java– 如何在使用可变宽度笔划绘制时使绘制路径平滑

概述我创建了一个示例绘图应用程序,用户可以使用可变宽度笔划绘制,到目前为止,可变笔划的绘图路径正在工作,但绘制的线条不平滑.我用来实现的代码如下所示.帮助我解决这个问题,因为最近两天我坚持这一点.使用可变笔画宽度绘制路径的代码publicclassFingerPaintextendsGraphicsA

我创建了一个示例绘图应用程序,用户可以使用可变宽度笔划绘制,到目前为止,可变笔划的绘图路径正在工作,但绘制的线条不平滑.我用来实现的代码如下所示.

帮助我解决这个问题,因为最近两天我坚持这一点.

使用可变笔画宽度绘制路径的代码

public class FingerPaint extends GraphicsActivity {    @OverrIDe    protected voID onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentVIEw(new MyVIEw(this));    }    public voID colorChanged(int color)  {    }    public class MyVIEw extends VIEw {        private static final float stroke_WIDTH = 5f;            private Paint paint = new Paint();        private Path mPath = new Path();        ArrayList<Path> mPaths = new ArrayList<Path>();        ArrayList<Integer> mstrokes = new ArrayList<Integer>();        private float lasttouchX;        private float lasttouchY;        private final RectF dirtyRect = new RectF();        private int laststroke = -1;        int variableWIDthDelta = 0;        private static final float stroke_DELTA = 0.0001f; // for float comparison        private static final float stroke_INCREMENT = 0.01f; // amount to interpolate        private float currentstroke = stroke_WIDTH;        private float targetstroke = stroke_WIDTH;        private float mX, mY;        private static final float touch_TolERANCE = 4;        public MyVIEw(Context context)  {            super(context);            paint.setAntiAlias(true);            paint.setDither(true);            paint.setStyle(Paint.Style.stroke);            paint.setstrokeJoin(Paint.Join.ROUND);            paint.setstrokeCap(Paint.Cap.ROUND);                paint.setstrokeWIDth(stroke_WIDTH);        }        public voID clear() {            mPath.reset();            // Repaints the entire vIEw.            invalIDate();        }        @OverrIDe        protected voID onDraw(Canvas canvas)  {            for(int i=0; i<mPaths.size();i++) {                paint.setstrokeWIDth(mstrokes.get(i));                canvas.drawPath(mPaths.get(i), paint);            }        }        @OverrIDe        public boolean ontouchEvent(MotionEvent event) {            float eventX = event.getX();            float eventY = event.getY();            int historySize = event.getHistorySize();            switch (event.getAction()) {                case MotionEvent.ACTION_DOWN: {                    resetDirtyRect(eventX, eventY);//                  mPath.reset();                    mPath.moveto(eventX, eventY);                    mX = eventX;                    mY = eventY;                    break;                                  }                case MotionEvent.ACTION_MOVE: {                                     if (event.getPressure()>=0.00 && event.getPressure()<0.05) {                        variableWIDthDelta = -2;                    } else if (event.getPressure()>=0.05 && event.getPressure()<0.10) {                        variableWIDthDelta = -2;                    } else if (event.getPressure()>=0.10 && event.getPressure()<0.15) {                        variableWIDthDelta = -2;                    } else if (event.getPressure()>=0.15 && event.getPressure()<0.20) {                        variableWIDthDelta = -2;                    } else if (event.getPressure()>=0.20 && event.getPressure()<0.25) {                        variableWIDthDelta = -2;                    } else if (event.getPressure() >= 0.25 && event.getPressure()<0.30) {                        variableWIDthDelta = 1;                    } else if (event.getPressure() >= 0.30 && event.getPressure()<0.35) {                        variableWIDthDelta = 2;                    } else if (event.getPressure() >= 0.35 && event.getPressure()<0.40) {                        variableWIDthDelta = 3;                    } else if (event.getPressure() >= 0.40 && event.getPressure()<0.45) {                        variableWIDthDelta = 4;                    } else if (event.getPressure() >= 0.45 && event.getPressure()<0.60) {                        variableWIDthDelta = 5;                    }                                                              // if current not roughly equal to target                    if( Math.abs(targetstroke - currentstroke) > stroke_DELTA )                     {                        // move towards target by the increment                        if( targetstroke > currentstroke)                        {                            currentstroke = Math.min(targetstroke, currentstroke + stroke_INCREMENT);                        }                        else                        {                            currentstroke = Math.max(targetstroke, currentstroke - stroke_INCREMENT);                        }                    }                     mstrokes.add((int) currentstroke);                    targetstroke = variableWIDthDelta;                    float dx = Math.abs(eventX - mX);                    float dy = Math.abs(eventY - mY);                    if (dx >= touch_TolERANCE || dy >= touch_TolERANCE) {                        if(laststroke != variableWIDthDelta) {                            mPath.lineto(mX, mY);                            mPath = new Path();                            mPath.moveto(mX,mY);                            mPaths.add(mPath);                        }                        mPath.quadTo(mX, mY, (eventX + mX)/2, (eventY + mY)/2);                        mX = eventX;                        mY = eventY;                    }                    for (int i = 0; i < historySize; i++) {                        float historicalX = event.getHistoricalX(i);                        float historicalY = event.getHistoricalY(i);                        expandDirtyRect(historicalX, historicalY);                    }                    break;                }                case MotionEvent.ACTION_UP: {                    for (int i = 0; i < historySize; i++) {                        float historicalX = event.getHistoricalX(i);                        float historicalY = event.getHistoricalY(i);                        expandDirtyRect(historicalX, historicalY);                    }                   mPath.lineto(mX, mY);                                      break;                }            }            // Include half the stroke wIDth to avoID clipPing.            invalIDate();            lasttouchX = eventX;            lasttouchY = eventY;            laststroke = variableWIDthDelta;            return true;        }        private voID expandDirtyRect(float historicalX, float historicalY) {            if (historicalX < dirtyRect.left) {                dirtyRect.left = historicalX;            }  else if (historicalX > dirtyRect.right) {                dirtyRect.right = historicalX;            }            if (historicalY < dirtyRect.top) {                dirtyRect.top = historicalY;            } else if (historicalY > dirtyRect.bottom) {                dirtyRect.bottom = historicalY;            }        }        /**         * resets the dirty region when the motion event occurs.         */        private voID resetDirtyRect(float eventX, float eventY) {            // The lasttouchX and lasttouchY were set when the ACTION_DOWN            // motion event occurred.            dirtyRect.left = Math.min(lasttouchX, eventX);            dirtyRect.right = Math.max(lasttouchX, eventX);            dirtyRect.top = Math.min(lasttouchY, eventY);            dirtyRect.bottom = Math.max(lasttouchY, eventY);        }    }}

我得到的输出结果

我希望实现的输出

解决方法:

当您检测到更改时,您可以设置目标并插入目标,直到达到它为止,而不是立即跳到新的笔触宽度.你的mstrokes需要是floats而不是Integers.

private static final float stroke_DELTA = 0.0001f; // for float comparisonprivate static final float stroke_INCREMENT = 0.01f; // amount to interpolateprivate float currentstroke = stroke_WIDTH;private float targetstroke = stroke_WIDTH;

您当前为新笔触宽度创建新路径的位置,请执行以下 *** 作：

// if current not roughly equal to targetif( Math.abs(targetstroke - currentstroke) > stroke_DELTA ) {    // move towards target by the increment    if( targetstroke > currentstroke )        currentstroke = Math.min(targetstroke, currentstroke + stroke_INCREMENT);    else        currentstroke = Math.max(targetstroke, currentstroke - stroke_INCREMENT);    mPath.lineto(mX, mY);    mPath = new Path();    mPath.moveto(mX,mY);    mPaths.add(mPath);    mstrokes.add(currentstroke);}

您将更新当前设置variableWIDthDelta的targetstroke.

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