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

package imagerender

import (
	"fmt"
	"image"
	"image/draw"
	"math"
	"strings"

	"golang.org/x/image/math/fixed"

	"github.com/unidoc/unipdf/v3/internal/transform"
)

func degreesToRadians(degrees float64) float64 {
	return degrees * math.Pi / 180
}

func imageToRGBA(src image.Image) *image.RGBA {
	bounds := src.Bounds()
	dst := image.NewRGBA(bounds)
	draw.Draw(dst, bounds, src, bounds.Min, draw.Src)
	return dst
}

func parseHexColor(x string) (r, g, b, a int) {
	x = strings.TrimPrefix(x, "#")
	a = 255
	if len(x) == 3 {
		format := "%1x%1x%1x"
		fmt.Sscanf(x, format, &r, &g, &b)
		r |= r << 4
		g |= g << 4
		b |= b << 4
	}
	if len(x) == 6 {
		format := "%02x%02x%02x"
		fmt.Sscanf(x, format, &r, &g, &b)
	}
	if len(x) == 8 {
		format := "%02x%02x%02x%02x"
		fmt.Sscanf(x, format, &r, &g, &b, &a)
	}
	return
}

func fixedPoint(p transform.Point) fixed.Point26_6 {
	return fixed.Point26_6{
		X: fix(p.X),
		Y: fix(p.Y),
	}
}

func fix(x float64) fixed.Int26_6 {
	return fixed.Int26_6(x * 64)
}

func unfix(x fixed.Int26_6) float64 {
	const shift, mask = 6, 1<<6 - 1
	if x >= 0 {
		return float64(x>>shift) + float64(x&mask)/64
	}
	x = -x
	if x >= 0 {
		return -(float64(x>>shift) + float64(x&mask)/64)
	}
	return 0
}