* @param {Scale} scale * @param {number} index * @param {boolean} offsetGridLines
(scale, index, offsetGridLines)
| 38 | * @param {boolean} offsetGridLines |
| 39 | */ |
| 40 | function getPixelForGridLine(scale, index, offsetGridLines) { |
| 41 | const length = scale.ticks.length; |
| 42 | const validIndex = Math.min(index, length - 1); |
| 43 | const start = scale._startPixel; |
| 44 | const end = scale._endPixel; |
| 45 | const epsilon = 1e-6; // 1e-6 is margin in pixels for accumulated error. |
| 46 | let lineValue = scale.getPixelForTick(validIndex); |
| 47 | let offset; |
| 48 | |
| 49 | if (offsetGridLines) { |
| 50 | if (length === 1) { |
| 51 | offset = Math.max(lineValue - start, end - lineValue); |
| 52 | } else if (index === 0) { |
| 53 | offset = (scale.getPixelForTick(1) - lineValue) / 2; |
| 54 | } else { |
| 55 | offset = (lineValue - scale.getPixelForTick(validIndex - 1)) / 2; |
| 56 | } |
| 57 | lineValue += validIndex < index ? offset : -offset; |
| 58 | |
| 59 | // Return undefined if the pixel is out of the range |
| 60 | if (lineValue < start - epsilon || lineValue > end + epsilon) { |
| 61 | return; |
| 62 | } |
| 63 | } |
| 64 | return lineValue; |
| 65 | } |
| 66 | |
| 67 | /** |
| 68 | * @param {object} caches |
no test coverage detected