From e5892c0fae770c682517f3d28026be555282a89d Mon Sep 17 00:00:00 2001
From: nightmareci <nightmareci@gmail.com>
Date: Thu, 28 Apr 2022 11:47:31 -0700
Subject: [PATCH] Rename shell scripts and implement better frame timing

---
 main.lua                      | 42 ++++++++++++++++++++++++-----------
 package => package.sh         |  2 ++
 release => release-windows.sh |  6 +++--
 3 files changed, 35 insertions(+), 15 deletions(-)
 rename package => package.sh (88%)
 rename release => release-windows.sh (89%)

diff --git a/main.lua b/main.lua
index 9c04823..52fecf9 100644
--- a/main.lua
+++ b/main.lua
@@ -81,7 +81,7 @@ function love.draw()
 		love.graphics.setFont(font_3x5_2)
 		love.graphics.setColor(1, 1, 1, 1)
 		love.graphics.printf(
-			string.format("%.2f", 1 / love.timer.getAverageDelta()) ..
+			string.format("%.2f", 1.0 / love.timer.getAverageDelta()) ..
 			"fps - " .. version, 0, 460, 635, "right"
 		)
 	end
@@ -290,6 +290,7 @@ function love.resize(w, h)
 end
 
 local TARGET_FPS = 60
+local FRAME_DURATION = 1.0 / TARGET_FPS
 
 function love.run()
 	if love.load then love.load(love.arg.parseGameArguments(arg), arg) end
@@ -299,7 +300,7 @@ function love.run()
 	local dt = 0
 
 	local last_time = love.timer.getTime()
-	local time_accumulator = 0
+	local time_accumulator = 0.0
 	return function()
 		if love.event then
 			love.event.pump()
@@ -319,25 +320,40 @@ function love.run()
 		
 		if scene and scene.update and love.timer then
 			scene:update()
-			
-			local frame_duration = 1.0 / TARGET_FPS
-			if time_accumulator < frame_duration then
+
+			if time_accumulator < FRAME_DURATION then
 				if love.graphics and love.graphics.isActive() and love.draw then
 					love.graphics.origin()
 					love.graphics.clear(love.graphics.getBackgroundColor())
 					love.draw()
 					love.graphics.present()
 				end
-				local end_time = last_time + frame_duration
-				local time = love.timer.getTime()
-				while time < end_time do
-					love.timer.sleep(0.001)
-					time = love.timer.getTime()
+
+				-- request 1ms delays first but stop short of overshooting, then do "0ms" delays without overshooting (0ms requests generally do a delay of some nonzero amount of time, but maybe less than 1ms)
+				for milliseconds=0.001,0.000,-0.001 do
+					local max_delay = 0.0
+					while max_delay < FRAME_DURATION do
+						local delay_start_time = love.timer.getTime()
+						if delay_start_time - last_time < FRAME_DURATION - max_delay then
+							love.timer.sleep(milliseconds)
+							local last_delay = love.timer.getTime() - delay_start_time
+							if last_delay > max_delay then
+								max_delay = last_delay
+							end
+						else
+							break
+						end
+					end
+				end
+				while love.timer.getTime() - last_time < FRAME_DURATION do
+					-- busy loop, do nothing here until delay is finished; delays above stop short of finishing, so this part can finish it off precisely
 				end
-				time_accumulator = time_accumulator + time - last_time
 			end
-			time_accumulator = time_accumulator - frame_duration
+
+			local finish_delay_time = love.timer.getTime()
+			local real_frame_duration = finish_delay_time - last_time
+			time_accumulator = time_accumulator + real_frame_duration - FRAME_DURATION
+			last_time = finish_delay_time
 		end
-		last_time = love.timer.getTime()
 	end
 end
diff --git a/package b/package.sh
similarity index 88%
rename from package
rename to package.sh
index ed6f662..530ffe7 100755
--- a/package
+++ b/package.sh
@@ -1 +1,3 @@
+#!/bin/sh
+
 zip -r cambridge.love libs load res scene tetris conf.lua main.lua scene.lua funcs.lua
diff --git a/release b/release-windows.sh
similarity index 89%
rename from release
rename to release-windows.sh
index 5a31406..ad32024 100755
--- a/release
+++ b/release-windows.sh
@@ -1,4 +1,6 @@
-./package
+#!/bin/sh
+
+./package-love.sh
 mkdir dist
 mkdir dist/windows
 mkdir dist/win32
@@ -8,4 +10,4 @@ zip dist/cambridge-windows.zip dist/windows/* SOURCES.md LICENSE.md
 cat dist/win32/love.exe cambridge.love > dist/win32/cambridge.exe
 zip dist/cambridge-win32.zip dist/win32/* SOURCES.md LICENSE.md
 cp cambridge.love dist/other/
-zip dist/cambridge-other.zip cambridge.love libs/discord-rpc.* SOURCES.md LICENSE.md
\ No newline at end of file
+zip dist/cambridge-other.zip cambridge.love libs/discord-rpc.* SOURCES.md LICENSE.md