Ashton

Description

Add extra visual effects to the Gosu game-development library, utilising OpenGL shaders (using shader model 1.0, for maximum compatibility) and frame-buffers.

"Ashton" is named after Clark Ashton Smith, an fantasy/horror author with a particularly colourful imagination.

• Author: Bil Bas (Spooner)
• Wiki
• License: MIT

Usage

gem install ashton

Features

• Gosu extensions

  • {Gosu::Color} - Converting to and from opengl values.

  • {Gosu::Font} - Apply shader to draw operations.

  • {Gosu::Image} - Apply shader to each draw operation or group of draws. Manipulation, such as flipping and scaling.

  • {Gosu::Window} - Post-processing with shaders. Converting to image.

• Ashton

  • {Ashton::Texture} - Single texture (compared to Gosu::Image which uses a spritesheet) which can be drawn directly onto and drawn to the Window.

  • {Ashton::Lighting::Manager} - Manages and combines the lighting from {Ashton::Lighting::LightSource} objects.

  • {Ashton::Lighting::LightSource} - A single light-source that illuminates and whose can be blocked by shadow-casting objects.

  • {Ashton::ParticleEmitter} - Generates, manages and displays particles.

  • {Ashton::PixelCache} - Cached image data attached to an {Ashton::Texture} or {Gosu::Image}.

  • {Ashton::SignedDistanceField} - A signed distance field based on a an image mask.

  • {Ashton::Shader} - Wrapper around a GLSL shaders, Supports vertex and fragment shaders. Small shader/function library.

  • {Ashton::WindowBuffer} - Texture that is the same size as the Gosu Window that can capture the contents of the screen.

Requirements

• OSX/Linux: Requires OpenGL library be installed.

• {Ashton::Shader} and {Ashton::Lighting} or anything else using shaders, require OpenGL 2.0.

Similar Libraries

• TexPlay - Deals with Gosu::Image manipulation, such as per-pixel editing and drawing. It is compatible with, and complementary to, this gem.

Third party

• OpenGL static library (in Windows binary gem) and headers.

• GLee source.

• Various trivial shaders - "randomly found on the Internet" :$

• Classic and Simplex noise functions - Copyright (C) 2011 Ashima Arts - MIT license.

  • classicnoise2d.glsl - 2D Classic Perlin noise implementation - cnoise(vec2)
  • classicnoise3d.glsl - 3D Classic Perlin noise implementation - cnoise(vec3)
  • classicnoise4d.glsl - 4D Classic Perlin noise implementation - cnoise(vec4)
  • noise2d.glsl - 2D Simplex noise implementation - snoise(vec2)
  • noise3d.glsl - 3D Simplex noise implementation - snoise(vec3)
  • noise4d.glsl - 4D Simplex noise implementation - snoise(vec4)

• Bloom filter by myheroics

  • bloom.frag

• Shockwave by Crystalin

  • shockwave.frag

• Radial Blur by gamerendering.com

  • radial_blur.frag

• Lighting based on, but much optimised from, Catalin Zima's shader based dynamic shadows system.

  • http://www.catalinzima.com/2010/07/my-technique-for-the-shader-based-dynamic-2d-shadows/
  • {Ashton::Lighting::LightSource} and {Ashton::Lighting::Manager} classes.
  • shadow_blur.frag
  • shadow_distory.frag
  • shadow_draw_shadows.frag