isPointInPathmethods

  • This method determines whether the (x,y) points are on the path, returning true if they are on the path, false otherwise
  • This method is mainly aimed atThe path, rightfillRectThere’s no effect here
  • This method applies to the current path. If the current path has multiple paths, this method applies only to the first subpath

Steps to draw a graph or image to the Canvas:

  • Draw the image onto an infinitely large transparent bitmap
  • Draws the shadows of the image onto another bitmap
  • The alpha component of each pixel in the shadow is multiplied by the one set in the drawing environmentglobalAlphaProperty value, which sets an opacity for each pixel
  • The above two bitmaps are combined for image synthesis, and the synthesis model parameters can be used during the operation

Drawing a rounded rectangle

  • If no specific pixel is specified, it can passlineJoinTo make the corners round

Rect creates a closed path, but ARC does not. If another subpath exists, arc uses a line segment to connect the end of the existing path to the beginning of the arc. Rect can only be created clockwise, and ARC can change the direction of the path with parameters

The question is how do you make sure that you’re in between pixels

  • Paths and subpaths

The junction of a line segment

When two line segments are connected, lineJoin = miter. You can use the miterLimit attribute to indicate the ratio of the length of the diagonal connection to the width of the half line. If the length of the tangent line exceeds this value. The browser draws the join points of the segments in beVEL mode

  • roundTo create a rounded rectangle
  • arcToTo create a rounded rectangle
  • lineToTo create a rule-based multilateralism

Bessel curve

unfinished

Image and video

  • drawImageparameter
    • drawImage(image,dx,dy)
    • If no target canvas width is passed in, the image is drawn with its original default size
    • drawImage(image,dx,dy,dw,dh)
    • drawImage(image,sx,sy,sw,sh,dx,dy,dw,dh)
    • In which the letterdThe variable at the beginning refers to the target canvas, to the lettersThe variable at the beginning refers to the source image
    • ifdrawImageIs passed in the video objectHTMLVideoElement, the method is to draw the current video frame