From 39976ab7767c88644ba3fa59c7e0e626d79be6a9 Mon Sep 17 00:00:00 2001
From: Andri Yngvason <andri@yngvason.is>
Date: Tue, 7 Jul 2020 14:22:38 +0000
Subject: [PATCH] Allow the user to adjust the FPS limit

---
 include/screencopy.h | 2 ++
 src/main.c           | 9 ++++++++-
 src/screencopy.c     | 3 +--
 3 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/include/screencopy.h b/include/screencopy.h
index 5387ade..0f7aca9 100644
--- a/include/screencopy.h
+++ b/include/screencopy.h
@@ -68,6 +68,8 @@ struct screencopy {
 	bool have_linux_dmabuf;
 	uint32_t dmabuf_width, dmabuf_height;
 	uint32_t fourcc;
+
+	double rate_limit;
 };
 
 void screencopy_init(struct screencopy* self);
diff --git a/src/main.c b/src/main.c
index c62d6c8..617ff54 100644
--- a/src/main.c
+++ b/src/main.c
@@ -571,6 +571,7 @@ int wayvnc_usage(FILE* stream, int rc)
 "    -k,--keyboard=<layout>                    Select keyboard layout.\n"
 "    -s,--seat=<name>                          Select seat by name.\n"
 "    -r,--render-cursor                        Enable overlay cursor rendering.\n"
+"    -f,--max-fps=<fps>                        Set the rate limit (default 30).\n"
 "    -h,--help                                 Get help (this text).\n"
 "\n";
 
@@ -628,8 +629,9 @@ int main(int argc, char* argv[])
 	const char* seat_name = NULL;
 	
 	bool overlay_cursor = false;
+	int max_rate = 30;
 
-	static const char* shortopts = "C:o:k:s:rh";
+	static const char* shortopts = "C:o:k:s:rf:h";
 	int drm_fd = -1;
 
 	static const struct option longopts[] = {
@@ -638,6 +640,7 @@ int main(int argc, char* argv[])
 		{ "keyboard", required_argument, NULL, 'k' },
 		{ "seat", required_argument, NULL, 's' },
 		{ "render-cursor", no_argument, NULL, 'r' },
+		{ "max-fps", required_argument, NULL, 'f' },
 		{ "help", no_argument, NULL, 'h' },
 		{ NULL, 0, NULL, 0 }
 	};
@@ -663,6 +666,9 @@ int main(int argc, char* argv[])
 		case 'r':
 			overlay_cursor = true;
 			break;
+		case 'f':
+			max_rate = atoi(optarg);
+			break;
 		case 'h':
 			return wayvnc_usage(stdout, 0);
 		default:
@@ -740,6 +746,7 @@ int main(int argc, char* argv[])
 	self.selected_output = out;
 	self.selected_seat = seat;
 	self.screencopy.wl_output = out->wl_output;
+	self.screencopy.rate_limit = max_rate;
 
 	self.keyboard_backend.virtual_keyboard =
 		zwp_virtual_keyboard_manager_v1_create_virtual_keyboard(
diff --git a/src/screencopy.c b/src/screencopy.c
index b47f650..4c8b8d6 100644
--- a/src/screencopy.c
+++ b/src/screencopy.c
@@ -32,7 +32,6 @@
 #include "time-util.h"
 #include "usdt.h"
 
-#define RATE_LIMIT 30.0 // Hz
 #define DELAY_SMOOTHER_TIME_CONSTANT 0.5 // s
 
 void screencopy_stop(struct screencopy* self)
@@ -231,7 +230,7 @@ static int screencopy__start(struct screencopy* self, bool is_immediate_copy)
 
 	uint64_t now = gettime_us();
 	double dt = (now - self->last_time) * 1.0e-6;
-	double time_left = (1.0 / RATE_LIMIT - dt - self->delay) * 1.0e3;
+	double time_left = (1.0 / self->rate_limit - dt - self->delay) * 1.0e3;
 
 	self->status = SCREENCOPY_IN_PROGRESS;