Class: Quake::Renderer::GLWater

Inherits:
Object
  • Object
show all
Defined in:
lib/quake/renderer/gl_water.rb

Overview

Renders turbulent water/lava/slime surfaces with sine-wave warping. Quake liquid textures have names starting with ‘*’.

Constant Summary collapse

TURBSCALE =

~40.74

256.0 / (2.0 * ::Math::PI)
SUBDIVIDE_SIZE = 
64.0

Instance Method Summary collapse

Constructor Details

#initialize(level, texture_manager) ⇒ GLWater

Returns a new instance of GLWater.



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# File 'lib/quake/renderer/gl_water.rb', line 14

def initialize(level, texture_manager)
  @level = level
  @texture_manager = texture_manager
  @water_surfaces = []
  @time = 0.0

  # Precompute 256-entry sine table matching Quake's turbsin
  @turbsin = Array.new(256) do |i|
    (::Math.sin(i * 2.0 * ::Math::PI / 256.0) * 8.0)
  end

  precompute_water_surfaces
end

Instance Method Details

#render(alpha: 1.0) ⇒ Object

Render water surfaces with turbulent sine-wave warp. alpha: 1.0 = fully opaque (GLQuake default r_wateralpha).

Values < 1.0 enable semi-transparent water.



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# File 'lib/quake/renderer/gl_water.rb', line 35

def render(alpha: 1.0)
  return if @water_surfaces.empty?

  GL.Enable(GL::TEXTURE_2D)
  # Quake BSP stores liquid surfaces as front/back face pairs on the
  # same plane so the surface is visible from above and below. Without
  # culling both copies rasterize at the same depth, z-fight, and (with
  # alpha < 1) double-blend, producing flicker. Match TyrQuake:
  # glCullFace(GL_FRONT) with default CCW front face.
  GL.Enable(GL::CULL_FACE)
  GL.CullFace(GL::FRONT)

  if alpha < 1.0
    GL.Enable(GL::BLEND)
    GL.BlendFunc(GL::SRC_ALPHA, GL::ONE_MINUS_SRC_ALPHA)
    GL.TexEnvi(GL::TEXTURE_ENV, GL::TEXTURE_ENV_MODE, GL::MODULATE)
    GL.Color4f(1.0, 1.0, 1.0, alpha)
  else
    GL.TexEnvi(GL::TEXTURE_ENV, GL::TEXTURE_ENV_MODE, GL::REPLACE)
  end

  @water_surfaces.each do |ws|
    @texture_manager.bind(ws[:miptex_index])

    ws[:faces].each do |face_data|
      GL.Begin(GL::TRIANGLE_FAN)
      face_data[:verts].each_with_index do |v, i|
        os, ot = face_data[:texcoords][i]

        # Cross-modulated sine warp
        s = os + @turbsin[((ot * 0.125 + @time) * TURBSCALE).to_i & 255]
        s /= 64.0

        t = ot + @turbsin[((os * 0.125 + @time) * TURBSCALE).to_i & 255]
        t /= 64.0

        GL.TexCoord2f(s, t)
        GL.Vertex3f(v.x, v.y, v.z)
      end
      GL.End
    end
  end

  GL.Disable(GL::CULL_FACE)

  if alpha < 1.0
    GL.Disable(GL::BLEND)
    GL.Color4f(1.0, 1.0, 1.0, 1.0)
  end
  GL.TexEnvi(GL::TEXTURE_ENV, GL::TEXTURE_ENV_MODE, GL::MODULATE)
end

#update(dt) ⇒ Object 



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# File 'lib/quake/renderer/gl_water.rb', line 28

def update(dt)
  @time += dt
end