eBookReaderSwitch/mupdf/docs/examples/bbox-device.js

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function BBoxDevice(bbox) {
function extend(x,y) {
if (x < bbox[0]) bbox[0] = x;
if (x > bbox[2]) bbox[2] = x;
if (y < bbox[1]) bbox[1] = y;
if (y > bbox[3]) bbox[3] = y;
}
function extendPoint(m, px, py) {
var x = px * m[0] + py * m[2] + m[4];
var y = px * m[1] + py * m[3] + m[5];
extend(x, y);
}
function extendRect(m, r) {
var x0 = r[0], y0 = r[1];
var x1 = r[2], y1 = r[3];
extendPoint(m, x0, y0);
extendPoint(m, x1, y0);
extendPoint(m, x0, y1);
extendPoint(m, x1, y1);
}
function PathBounder(ctm) {
return {
moveTo: function (x,y) { extendPoint(ctm, x, y) },
lineTo: function (x,y) { extendPoint(ctm, x, y) },
curveTo: function (x1,y1,x2,y2,x3,y3) {
extendPoint(ctm, x1, y1);
extendPoint(ctm, x2, y2);
extendPoint(ctm, x3, y3);
},
};
}
function TextBounder(ctm) {
return {
showGlyph: function (font,trm,gid,ucs,wmode,bidi) {
var bbox = [ 0, -0.2, font.advanceGlyph(gid, 0), 0.8 ];
extendRect(Concat(trm, ctm), bbox);
},
};
}
return {
fillPath: function (path, evenOdd, ctm, colorSpace, color, alpha) {
path.walk(new PathBounder(ctm));
},
clipPath: function (path, evenOdd, ctm) {
path.walk(new PathBounder(ctm));
},
strokePath: function (path, stroke, ctm, colorSpace, color, alpha) {
path.walk(new PathBounder(ctm));
},
clipStrokePath: function (path, stroke, ctm) {
path.walk(new PathBounder(ctm));
},
fillText: function (text, ctm, colorSpace, color, alpha) {
text.walk(new TextBounder(ctm));
},
clipText: function (text, ctm) {
text.walk(new TextBounder(ctm));
},
strokeText: function (text, stroke, ctm, colorSpace, color, alpha) {
text.walk(new TextBounder(ctm));
},
clipStrokeText: function (text, stroke, ctm) {
text.walk(new TextBounder(ctm));
},
ignoreText: function (text, ctm) {
text.walk(new TextBounder(ctm));
},
fillShade: function (shade, ctm, alpha) {
var bbox = shade.bound(ctm);
extend(bbox[0], bbox[1]);
extend(bbox[2], bbox[3]);
},
fillImage: function (image, ctm, alpha) {
extendRect(ctm, [0,0,1,1]);
},
fillImageMask: function (image, ctm, colorSpace, color, alpha) {
extendRect(ctm, [0,0,1,1]);
},
};
}
if (scriptArgs.length != 2)
print("usage: mutool run bbox-device.js document.pdf pageNumber")
else {
var doc = new Document(scriptArgs[0]);
var page = doc.loadPage(parseInt(scriptArgs[1])-1);
var bbox = [Infinity, Infinity, -Infinity, -Infinity];
page.run(new BBoxDevice(bbox), Identity);
print("original bbox:", page.bound());
print("computed bbox:", bbox.map(function (x) { return Math.round(x); }));
}