82 lines
2.1 KiB
JavaScript
82 lines
2.1 KiB
JavaScript
import * as Encoder from Share.Encoder.Class;
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import {at, iter, square} 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 != undefined) {
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encodeBlock(encoder, block);
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} else {
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encodeSingleCell(
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encoder,
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getColorGradient(gradients, grid, cell)
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);
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}
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}
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});
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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 longestDirection = findLongestDirection(grid, origin, color);
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var size = extend(grid, origin, color, longestDirection);
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if(size >= Protocol.MIN_BLOCK_SIZE) {
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return {
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direction: longestDirection.coordinate == 'row' ? 'vertical' : 'horizontal',
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size: size,
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color: color
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};
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}
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}
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function findLongestDirection(grid, p, originColor) {
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var delta = 1;
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while(true) {
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var newRow = p.row + delta;
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var newColumn = p.column + delta;
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if(newRow >= grid.length || grid[newRow][p.column] != originColor) {
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return {coordinate: 'column', delta: delta};
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} else if(newColumn >= grid[p.row].length || grid[p.row][newColumn] != originColor) {
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return {coordinate: 'row', delta: delta+1};
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}
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delta++;
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}
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}
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function extend(grid, p, originColor, direction) {
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var origin = p[direction.coordinate];
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p[direction.coordinate] += direction.delta;
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while(isSmaller(p, diagonal(grid.length)) && at(grid, p) == originColor) {
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p[direction.coordinate]++;
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}
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return p[direction.coordinate] - origin;
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}
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function encodeBlock(encoder, block) {
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encoder.push(1);
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encoder.push(block.direction == 'vertical');
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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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}
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function getColorGradient(gradients, grid, 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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