Result.go

/*
Copyright (c) 2016, The go-imagequant author(s)

Permission to use, copy, modify, and/or distribute this software for any purpose
with or without fee is hereby granted, provided that the above copyright notice
and this permission notice appear in all copies.

THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH REGARD TO
THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS.
IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR
CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA
OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
SOFTWARE.
*/

package imagequant

import (
	"image/color"
	"unsafe"
)

/*
#include "libimagequant.h"
*/
import "C"

// Callers must not use this object once Release has been called on the parent
// Image struct.
type Result struct {
	p  *C.struct_liq_result
	im *Image
}

func (this *Result) SetDitheringLevel(dither_level float32) error {
	return translateError(C.liq_set_dithering_level(this.p, C.float(dither_level)))
}

func (this *Result) GetQuantizationError() float64 {
	return float64(C.liq_get_quantization_error(this.p))
}

func (this *Result) GetRemappingError() float64 {
	return float64(C.liq_get_remapping_error(this.p))
}

func (this *Result) GetQuantizationQuality() float64 {
	return float64(C.liq_get_quantization_quality(this.p))
}

func (this *Result) GetRemappingQuality() float64 {
	return float64(C.liq_get_remapping_quality(this.p))
}

func (this *Result) SetOutputGamma(gamma float64) error {
	return translateError(C.liq_set_output_gamma(this.p, C.double(gamma)))
}

func (this *Result) GetImageWidth() int {
	// C.liq_image_get_width
	return this.im.w
}

func (this *Result) GetImageHeight() int {
	// C.liq_image_get_height
	return this.im.h
}

func (this *Result) GetOutputGamma() float64 {
	return float64(C.liq_get_output_gamma(this.p))
}

func (this *Result) WriteRemappedImage() ([]byte, error) {
	if this.im.released {
		return nil, ErrUseAfterFree
	}

	buff_size := this.im.w * this.im.h
	buff := make([]byte, buff_size)

	iqe := C.liq_write_remapped_image(this.p, this.im.p, unsafe.Pointer(&buff[0]), C.size_t(buff_size))
	if iqe != C.LIQ_OK {
		return nil, translateError(iqe)
	}

	return buff, nil
}

func (this *Result) GetPalette() color.Palette {
	ptr := C.liq_get_palette(this.p) // copy struct content
	max := int(ptr.count)

	ret := make([]color.Color, max)
	for i := 0; i < max; i += 1 {
		ret[i] = color.RGBA{
			R: uint8(ptr.entries[i].r),
			G: uint8(ptr.entries[i].g),
			B: uint8(ptr.entries[i].b),
			A: uint8(ptr.entries[i].a),
		}
	}

	return ret
}

// Free memory. Callers must not use this object after Release has been called.
func (this *Result) Release() {
	C.liq_result_destroy(this.p)
}