android textured text

2019-02-14 17:41发布

How can I make a text with texture instead of text color or gradient(for example png file)? Something like this. I understand the logic, that I should make text color transparency and put under the text bitmap. I think I can't achive this with a Textview. And I don't know how to do it with a canvas or OpenGL. Any ideas please?

3条回答
爷的心禁止访问
2楼-- · 2019-02-14 17:52

this is a snippet from http://teamyoda.wordpress.com/2012/07/23/drawing-text-in-opengl-for-android/ - Answer from JVitela

 // Create an empty, mutable bitmap
Bitmap bitmap = Bitmap.createBitmap(256, 256, Bitmap.Config.ARGB_4444);

// get a canvas to paint over the bitmap
Canvas canvas = new Canvas(bitmap);
bitmap.eraseColor(0);

// get a background image from resources
// note the image format must match the bitmap format
Drawable background = context.getResources().getDrawable(R.drawable.background);
background.setBounds(0, 0, 256, 256);
background.draw(canvas); // draw the background to our bitmap

// Draw the text
Paint textPaint = new Paint();
textPaint.setTextSize(32);
textPaint.setAntiAlias(true);
textPaint.setARGB(0xff, 0×00, 0×00, 0×00);

// draw the text centered
canvas.drawText(“Hello World”, 16,112, textPaint);

//Generate one texture pointer…
gl.glGenTextures(1, textures, 0);

//…and bind it to our array
gl.glBindTexture(GL10.GL_TEXTURE_2D, textures[0]);

//Create Nearest Filtered Texture
gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_MIN_FILTER, GL10.GL_NEAREST);
gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_MAG_FILTER, GL10.GL_LINEAR);

//Different possible texture parameters, e.g. GL10.GL_CLAMP_TO_EDGE
gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_WRAP_S, GL10.GL_REPEAT);
gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_WRAP_T, GL10.GL_REPEAT);

//Use the Android GLUtils to specify a two-dimensional texture image from our bitmap
GLUtils.texImage2D(GL10.GL_TEXTURE_2D, 0, bitmap, 0);

//Clean up
bitmap.recycle();
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Bombasti
3楼-- · 2019-02-14 18:04

Here's a way of doing it using PorterDuffXfermode.

public class MainActivity extends Activity {
    private EditText mEditText;
    private ImageView mImageView;
    private Bitmap mTexture;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        mEditText = (EditText) findViewById(R.id.activity_main_edittext);
        mImageView = (ImageView) findViewById(R.id.activity_main_image);

        mTexture = BitmapFactory.decodeResource(getResources(),
                R.drawable.texture);
    }

    public void onTextCreate(View v) {
        final String text = mEditText.getEditableText().toString();

        Bitmap result = Bitmap.createBitmap(mTexture.getWidth(),
                mTexture.getHeight(), Bitmap.Config.ARGB_8888);
        Canvas canvas = new Canvas(result);
        Paint paint = new Paint();
        paint.setAntiAlias(true);
        paint.setTextSize(200);
        paint.setARGB(255, 0, 0, 0);

        canvas.drawText(text, 200, 200, paint);
        paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN));
        canvas.drawBitmap(mTexture, 0, 0, paint);
        paint.setXfermode(null);

        mImageView.setImageBitmap(result);
    }
}

The layout is pretty simple:

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <EditText
        android:id="@+id/activity_main_edittext"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentTop="true"
        android:hint="Write a sample text" />

    <ImageView
        android:id="@+id/activity_main_image"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerInParent="true" />

    <Button
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:onClick="onTextCreate"
        android:text="Do it!" />

</RelativeLayout>

This code with write text using canvas.drawText(). If you want to use a regular TextView, you can:

  • create the TextView
  • Set the text
  • drawing the TextView into a canvas using textView.draw(canvas);
  • Instead of doing canvas.drawText() use canvas.drawBitmap()
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不美不萌又怎样
4楼-- · 2019-02-14 18:05

Sorry for posting this late but I think I will be helpful. So to make a textured text, say for example you have a file named my_layout.xml in your layout/ folder that is defined like this :

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent">

    <TextView
    android:id="@+id/some_text_id"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_centerInParent="true"
    android:text="@string/some_text"/>

</RelativeLayout>

and in your drawable/ folder you have a picture named texture.png, you just reference in your java code (say in the class MainActivity for instance) this way :

public class MainActivity extends Activity
{
    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.my_layout);
        TextView welcome = (TextView) findViewById(R.id.some_text_id);
        Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.texture);
        Shader shader = new BitmapShader(bitmap,Shader.TileMode.REPEAT, Shader.TileMode.REPEAT);
        welcome.getPaint().setShader(shader);

    }
}
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