andrew-raphael-lukasik / pngcs

PNG encoding and decoding for Unity engine

GOALS: Complete PNG encoding and decoding for Unity engine

• Simple API to read and write Texture2D objects, raw data
• Drop "Pngcs" folder in your project, no other dependencies, just works.

API:

• Texture2D PNG.Read
• Texture2D PNG.ReadAsync (experimental)
• Color[] PNG.ReadColors
• Color[] PNG.ReadColorsAsync (experimental)
• PNG.Write
• PNG.WriteAsync (experimental)
• PNG.WriteLargeAsync (experimental)
• PNG.WriteGrayscaleAsync (experimental)

TODO:

• PNG.Read creating Texture2D in every useful TextureFormat, infered from file (partially done already)
• Improve READ/WRITE speeds
• PNG.Read/Write byte[]
• PNG.Read with target width and height arguments (to preview bigger image etc.)
• PNG.Read with image rect argument (read texture atlas region)

HOW TO USE:

using UnityEngine;
using Pngcs.Unity;
public class PngcsTest : MonoBehaviour
{
    void Awake ()
    {
        // THIS IS HOW YOU READ:
        Texture2D texture = PNG.Read( @"D:/input.png" );

        // THIS IS HOW YOU WRITE:
        PNG.Write( texture , @"D:/output.png" );
    }
    
    void OnDestroy ()
    {
        //remember to always release memory when texture is not needed anymore:
        Destroy( texture );
    }
}

REQUIREMENTS:

• Unity 2017.1
• Scripting runtime version: C# 4.x

This window is available under top menu bar/Test/Pngcs Load Note: Alpha8 images appear inverted here but aren't - it's due to no color info but black fill and transparency.

pngcs's Issues

No support for indexed color format in PNG class

No (easy) support for indexed color format in PNG class so far.
Pull requests are welcome!

Index was outside the bounds of the array

I tried the following code and got this error.

IndexOutOfRangeException: Index was outside the bounds of the array.
Pngcs.PngWriter.EncodeRowFromInt (System.Int32[] row) (at Assets/pngcs-master/Pngcs/PngWriter.cs:270)
Pngcs.PngWriter.WriteRowInt (System.Int32[] newrow, System.Int32 rown) (at Assets/pngcs-master/Pngcs/PngWriter.cs:549)
Pngcs.PngWriter.WriteRow (Pngcs.ImageLine line, System.Int32 rownumber) (at Assets/pngcs-master/Pngcs/PngWriter.cs:530)
Pngcs.Unity.PNG.Write (UnityEngine.Color[] pixels, System.Int32 width, System.Int32 height, System.Int32 bitDepth, System.Boolean alpha, System.Boolean greyscale, System.String filePath) (at Assets/pngcs-master/Pngcs/Unity/Unity.cs:238)
Pngcs.Unity.PNG.Write (UnityEngine.Texture2D texture, System.String filePath) (at Assets/pngcs-master/Pngcs/Unity/Unity.cs:152)
PngcsTest+d__0.MoveNext () (at Assets/pngcs-master/PngcsTest.cs:15)
UnityEngine.SetupCoroutine.InvokeMoveNext (System.Collections.IEnumerator enumerator, System.IntPtr returnValueAddress) (at /Users/builduser/buildslave/unity/build/Runtime/Export/Scripting/Coroutines.cs:17)

IEnumerator Start()
{
    yield return new WaitForEndOfFrame();

    var texture = ScreenCapture.CaptureScreenshotAsTexture();
    var output = Path.Combine(Application.persistentDataPath, "test.png");

    PNG.Write(texture, output);
}

WriteAsync silly mistake

This is caused by actually really silly mistake on my part. I will fix it today

Originally posted by @ddutchie in #2 (comment)

Memory Management

There seems so be quite a lot of garbage being created when using these calls.

My use case.
I export 7 Large PNG's in succession or in parallel with async.
When I run the same process again the Mobile Version crashes due to memory issues.

This suggests that something is not properly discarded. Will run through code and see if I have any suggestions.

API Async methods sometimes fail to return texture object

You may want to stay away from async calls until this is solved. Because these methods sometimes return null. Any info and repro steps on this will be highly appreciated