Class: Doom::Render::ZBufferRenderer

Inherits:
Renderer
  • Object
show all
Defined in:
lib/doom/render/zbuffer_renderer.rb

Overview

Experimental renderer path. It deliberately reuses the proven BSP visibility and texture sampling code while replacing the visibility target with a full, per-pixel depth buffer. This makes it possible to add mesh rasterisation and ray traced passes without changing game logic.

Defined Under Namespace

Classes: Light

Constant Summary collapse

MAX_DYNAMIC_LIGHTS = 
8
LIGHT_LEVELS = 
16

Constants inherited from Renderer

Renderer::SKY_TEXTUREMID, Renderer::SKY_XSCALE, Renderer::SKY_YSCALE

Instance Attribute Summary collapse

Attributes inherited from Renderer

#animations, #colormap, #combat, #cos_angle, #flats, #framebuffer, #hidden_things, #leveltime, #map, #monster_ai, #palette, #player_angle, #player_x, #player_y, #player_z, #players, #sin_angle, #skip_background_fill, #sprites, #textures, #view_player, #wad

Instance Method Summary collapse

Methods inherited from Renderer

#apply_view, #build_native_renderer, #check_plane, #draw_all_visplanes, #draw_floor_ceiling_background, #draw_sky_plane, #draw_span, #fill_uncovered_with_sector, #find_or_create_visplane, #native_wall_pass, #precompute_column_data, #render_visplane_spans, #set_player, #sprite_diagnostics

Constructor Details

#initialize ⇒ ZBufferRenderer

Returns a new instance of ZBufferRenderer.



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# File 'lib/doom/render/zbuffer_renderer.rb', line 16

def initialize(...)
  super
  @depth_buffer = Array.new(SCREEN_WIDTH * SCREEN_HEIGHT, Float::INFINITY)
  @light_lut = build_light_lut
end

Instance Attribute Details

#depth_buffer ⇒ Object (readonly)

Returns the value of attribute depth_buffer.



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# File 'lib/doom/render/zbuffer_renderer.rb', line 10

def depth_buffer
  @depth_buffer
end

Instance Method Details

#draw_wall_column_ex(x, y1, y2, texture_name, dist, light_level, tex_col, tex_y_start, scale, world_top) ⇒ Object

Opaque walls are the first geometry producer for the new depth target. BSP clipping remains the visibility algorithm for this initial stage; later raster passes can consume the per-pixel depth values written here.



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# File 'lib/doom/render/zbuffer_renderer.rb', line 31

def draw_wall_column_ex(x, y1, y2, texture_name, dist, light_level,
                        tex_col, tex_y_start, scale, world_top)
  clip_top = @ceiling_clip[x] + 1
  clip_bottom = @floor_clip[x] - 1
  first = [[y1, clip_top, 0].max, SCREEN_HEIGHT].min
  last = [[y2, clip_bottom, SCREEN_HEIGHT - 1].min, -1].max

  super

  return if first > last || texture_name.nil? || texture_name.empty? || texture_name == '-'
  return unless @textures[anim_texture(texture_name)]

  # Reconstruct the world-space wall hit. Each dynamic source casts a
  # visibility ray to it; one-sided linedefs produce hard shadows.
  ray_distance = dist * @column_distscale[x]
  hit_x = @player_x + (ray_distance * @column_cos[x])
  hit_y = @player_y - (ray_distance * @column_sin[x])
  visible_lights = @dynamic_lights.select do |light|
    dx = light.x - hit_x
    dy = light.y - hit_y
    (dx * dx) + (dy * dy) < light.radius * light.radius && light_visible?(hit_x, hit_y, light)
  end

  y = first
  while y <= last
    offset = (y * SCREEN_WIDTH) + x
    @depth_buffer[offset] = dist if dist < @depth_buffer[offset]
    unless visible_lights.empty?
      world_z = world_top - ((y - (HALF_HEIGHT - ((world_top - @player_z) * scale))) / scale)
      intensity = visible_lights.sum do |light|
        distance = Math.sqrt(((light.x - hit_x)**2) + ((light.y - hit_y)**2) + ((light.z - world_z)**2))
        distance < light.radius ? light.energy * ((1.0 - (distance / light.radius))**2) : 0.0
      end
      level = (intensity * (LIGHT_LEVELS - 1)).to_i.clamp(0, LIGHT_LEVELS - 1)
      @framebuffer[offset] = @light_lut[level][@framebuffer[offset]] if level.positive?
    end
    y += 1
  end
end

#render_frame ⇒ Object 



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# File 'lib/doom/render/zbuffer_renderer.rb', line 22

def render_frame
  @depth_buffer.fill(Float::INFINITY)
  @dynamic_lights = collect_dynamic_lights
  super
end