100 lines
2.3 KiB
JavaScript
100 lines
2.3 KiB
JavaScript
/**
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* render - renders the universe to a 2D canvas.
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*
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* @param langtonsAnt - the universe.
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* @param canvas - The 2D canvas.
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* @param options - The rendering options (all optional).
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* @returns {undefined} - Nothing is returned.
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*/
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function render(langtonsAnt, canvas, options) {
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// Grab our options.
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const {
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tileStateColors,
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antStateColors,
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tileSize
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} = options;
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// Drawing style.
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const backgroundColor = '#FFFFFF';
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// Size constants.
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const w = canvas.width;
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const h = canvas.height;
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// Bounds constants.
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const gridSizeW = langtonsAnt.tiles.length;
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const gridSizeH = langtonsAnt.tiles[0].length;
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// We're going to draw each square with a given edge size
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const tileSizeW = tileSize//w / gridSizeW ;
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const tileSizeH = tileSize //h / gridSizeH ;
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// Get the drawing context.
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var ctx = canvas.getContext('2d');
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// Clear the background.
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ctx.fillStyle = backgroundColor;
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ctx.fillRect(0, 0, w, h);
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// Draw the grid.
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ctx.strokeStyle='#00000011';
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for (let x = 0; x <= gridSizeW; x++) {
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ctx.beginPath();
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ctx.moveTo(x * tileSizeW , 0);
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ctx.lineTo(x * tileSizeW , h);
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ctx.closePath();
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ctx.stroke();
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}
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for (let y = 0 ; y <= gridSizeH; y++) {
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ctx.beginPath();
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ctx.moveTo(0, y * tileSizeH);
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ctx.lineTo(w, y * tileSizeH);
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ctx.closePath();
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ctx.stroke();
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}
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// Start drawing those tiles.
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langtonsAnt.tiles.forEach((tileRow,i) => {
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tileRow.forEach((tile,j)=>{
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// Get the tile state index.
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// Skip state zero tiles (i.e. white tiles)
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if (tile !== 0) {
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// Set the tile colour, defaulting to grey if it is not set.
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ctx.fillStyle = tileStateColors[tile] || '#CCCCCC';
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ctx.fillRect(i * tileSizeW + 1, j * tileSizeH +1, tileSizeW - 1, tileSizeH - 1);
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}
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})
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})
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// Draw the ant.
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var antX = langtonsAnt.x * tileSizeW,
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antY = langtonsAnt.y * tileSizeH;
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const antState = langtonsAnt.state;
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ctx.fillStyle = antStateColors[antState];
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// Tranform before we draw the ant, it makes it easier.
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//
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ctx.save();
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ctx.translate(antX + tileSizeW/2, antY+tileSizeH/2);
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ctx.rotate((langtonsAnt.direction / 180) * Math.PI);
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ctx.beginPath();
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ctx.moveTo(-tileSizeW/2, -tileSizeH/2);
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ctx.lineTo(tileSizeW/2, 0);
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ctx.lineTo(-tileSizeW/2, tileSizeH/2);
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ctx.fill();
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ctx.closePath();
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ctx.restore();
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}
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export default render;
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