1/*
2 * Copyright (C) 2008 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package com.example.android.apis.graphics;
18
19import com.example.android.apis.R;
20
21import android.content.Context;
22import android.graphics.*;
23import android.os.Bundle;
24import android.view.*;
25
26public class Vertices extends GraphicsActivity {
27
28    @Override
29    protected void onCreate(Bundle savedInstanceState) {
30        super.onCreate(savedInstanceState);
31        setContentView(new SampleView(this));
32    }
33
34    private static class SampleView extends View {
35        private final Paint mPaint = new Paint();
36        private final float[] mVerts = new float[10];
37        private final float[] mTexs = new float[10];
38        private final short[] mIndices = { 0, 1, 2, 3, 4, 1 };
39
40        private final Matrix mMatrix = new Matrix();
41        private final Matrix mInverse = new Matrix();
42
43        private static void setXY(float[] array, int index, float x, float y) {
44            array[index*2 + 0] = x;
45            array[index*2 + 1] = y;
46        }
47
48        public SampleView(Context context) {
49            super(context);
50            setFocusable(true);
51
52            Bitmap bm = BitmapFactory.decodeResource(getResources(),
53                                                     R.drawable.beach);
54            Shader s = new BitmapShader(bm, Shader.TileMode.CLAMP,
55                                        Shader.TileMode.CLAMP);
56            mPaint.setShader(s);
57
58            float w = bm.getWidth();
59            float h = bm.getHeight();
60            // construct our mesh
61            setXY(mTexs, 0, w/2, h/2);
62            setXY(mTexs, 1, 0, 0);
63            setXY(mTexs, 2, w, 0);
64            setXY(mTexs, 3, w, h);
65            setXY(mTexs, 4, 0, h);
66
67            setXY(mVerts, 0, w/2, h/2);
68            setXY(mVerts, 1, 0, 0);
69            setXY(mVerts, 2, w, 0);
70            setXY(mVerts, 3, w, h);
71            setXY(mVerts, 4, 0, h);
72
73            mMatrix.setScale(0.8f, 0.8f);
74            mMatrix.preTranslate(20, 20);
75            mMatrix.invert(mInverse);
76        }
77
78        @Override protected void onDraw(Canvas canvas) {
79            canvas.drawColor(0xFFCCCCCC);
80            canvas.save();
81            canvas.concat(mMatrix);
82
83            canvas.drawVertices(Canvas.VertexMode.TRIANGLE_FAN, 10, mVerts, 0,
84                                mTexs, 0, null, 0, null, 0, 0, mPaint);
85
86            canvas.translate(0, 240);
87            canvas.drawVertices(Canvas.VertexMode.TRIANGLE_FAN, 10, mVerts, 0,
88                                mTexs, 0, null, 0, mIndices, 0, 6, mPaint);
89
90            canvas.restore();
91        }
92
93        @Override public boolean onTouchEvent(MotionEvent event) {
94            float[] pt = { event.getX(), event.getY() };
95            mInverse.mapPoints(pt);
96            setXY(mVerts, 0, pt[0], pt[1]);
97            invalidate();
98            return true;
99        }
100
101    }
102}
103
104