From 9e96d4735c86e04784c882430e892453ba29ab15 Mon Sep 17 00:00:00 2001
From: "E. Almqvist" <elalmqvist@gmail.com>
Date: Mon, 11 Oct 2021 22:45:01 +0200
Subject: [PATCH] Physobj

---
 Gemfile      |  3 +++
 Gemfile.lock | 13 +++++++++++
 app.rb       | 40 +++++++++++++++++++++++++++++++++
 physobj.rb   | 62 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 118 insertions(+)
 create mode 100644 Gemfile
 create mode 100644 Gemfile.lock
 create mode 100755 app.rb
 create mode 100644 physobj.rb

diff --git a/Gemfile b/Gemfile
new file mode 100644
index 0000000..dc11dbe
--- /dev/null
+++ b/Gemfile
@@ -0,0 +1,3 @@
+source "https://rubygems.org"
+
+gem "gosu"
diff --git a/Gemfile.lock b/Gemfile.lock
new file mode 100644
index 0000000..43de112
--- /dev/null
+++ b/Gemfile.lock
@@ -0,0 +1,13 @@
+GEM
+  remote: https://rubygems.org/
+  specs:
+    gosu (1.2.0)
+
+PLATFORMS
+  x86_64-linux
+
+DEPENDENCIES
+  gosu
+
+BUNDLED WITH
+   2.2.26
diff --git a/app.rb b/app.rb
new file mode 100755
index 0000000..3285280
--- /dev/null
+++ b/app.rb
@@ -0,0 +1,40 @@
+#!/usr/bin/ruby -w
+require "gosu"
+load "physobj.rb"
+
+class Window < Gosu::Window
+	attr_accessor :caption, :physobjs
+	attr_reader :width, :height
+
+	def initialize(title, width, height, physobjs = [])
+		super width, height
+		@width, @height = width, height
+		self.caption = "#{title}| #{width}x#{height}"
+
+		@physobjs = physobjs
+	end
+
+	def update
+		@physobjs.each do |obj| 
+			obj.physics 
+		end
+	end
+
+	def draw
+		@physobjs.each do |obj| 
+			obj.render
+		end
+	end
+end
+
+
+window = Window.new("Physics!", 1600, 900)
+
+planet = PhysCube.new(window, 16, 16, 0xff_aaffaa)
+
+cube = PhysCube.new(window, 8, 8)
+cube.accel = Vector[0, 0.1]
+cube.vel = Vector[0.01, 0]
+
+window.physobjs << cube
+window.show
diff --git a/physobj.rb b/physobj.rb
new file mode 100644
index 0000000..2f9369b
--- /dev/null
+++ b/physobj.rb
@@ -0,0 +1,62 @@
+require "matrix"
+
+class PhysObj
+	attr_accessor :world, :pos, :vel, :accel, :x, :y
+	def initialize(world)
+		@world = world
+		@pos = Vector.zero(2)
+		@vel = Vector.zero(2)
+		@accel = Vector.zero(2)
+		@x, @y = 0, 0
+	end
+
+	def tick
+		if( @accel.magnitude != 0 ) then
+			@vel += @accel
+		end
+
+		if( @vel.magnitude != 0 ) then
+			@pos += @vel
+		end
+		@x, @y = @pos[0], @pos[1]
+	end
+
+end
+
+
+class PhysCube < PhysObj
+	attr_reader :width, :height
+	def initialize(world, width, height, color=0xff_ffffff, ela=-0.8)
+		super world
+
+		@width, @height = width, height
+		@color = Gosu::Color.argb(color)
+		@ela = ela
+	end
+
+	def draw_vector(vec, scale=0.1, color=0xaf_ffaaaa)
+		clr = Gosu::Color.argb(color)
+		dx, dy = vec[0], vec[1]
+		xx, yy = @x + @width/2, @y + @height/2
+		Gosu.draw_line(xx, yy, clr, (xx + dx).round(1) * scale, (yy + dy).round(1) * scale, clr)
+		puts("#{dx} #{dy} #{[xx - (xx + dx), yy - (yy + dy)]}")
+	end
+
+	def render
+		x, y = self.pos[0], self.pos[1]
+		Gosu.draw_quad(x, y, @color, x + self.width, y, @color, x, y + self.height, @color, x + self.width, y + self.height, @color)
+		self.draw_vector(@accel, 10, 0xff_00ff00)
+	end
+
+	def physics
+		self.tick
+
+		x, y = self.pos[0], self.pos[1]
+		x_max = world.width - self.width
+		y_max = world.height - self.height
+
+		if( x > x_max ) then self.pos[0] = x_max end
+		if( y > y_max ) then self.pos[1] = y_max end
+
+	end
+end