liquid fun example

Author: monkstone

external_library/java/LiquidFunProcessing/liquid_fun_dam_break.rb

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+#
+# LiquidFunProcessing | Copyright 2017 Thomas Diewald - www.thomasdiewald.com
+#
+# https://github.com/diwi/LiquidFunProcessing.git
+#
+# Box2d / LiquidFun Library for Processing.
+# MIT License: https:#opensource.org/licenses/MIT
+#
+load_library :LiquidFunProcessing
+java_import 'com.thomasdiewald.liquidfun.java.DwWorld'
+java_import 'com.thomasdiewald.liquidfun.java.render.DwParticleRenderGL'
+java_import 'com.thomasdiewald.liquidfun.java.render.DwParticleRenderP5'
+java_import 'org.jbox2d.collision.shapes.ChainShape'
+java_import 'org.jbox2d.collision.shapes.PolygonShape'
+java_import 'org.jbox2d.common.Color3f'
+java_import 'org.jbox2d.common.Vec2'
+java_import 'org.jbox2d.dynamics.Body'
+java_import 'org.jbox2d.dynamics.BodyDef'
+java_import 'org.jbox2d.particle.ParticleGroupDef'
+java_import 'org.jbox2d.particle.ParticleType'
+
+# Simulation of a clash of two big particle-groups.
+#
+#
+# Controls:
+#
+# 'r'         ... reset
+# 't'         ... update/pause physics
+# 'f'         ... toggle debug draw
+# 'd'         ... display particle renderer type
+VIEWPORT_W = 1280
+VIEWPORT_H = 720
+VIEWPORT_X = 230
+VIEWPORT_Y = 0
+attr_reader :world, :update_physics, :use_debug_draw
+
+def settings
+  size(VIEWPORT_W, VIEWPORT_H, P2D)
+  smooth(8)
+end
+
+def setup
+  surface.set_location(VIEWPORT_X, VIEWPORT_Y)
+  sketch_title 'Liquid fun dambreak particles'
+  @update_physics = true
+  @use_debug_draw = false
+  reset
+  frame_rate(120)
+end
+
+def release
+  return if world.nil?
+  world.release
+  @world = nil
+end
+
+def reset
+  # release old resources
+  release
+  # if false, PShape-Quads are used for particles, instead of openGL points.
+  # this replaces the default particle renderer (OpenGL) with an alternative
+  # renderer where particles are rendered as PShape-Quads.
+  # It renders a bit slower then the OpenGL version and grouped rendering
+  # is also not possible.
+  DwWorld.INIT_GL_PARTICLES = true
+  # create world
+  @world = DwWorld.new(self, 18)
+  # create scene: rigid bodies, particles, etc ...
+  init_scene
+end
+
+def draw
+  world.update if update_physics
+  canvas = g
+  canvas.background(32)
+  canvas.push_matrix
+  world.apply_transform(canvas)
+  world.draw_bullet_spawn_track(canvas)
+  if use_debug_draw
+    world.display_debug_draw(canvas)
+    # DwDebugDraw.display(canvas, world)
+  else
+    world.display(canvas)
+  end
+  canvas.pop_matrix
+  # info
+  num_bodies = world.get_body_count
+  num_particles = world.get_particle_count
+  string_format = 'liquid fun [bodies: %d] [particles: %d] [fps: %6.2f]'
+  txt_fps = format(string_format, num_bodies, num_particles, frame_rate)
+  surface.set_title(txt_fps)
+end
+
+def particle_renderer(particles)
+  return 'GL Particle Renderer' if particles.java_kind_of? DwParticleRenderGL
+  return 'P5 Particle Renderer' if particles.java_kind_of? DwParticleRenderP5
+  'Something wrong with particle renderer'
+end
+
+#######################################
+# User Interaction
+#######################################
+def key_released
+  case key
+  when 't'
+    @update_physics = !update_physics
+  when 'r'
+    reset
+  when 'f'
+    @use_debug_draw = !use_debug_draw
+  when 'd'
+    puts particle_renderer(world.particles)
+  end
+end
+
+###############init_scene########################
+# Scene Setup
+# https://github.com/jbox2d/jbox2d/blob/master/jbox2d-testbed/src/main/java/org/jbox2d/testbed/tests/DamBreak.java
+#######################################
+def init_scene
+  dimx = world.transform.box2d_dimx
+  dimy = world.transform.box2d_dimy
+  dimxh = dimx / 2
+  dimyh = dimy / 2
+  bd = BodyDef.new
+  ground = world.create_body(bd)
+  shape = ChainShape.new
+  vertices = [
+    Vec2.new(-dimxh, 0),
+    Vec2.new(dimxh, 0),
+    Vec2.new(dimxh, dimy),
+    Vec2.new(-dimxh, dimy)
+  ]
+  shape.create_loop(vertices, 4)
+  ground.create_fixture(shape, 0.0)
+  world.bodies.add(ground, false, color(0), true, color(0), 1)
+  pshape = PolygonShape.new
+  pd = ParticleGroupDef.new
+  pd.flags = 0
+  sx = dimxh * 0.25
+  sy = dimyh * 0.95
+  pshape.set_as_box(sx, sy, Vec2.new(-dimxh / 2, dimyh), 0)
+  pd.shape = pshape
+  pd.set_color(Color3f.new(0.00, 0.2, 1))
+  world.create_particle_group(pd)
+  pshape.set_as_box(sx, sy, Vec2.new(+dimxh / 2, dimyh), 0)
+  pd.shape = pshape
+  pd.set_color(Color3f.new(1.00, 0.2, 0.00))
+  world.create_particle_group(pd)
+end