js / canvas填充地图 [英] js / canvas populate map

问题描述

我正在学习js和canvas.I'ed喜欢填充一个小瓷砖地图（例如，20px x 20px）到目前为止，我有一种填充它的字符，但瓷砖会更好。我必须得到一组小图像或有一种绘制瓷砖的方法吗？
我想我可以在主画布中创建大量的20x20画布，但我猜，这将是远离最佳。

I'm learning js and canvas.I'd like to populate a map with small tiles (eg. 20px by 20px) So far I've kind of populated it with characters but tiles would be better. Do I have to get a set of small images or is there a way of drawing the tiles? I guess I could create a lot of 20x20 canvases inside the main canvas but I guess that would be far from the optimal.

这是我到目前为止。

var mapArray = [
[0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0],
[0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0],
[0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0],
[0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0],
[0,0,0,0,0,1,1,1,1,1,0,0,0,0,0,0,0,0,0,0,0],
[0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0],
[0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0],
[0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0],
[0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0],
[0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0],
[0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0],
[0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0],
[0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0],
[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0],
[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0],
[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0],
[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0],
[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0],
[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0],
[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]
];

function popMap() {
    var canvas = document.getElementById('playground');
    var ctx = canvas.getContext('2d');

    ctx.font="18px Georgia";
    ctx.fillStyle="white";
    for (i=0;i<mapArray.length;i++) {
        for (j=0;j<mapArray.length;j++) {
            ctx.fillText(mapArray[i][j], i*20, j*20);
        }
    }
}

popMap();

顺便说一下，最后，我想制作一个简单的RPG游戏键在地图上移动），因此请在地图上提供最佳方法。谢谢。

By the way, eventually, I'd like to make a simple rpg game (a character controlled with keys moves over the map) out of it so please advise on the best approach on the map. Thank you.

推荐答案

以下是如何在您的游戏画布上绘制图块。

Here's how to draw tiles onto your game canvas.

开始使用这样的瓦片spritesheet图片：

Start with a tile spritesheet image like this:

左（草）图块由 mapArray value 0.右边的（粘土）图块由值1表示。

The left (grass) tile is represented by the mapArray value 0. The right (clay) tile is represented by the value 1.

然后在游戏画布的任何位置形式 drawImage 。

Then draw either tile at any position on the game canvas using the extended form of drawImage.

drawImage(

    // use the spritesheet image as the image source
    spritesheetImage, 

    // clip a portion from the spritesheet image
    clipAtX, clipAtY, clipWidth, clipHeight,

    // draw the clipped portion to the canvas
    canvasX, canvasY, scaledWidth, scaledHeight

);

以下是示例代码和演示：

Here's example code and a Demo:

var canvas=document.getElementById("canvas");
var ctx=canvas.getContext("2d");
var cw=canvas.width;
var ch=canvas.height;

var mapArray = [
  [0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0],
  [0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0],
  [0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0],
  [0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0],
  [0,0,0,0,0,1,1,1,1,1,0,0,0,0,0,0,0,0,0,0,0],
  [0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0],
  [0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0],
  [0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0],
  [0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0],
  [0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0],
  [0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0],
  [0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0],
  [0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0],
  [0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0],
  [0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0],
  [0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0],
  [0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0],
  [0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0],
  [0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0],
  [0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]
];

var tw=20;
var th=20;
var spritesheet=new Image();
spritesheet.onload=function(){
  canvas.width=tw*mapArray[0].length;
  canvas.height=th*mapArray.length;
  popMap();
}
spritesheet.src='https://dl.dropboxusercontent.com/u/139992952/multple/gametiles.png';

function popMap() {
  for (i=0;i<mapArray.length;i++) {
    for (j=0;j<mapArray[i].length;j++){
      var tile=mapArray[i][j];
      ctx.drawImage(spritesheet,
                    tile*20,0,tw,th,
                    j*20,i*20,tw,th

                   );
    }
  }
}

body{ background-color: ivory; }
#canvas{border:1px solid red; margin:0 auto; }

<canvas id="canvas" width=500 height=500></canvas>

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