fillRect method

Artículo
05/02/2017

Paints a rectangle onto a CanvasRenderingContext2D object by using the current ICanvasRenderingContext2D::fillStyle.

Syntax

object.fillRect(x, y, w, h);

Parameters

x [in]
Type: number

The x-coordinate, in pixels, of the upper-left corner of the rectangle in relation to the coordinates of the canvas.
y [in]
Type: number

The y-coordinate, in pixels, of the upper-left corner of the rectangle in relation to the coordinates of the canvas.
w [in]
Type: number

The width, in pixels, of the rectangle in relation to the coordinates of the canvas.
h [in]
Type: number

The height, in pixels, of the rectangle in relation to the coordinates of the canvas.

Return value

This method does not return a value.

Standards information

HTML Canvas 2D Context, Section 8

Remarks

If the w or h parameter is zero, the ICanvasRenderingContext2D::fillRect method does not draw the rectangle.

Examples

This example shows the how to use fillRect with a video for the pattern. The video pattern works best when the video size is small. The width of the canvas is automatically scaled to the IHTMLWindow7::innerWidth of the browser window. If you expand your window, refresh the example.

<!DOCTYPE html> 
<html>
  <head>
    <title>Video pattern example</title>   
    <!-- only force Internet Explorer standards mode for testing on local or intranet machine -->
    <!-- <meta http-equiv="X-UA-Compatible" content="IE=edge" /> -->
    <style>
      button {
      width:150px;
      }

    </style>
  </head>
  <body>

    <table>
      <tr>
        <td> 
          <div>
            <h1>Canvas Patterns with Video</h1>
            <h3>Make your page full screen, and click the buttons to change the view</h3>
            <button onclick="draw('repeat')">Repeat all</button>
            <button onclick="draw('repeat-x')">Repeat across</button> 
            <button onclick="draw('repeat-y')">Repeat down</button>
            <button onclick="draw('no-repeat')">No Repeat</button><br />     
            <label>Enter a video URL: <input type="text" id="videoSrc" size="80" value="http://ie.microsoft.com/testdrive/ieblog/2011/nov/pp4_blog_demo.mp4" /></label> <br />
          </div>
        </td>
        <td>  
          <video id="pix" controls autoplay width="300">
            This browser or document mode doesn't support video
          </video><br />
        </td>
      </tr>
    </table>   
    <canvas id="MyCanvas" width="2000" height="2000">This browser or document mode doesn't support canvas</canvas>
    <script >
      // Some global variables    
      var canvas = document.getElementById("MyCanvas");
      var lastDirection;
      var timerID;
      var pattern;
      var lastSrc;
      var video = document.getElementById("pix"); // Get the video object.
      //  Check for canvas, and get context
      if (canvas.getContext) {
        var ctx = canvas.getContext("2d");  // Get the context.
        //  Optionally set based on window width/height
   //     canvas.width = window.innerWidth;  // Set canvas width and height
   //     canvas.height = window.innerHeight;
        var w = canvas.width;  // Set up w and h for loop below.              
        var h = canvas.height;
      }

      function draw(direction) {
        if (ctx) {
          var src = document.getElementById("videoSrc").value;
          if (src == "") {
            return false;
          }

          if (lastSrc != src) {   // Change of video
            video.src = src;    // Assign the video src
            lastSrc = src;      // Reassign lastSrc          
            video.load();       // Load src into video control
            video.play();       // Play it
          }

          // Clear the screen every time a new direction is selected.
          if (lastDirection != direction) {  // Check if direction has changed
            window.cancelAnimationFrame(timerID);
            ctx.clearRect(0, 0, canvas.width, canvas.height);    // Clear the last image.
            lastDirection = direction;  // Reset the direction flag
          }
          draw2();
        }
      }

      function draw2() {
        if (video.paused || video.ended) {
          return false;
        } // Stop loop when video ends
        pattern = ctx.createPattern(video, lastDirection); // Get the video frame   
        ctx.fillStyle = pattern;  // Assign pattern as a fill style. 
        ctx.fillRect(0, 0, w, h); // Fill the canvas. 
        timerID = window.requestAnimationFrame(draw2);
      }
      draw("repeat");   // Start video when loaded
    </script>
  </body>
</html>

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