unipdf/extractor/text_utils.go

/*
 * This file is subject to the terms and conditions defined in
 * file 'LICENSE.md', which is part of this source code package.
 */

package extractor

import (
	"fmt"
	"math"
	"path/filepath"
	"runtime"
)

// serial is used to add serial numbers to all text* instances.
var serial serialState

// serialState keeps serial number for text* structs.
type serialState struct {
	mark   int // textMark
	word   int // textWord
	strata int // textStrata
	line   int // textLine
	para   int // textPara
}

// reset resets `serial` to all zeros.
func (serial *serialState) reset() {
	var empty serialState
	*serial = empty
}

// TOL is the tolerance for coordinates to be consideted equal. It is big enough to cover all
// rounding errors and small enough that TOL point differences on a page aren't visible.
const TOL = 1.0e-6

// isZero returns true if x is with TOL of 0.0
func isZero(x float64) bool {
	return math.Abs(x) < TOL
}

// minInt return the lesser of `a` and `b`.
func minInt(a, b int) int {
	if a < b {
		return a
	}
	return b
}

// maxInt return the greater of `a` and `b`.
func maxInt(a, b int) int {
	if a > b {
		return a
	}
	return b
}

// fileLine printed out a file:line string for the caller `skip` levels up the call stack.
func fileLine(skip int, doSecond bool) string {
	_, file, line, ok := runtime.Caller(skip + 1)
	if !ok {
		file = "???"
		line = 0
	} else {
		file = filepath.Base(file)
	}
	depth := fmt.Sprintf("%s:%-4d", file, line)
	if !doSecond {
		return depth
	}
	_, _, line2, _ := runtime.Caller(skip + 2)
	return fmt.Sprintf("%s:%-4d", depth, line2)
}