DragonRuby Game Toolkit - Raycasting

main.rb

# https://github.com/BrennerLittle/DragonRubyRaycast/tree/main

$mapX = 8
$mapY = 8
$mapS = 64
$map = [
  1, 1, 1, 1, 1, 1, 1, 1,
  1, 0, 1, 0, 0, 0, 0, 1,
  1, 0, 1, 0, 0, 0, 0, 1,
  1, 0, 1, 0, 0, 0, 0, 1,
  1, 0, 0, 0, 0, 0, 0, 1,
  1, 0, 0, 0, 0, 1, 0, 1,
  1, 0, 0, 0, 0, 0, 0, 1,
  1, 1, 1, 1, 1, 1, 1, 1,
]
$px = 250
$py = 250
$pdx = 0
$pdy = 0
$pa = 0

def draw_minimap args
  ($mapY - 1).times do |y|
    ($mapX - 1).times do |x|
      if $map[y.to_i * $mapX + x.to_i] == 1
        color = { r: 1, g: 1, b: 1 }
      else
        color = { r: 255, g: 255, b: 255 }
      end
      xo = x.to_i * $mapS
      yo = y.to_i * $mapS

      args.outputs[:map].sprites << {  x: xo, y: yo, w: 64, h: 64, path: :pixel, **color }
    end
  end
end

def FixAng a
  if a > 359
    a -= 360
  end
  if a < 0
    a += 360
  end
  return a
end

def draw_minimap_player args
  args.outputs[:map].sprites << { x: $px,
                                  y: $py,
                                  w: 8,
                                  h: 8,
                                  path: :pixel,
                                  r: 255,
                                  g: 255,
                                  b: 0 }
end

def pinput args
  xo=0
  if $pdx<0
    xo=-20
  else
    xo=20
  end
  yo=0
  if $pdy<0
    yo=-20
  else
    yo= 20
  end

  ipx=$px/64.0
  ipx = ipx.to_i
  ipx_add_xo=($px+xo)/64.0
  ipx_add_xo = ipx_add_xo.to_i
  ipx_sub_xo=($px-xo)/64.0
  ipx_sub_xo = ipx_sub_xo.to_i
  ipy=$py/64.0
  ipy = ipy.to_i
  ipy_add_yo=($py+yo)/64.0
  ipy_add_yo = ipy_add_yo.to_i
  ipy_sub_yo=($py-yo)/64.0
  ipy_sub_yo = ipy_sub_yo.to_i

  if args.inputs.keyboard.key_held.right
    $pa -= 5
    $pa = $pa % 360
    $pdx = $pa.vector_x
    $pdy = -$pa.vector_y
  end

  if args.inputs.keyboard.key_held.left
    $pa += 5
    $pa = $pa % 360
    $pdx = $pa.vector_x
    $pdy = -$pa.vector_y
  end

  if args.inputs.keyboard.key_held.up
    if $map[ipy*$mapX + ipx_add_xo]==0
      $px += $pdx * 5
    end

    if $map[ipy_add_yo * $mapX + ipx]==0
      $py += $pdy * 5
    end
  end

  if args.inputs.keyboard.key_held.down
    if $map[ipy*$mapX        + ipx_sub_xo] == 0
      $px -= $pdx * 5
    end
    if $map[ipy_sub_yo*$mapX + ipx       ] == 0
      $py -= $pdy * 5
    end
  end

  args.outputs[:map].sprites << { x: ipx * 64.to_i,
                                  y: ipy * 64.to_i,
                                  w: 64,
                                  h: 64,
                                  path: :pixel,
                                  r: 255,
                                  g: 0,
                                  b: 0 }
end

def distance ax, ay, bx, by, ang
  return ang.vector_x * (bx - ax) - ang.vector_y * (by - ay)
end

def draw_rays args
  args.outputs[:screen].sprites << { x: 0,
                                     y: 0,
                                     w: 750,
                                     h: 160,
                                     path: :pixel,
                                     r: 0,
                                     g: 255,
                                     b: 255 }

  args.outputs[:screen].sprites << { x: 0,
                                     y: 160,
                                     w: 750,
                                     h: 160,
                                     path: :pixel,
                                     r: 0,
                                     g: 0,
                                     b: 255 }

  ra = ($pa + 30) % 360

  60.times do |r|
    dof = 0
    side = 0
    disV = 100000
    tan = Math.tan ra.to_radians

    if ra.vector_x > 0.001
      rx = (($px >> 6) << 6) + 64
      ry = ($px - rx) * tan + $py;
      xo = 64
      yo = -xo * tan
    elsif ra.vector_x < -0.001
      rx = (($px >> 6) << 6) - 0.0001
      ry = ($px - rx) * tan + $py
      xo = -64
      yo = -xo * tan
    else
      rx = $px
      ry = $py
      dof = 8
    end

    while dof < 8
      mx = rx >> 6
      mx = mx.to_i
      my = ry >> 6
      my = my.to_i
      mp = my * $mapX + mx
      if mp > 0 && mp < $mapX * $mapY && $map[mp] == 1
        dof = 8
        disV = ra.vector_x * (rx - $px) - ra.vector_y * (ry - $py)
      else
        rx += xo
        ry += yo
        dof += 1
      end
    end

    vx = rx
    vy = ry

    dof = 0
    disH = 100000
    tan = 1.0 / tan

    if ra.vector_y > 0.001
      ry = (($py >> 6) << 6) - 0.0001;
      rx = ($py - ry) * tan + $px;
      yo = -64;
      xo = -yo * tan;
    elsif ra.vector_y < -0.001
      ry = (($py >> 6) << 6) + 64;
      rx = ($py - ry) * tan + $px;
      yo = 64;
      xo = -yo * tan;
    else
      rx = $px
      ry = $py
      dof = 8
    end

    while dof < 8
      mx = (rx) >> 6
      my = (ry) >> 6
      mp = my * $mapX + mx
      if mp > 0 && mp < $mapX * $mapY && $map[mp] == 1
        dof = 8
        disH = ra.vector_x * (rx - $px) - ra.vector_y * (ry - $py) # //hit
      else
        rx += xo
        ry += yo
        dof += 1
      end
    end

    col = { r: 0, g: 204, b: 0 }

    if disV < disH
      rx = vx
      ry = vy
      disH = disV

      col = { r: 0, g: 153, b: 0 }
    end

    args.outputs[:map].lines << { x: $px, y: $py, x2: rx, y2: ry, **col }

    ca = ($pa - ra) % 360
    disH = disH * ca.cos
    lineH = ($mapS * 320) / (disH)
    lineH = 320 if lineH > 320

    lineOff = 160 - (lineH >> 1)

    args.outputs[:screen].sprites << { x: r * 8, y: lineOff, w: 8, h: lineH, path: :pixel, **col }

    ra = (ra - 1) % 360
  end
end

def tick args
  draw_minimap args
  draw_minimap_player args
  pinput args
  draw_rays args
  args.outputs.sprites << { x: 0, y: 0, w: 1280 * 2.66, h: 720 * 2.25, path: :screen }
  args.outputs.sprites << { x: 0, y: 592, w: 1280/4, h: 720/4, path: :map }
  args.outputs.labels  << { x: 0, y: 20, text: "FPS: #{args.gtk.current_framerate.to_sf}" }
end