| /* |
| * 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 com.example.android.apis.graphics; |
| |
| // Need the following import to get access to the app resources, since this |
| // class is in a sub-package. |
| //import com.example.android.apis.R; |
| |
| import android.content.Context; |
| import android.graphics.*; |
| import android.os.Bundle; |
| import android.view.View; |
| |
| public class PolyToPoly extends GraphicsActivity { |
| |
| @Override |
| protected void onCreate(Bundle savedInstanceState) { |
| super.onCreate(savedInstanceState); |
| setContentView(new SampleView(this)); |
| } |
| |
| private static class SampleView extends View { |
| private Paint mPaint = new Paint(Paint.ANTI_ALIAS_FLAG); |
| private Matrix mMatrix = new Matrix(); |
| private Paint.FontMetrics mFontMetrics; |
| |
| private void doDraw(Canvas canvas, float src[], float dst[]) { |
| canvas.save(); |
| mMatrix.setPolyToPoly(src, 0, dst, 0, src.length >> 1); |
| canvas.concat(mMatrix); |
| |
| mPaint.setColor(Color.GRAY); |
| mPaint.setStyle(Paint.Style.STROKE); |
| canvas.drawRect(0, 0, 64, 64, mPaint); |
| canvas.drawLine(0, 0, 64, 64, mPaint); |
| canvas.drawLine(0, 64, 64, 0, mPaint); |
| |
| mPaint.setColor(Color.RED); |
| mPaint.setStyle(Paint.Style.FILL); |
| // how to draw the text center on our square |
| // centering in X is easy... use alignment (and X at midpoint) |
| float x = 64/2; |
| // centering in Y, we need to measure ascent/descent first |
| float y = 64/2 - (mFontMetrics.ascent + mFontMetrics.descent)/2; |
| canvas.drawText(src.length/2 + "", x, y, mPaint); |
| |
| canvas.restore(); |
| } |
| |
| public SampleView(Context context) { |
| super(context); |
| |
| // for when the style is STROKE |
| mPaint.setStrokeWidth(4); |
| // for when we draw text |
| mPaint.setTextSize(40); |
| mPaint.setTextAlign(Paint.Align.CENTER); |
| mFontMetrics = mPaint.getFontMetrics(); |
| } |
| |
| @Override |
| protected void onDraw(Canvas canvas) { |
| canvas.drawColor(Color.WHITE); |
| |
| canvas.save(); |
| canvas.translate(10, 10); |
| // translate (1 point) |
| doDraw(canvas, new float[] { 0, 0 }, new float[] { 5, 5 }); |
| canvas.restore(); |
| |
| canvas.save(); |
| canvas.translate(160, 10); |
| // rotate/uniform-scale (2 points) |
| doDraw(canvas, new float[] { 32, 32, 64, 32 }, |
| new float[] { 32, 32, 64, 48 }); |
| canvas.restore(); |
| |
| canvas.save(); |
| canvas.translate(10, 110); |
| // rotate/skew (3 points) |
| doDraw(canvas, new float[] { 0, 0, 64, 0, 0, 64 }, |
| new float[] { 0, 0, 96, 0, 24, 64 }); |
| canvas.restore(); |
| |
| canvas.save(); |
| canvas.translate(160, 110); |
| // perspective (4 points) |
| doDraw(canvas, new float[] { 0, 0, 64, 0, 64, 64, 0, 64 }, |
| new float[] { 0, 0, 96, 0, 64, 96, 0, 64 }); |
| canvas.restore(); |
| } |
| } |
| } |