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Merge pull request #15715 from Snuffleupagus/getQuadPoints-refactor

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Re-factor and simplify the `getQuadPoints` helper function
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Jonas Jenwald 2022-11-25 12:38:52 +01:00 committed by GitHub
commit 4f1b6f345b
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1 changed files with 34 additions and 43 deletions
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77
src/core/annotation.js
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@ -367,10 +367,6 @@ function getPdfColorArray(color) {
}
function getQuadPoints(dict, rect) {
if (!dict.has("QuadPoints")) {
return null;
}
// The region is described as a number of quadrilaterals.
// Each quadrilateral must consist of eight coordinates.
const quadPoints = dict.getArray("QuadPoints");
@ -387,54 +383,49 @@ function getQuadPoints(dict, rect) {
// Each series of eight numbers represents the coordinates for one
// quadrilateral in the order [x1, y1, x2, y2, x3, y3, x4, y4].
// Convert this to an array of objects with x and y coordinates.
quadPointsLists.push([]);
let minX = Infinity,
maxX = -Infinity,
minY = Infinity,
maxY = -Infinity;
for (let j = i * 8, jj = i * 8 + 8; j < jj; j += 2) {
const x = quadPoints[j];
const y = quadPoints[j + 1];
// The quadpoints should be ignored if any coordinate in the array
// lies outside the region specified by the rectangle. The rectangle
// can be `null` for markup annotations since their rectangle may be
// incorrect (fixes bug 1538111).
if (
rect !== null &&
(x < rect[0] || x > rect[2] || y < rect[1] || y > rect[3])
) {
return null;
}
quadPointsLists[i].push({ x, y });
minX = Math.min(x, minX);
maxX = Math.max(x, maxX);
minY = Math.min(y, minY);
maxY = Math.max(y, maxY);
}
}
// The PDF specification states in section 12.5.6.10 (figure 64) that the
// order of the quadpoints should be bottom left, bottom right, top right
// and top left. However, in practice PDF files use a different order,
// namely bottom left, bottom right, top left and top right (this is also
// mentioned on https://github.com/highkite/pdfAnnotate#QuadPoints), so
// this is the actual order we should work with. However, the situation is
// even worse since Adobe's own applications and other applications violate
// the specification and create annotations with other orders, namely top
// left, top right, bottom left and bottom right or even top left, top right,
// bottom right and bottom left. To avoid inconsistency and broken rendering,
// we normalize all lists to put the quadpoints in the same standard order
// (see https://stackoverflow.com/a/10729881).
return quadPointsLists.map(quadPointsList => {
const [minX, maxX, minY, maxY] = quadPointsList.reduce(
([mX, MX, mY, MY], quadPoint) => [
Math.min(mX, quadPoint.x),
Math.max(MX, quadPoint.x),
Math.min(mY, quadPoint.y),
Math.max(MY, quadPoint.y),
],
[Number.MAX_VALUE, Number.MIN_VALUE, Number.MAX_VALUE, Number.MIN_VALUE]
);
return [
// The quadpoints should be ignored if any coordinate in the array
// lies outside the region specified by the rectangle. The rectangle
// can be `null` for markup annotations since their rectangle may be
// incorrect (fixes bug 1538111).
if (
rect !== null &&
(minX < rect[0] || maxX > rect[2] || minY < rect[1] || maxY > rect[3])
) {
return null;
}
// The PDF specification states in section 12.5.6.10 (figure 64) that the
// order of the quadpoints should be bottom left, bottom right, top right
// and top left. However, in practice PDF files use a different order,
// namely bottom left, bottom right, top left and top right (this is also
// mentioned on https://github.com/highkite/pdfAnnotate#QuadPoints), so
// this is the actual order we should work with. However, the situation is
// even worse since Adobe's own applications and other applications violate
// the specification and create annotations with other orders, namely top
// left, top right, bottom left and bottom right or even top left,
// top right, bottom right and bottom left. To avoid inconsistency and
// broken rendering, we normalize all lists to put the quadpoints in the
// same standard order (see https://stackoverflow.com/a/10729881).
quadPointsLists.push([
{ x: minX, y: maxY },
{ x: maxX, y: maxY },
{ x: minX, y: minY },
{ x: maxX, y: minY },
];
});
]);
}
return quadPointsLists;
}
function getTransformMatrix(rect, bbox, matrix) {