不规则碰撞检测，可以用投影，有一点沿着和X轴平行，判断与不规则图形的交点来知道是否碰撞了。

向量见附件：

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;

import android.app.Activity;
import android.content.res.AssetManager;
import android.os.Bundle;
import android.util.Log;
import android.widget.EditText;

/**
 * Class which shows how to use assets
 *
 * @author FaYnaSoft Labs
 */
public class Main extends Activity {
	private EditText firstField;
	private EditText secondField;

	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);
		AssetManager assetManager = getAssets();
		String[] files = null;
		try {
			files = assetManager.list("image");
		} catch (IOException e) {
			Log.e("tag", e.getMessage());
		}
		firstField = (EditText) findViewById(R.id.firstId);
		firstField.setText(Integer.toString(files.length) + " file. File name is "
				+ files[0]);
		InputStream inputStream = null;
		try {
			inputStream = assetManager.open("readme.txt");
		} catch (IOException e) {
			Log.e("tag", e.getMessage());
		}

		String s = readTextFile(inputStream);
		secondField = (EditText) findViewById(R.id.secondId);
		secondField.setText(s);
	}

	/**
	 * This method reads simple text file
	 * @param inputStream
	 * @return data from file
	 */
	private String readTextFile(InputStream inputStream) {
		ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
		byte buf[] = new byte[1024];
		int len;
		try {
			while ((len = inputStream.read(buf)) != -1) {
				outputStream.write(buf, 0, len);
			}
			outputStream.close();
			inputStream.close();
		} catch (IOException e) {
		}
		return outputStream.toString();
	}
}

模拟数学基本运算如cos,sin,div,add等等，不支持浮点运算