From cfdc86fe2e8ca69a24972ee25e2cd9dd59358c30 Mon Sep 17 00:00:00 2001
From: Witold Filipczyk <witekfl@poczta.onet.pl>
Date: Mon, 9 Jun 2025 19:37:34 +0200
Subject: [PATCH] [kitty] Try to compress images

---
 src/cache/cache.h               |  1 +
 src/document/html/parser/link.c |  6 +++++-
 src/terminal/kitty.c            | 29 ++++++++++++++++++++++++++---
 src/terminal/kitty.h            |  3 ++-
 4 files changed, 34 insertions(+), 5 deletions(-)

diff --git a/src/cache/cache.h b/src/cache/cache.h
index 646aafecc..56300ddb4 100644
--- a/src/cache/cache.h
+++ b/src/cache/cache.h
@@ -82,6 +82,7 @@ struct cache_entry {
 
 	unsigned int sixel:1; /* Is in sixel format? */
 	unsigned int kitty:1; /* Is in kitty base64? */
+	unsigned int compressed:1; /* Is kitty zlib? */
 
 	cache_mode_T cache_mode;	/* Reload condition */
 };
diff --git a/src/document/html/parser/link.c b/src/document/html/parser/link.c
index 6afc6c4fa..c227a92cc 100644
--- a/src/document/html/parser/link.c
+++ b/src/document/html/parser/link.c
@@ -254,6 +254,7 @@ html_img_kitty(struct html_context *html_context, char *a,
 	int width = 0;
 	int height = 0;
 	int im_number = 0;
+	int compressed = 0;
 	char *url = get_attr_val(a, "src", html_context->doc_cp);
 
 	if (!url) {
@@ -277,8 +278,9 @@ html_img_kitty(struct html_context *html_context, char *a,
 						width = cached->width;
 						height = cached->height;
 						im_number = cached->number;
+						compressed = cached->compressed;
 					} else {
-						data = el_kitty_get_image(fragment->data, fragment->length, &datalen, &width, &height);
+						data = el_kitty_get_image(fragment->data, fragment->length, &datalen, &width, &height, &compressed);
 
 						if (data) {
 							(void)add_fragment(cached, 0, (const char *)data, datalen);
@@ -287,6 +289,7 @@ html_img_kitty(struct html_context *html_context, char *a,
 							cached->width = width;
 							cached->height = height;
 							cached->number = im_number = ++kitty_image_number;
+							cached->compressed = compressed;
 						}
 					}
 				}
@@ -322,6 +325,7 @@ html_img_kitty(struct html_context *html_context, char *a,
 	int y;
 	im->number = html_top->name - document->text.source;
 	im->ID = im_number;
+	im->compressed = compressed;
 
 	for (y = 0; y < how_many; y++) {
 		int x;
diff --git a/src/terminal/kitty.c b/src/terminal/kitty.c
index ee625e420..2b28bccdb 100644
--- a/src/terminal/kitty.c
+++ b/src/terminal/kitty.c
@@ -10,6 +10,10 @@
 #include <fcntl.h>
 #include <sys/stat.h>
 
+#ifdef CONFIG_GZIP
+#include <zlib.h>
+#endif
+
 #include "elinks.h"
 
 #include "document/document.h"
@@ -20,13 +24,13 @@
 #include "terminal/screen.h"
 #include "terminal/terminal.h"
 #include "util/base64.h"
-#include "util/memcount.h"
+#include "util/memory.h"
 
 #define STB_IMAGE_IMPLEMENTATION
 #include "terminal/stb_image.h"
 
 unsigned char *
-el_kitty_get_image(char *data, int length, int *outlen, int *width, int *height)
+el_kitty_get_image(char *data, int length, int *outlen, int *width, int *height, int *compressed)
 {
 	ELOG
 	int comp;
@@ -37,7 +41,25 @@ el_kitty_get_image(char *data, int length, int *outlen, int *width, int *height)
 		return NULL;
 	}
 	int size = *width * *height * 4;
+	*compressed = 0;
 
+#ifdef CONFIG_GZIP
+	unsigned char *complace = (unsigned char *)mem_alloc(size);
+
+	if (complace) {
+		unsigned long compsize = size;
+		int res = compress(complace, &compsize, pixels, size);
+
+		if (res == Z_OK) {
+			*compressed = 1;
+			b64 = base64_encode_bin(complace, compsize, outlen);
+			stbi_image_free(pixels);
+			mem_free(complace);
+			return b64;
+		}
+		mem_free(complace);
+	}
+#endif
 	b64 = base64_encode_bin(pixels, size, outlen);
 	stbi_image_free(pixels);
 
@@ -127,7 +149,7 @@ try_to_draw_k_images(struct terminal *term)
 			int sent = 0;
 			while (1) {
 				m = left >= 4000;
-				add_format_to_string(&text, "\033_Gf=32,I=%d,s=%d,v=%d,m=%d,t=d,a=T;", im->ID, im->width, im->height, m);
+				add_format_to_string(&text, "\033_Gf=32,I=%d,s=%d,v=%d,m=%d,t=d,a=T%s;", im->ID, im->width, im->height, m, (im->compressed ? ",o=z": ""));
 				add_bytes_to_string(&text, im->pixels.source + sent, m ? 4000 : left);
 				add_to_string(&text, "\033\\");
 				if (!m) {
@@ -200,6 +222,7 @@ copy_k_frame(struct k_image *src, struct el_box *box, int cell_width, int cell_h
 	dest->ID = src->ID;
 	dest->number = src->number;
 	dest->sent = src->sent;
+	dest->compressed = src->compressed;
 
 	return dest;
 }
diff --git a/src/terminal/kitty.h b/src/terminal/kitty.h
index f199c057a..2f24d8843 100644
--- a/src/terminal/kitty.h
+++ b/src/terminal/kitty.h
@@ -28,6 +28,7 @@ struct k_image {
 	int w;
 	int h;
 	unsigned int sent:1;
+	unsigned int compressed:1;
 };
 
 void delete_k_image(struct k_image *im);
@@ -39,7 +40,7 @@ int add_kitty_image_to_document(struct document *doc, const char *data, int data
 
 struct k_image *copy_k_frame(struct k_image *src, struct el_box *box, int cell_width, int cell_height, int dx, int dy);
 
-unsigned char *el_kitty_get_image(char *data, int len, int *outlen, int *width, int *height);
+unsigned char *el_kitty_get_image(char *data, int len, int *outlen, int *width, int *height, int *compressed);
 
 #endif