How to use unity CreateExternalTexture on Android?

问题

Can someone please help me figure out what is the problem with my code? I am trying to load an image from the native side and send the texture to Unity. I am using Unity Pro 5.0.2f1.

Unity Side:

void Start () {
AndroidJavaObject mImageLoader = new AndroidJavaObject("com.saeid.android.LoadTexture2D");
Texture2D texture2D = new Texture2D(1920, 1080, TextureFormat.ARGB32, false);

Int32 texPtr = mImageLoader.Call <Int32> ("loadImageReturnTexturePtr", "/storage/sdcard0/Images/test.jpg");
Debug.Log("texture pointer? " + texPtr);
Texture2D nativeTexture = Texture2D.CreateExternalTexture (1920, 1080, TextureFormat.ARGB32 , false, false, (IntPtr)texPtr);
texture2D.UpdateExternalTexture(nativeTexture.GetNativeTexturePtr());
gameObject.GetComponent<Renderer>().material.mainTexture = texture2D;
}

Java Side:

public int loadImageReturnTexturePtr(String imagePath) {
Log.d(LOGTAG, "loading image1: " + imagePath);

Bitmap bitmap = BitmapFactory.decodeFile(imagePath);
Log.d(LOGTAG, "Bitmap is: " + bitmap);

ByteBuffer buffer = ByteBuffer.allocate(bitmap.getByteCount());
bitmap.copyPixelsToBuffer(buffer);

int textures[] = new int[1];
GLES20.glGenTextures(1, textures, 0);
int textureId = textures[0];

GLES20.glActiveTexture(GLES20.GL_TEXTURE0);
GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, textureId);
GLES20.glTexImage2D(GLES20.GL_TEXTURE_2D, 0, GLES20.GL_RGBA, 1920, 1080, 0, GLES20.GL_RGBA, GLES20.GL_UNSIGNED_BYTE, buffer);
GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MIN_FILTER, GLES20.GL_LINEAR);
GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MAG_FILTER, GLES20.GL_LINEAR);
GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_WRAP_S,
GLES20.GL_CLAMP_TO_EDGE);
GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_WRAP_T,
GLES20.GL_CLAMP_TO_EDGE);
GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, 0);
Log.d(LOGTAG, "texture id returned: " + textureId);

return textureId;
}

回答1:

So, I figured it out... The code is actually correct. except the texture format in both side should be the same. In my case, I have TextureFormat.ARGB32 (in unity side) and GLES20.GL_RGBA (in Java side) which don't match. Also somehow GLES20.glTexImage2D(...) didn't work for me. I replaced it with GLUtils.texImage2D(GLES20.GL_TEXTURE_2D,0, bitmap,0); and finally I noticed the same code works on same Unity versions and doesn't work on some other. for example it is not working in 5.0.2f1 but it works in 5.0.3.

回答2:

In addition to ensuring that both Unity and the native plugin expect the same image format, an issue I've experienced is that creating the texture on the CPU thread fails because the thread doesn't have access to the opengl context.

My solution to the problem was to instead create the texture on the render thread, using Unity's GL.IssuePluginEvent.

来源：https://stackoverflow.com/questions/33324753/how-to-use-unity-createexternaltexture-on-android

标签

android

unity3d

opengl-es