#!ruby
# -*- mode: ruby; coding: utf-8 -*-
# Last updated: <2017/04/07 20:56:48 +0900>
#
# tinypixelartgen.rb
# ドット絵自動生成のテスト
# sinカーブで型を与えて生成、かつ、境界線を付加してみる
#
# License : CC0 / Public Domain

class TinyPixelArtGen

  attr_accessor :pixels

  def initialize(w, h, mirror_x: true, mirror_y: false, seed: 0, color: 8)
    srand(seed)
    @color = color
    @w, @h = w, h
    @mirror_x, @mirror_y = mirror_x, mirror_y
    @canvas = Array.new(@h).map { Array.new(@w, 0) }
    @pixels = Array.new(@h).map { Array.new(@w).map { Array.new(4, 0) } }

    ww, hh = (@w / 2.0).round, (@h / 2.0).round
    wwf, hhf = @w % 2, @h % 2

    # generate dot pattern
    ang = rand(360)
    ang_d = rand(270.0 / @h) + (45.0 / @h)
    (1..(@h-2)).each do |y|
      rad = (ang + (ang_d * y)) * Math::PI / 180.0
      rw = (((w * 4 / 10.0 - 1) * Math.sin(rad)).to_i + (w * 5 / 10.0)) * 2
      rx = (w - rw) / 2
      @w.times do |x|
        xx = rand(rw) + rx
        @canvas[y][xx] = rand(@color)
      end
    end

    # generate edge
    @h.times do |y|
      @w.times do |x|
        next if @canvas[y][x] <= 1
        @canvas[y - 1][x] = 1 if (y - 1 >= 0 and @canvas[y - 1][x] == 0)
        @canvas[y + 1][x] = 1 if (y + 1 < @h and @canvas[y + 1][x] == 0)
        @canvas[y][x - 1] = 1 if (x - 1 >= 0 and @canvas[y][x - 1] == 0)
        @canvas[y][x + 1] = 1 if (x + 1 < @w and @canvas[y][x + 1] == 0)
      end
    end

    # generate palette
    @pal = Array.new(@color)
    rr, gg, bb = rand(128), rand(128), rand(128)
    @pal.size.times do |i|
      if i == 0
        r, g, b, a = 0, 0, 0, 0
      elsif i == 1
        r, g, b, a = 0, 0, 0, 255
      elsif i == (@pal.size - 1)
        c = 255 - rand(48)
        r, g, b, a = c, c, c, 255
      else
        r = rr + rand(128)
        g = gg + rand(128)
        b = bb + rand(128)
        a = 255
      end
      @pal[i] = [r, g, b, a]
    end

    # make pixel data
    @h.times do |y|
      @w.times do |x|
        sx, sy = x, y
        sx = (x >= ww and @mirror_x)? (ww - 1 - wwf - (x - ww)) : x
        sy = (y >= hh and @mirror_y)? (hh - 1 - hhf - (y - hh)) : y
        r, g, b, a = @pal[@canvas[sy][sx]]
        @pixels[y][x] = [r, g, b, a]
      end
    end
  end
end

if $0 == __FILE__
  # ----------------------------------------
  require 'dxruby'

  def conv_pixels_to_image(pixels)
    w, h = pixels[0].size, pixels.size
    img = Image.new(w, h, [0, 0, 0, 0])
    h.times do |y|
      w.times do |x|
        r, g, b, a = pixels[y][x]
        img[x, y] = [a, r, g, b]
      end
    end
    return img
  end

  def generate_images(n, seed)
    sz = 16
    imgs = []
    n.times do |i|
      pat = TinyPixelArtGen.new(
        sz, sz,
        mirror_x: (rand > 0.5)? true : false,
        mirror_y: (rand > 0.5)? true : false,
        seed: seed + i,
        color: 8
      )
      imgs.push(conv_pixels_to_image(pat.pixels))
    end
    return imgs
  end

  Window.resize(640, 480)
  Window.bgcolor = [32, 128, 196]
  Window.minFilter = TEXF_POINT
  Window.magFilter = TEXF_POINT
  cnt = 96
  seed = 0
  imgs = generate_images(cnt, seed)
  seed += cnt

  Window.loop do
    break if Input.keyPush?(K_ESCAPE)

    if Input.keyPush?(K_SPACE)
      imgs = generate_images(cnt, seed)
      seed += cnt
    end

    scale = 3
    x, y = 0, 0
    imgs.each do |img|
      Window.drawScale(x, y, img, scale, scale, 0, 0)
      x += img.width * scale + 4
      if (x + img.width * scale) >= Window.width
        x = 0
        y += img.height * scale + 4
      end
    end
  end
end