From dfd363a962df8ee4afb3d7a254a923301f082b29 Mon Sep 17 00:00:00 2001
From: Azuma Fan <azuma@theplant.jp>
Date: Mon, 8 Jun 2020 16:43:04 +0800
Subject: [PATCH] support Palette option for png

---
 options.go | 1 +
 resizer.go | 1 +
 vips.go    | 4 +++-
 vips.h     | 5 +++--
 4 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/options.go b/options.go
index dd59031..5212ef9 100644
--- a/options.go
+++ b/options.go
@@ -225,4 +225,5 @@ type Options struct {
 	Gamma          float64
 	OutputICC      string
 	InputICC       string
+	Palette        bool
 }
diff --git a/resizer.go b/resizer.go
index 461af5e..6056f7b 100644
--- a/resizer.go
+++ b/resizer.go
@@ -176,6 +176,7 @@ func saveImage(image *C.VipsImage, o Options) ([]byte, error) {
 		OutputICC:      o.OutputICC,
 		StripMetadata:  o.StripMetadata,
 		Lossless:       o.Lossless,
+		Palette:        o.Palette,
 	}
 	// Finally get the resultant buffer
 	return vipsSave(image, saveOptions)
diff --git a/vips.go b/vips.go
index 77dd7ac..2e233eb 100644
--- a/vips.go
+++ b/vips.go
@@ -55,6 +55,7 @@ type vipsSaveOptions struct {
 	InputICC       string // Absolute path to the input ICC profile
 	OutputICC      string // Absolute path to the output ICC profile
 	Interpretation Interpretation
+	Palette        bool
 }
 
 type vipsWatermarkOptions struct {
@@ -458,6 +459,7 @@ func vipsSave(image *C.VipsImage, o vipsSaveOptions) ([]byte, error) {
 	quality := C.int(o.Quality)
 	strip := C.int(boolToInt(o.StripMetadata))
 	lossless := C.int(boolToInt(o.Lossless))
+	palette := C.int(boolToInt(o.Palette))
 
 	if o.Type != 0 && !IsTypeSupportedSave(o.Type) {
 		return nil, fmt.Errorf("VIPS cannot save to %#v", ImageTypes[o.Type])
@@ -467,7 +469,7 @@ func vipsSave(image *C.VipsImage, o vipsSaveOptions) ([]byte, error) {
 	case WEBP:
 		saveErr = C.vips_webpsave_bridge(tmpImage, &ptr, &length, strip, quality, lossless)
 	case PNG:
-		saveErr = C.vips_pngsave_bridge(tmpImage, &ptr, &length, strip, C.int(o.Compression), quality, interlace)
+		saveErr = C.vips_pngsave_bridge(tmpImage, &ptr, &length, strip, C.int(o.Compression), quality, interlace, palette)
 	case TIFF:
 		saveErr = C.vips_tiffsave_bridge(tmpImage, &ptr, &length)
 	case HEIF:
diff --git a/vips.h b/vips.h
index 69e3903..4107d17 100644
--- a/vips.h
+++ b/vips.h
@@ -309,13 +309,14 @@ vips_jpegsave_bridge(VipsImage *in, void **buf, size_t *len, int strip, int qual
 }
 
 int
-vips_pngsave_bridge(VipsImage *in, void **buf, size_t *len, int strip, int compression, int quality, int interlace) {
-#if (VIPS_MAJOR_VERSION >= 8 || (VIPS_MAJOR_VERSION >= 7 && VIPS_MINOR_VERSION >= 42))
+vips_pngsave_bridge(VipsImage *in, void **buf, size_t *len, int strip, int compression, int quality, int interlace, int palette) {
+#if (VIPS_MAJOR_VERSION >= 8 &&  VIPS_MINOR_VERSION >= 7)
 	return vips_pngsave_buffer(in, buf, len,
 		"strip", INT_TO_GBOOLEAN(strip),
 		"compression", compression,
 		"interlace", INT_TO_GBOOLEAN(interlace),
 		"filter", VIPS_FOREIGN_PNG_FILTER_ALL,
+        "palette", INT_TO_GBOOLEAN(palette),
 		NULL
 	);
 #else