From 79e9090c7e50eb726c46a108f5762723c05c7f78 Mon Sep 17 00:00:00 2001
From: yaw-man <ywmn@protonmail.com>
Date: Fri, 13 Jan 2023 17:34:01 -0400
Subject: [PATCH] Character controller, render trail

---
 main.lua   | 10 ++++++++--
 marble.lua | 45 +++++++++++++++++++++++++++++++++++++++------
 2 files changed, 47 insertions(+), 8 deletions(-)

diff --git a/main.lua b/main.lua
index 7dbb7e4..0db9fb3 100644
--- a/main.lua
+++ b/main.lua
@@ -134,15 +134,21 @@ end
 
 
 function love.draw()
+  local w, h = love.graphics.getDimensions()
+  
+  
   love.graphics.setColor(1.0, 1.0, 1.0)
   love.graphics.print( state.beat.mu or 0, 0)
   love.graphics.print( state.beat.t or 0, 0, 10)
   love.graphics.print( state.beatScoreThreshold, 0, 20)
   love.graphics.print( state.lastBeatScore, 0, 30 )
+  
+  love.graphics.setColor(  91 / 255, 206 / 255, 250 / 255 )
+  love.graphics.circle("fill", w / 2, h / 2, 200)
+
   sitelenpona.Draw( text.tok[state.currentBeat] )
   marble.Draw()
-  love.graphics.setColor(0.5, 0.2, 0.8, 0.5)
-  love.graphics.circle("fill", 0, 0, 10)
+
 end
 
 
diff --git a/marble.lua b/marble.lua
index dce7e69..03cdd70 100644
--- a/marble.lua
+++ b/marble.lua
@@ -1,8 +1,10 @@
 --Character controller. Renders point particle.
 local love = love
+local oldBuffer = love.graphics.newCanvas()
+local newBuffer = love.graphics.newCanvas()
 local step = assert( step )
 local state 
-local FRICTION = 0.005
+local FRICTION = 0.008
 local MAXSPEED = 1.0
 
 local t, x, y, dx, dy, ddx, ddy
@@ -12,8 +14,8 @@ local function Update()
 
   dx = (1.0 - FRICTION) * dx + FRICTION * ddx
   dy = (1.0 - FRICTION) * dy + FRICTION * ddy
-  x = x + dx * step * MAXSPEED
-  y = y + dy * step * MAXSPEED
+  local xf = x + dx * step * MAXSPEED
+  local yf = y + dy * step * MAXSPEED
 end
 
 local function OnKey()
@@ -27,15 +29,44 @@ end
 
 local function Draw()
   local dt = love.timer.getTime() - t
-  local rx, ry = x + dt * dx, y + dt * dy
-  love.graphics.setColor( 0.0, 0.0, 0.0, 0.8 )
-  love.graphics.circle( "fill", rx, ry, 10 )
+  local xf, yf = x + dt * dx, y + dt * dy
+  
+  local w, h = love.graphics.getDimensions()
+  local xi, yi = 1000.0 * x + 0.5 * w, 1000.0 * y + 0.5 * h
+  xf, yf = 1000.0 * xf + 0.5 * w, 1000.0 * yf + 0.5 * h
+  
+    
+  love.graphics.setCanvas( newBuffer )
+  love.graphics.setColor(  1.0, 1.0, 1.0 , 0.9 ) --Trans blue.
+  love.graphics.draw( oldBuffer ) --Time-dependent fade: overlay canvas over itself.
+  
+  --Render latest segment in trail.
+  love.graphics.setColor( 1.0, 1.0, 1.0, 1.0 ) --White?
+  love.graphics.circle( "fill", xf, yf, 4.0 ) --TODO: replace with segments.
+  love.graphics.line( xi, yi, xf, yf )
+  
+  love.graphics.setCanvas( oldBuffer )
+  love.graphics.clear( 1.0, 1.0, 1.0, 0.0 )
+  
+  --Render circle directly to screen.
+  love.graphics.setCanvas()
+  love.graphics.draw( newBuffer )
+  love.graphics.setColor( 245 / 255, 169 / 255, 184 / 255 ) --Trans pink.
+  love.graphics.circle( "fill", xf, yf, 5.0 )
+  
+  oldBuffer, newBuffer = newBuffer, oldBuffer
+
 end
 
 local function Impact( impact )
   
 end
 
+--Window resize.
+local function Resize()
+  
+end
+
 local function Reset()
   t = love.timer.getTime()
   x = 0
@@ -46,6 +77,8 @@ local function Reset()
   ddy = 0
 end
 
+
+
 Reset()
 
 return {