75 lines
1.9 KiB
JavaScript
75 lines
1.9 KiB
JavaScript
import {diagonal, isSmaller, plus} from Geometry.Vector;
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import * as Vector from Geometry.Vector;
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import * as Encoder from Share.Encoder.Class;
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import {at, iter, square} from Grid.Util;
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import * as Grid from Grid.Util;
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import * as Protocol from Share.Protocol;
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return {
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grid: encodeGrid
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};
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function encodeGrid(grid) {
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var encoder = Encoder.make();
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var done = square(grid.length, false);
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var gradients = square(grid.length);
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iter(grid, function(_, cell) {
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if(!at(done, cell)) {
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let block = getLongestBlock(grid, cell);
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if(block.size >= Protocol.MIN_BLOCK_SIZE) {
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encodeBlock(encoder, done, block);
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} else {
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encodeSingleCell(
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encoder,
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getColorGradient(gradients, grid, done, cell)
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);
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}
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}
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});
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return encoder.output();
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}
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function getLongestBlock(grid, origin) {
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var color = at(grid, origin);
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var hSize = getStreak(Grid.row(grid, origin.row), origin.column, color);
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var vSize = getStreak(Grid.column(grid, origin.column), origin.row, color);
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return {
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isVertical: vSize > hSize,
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size: Math.max(hSize, vSize),
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color: color,
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origin: origin
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};
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}
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function getStreak(t, firstIndex, color) {
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var fromFirst = t.slice(firstIndex);
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var index = fromFirst.findIndex(
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function(x) {return x != color;}
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);
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return index >= 0 ? index : fromFirst.length;
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}
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function encodeBlock(encoder, done, block) {
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encoder.push(1);
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encoder.push(block.isVertical);
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encoder.variableLength6(block.size - Protocol.MIN_BLOCK_SIZE);
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encoder.int(3)(block.color);
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var cell = Vector.make(block.origin.row, block.origin.column);
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for(var i = 0; i < block.size; i++) {
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Grid.set(done, cell, true);
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cell[block.isVertical ? 'row' : 'column']++;
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}
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}
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function getColorGradient(gradients, grid, done, cell) {
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if(at(gradients, cell) == undefined) {
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}
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return at(gradients, cell);
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}
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function encodeSingleCell(encoder, direction) {
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encoder.push(0);
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encoder.int(2)(Protocol.directions.indexOf(direction));
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}
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