x, y) & 0xffffff00);
I thought about the best way to draw a picture in OpenGL / JOGL.
I currently program a Game and it is my goal to save the information about a picture in a text file instead of saving the picture.
My idea was to program a method that saves every pixel information (RGB) at the position of X and Y.
Then I draw every pixel and it is finished.
What you think about that idea?
You should simply use TextureIO to make a texture from your picture and use this texture with 4 vertices that have some texture coordinates while drawing. glReadPixels() is very slow, reading each pixel of a picture would take a lot of time, saving its content as a text file would require a lot of memory (saving it as a compressed image in a loss-less format like PNG might be worth a try), drawing each pixel one by one would be a lot slower than drawing a texture. derhass is right. You could vectorize your picture (make a SVG from it) but you would have to rasterize it after or you would have to implement some rendering of vectorized contents and it would be probably slower than using a texture. I'm not sure you really need an offscreen buffer.
I had a similar problem when I began working on my first person shooter. I wasn't using JOGL at the very beginning, I reused the source code of someone else, it relied on software rendering in an image, it was very slow. Then, I used JOGL to draw each pixel one by one instead of using Java2D, it was about 4 times faster on my machine but still very slow for me. At the end, I had to redesign the whole rendering to use OpenGL for what it is for as derhass would say, I used triangles, quads and textures. The performance became acceptable and this is what you should do, use OpenGL to draw primitives and clarify what you're trying to achieve so that we can help you a bit better.
I'm developing Side Scroll 2D Game, using AndEngine
I'm using their SVG extension (I'm using vector graphic)
But I discovered strange and ugly effect, while moving my player (while camera is chasing player exactly, means while camera is changing its position)
Images of my sprites looks just different, they are like blurred or there is effect like those images would be moving (not changing their possition, just jittery effect, really hard to explain and call this effect properly) Hopefully this image may explain it a bit:
Its more or less, how does it look in the game, where:
a) "FIRST" image is showing square, while player is moving (CAMERA isn't) image looks as it should
b) "SECOND" the same image, but with this strange effect "which looks like image moving/blurring during camera moving [chasing player])
Friend of mine told me that it might be hardware problem:
"the blurring that you notice is actually a hardware problem. Some phones "smooth" the content on the screen to give a nicer feel to applications. I don't know if it's the screen or the graphics processor, but it doesn't occur on my wife's Samsung Captivate. It happens on my Atrix and Xoom though. It's really noticable on the Xoom due to the large screen size."
But seems there is way to prevent it, since I have tested many similar games, where camera is chasing player, and I could not notice such effect.
Is there a way to turn this off in code?
I'm grateful for previous answers, unfortunately, still problem exist.
Till now, I have tried:
casting (int) on setCenter method which is being executed on updateChaseEntity
testing game using PNG images, instead of SVG extension and vector graphic
different TextureOptions
hardwareAcceleration
If someone have different idea, what may cause this strange effect, I would be really grateful for help - thank you.
Some devices (Xperia Play) bleed everywhere when trying to draw things that are moving quickly. For example a red icon on the application list leaves a blur behind it. You could try hardwareAcceleration in the manifest (on and off) to see if it makes a difference.
You'd probably get the same effect if you weren't using svg
When your player's just going to the right and camera begins chasing him, all other sprites except player are moving to the left. Try to print the absolute coordinates of your "blurring" sprite (or some of its anchor points) to the log. The X-coord of sprite should be decreasing linearly. If you notice it's increasing some times, it could be a reason of blur.
Hope this will help.
It sounds like it's due to the camera moving in real increments, making the SVG components rest on non-integer bounds, and the SVG renderer making anti-aliasing come into effect to demonstrate this. Try moving the camera in integer increments by casting camera values to int.
I'm not familiar with this engine but I wonder why would you use vector graphics for pixelated art style. I'll be surprised if your character in the screenshot is really a vector art... maybe it's texture imported in SVG? I attempted back in the day to use flash a few times and I was making the same mistake... I'm not saying it's not possible but it's not intended to create pixel art with flash or any other vector software. There is a reason why most flash games have similar look.
Best way to debug it, is try a different looking sprite.
Maybe it is just the slow response time of your device display.
I'm also an Andengine developer, and never seen such behavior.
Sometimes you fix jittering using FixedStepEngine, it might help.
If you can post your code maybe we can better help you.
I'm currently developing my first Android app and am having some issues rendering images. The image itself is great quality to begin with, but upon rendering it the quality drastically lowers. Edges become jagged and it just looks poorly done. Everyone I've showed it to thus far has almost immediately noticed it, without any prompting about it. [start on left, end on right:]
I'm trying everything I am aware of and every tip I've been able to find by looking around online, but nothing seems to fix it.
Currently, I get the image as a Bitmap and scale it:
Bitmap holeImage = BitmapFactory.decodeResource(res, R.drawable.hole_image);
Bitmap holeImageBMP = Bitmap.createScaledBitmap(holeImage, width, height, true);
Once I have the image, I create a Paint, set a few smoothing attributes to true, and then draw it on the canvas:
Paint smoothingPaint = new Paint();
smoothingPaint.setAntiAlias(true);
smoothingPaint.setFilterBitmap(true);
smoothingPaint.setDither(true);
canvas.drawBitmap(holeImageBMP, 0, 0, smoothingPaint);
Yet, as you can obviously see above, the image quality drastically decreases. I've seen plenty of images being rendered beautifully and I'm honestly just not sure what's going on so any advice would be great!
Other notes: I'm using a SurfaceView method to handle the drawing, similar in nature to the LunarLander example given in the SDK.
Thanks again!
If you aren't restricted to much less colors than the original picture has (Does Android have 256 color modes?), I'd suggest to disable dithering, if you zoom into your picture, it does have a visible effect that perhaps destroys a smooth look.
I think in your case, dithering infers with anti-aliasing by destroying the additional colors that anti-aliasing needs for a smooth look. A quick color count on your pictures (left one about 850, right one about 140) confirms this.
That is probably related to converting images from one format to another. Also, android screens vary from device to device. Try to use another device and it might look better... Almost for sure it will have a different tone.
Try to read this great article on this problem (and banding and dithering) and consider adapting the image you created for it to work better in android devices: http://www.curious-creature.org/2010/12/08/bitmap-quality-banding-and-dithering/