Flame (Trickster)

require 'sfml/system'

require 'sfml/window'

require 'sfml/graphics'

include SFML



HOTSPOTS = 10

WIDTH = 128

HEIGHT = 64



class Game

    def initialize

        @screen = RenderWindow.new(VideoMode.new(WIDTH, HEIGHT, 32), "Flame")

        @buffer = Image.new

        @buffer.create(WIDTH, HEIGHT)

        @sprite = Sprite.new

        @sprite.image = @buffer

        init_palette

    end



    def run

        @temp = Array.new(WIDTH, 0)

        @hotspot = Array.new(HOTSPOTS) {rand(WIDTH)}

        loop do

            while event = @screen.get_event

                @screen.close if event.type == SFML::Event::Closed

            end

            break if update == false || !@screen.open?

        end

        quit

    end



    def update

        return false if @screen.input.isKeyDown(Key::Escape)

        draw_fire

        update_fire

        @screen.draw(@sprite)

        @screen.display

    end



    def quit

    end



    def init_palette

        @palette = Array.new(256)

        @palette.fill(0, 64) {|c| Color.new(c * 4, 0, 0)}

        @palette.fill(64, 64) {|c| Color.new(255, (c - 64) * 4, 0)}

        @palette.fill(128, 64) {|c| Color.new(255, 255, (c-128) * 4)}

        @palette.fill(Color.new(255, 255, 255), 192, 255)

    end



    def draw_fire

        @temp.fill(0)

        0.upto(HOTSPOTS-1) do |c|

            (@hotspot[c]-20).upto(@hotspot[c]+20) do |x|

                if x >= 0 and x < @buffer.width

                    @temp[x] = [@temp[x] + 20 - (@hotspot[c] - x).abs, 192].min

                end

            end

            @hotspot[c] = (@hotspot[c] + rand(8) - 3) % @buffer.width

        end

        @temp.each_index do |i|

            @buffer.setPixel(i, HEIGHT - 1, @palette[@temp[i]])

        end

    end



    def update_fire

        0.upto(@buffer.height-2) do |y|

            0.upto(@buffer.width-1) do |x|

                c = @palette.index(@buffer.getPixel(x, y + 1))

                color = @buffer.getPixel(x, y+1)

                c -= 1 if c > 0

                @buffer.setPixel(x, y, @palette[c])

            end

        end

    end

end



Game.new.run