WiP: Add Tight PNG encoding

Makefile

@@ -1,4 +1,4 @@
-DEPENDENCIES := pixman-1 libuv libturbojpeg
+DEPENDENCIES := pixman-1 libuv libturbojpeg libpng
 
 SOURCES := \
 	src/server.c \
@@ -19,7 +19,7 @@ DSO_NAME=libneatvnc
 DSO_MAJOR=0
 DSO_MINOR=0
 
-CFLAGS += -fvisibility=hidden -Icontrib/miniz
+CFLAGS += -fvisibility=hidden -Icontrib/miniz -DENABLE_TIGHT
 OBJECTS += $(BUILD_DIR)/miniz.o
 
 DSO_PATH := $(BUILD_DIR)/$(DSO_NAME)

include/rfb-proto.h

@@ -51,6 +51,7 @@ enum rfb_encodings {
 	RFB_ENCODING_RRE = 2,
 	RFB_ENCODING_HEXTILE = 5,
 	RFB_ENCODING_TIGHT = 7,
+	RFB_ENCODING_TIGHT_PNG = -260,
 	RFB_ENCODING_TRLE = 15,
 	RFB_ENCODING_ZRLE = 16,
 	RFB_ENCODING_CURSOR = -239,

meson.build

@@ -11,6 +11,7 @@ project(
 add_project_arguments([
 	'-D_GNU_SOURCE',
 	'-fvisibility=hidden',
+	'-DENABLE_TIGHT',
 ], language: 'c')
 
 cpu = host_machine.cpu_family()
@@ -36,6 +37,7 @@ libm = cc.find_library('m', required: false)
 pixman = dependency('pixman-1')
 libuv = dependency('libuv')
 libturbojpeg = dependency('libturbojpeg')
+libpng = dependency('libpng')
 
 inc = include_directories('include', 'contrib/miniz')
 
@@ -57,6 +59,7 @@ dependencies = [
 	pixman,
 	libuv,
 	libturbojpeg,
+	libpng,
 ]
 
 neatvnc = shared_library(

src/tight.c

@@ -4,9 +4,12 @@
 #include "fb.h"
 #include "tight.h"
 #include "common.h"
+#include "pixels.h"
+#include "rfb-proto.h"
 
 #include <pixman.h>
 #include <turbojpeg.h>
+#include <png.h>
 #include <stdlib.h>
 #include <libdrm/drm_fourcc.h>
 
@@ -44,7 +47,7 @@ static void tight_encode_size(struct vec* dst, size_t size)
 		vec_fast_append_8(dst, (size >> 14) & 0x7f);
 }
 
-int tight_encode_box(struct vec* dst, struct nvnc_client* client,
+int tight_encode_box_jpeg(struct vec* dst, struct nvnc_client* client,
                           const struct nvnc_fb* fb, uint32_t x, uint32_t y,
                           uint32_t stride, uint32_t width, uint32_t height)
 {
@@ -59,16 +62,6 @@ int tight_encode_box(struct vec* dst, struct nvnc_client* client,
 
 	vec_reserve(dst, 4096);
 
-	struct rfb_server_fb_rect rect = {
-		.encoding = htonl(RFB_ENCODING_TIGHT),
-		.x = htons(x),
-		.y = htons(y),
-		.width = htons(width),
-		.height = htons(height),
-	};
-
-	vec_append(dst, &rect, sizeof(rect));
-
 	tjhandle handle = tjInitCompress();
 
 	void* img = (uint32_t*)fb->addr + x + y * stride;
@@ -88,6 +81,94 @@ int tight_encode_box(struct vec* dst, struct nvnc_client* client,
 	return 0;
 }
 
+static void tight_png_write(png_structp png_ptr, png_bytep data, png_size_t size)
+{
+	struct vec* out = png_get_io_ptr(png_ptr);
+	assert(out);
+
+	vec_append(out, data, size);
+}
+
+static void tight_png_flush(png_structp png_ptr)
+{
+}
+
+int tight_encode_box_png(struct vec* dst, struct nvnc_client* client,
+                         const struct nvnc_fb* fb, uint32_t x, uint32_t y,
+                         uint32_t stride, uint32_t width, uint32_t height)
+{
+	png_structp png_ptr =
+		png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
+
+	png_infop info_ptr = png_create_info_struct(png_ptr);
+
+	if (setjmp(png_jmpbuf(png_ptr)))
+		return -1;
+
+	int colour_type = PNG_COLOR_TYPE_RGB;
+
+	struct vec pngout;
+	vec_init(&pngout, 4096);
+
+	png_set_write_fn(png_ptr, &pngout, tight_png_write, tight_png_flush);
+
+	png_set_IHDR(png_ptr, info_ptr, width, height, 8, colour_type,
+	             PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_DEFAULT,
+		     PNG_COMPRESSION_TYPE_DEFAULT);
+
+	png_write_info(png_ptr, info_ptr);
+
+	png_byte* buffer = malloc(3 * width * sizeof(*buffer));
+
+	struct rfb_pixel_format dst_fmt = { 0 };
+	rfb_pixfmt_from_fourcc(&dst_fmt, DRM_FORMAT_RGB888 | DRM_FORMAT_BIG_ENDIAN);
+
+	struct rfb_pixel_format src_fmt = { 0 };
+	rfb_pixfmt_from_fourcc(&dst_fmt, fb->fourcc_format);
+
+	for (uint32_t r = 0; r < height; ++r) {
+		uint32_t* row = (uint32_t*)fb->addr + x + (y + r) * stride;
+
+		pixel32_to_cpixel(buffer, &dst_fmt, row, &src_fmt, 3, width);
+
+		png_write_row(png_ptr, buffer);
+	}
+
+	png_write_end(png_ptr, info_ptr);
+	png_write_flush(png_ptr);
+
+	free(buffer);
+	png_destroy_write_struct(&png_ptr, &info_ptr);
+
+	vec_reserve(dst, 4096);
+	vec_fast_append_8(dst, TIGHT_PNG);
+
+	tight_encode_size(dst, pngout.len);
+
+	vec_append(dst, pngout.data, pngout.len);
+
+	vec_destroy(&pngout);
+	return 0;
+}
+
+int tight_encode_box(struct vec* dst, struct nvnc_client* client,
+                     const struct nvnc_fb* fb, uint32_t x, uint32_t y,
+                     uint32_t stride, uint32_t width, uint32_t height)
+{
+	struct rfb_server_fb_rect rect = {
+		.encoding = htonl(RFB_ENCODING_TIGHT_PNG),
+		.x = htons(x),
+		.y = htons(y),
+		.width = htons(width),
+		.height = htons(height),
+	};
+
+	vec_append(dst, &rect, sizeof(rect));
+
+	return tight_encode_box_png(dst, client, fb, x, y, stride, width,
+	                             height);
+}
+
 int tight_encode_frame(struct vec* dst, struct nvnc_client* client,
                        const struct nvnc_fb* fb, struct pixman_region16* region)
 {