Vertices : Canvas « 2D Graphics « Android






Vertices

    
/*
 * 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 android.app.Activity;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.BitmapShader;
import android.graphics.Canvas;
import android.graphics.Matrix;
import android.graphics.Paint;
import android.graphics.Picture;
import android.graphics.Rect;
import android.graphics.Shader;
import android.graphics.drawable.Drawable;
import android.os.Bundle;
import android.util.AttributeSet;
import android.view.MotionEvent;
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 final Paint mPaint = new Paint();
    private final float[] mVerts = new float[10];
    private final float[] mTexs = new float[10];
    private final short[] mIndices = { 0, 1, 2, 3, 4, 1 };

    private final Matrix mMatrix = new Matrix();
    private final Matrix mInverse = new Matrix();

    private static void setXY(float[] array, int index, float x, float y) {
      array[index * 2 + 0] = x;
      array[index * 2 + 1] = y;
    }

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

      Bitmap bm = BitmapFactory.decodeResource(getResources(),
          R.drawable.icon);
      Shader s = new BitmapShader(bm, Shader.TileMode.CLAMP,
          Shader.TileMode.CLAMP);
      mPaint.setShader(s);

      float w = bm.getWidth();
      float h = bm.getHeight();
      // construct our mesh
      setXY(mTexs, 0, w / 2, h / 2);
      setXY(mTexs, 1, 0, 0);
      setXY(mTexs, 2, w, 0);
      setXY(mTexs, 3, w, h);
      setXY(mTexs, 4, 0, h);

      setXY(mVerts, 0, w / 2, h / 2);
      setXY(mVerts, 1, 0, 0);
      setXY(mVerts, 2, w, 0);
      setXY(mVerts, 3, w, h);
      setXY(mVerts, 4, 0, h);

      mMatrix.setScale(0.8f, 0.8f);
      mMatrix.preTranslate(20, 20);
      mMatrix.invert(mInverse);
    }

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

      canvas.drawVertices(Canvas.VertexMode.TRIANGLE_FAN, 10, mVerts, 0,
          mTexs, 0, null, 0, null, 0, 0, mPaint);

      canvas.translate(0, 240);
      canvas.drawVertices(Canvas.VertexMode.TRIANGLE_FAN, 10, mVerts, 0,
          mTexs, 0, null, 0, mIndices, 0, 6, mPaint);

      canvas.restore();
    }

    @Override
    public boolean onTouchEvent(MotionEvent event) {
      float[] pt = { event.getX(), event.getY() };
      mInverse.mapPoints(pt);
      setXY(mVerts, 0, pt[0], pt[1]);
      invalidate();
      return true;
    }

  }
}

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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