在2D视图中上下移动/调整画布上的线条
我正在使用Android应用程序进行备份相机模拟，需要绘制虚拟停车网格线（红色，黄色和绿色）。
的要求：
- 用户可以左右移动/调整停车线
（完成!!）。
- 用户能够上下移动网格线的每一边（in
2D，如果我正确的话）就像这个视频link一样（我是谁？
试图找出）
我想的是X应该是固定的，Y会根据用户输入而改变，无论是触摸还是按钮点击。
我是机器人的新手，我希望有人可以指引我走正确的道路。
在画布上绘制网格线的方法：
private void drawHorizontalLines(Canvas canvas){
Paint paintGreen = new Paint();
//Log.d(TAG, "Width = " + canvas.getClipBounds().width() + " Height = " + canvas.getClipBounds().height());
//if(this.getResources().getConfiguration().orientation == ORIENTATION_PORTRAIT)
if(inCalibrationMode == false)
getGridLines(canvas);
{
paintGreen.setStrokeWidth(10);
//Log.d(TAG, ""+ Math.tan(Math.toRadians(DISTANCE_GRID_ANGLE)));
//left side
paintGreen.setColor(Color.RED );
int topPoint = dangerousLineY;//height - (gridTopPoint*3)/10;
int bottomPoint = gridBottomPoint;
int letfPoint = gridLeftPoint;
canvas.drawLine(letfPoint, bottomPoint, letfPoint + (int) ((bottomPoint - topPoint) * Math.tan(Math.toRadians(DISTANCE_GRID_ANGLE))), topPoint, paintGreen);
letfPoint = dangerousLineXLeft; //letfPoint + (int) ((bottomPoint - topPoint) * Math.tan(Math.toRadians(DISTANCE_GRID_ANGLE)));
bottomPoint = topPoint;
canvas.drawLine(letfPoint, bottomPoint, letfPoint + 100, bottomPoint, paintGreen);
//letfPoint = letfPoint + 10;
bottomPoint -= 30;
letfPoint = letfPoint + (int) (30 * Math.tan(Math.toRadians(DISTANCE_GRID_ANGLE)));
topPoint = warningLineY;
paintGreen.setColor(Color.YELLOW);
canvas.drawLine(letfPoint, bottomPoint, letfPoint + (int) ((bottomPoint - topPoint) * Math.tan(Math.toRadians(DISTANCE_GRID_ANGLE + 5))), topPoint, paintGreen);
letfPoint = letfPoint + (int) ((bottomPoint - topPoint) * Math.tan(Math.toRadians(DISTANCE_GRID_ANGLE + 5)));
bottomPoint = topPoint;
canvas.drawLine(letfPoint, bottomPoint, letfPoint + 100, bottomPoint, paintGreen);
bottomPoint -= 30;
letfPoint = letfPoint + (int) (30 * Math.tan(Math.toRadians(DISTANCE_GRID_ANGLE + 5)));
topPoint = safeLineY;
paintGreen.setColor(Color.GREEN );
canvas.drawLine(letfPoint, bottomPoint, letfPoint + (int) ((bottomPoint - topPoint) * Math.tan(Math.toRadians(DISTANCE_GRID_ANGLE + 10))), topPoint, paintGreen);
letfPoint = letfPoint + (int) ((bottomPoint - topPoint) * Math.tan(Math.toRadians(DISTANCE_GRID_ANGLE + 10)));
bottomPoint = topPoint;
canvas.drawLine(letfPoint, bottomPoint, letfPoint + 100, bottomPoint, paintGreen);
//right side
paintGreen.setColor(Color.RED );
topPoint = dangerousLineY;
bottomPoint = gridBottomPoint;
int rightPoint = gridRightPoint;
canvas.drawLine(rightPoint, bottomPoint, rightPoint - (int) ((bottomPoint - topPoint) * Math.tan(Math.toRadians(DISTANCE_GRID_ANGLE))), topPoint, paintGreen);
rightPoint = dangerousLineXRight;
bottomPoint = topPoint;
canvas.drawLine(rightPoint, bottomPoint, rightPoint - 100, bottomPoint, paintGreen);
bottomPoint -= 30;
rightPoint = rightPoint - (int) (30 * Math.tan(Math.toRadians(DISTANCE_GRID_ANGLE)));
topPoint = warningLineY;
paintGreen.setColor(Color.YELLOW);
canvas.drawLine(rightPoint, bottomPoint, rightPoint - (int) ((bottomPoint - topPoint) * Math.tan(Math.toRadians(DISTANCE_GRID_ANGLE + 5))), topPoint, paintGreen);
rightPoint = rightPoint - (int) ((bottomPoint - topPoint) * Math.tan(Math.toRadians(DISTANCE_GRID_ANGLE + 5)));
bottomPoint = topPoint;
canvas.drawLine(rightPoint, bottomPoint, rightPoint - 100, bottomPoint, paintGreen);
bottomPoint -= 30;
rightPoint = rightPoint - (int) (30 * Math.tan(Math.toRadians(DISTANCE_GRID_ANGLE + 5)));
topPoint = safeLineY;
paintGreen.setColor(Color.GREEN);
canvas.drawLine(rightPoint, bottomPoint, rightPoint - (int) ((bottomPoint - topPoint) * Math.tan(Math.toRadians(DISTANCE_GRID_ANGLE + 10))), topPoint, paintGreen);
rightPoint = rightPoint - (int) ((bottomPoint - topPoint) * Math.tan(Math.toRadians(DISTANCE_GRID_ANGLE + 10)));
bottomPoint = topPoint;
canvas.drawLine(rightPoint, bottomPoint, rightPoint - 100, bottomPoint, paintGreen);
setLayerType(LAYER_TYPE_SOFTWARE, blue);
}
}
}
onTouchEvent左右移动网格
@Override
public boolean onTouchEvent(MotionEvent event) {
if (isInCalibrationMode()) {
float eventX = event.getX();
float eventY = event.getY();
Log.d(TAG, "-------------------------" + eventX + ":" + eventY);
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
//first check if we fall into the range of distance line
Log.d(TAG, "" + eventX + ":" + eventY);
if (inCalibrationMode == true) {
Log.d(TAG, "*" + safeLineXLeft + ":" + safeLineXRight + ":" + safeLineY);
if (
Math.abs(eventX - gridLeftPoint) <= DISTANCE_MOVE_RANGE && Math.abs(eventY - gridBottomPoint) <= DISTANCE_MOVE_RANGE
) {
//move left side
moveGrid = MOVE_GRID_LEFT;
} else if (
Math.abs(eventX - gridRightPoint) <= DISTANCE_MOVE_RANGE && Math.abs(eventY - gridBottomPoint) <= DISTANCE_MOVE_RANGE) {
//move right side
moveGrid = MOVE_GRID_RIGHT;
}
}
break;
case MotionEvent.ACTION_MOVE:
Log.d(TAG, "TOUCH MOVE");
if (moveGrid == MOVE_GRID_LEFT) {
gridLeftPoint = (int) eventX;
} else if (moveGrid == MOVE_GRID_RIGHT) {
gridRightPoint = (int) eventX;
} else if (moveGrid == MOVE_GRID_DANGEROUS) {
dangerousLineY = (int) eventY;
} else if (moveGrid == MOVE_GRID_WARNING) {
warningLineY = (int) eventY;
} else if (moveGrid == MOVE_GRID_SAFE) {
safeLineY = (int) eventY;
}
updateDistancePoints(); //update distance points when moving
break;
case MotionEvent.ACTION_UP:
// Log.d(TAG, "TOUCH UP");
//path.lineTo(eventX, eventY);
//slearScreen = true;
moveGrid = MOVE_GRID_NONE;
//Toast.makeText(getContext(), "test", Toast.LENGTH_SHORT).show();
break;
default:
return false;
}
// Schedules a repaint.
if (inCalibrationMode == true)
invalidate();
return true;
}
return false;
}
更新网格距离点
//update distance points method
private void updateDistancePoints(){
//gridTopPoint = height/2+10;
dangerousLineXLeft = gridLeftPoint + (int) ((gridBottomPoint - dangerousLineY) * Math.tan(Math.toRadians(DISTANCE_GRID_ANGLE)));
dangerousLineXRight = gridRightPoint - (int) ((gridBottomPoint - dangerousLineY) * Math.tan(Math.toRadians(DISTANCE_GRID_ANGLE)));
warningLineXLeft = gridLeftPoint +
(int) ((gridBottomPoint - (dangerousLineY - 30)) * Math.tan(Math.toRadians(DISTANCE_GRID_ANGLE))) +
(int) (((dangerousLineY - 30) - warningLineY) * Math.tan(Math.toRadians(DISTANCE_GRID_ANGLE+5)));
warningLineXRight = gridRightPoint -
(int) ((gridBottomPoint - (dangerousLineY - 30)) * Math.tan(Math.toRadians(DISTANCE_GRID_ANGLE))) -
(int) (((dangerousLineY - 30) - warningLineY) * Math.tan(Math.toRadians(DISTANCE_GRID_ANGLE+5)))+200; //test Samira
safeLineXLeft = gridLeftPoint +
(int) ((gridBottomPoint - (dangerousLineY - 30)) * Math.tan(Math.toRadians(DISTANCE_GRID_ANGLE))) +
(int) (((dangerousLineY - 30) - warningLineY) * Math.tan(Math.toRadians(DISTANCE_GRID_ANGLE+5))) +
(int) (((warningLineY) - safeLineY) * Math.tan(Math.toRadians(DISTANCE_GRID_ANGLE+10)));
safeLineXRight = gridRightPoint -
(int) ((gridBottomPoint - dangerousLineY - 30) * Math.tan(Math.toRadians(DISTANCE_GRID_ANGLE))) -
(int) (((dangerousLineY - 30) - warningLineY) * Math.tan(Math.toRadians(DISTANCE_GRID_ANGLE+5))) -
(int) (( warningLineY - safeLineY) * Math.tan(Math.toRadians(DISTANCE_GRID_ANGLE+10)));
}
谢谢
1 个答案:
答案 0 :(得分：0)
我可以按如下方式旋转线：
1-找到每条线的中心/旋转点（Xm，Ym）
Xm =（startX + stopX）/ 2;
Xy =（startY + stopY）/ 2;
2-计算新点以绘制线
x=a*cos(θ)-b*sin(θ)-Xm*cos(θ)+Ym*sin(θ)+Xm
y=a*sin(θ)+b*cos(θ)-Xm*sin(θ)-Ym*cos(θ)+Ym
（a，b）旧点。
3-使用上述旋转角度和公式编写一个绘制线条的函数
private void drawLinesRotate(Canvas canvas) {
Paint paint = new Paint();
paint.setStrokeWidth(10);
//rotation angle
SharedPreferences Angleprefs = this.getContext().getSharedPreferences("prefAngles", Context.MODE_PRIVATE);
double angle = Angleprefs.getFloat("angle", 0);
double rotateAngle = Math.toRadians(angle); //rotate angle has to be in radians
//rotation point on the left
SharedPreferences prefs = this.getContext().getSharedPreferences("prefRotate", Context.MODE_PRIVATE);
float cX_Left = prefs.getFloat("centerPointLeftX", 0);
float cY_Left = prefs.getFloat("centerPointLeftY", 0);
//*******left side*********
//RED line
paint.setColor(Color.RED);
int topPoint = dangerousLineY;
int bottomPoint = gridBottomPoint;
int leftPoint = gridLeftPoint;
int newX1 = (int) (Math.cos(rotateAngle) * ((float) leftPoint) - Math.sin(rotateAngle) * (float) bottomPoint - cX_Left * Math.cos(rotateAngle) + cY_Left * Math.sin(rotateAngle) + cX_Left);
int newY1 = (int) (Math.sin(rotateAngle) * leftPoint + bottomPoint * Math.cos(rotateAngle) - cX_Left * Math.sin(rotateAngle) - cY_Left * Math.cos(rotateAngle) + cY_Left);
int newX2 = (int) (Math.cos(rotateAngle) * (leftPoint + (int) ((bottomPoint - topPoint) * Math.tan(Math.toRadians(DISTANCE_GRID_ANGLE)))) - Math.sin(rotateAngle) * topPoint -
cX_Left * Math.cos(rotateAngle) + cY_Left * Math.sin(rotateAngle) + cX_Left);
int newY2 = (int) (Math.sin(rotateAngle) * (leftPoint + (int) ((bottomPoint - topPoint) * Math.tan(Math.toRadians(DISTANCE_GRID_ANGLE)))) + Math.cos(rotateAngle) * topPoint -
cX_Left * Math.sin(rotateAngle) - cY_Left * Math.cos(rotateAngle) + cY_Left);
canvas.drawLine(newX1, newY1, newX2, newY2, paint);
leftPoint = dangerousLineXLeft;
bottomPoint = topPoint;
//horizontal line
canvas.drawLine(newX2, newY2, newX2 + 100, newY2, paint);
// //YELLOW line
bottomPoint -= 30;
leftPoint = leftPoint + (int) (30 * Math.tan(Math.toRadians(DISTANCE_GRID_ANGLE)));
topPoint = warningLineY;
paint.setColor(Color.YELLOW);
newX1 = (int) (Math.cos(rotateAngle) * ((float) leftPoint) - Math.sin(rotateAngle) * (float) bottomPoint - cX_Left * Math.cos(rotateAngle) + cY_Left * Math.sin(rotateAngle) + cX_Left);
newY1 = (int) (Math.sin(rotateAngle) * leftPoint + bottomPoint * Math.cos(rotateAngle) - cX_Left * Math.sin(rotateAngle) - cY_Left * Math.cos(rotateAngle) + cY_Left);
newX2 = (int) (Math.cos(rotateAngle) * (leftPoint + (int) ((bottomPoint - topPoint) * Math.tan(Math.toRadians(DISTANCE_GRID_ANGLE + 5)))) - Math.sin(rotateAngle) * topPoint -
cX_Left * Math.cos(rotateAngle) + cY_Left * Math.sin(rotateAngle) + cX_Left);
newY2 = (int) (Math.sin(rotateAngle) * (leftPoint + (int) ((bottomPoint - topPoint) * Math.tan(Math.toRadians(DISTANCE_GRID_ANGLE + 5)))) + Math.cos(rotateAngle) * topPoint -
cX_Left * Math.sin(rotateAngle) - cY_Left * Math.cos(rotateAngle) + cY_Left);
canvas.drawLine(newX1, newY1, newX2, newY2, paint);
leftPoint = leftPoint + (int) ((bottomPoint - topPoint) * Math.tan(Math.toRadians(DISTANCE_GRID_ANGLE + 5)));
bottomPoint = topPoint;
canvas.drawLine(newX2, newY2, newX2 + 100, newY2, paint);
// //GREEN line
bottomPoint -= 30;
leftPoint = leftPoint + (int) (30 * Math.tan(Math.toRadians(DISTANCE_GRID_ANGLE + 5)));
topPoint = safeLineY;
paint.setColor(Color.GREEN);
newX1 = (int) (Math.cos(rotateAngle) * ((float) leftPoint) - Math.sin(rotateAngle) * (float) bottomPoint - cX_Left * Math.cos(rotateAngle) + cY_Left * Math.sin(rotateAngle) + cX_Left);
newY1 = (int) (Math.sin(rotateAngle) * leftPoint + bottomPoint * Math.cos(rotateAngle) - cX_Left * Math.sin(rotateAngle) - cY_Left * Math.cos(rotateAngle) + cY_Left);
newX2 = (int) (Math.cos(rotateAngle) * (leftPoint + (int) ((bottomPoint - topPoint) * Math.tan(Math.toRadians(DISTANCE_GRID_ANGLE + 10)))) - Math.sin(rotateAngle) * topPoint -
cX_Left * Math.cos(rotateAngle) + cY_Left * Math.sin(rotateAngle) + cX_Left);
newY2 = (int) (Math.sin(rotateAngle) * (leftPoint + (int) ((bottomPoint - topPoint) * Math.tan(Math.toRadians(DISTANCE_GRID_ANGLE + 10)))) + Math.cos(rotateAngle) * topPoint -
cX_Left * Math.sin(rotateAngle) - cY_Left * Math.cos(rotateAngle) + cY_Left);
canvas.drawLine(newX1, newY1, newX2, newY2, paint);
canvas.drawLine(newX2, newY2, newX2 + 100, newY2, paint);
//*******right side*********
//rotation point on the right
float cX_Right = prefs.getFloat("centerPointRightX", 0);
float cY_Right = prefs.getFloat("centerPointRightY", 0);
angle *= -1; //right side angle should be (-)
rotateAngle = Math.toRadians(angle);
//RED line
paint.setColor(Color.RED);
topPoint = dangerousLineY;
bottomPoint = gridBottomPoint;
int rightPoint = gridRightPoint;
newX1 = (int) (Math.cos(rotateAngle) * ((float) rightPoint) - Math.sin(rotateAngle) * (float) bottomPoint - cX_Right * Math.cos(rotateAngle) + cY_Right * Math.sin(rotateAngle) + cX_Right);
newY1 = (int) (Math.sin(rotateAngle) * rightPoint + bottomPoint * Math.cos(rotateAngle) - cX_Right * Math.sin(rotateAngle) - cY_Right * Math.cos(rotateAngle) + cY_Right);
newX2 = (int) (Math.cos(rotateAngle) * (rightPoint - (int) ((bottomPoint - topPoint) * Math.tan(Math.toRadians(DISTANCE_GRID_ANGLE)))) - Math.sin(rotateAngle) * topPoint -
cX_Right * Math.cos(rotateAngle) + cY_Right * Math.sin(rotateAngle) + cX_Right);
newY2 = (int) (Math.sin(rotateAngle) * (rightPoint - (int) ((bottomPoint - topPoint) * Math.tan(Math.toRadians(DISTANCE_GRID_ANGLE)))) + Math.cos(rotateAngle) * topPoint -
cX_Right * Math.sin(rotateAngle) - cY_Right * Math.cos(rotateAngle) + cY_Right);
canvas.drawLine(newX1, newY1, newX2, newY2, paint); //vertical line
//horizontal line
rightPoint = dangerousLineXRight;
bottomPoint = topPoint;
canvas.drawLine(newX2, newY2, newX2 - 100, newY2, paint);
//YELLOW line
bottomPoint -= 30;
rightPoint = rightPoint - (int) (30 * Math.tan(Math.toRadians(DISTANCE_GRID_ANGLE)));
topPoint = warningLineY;
paint.setColor(Color.YELLOW);
newX1 = (int) (Math.cos(rotateAngle) * ((float) rightPoint) - Math.sin(rotateAngle) * (float) bottomPoint - cX_Right * Math.cos(rotateAngle) + cY_Right * Math.sin(rotateAngle) + cX_Right);
newY1 = (int) (Math.sin(rotateAngle) * rightPoint + bottomPoint * Math.cos(rotateAngle) - cX_Right * Math.sin(rotateAngle) - cY_Right * Math.cos(rotateAngle) + cY_Right);
newX2 = (int) (Math.cos(rotateAngle) * (rightPoint - (int) ((bottomPoint - topPoint) * Math.tan(Math.toRadians(DISTANCE_GRID_ANGLE + 5)))) - Math.sin(rotateAngle) * topPoint -
cX_Right * Math.cos(rotateAngle) + cY_Right * Math.sin(rotateAngle) + cX_Right);
newY2 = (int) (Math.sin(rotateAngle) * (rightPoint - (int) ((bottomPoint - topPoint) * Math.tan(Math.toRadians(DISTANCE_GRID_ANGLE + 5)))) + Math.cos(rotateAngle) * topPoint -
cX_Right * Math.sin(rotateAngle) - cY_Right * Math.cos(rotateAngle) + cY_Right);
canvas.drawLine(newX1, newY1, newX2, newY2, paint); //vertical line
//horizontal line
rightPoint = rightPoint - (int) ((bottomPoint - topPoint) * Math.tan(Math.toRadians(DISTANCE_GRID_ANGLE + 5)));
bottomPoint = topPoint;
canvas.drawLine(newX2, newY2, newX2 - 100, newY2, paint);
//GREEN line
bottomPoint -= 30;
rightPoint = rightPoint - (int) (30 * Math.tan(Math.toRadians(DISTANCE_GRID_ANGLE + 5)));
topPoint = safeLineY;
paint.setColor(Color.GREEN);
newX1 = (int) (Math.cos(rotateAngle) * ((float) rightPoint) - Math.sin(rotateAngle) * (float) bottomPoint - cX_Right * Math.cos(rotateAngle) + cY_Right * Math.sin(rotateAngle) + cX_Right);
newY1 = (int) (Math.sin(rotateAngle) * rightPoint + bottomPoint * Math.cos(rotateAngle) - cX_Right * Math.sin(rotateAngle) - cY_Right * Math.cos(rotateAngle) + cY_Right);
newX2 = (int) (Math.cos(rotateAngle) * (rightPoint - (int) ((bottomPoint - topPoint) * Math.tan(Math.toRadians(DISTANCE_GRID_ANGLE + 10)))) - Math.sin(rotateAngle) * topPoint -
cX_Right * Math.cos(rotateAngle) + cY_Right * Math.sin(rotateAngle) + cX_Right);
newY2 = (int) (Math.sin(rotateAngle) * (rightPoint - (int) ((bottomPoint - topPoint) * Math.tan(Math.toRadians(DISTANCE_GRID_ANGLE + 10)))) + Math.cos(rotateAngle) * topPoint -
cX_Right * Math.sin(rotateAngle) - cY_Right * Math.cos(rotateAngle) + cY_Right);
canvas.drawLine(newX1, newY1, newX2, newY2, paint); //vertical line
//horizontal line
canvas.drawLine(newX2, newY2, newX2 - 100, newY2, paint);
}
按钮点击（有2个按钮）增加/减少旋转角度并将其保存在SharedPreferences中。还必须保存旋转点，因为我还左右移动线。在onDraw(Canvas canvas)上调用此方法。为了更好地可视化我绘制的线条，请参阅附带的屏幕截图。
我相信那里有更好的解决方案，但这对我有用。
希望能帮到别人。
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