package gofpdi
import (
"strings"
)
// Determine if a value is numeric
// Courtesy of https://github.com/syyongx/php2go/blob/master/php.go
func is_numeric(val interface{}) bool {
switch val.(type) {
case int, int8, int16, int32, int64, uint, uint8, uint16, uint32, uint64:
case float32, float64, complex64, complex128:
return true
case string:
str := val.(string)
if str == "" {
return false
}
// Trim any whitespace
str = strings.TrimSpace(str)
//fmt.Println(str)
if str[0] == '-' || str[0] == '+' {
if len(str) == 1 {
return false
}
str = str[1:]
}
// hex
if len(str) > 2 && str[0] == '0' && (str[1] == 'x' || str[1] == 'X') {
for _, h := range str[2:] {
if !((h >= '0' && h <= '9') || (h >= 'a' && h <= 'f') || (h >= 'A' && h <= 'F')) {
return false
}
}
return true
}
// 0-9,Point,Scientific
p, s, l := 0, 0, len(str)
for i, v := range str {
if v == '.' { // Point
if p > 0 || s > 0 || i+1 == l {
return false
}
p = i
} else if v == 'e' || v == 'E' { // Scientific
if i == 0 || s > 0 || i+1 == l {
return false
}
s = i
} else if v < '0' || v > '9' {
return false
}
}
return true
}
return false
}
func in_array(needle interface{}, hystack interface{}) bool {
switch key := needle.(type) {
case string:
for _, item := range hystack.([]string) {
if key == item {
return true
}
}
case int:
for _, item := range hystack.([]int) {
if key == item {
return true
}
}
case int64:
for _, item := range hystack.([]int64) {
if key == item {
return true
}
}
default:
return false
}
return false
}
// Taken from png library
// intSize is either 32 or 64.
const intSize = 32 << (^uint(0) >> 63)
func abs(x int) int {
// m := -1 if x < 0. m := 0 otherwise.
m := x >> (intSize - 1)
// In two's complement representation, the negative number
// of any number (except the smallest one) can be computed
// by flipping all the bits and add 1. This is faster than
// code with a branch.
// See Hacker's Delight, section 2-4.
return (x ^ m) - m
}
// filterPaeth applies the Paeth filter to the cdat slice.
// cdat is the current row's data, pdat is the previous row's data.
func filterPaeth(cdat, pdat []byte, bytesPerPixel int) {
var a, b, c, pa, pb, pc int
for i := 0; i < bytesPerPixel; i++ {
a, c = 0, 0
for j := i; j < len(cdat); j += bytesPerPixel {
b = int(pdat[j])
pa = b - c
pb = a - c
pc = abs(pa + pb)
pa = abs(pa)
pb = abs(pb)
if pa <= pb && pa <= pc {
// No-op.
} else if pb <= pc {
a = b
} else {
a = c
}
a += int(cdat[j])
a &= 0xff
cdat[j] = uint8(a)
c = b
}
}
}