Bitmap Pixels : Bitmap « 2D Graphics « Android

1. Android
2. 2D Graphics
3. Bitmap

Bitmap Pixels

    
/*
 * Copyright (C) 2007 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package app.test;

import java.nio.IntBuffer;
import java.nio.ShortBuffer;

import android.app.Activity;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Picture;
import android.graphics.Rect;
import android.graphics.drawable.Drawable;
import android.os.Bundle;
import android.util.AttributeSet;
import android.view.View;
import android.view.ViewGroup;
import android.view.ViewParent;

public class Test extends GraphicsActivity {

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(new SampleView(this));
  }

  private static class SampleView extends View {
    private Bitmap mBitmap1;
    private Bitmap mBitmap2;
    private Bitmap mBitmap3;

    // access the red component from a premultiplied color
    private static int getR32(int c) {
      return (c >> 0) & 0xFF;
    }

    // access the red component from a premultiplied color
    private static int getG32(int c) {
      return (c >> 8) & 0xFF;
    }

    // access the red component from a premultiplied color
    private static int getB32(int c) {
      return (c >> 16) & 0xFF;
    }

    // access the red component from a premultiplied color
    private static int getA32(int c) {
      return (c >> 24) & 0xFF;
    }

    /**
     * This takes components that are already in premultiplied form, and
     * packs them into an int in the correct device order.
     */
    private static int pack8888(int r, int g, int b, int a) {
      return (r << 0) | (g << 8) | (b << 16) | (a << 24);
    }

    private static short pack565(int r, int g, int b) {
      return (short) ((r << 11) | (g << 5) | (b << 0));
    }

    private static short pack4444(int r, int g, int b, int a) {
      return (short) ((a << 0) | (b << 4) | (g << 8) | (r << 12));
    }

    private static int mul255(int c, int a) {
      int prod = c * a + 128;
      return (prod + (prod >> 8)) >> 8;
    }

    /**
     * Turn a color int into a premultiplied device color
     */
    private static int premultiplyColor(int c) {
      int r = Color.red(c);
      int g = Color.green(c);
      int b = Color.blue(c);
      int a = Color.alpha(c);
      // now apply the alpha to r, g, b
      r = mul255(r, a);
      g = mul255(g, a);
      b = mul255(b, a);
      // now pack it in the correct order
      return pack8888(r, g, b, a);
    }

    private static void makeRamp(int from, int to, int n, int[] ramp8888,
        short[] ramp565, short[] ramp4444) {
      int r = getR32(from) << 23;
      int g = getG32(from) << 23;
      int b = getB32(from) << 23;
      int a = getA32(from) << 23;
      // now compute our step amounts per componenet (biased by 23 bits)
      int dr = ((getR32(to) << 23) - r) / (n - 1);
      int dg = ((getG32(to) << 23) - g) / (n - 1);
      int db = ((getB32(to) << 23) - b) / (n - 1);
      int da = ((getA32(to) << 23) - a) / (n - 1);

      for (int i = 0; i < n; i++) {
        ramp8888[i] = pack8888(r >> 23, g >> 23, b >> 23, a >> 23);
        ramp565[i] = pack565(r >> (23 + 3), g >> (23 + 2),
            b >> (23 + 3));
        ramp4444[i] = pack4444(r >> (23 + 4), g >> (23 + 4),
            b >> (23 + 4), a >> (23 + 4));
        r += dr;
        g += dg;
        b += db;
        a += da;
      }
    }

    private static IntBuffer makeBuffer(int[] src, int n) {
      IntBuffer dst = IntBuffer.allocate(n * n);
      for (int i = 0; i < n; i++) {
        dst.put(src);
      }
      dst.rewind();
      return dst;
    }

    private static ShortBuffer makeBuffer(short[] src, int n) {
      ShortBuffer dst = ShortBuffer.allocate(n * n);
      for (int i = 0; i < n; i++) {
        dst.put(src);
      }
      dst.rewind();
      return dst;
    }

    public SampleView(Context context) {
      super(context);
      setFocusable(true);

      final int N = 100;
      int[] data8888 = new int[N];
      short[] data565 = new short[N];
      short[] data4444 = new short[N];

      makeRamp(premultiplyColor(Color.RED),
          premultiplyColor(Color.GREEN), N, data8888, data565,
          data4444);

      mBitmap1 = Bitmap.createBitmap(N, N, Bitmap.Config.ARGB_8888);
      mBitmap2 = Bitmap.createBitmap(N, N, Bitmap.Config.RGB_565);
      mBitmap3 = Bitmap.createBitmap(N, N, Bitmap.Config.ARGB_4444);

      mBitmap1.copyPixelsFromBuffer(makeBuffer(data8888, N));
      mBitmap2.copyPixelsFromBuffer(makeBuffer(data565, N));
      mBitmap3.copyPixelsFromBuffer(makeBuffer(data4444, N));
    }

    @Override
    protected void onDraw(Canvas canvas) {
      canvas.drawColor(0xFFCCCCCC);

      int y = 10;
      canvas.drawBitmap(mBitmap1, 10, y, null);
      y += mBitmap1.getHeight() + 10;
      canvas.drawBitmap(mBitmap2, 10, y, null);
      y += mBitmap2.getHeight() + 10;
      canvas.drawBitmap(mBitmap3, 10, y, null);
    }
  }
}

class GraphicsActivity extends Activity {
  // set to true to test Picture
  private static final boolean TEST_PICTURE = false;

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
  }

  @Override
  public void setContentView(View view) {
    if (TEST_PICTURE) {
      ViewGroup vg = new PictureLayout(this);
      vg.addView(view);
      view = vg;
    }

    super.setContentView(view);
  }
}

class PictureLayout extends ViewGroup {
  private final Picture mPicture = new Picture();

  public PictureLayout(Context context) {
    super(context);
  }

  public PictureLayout(Context context, AttributeSet attrs) {
    super(context, attrs);
  }

  @Override
  public void addView(View child) {
    if (getChildCount() > 1) {
      throw new IllegalStateException(
          "PictureLayout can host only one direct child");
    }

    super.addView(child);
  }

  @Override
  public void addView(View child, int index) {
    if (getChildCount() > 1) {
      throw new IllegalStateException(
          "PictureLayout can host only one direct child");
    }

    super.addView(child, index);
  }

  @Override
  public void addView(View child, LayoutParams params) {
    if (getChildCount() > 1) {
      throw new IllegalStateException(
          "PictureLayout can host only one direct child");
    }

    super.addView(child, params);
  }

  @Override
  public void addView(View child, int index, LayoutParams params) {
    if (getChildCount() > 1) {
      throw new IllegalStateException(
          "PictureLayout can host only one direct child");
    }

    super.addView(child, index, params);
  }

  @Override
  protected LayoutParams generateDefaultLayoutParams() {
    return new LayoutParams(LayoutParams.MATCH_PARENT,
        LayoutParams.MATCH_PARENT);
  }

  @Override
  protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    final int count = getChildCount();

    int maxHeight = 0;
    int maxWidth = 0;

    for (int i = 0; i < count; i++) {
      final View child = getChildAt(i);
      if (child.getVisibility() != GONE) {
        measureChild(child, widthMeasureSpec, heightMeasureSpec);
      }
    }

    maxWidth += getPaddingLeft() + getPaddingRight();
    maxHeight += getPaddingTop() + getPaddingBottom();

    Drawable drawable = getBackground();
    if (drawable != null) {
      maxHeight = Math.max(maxHeight, drawable.getMinimumHeight());
      maxWidth = Math.max(maxWidth, drawable.getMinimumWidth());
    }

    setMeasuredDimension(resolveSize(maxWidth, widthMeasureSpec),
        resolveSize(maxHeight, heightMeasureSpec));
  }

  private void drawPict(Canvas canvas, int x, int y, int w, int h, float sx,
      float sy) {
    canvas.save();
    canvas.translate(x, y);
    canvas.clipRect(0, 0, w, h);
    canvas.scale(0.5f, 0.5f);
    canvas.scale(sx, sy, w, h);
    canvas.drawPicture(mPicture);
    canvas.restore();
  }

  @Override
  protected void dispatchDraw(Canvas canvas) {
    super.dispatchDraw(mPicture.beginRecording(getWidth(), getHeight()));
    mPicture.endRecording();

    int x = getWidth() / 2;
    int y = getHeight() / 2;

    if (false) {
      canvas.drawPicture(mPicture);
    } else {
      drawPict(canvas, 0, 0, x, y, 1, 1);
      drawPict(canvas, x, 0, x, y, -1, 1);
      drawPict(canvas, 0, y, x, y, 1, -1);
      drawPict(canvas, x, y, x, y, -1, -1);
    }
  }

  @Override
  public ViewParent invalidateChildInParent(int[] location, Rect dirty) {
    location[0] = getLeft();
    location[1] = getTop();
    dirty.set(0, 0, getWidth(), getHeight());
    return getParent();
  }

  @Override
  protected void onLayout(boolean changed, int l, int t, int r, int b) {
    final int count = super.getChildCount();

    for (int i = 0; i < count; i++) {
      final View child = getChildAt(i);
      if (child.getVisibility() != GONE) {
        final int childLeft = getPaddingLeft();
        final int childTop = getPaddingTop();
        child.layout(childLeft, childTop,
            childLeft + child.getMeasuredWidth(),
            childTop + child.getMeasuredHeight());

      }
    }
  }
}

   
    
    
    
  

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