Class: CyberarmEngine::Shader

Inherits:
Object
  • Object
show all
Includes:
OpenGL
Defined in:
lib/cyberarm_engine/shader.rb

Overview

Ref: github.com/vaiorabbit/ruby-opengl/blob/master/sample/OrangeBook/brick.rb

Constant Summary collapse

PREPROCESSOR_CHARACTER =

magic character for preprocessor phase of CyberarmEngine::Shader compilation

"@".freeze
@@shaders =

Cache for CyberarmEngine::Shader instances

{}

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(name:, includes_dir: nil, vertex: "shaders/default.vert", fragment:) ⇒ Shader

Returns a new instance of Shader.



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# File 'lib/cyberarm_engine/shader.rb', line 111

def initialize(name:, includes_dir: nil, vertex: "shaders/default.vert", fragment:)
  raise "Shader name can not be blank" if name.length == 0

  @name = name
  @includes_dir = includes_dir
  @compiled = false

  @program = nil

  @error_buffer_size = 1024 * 8
  @variable_missing = {}

  @data = {shaders: {}}

  unless shader_files_exist?(vertex: vertex, fragment: fragment)
    raise ArgumentError, "Shader files not found: #{vertex} or #{fragment}"
  end

  create_shader(type: :vertex, source: File.read(vertex))
  create_shader(type: :fragment, source: File.read(fragment))

  compile_shader(type: :vertex)
  compile_shader(type: :fragment)
  link_shaders

  @data[:shaders].each { |key, id| glDeleteShader(id) }

  # Only add shader if it successfully compiles
  if @compiled
    puts "compiled!"
    puts "Compiled shader: #{@name}"
    Shader.add(@name, self)
  else
    glDeleteProgram(@program)
    warn "FAILED to compile shader: #{@name}", ""
  end
end

Instance Attribute Details

#name ⇒ Object (readonly)

Returns the value of attribute name.



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# File 'lib/cyberarm_engine/shader.rb', line 110

def name
  @name
end

#program ⇒ Object (readonly)

Returns the value of attribute program.



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# File 'lib/cyberarm_engine/shader.rb', line 110

def program
  @program
end

Class Method Details

.active_shader ⇒ Shader?

returns currently active CyberarmEngine::Shader, if one is active

Returns:



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# File 'lib/cyberarm_engine/shader.rb', line 71

def self.active_shader
  @active_shader
end

.active_shader=(instance) ⇒ Object

sets currently active CyberarmEngine::Shader

Parameters:



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# File 'lib/cyberarm_engine/shader.rb', line 78

def self.active_shader=(instance)
  @active_shader = instance
end

.add(name, instance) ⇒ Object

add instance of CyberarmEngine::Shader to cache

Parameters:

  • name (String)
  • instance (Shader) 


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# File 'lib/cyberarm_engine/shader.rb', line 12

def self.add(name, instance)
  @@shaders[name] = instance
end

.attribute_location(variable) ⇒ Object

returns location of OpenGL Shader uniform

Parameters:

  • variable (String)

Raises:

  • (RuntimeError) 


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# File 'lib/cyberarm_engine/shader.rb', line 96

def self.attribute_location(variable)
  raise RuntimeError, "No active shader!" unless Shader.active_shader
  Shader.active_shader.attribute_location(variable)
end

.available?(name) ⇒ Boolean

returns whether CyberarmEngine::Shader with name is in cache

Parameters:

  • name (String)

Returns:

  • (Boolean) 


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# File 'lib/cyberarm_engine/shader.rb', line 56

def self.available?(name)
  @@shaders.dig(name).is_a?(Shader)
end

.delete(name) ⇒ Object

removes CyberarmEngine::Shader from cache and cleans up

Parameters:

  • name (String) 


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# File 'lib/cyberarm_engine/shader.rb', line 19

def self.delete(name)
  shader = @@shaders.dig(name)

  if shader
    @@shaders.delete(name)

    if shader.compiled?
      glDeleteProgram(shader.program)
    end
  end
end

.get(name) ⇒ Shader?

returns instance of CyberarmEngine::Shader, if it exists

Parameters:

  • name (String)

Returns:



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# File 'lib/cyberarm_engine/shader.rb', line 64

def self.get(name)
  @@shaders.dig(name)
end

.set_uniform(variable, value) ⇒ Object

sets variable to value

Parameters:

  • variable (String)
  • value

Raises:

  • (RuntimeError) 


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# File 'lib/cyberarm_engine/shader.rb', line 105

def self.set_uniform(variable, value)
  raise RuntimeError, "No active shader!" unless Shader.active_shader
  Shader.active_shader.set_uniform(variable, value)
end

.stop ⇒ Object

stops using currently active CyberarmEngine::Shader



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# File 'lib/cyberarm_engine/shader.rb', line 83

def self.stop
  shader = Shader.active_shader

  if shader
    shader.stop
  else
    raise ArgumentError, "No active shader to stop!"
  end
end

.use(name, &block) ⇒ void

This method returns an undefined value.

runs block using CyberarmEngine::Shader with name

Examples:


CyberarmEngine::Shader.use("blur") do |shader|
  shader.uniform_float("radius", 20.0)
  # OpenGL Code that uses shader
end

Parameters:



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# File 'lib/cyberarm_engine/shader.rb', line 43

def self.use(name, &block)
  shader = @@shaders.dig(name)
  if shader
    shader.use(&block)
  else
    raise ArgumentError, "Shader '#{name}' not found!"
  end
end

Instance Method Details

#attribute_location(variable) ⇒ Integer

Note:

Use #variable for friendly error handling

returns location of a uniform variable

Parameters:

  • variable (String)

Returns:

  • (Integer)

See Also:



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# File 'lib/cyberarm_engine/shader.rb', line 323

def attribute_location(variable)
  glGetUniformLocation(@program, variable)
end

#compile_shader(type:) ⇒ Boolean

compile OpenGL Shader of type

Returns:

  • (Boolean) —

    whether compilation succeeded

Raises:

  • (ArgumentError) 


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# File 'lib/cyberarm_engine/shader.rb', line 227

def compile_shader(type:)
  _compiled = false
  _shader = @data[:shaders][type]
  raise ArgumentError, "No shader for #{type.inspect}" unless _shader

  glCompileShader(_shader)
  buffer = '    '
  glGetShaderiv(_shader, GL_COMPILE_STATUS, buffer)
  compiled = buffer.unpack('L')[0]

  if compiled == 0
    log = ' ' * @error_buffer_size
    glGetShaderInfoLog(_shader, @error_buffer_size, nil, log)
    puts "Shader Error: Program \"#{@name}\""
    puts "  #{type.to_s.capitalize} Shader InfoLog:", "  #{log.strip.split("\n").join("\n  ")}\n\n"
    puts "  Shader Compiled status: #{compiled}"
    puts "    NOTE: assignment of uniforms in shaders is illegal!"
    puts
  else
    _compiled = true
  end

  return _compiled
end

#compiled? ⇒ Boolean

Returns whether CyberarmEngine::Shader successfully compiled.

Returns:



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# File 'lib/cyberarm_engine/shader.rb', line 312

def compiled?
  @compiled
end

#create_shader(type:, source:) ⇒ Object

creates an OpenGL Shader of type using source

Parameters:

  • type (Symbol) —

    valid values are: :vertex, :fragment

  • source (String) —

    source code for shader



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# File 'lib/cyberarm_engine/shader.rb', line 160

def create_shader(type:, source:)
  _shader = nil

  case type
  when :vertex
    _shader = glCreateShader(GL_VERTEX_SHADER)
  when :fragment
    _shader = glCreateShader(GL_FRAGMENT_SHADER)
  else
    raise ArgumentError, "Unsupported shader type: #{type.inspect}"
  end

  processed_source = preprocess_source(source: source)

  _source = [processed_source].pack("p")
  _size = [processed_source.length].pack("I")
  glShaderSource(_shader, 1, _source, _size)

  @data[:shaders][type] =_shader
end

#link_shaders ⇒ Boolean

Note:

linking must succeed or shader cannot be used

link compiled OpenGL Shaders in to a OpenGL Program

Returns:

  • (Boolean) —

    whether linking succeeded



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# File 'lib/cyberarm_engine/shader.rb', line 257

def link_shaders
  @program = glCreateProgram
  @data[:shaders].values.each do |_shader|
    glAttachShader(@program, _shader)
  end
  glLinkProgram(@program)

  buffer = '    '
  glGetProgramiv(@program, GL_LINK_STATUS, buffer)
  linked = buffer.unpack('L')[0]

  if linked == 0
    log = ' ' * @error_buffer_size
    glGetProgramInfoLog(@program, @error_buffer_size, nil, log)
    puts "Shader Error: Program \"#{@name}\""
    puts "  Program InfoLog:", "  #{log.strip.split("\n").join("\n  ")}\n\n"
  end

  @compiled = linked == 0 ? false : true
end

#preprocess_source(source:) ⇒ Object

evaluates shader preprocessors

currently supported preprocessors:

@include "file/path" "another/file/path" # => Replace line with contents of file; Shader includes_dir must be specified in constructor

Examples:

# Example Vertex Shader #
# #version 330 core
# @include "material_struct"
# void main() {
#   gl_Position = vec4(1, 1, 1, 1);
# }

Shader.new(name: "model_renderer", includes_dir: "path/to/includes", vertex: "path/to/vertex_shader.glsl")

Parameters:

  • source —

    shader source code



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# File 'lib/cyberarm_engine/shader.rb', line 198

def preprocess_source(source:)
  lines = source.lines

  lines.each_with_index do |line, i|
    if line.start_with?(PREPROCESSOR_CHARACTER)
      preprocessor = line.strip.split(" ")
      lines.delete(line)

      case preprocessor.first
      when "@include"
        raise ArgumentError, "Shader preprocessor include directory was not given for shader #{@name}" unless @includes_dir

        preprocessor[1..preprocessor.length - 1].join.scan(/"([^"]*)"/).flatten.each do |file|
          source = File.read("#{@includes_dir}/#{file}.glsl")

          lines.insert(i, source)
        end
      else
        warn "Unsupported preprocessor #{preprocessor.first} for #{@name}"
      end
    end
  end

  lines.join
end

#shader_files_exist?(vertex:, fragment:) ⇒ Boolean

whether vertex and fragment files exist on disk

Returns:

  • (Boolean) 


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# File 'lib/cyberarm_engine/shader.rb', line 152

def shader_files_exist?(vertex:, fragment:)
  File.exist?(vertex) && File.exist?(fragment)
end

#stop ⇒ Object

stop using shader, if shader is active



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# File 'lib/cyberarm_engine/shader.rb', line 306

def stop
  Shader.active_shader = nil if Shader.active_shader == self
  glUseProgram(0)
end

#uniform_boolean(variable, value, location = nil) ⇒ void

This method returns an undefined value.

send Boolean to CyberarmEngine::Shader

Parameters:

  • variable (String)
  • value (Boolean)
  • location (Integer) (defaults to: nil) 


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# File 'lib/cyberarm_engine/shader.rb', line 345

def uniform_boolean(variable, value, location = nil)
  attr_loc = location ? location : attribute_location(variable)

  glUniform1i(attr_loc, value ? 1 : 0)
end

#uniform_float(variable, value, location = nil) ⇒ void

This method returns an undefined value.

send Float to CyberarmEngine::Shader

Parameters:

  • variable (String)
  • value (Float)
  • location (Integer) (defaults to: nil) 


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# File 'lib/cyberarm_engine/shader.rb', line 368

def uniform_float(variable, value, location = nil)
  attr_loc = location ? location : attribute_location(variable)

  glUniform1f(attr_loc, value)
end

#uniform_integer(variable, value, location = nil) ⇒ void

This method returns an undefined value.

send Integer to CyberarmEngine::Shader

Parameters:

  • variable (String)
  • value (Integer)
  • location (Integer) (defaults to: nil) 


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# File 'lib/cyberarm_engine/shader.rb', line 356

def uniform_integer(variable, value, location = nil)
  attr_loc = location ? location : attribute_location(variable)

  glUniform1i(attr_loc, value)
end

#uniform_transform(variable, value, location = nil) ⇒ void

This method returns an undefined value.

send Transform to CyberarmEngine::Shader

Parameters:

  • variable (String)
  • value (Transform)
  • location (Integer) (defaults to: nil) 


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# File 'lib/cyberarm_engine/shader.rb', line 333

def uniform_transform(variable, value, location = nil)
  attr_loc = location ? location : attribute_location(variable)

  glUniformMatrix4fv(attr_loc, 1, GL_FALSE, value.to_gl.pack("F16"))
end

#uniform_vec3(variable, value, location = nil) ⇒ void

This method returns an undefined value.

send Vector (x, y, z) to CyberarmEngine::Shader

Parameters:

  • variable (String)
  • value (Vector)
  • location (Integer) (defaults to: nil) 


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# File 'lib/cyberarm_engine/shader.rb', line 380

def uniform_vec3(variable, value, location = nil)
  attr_loc = location ? location : attribute_location(variable)

  glUniform3f(attr_loc, *value.to_a[0..2])
end

#uniform_vec4(variable, value, location = nil) ⇒ void

This method returns an undefined value.

send Vector to CyberarmEngine::Shader

Parameters:

  • variable (String)
  • value (Vector)
  • location (Integer) (defaults to: nil) 


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# File 'lib/cyberarm_engine/shader.rb', line 392

def uniform_vec4(variable, value, location = nil)
  attr_loc = location ? location : attribute_location(variable)

  glUniform4f(attr_loc, *value.to_a)
end

#use(&block) ⇒ Object

See Also:



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# File 'lib/cyberarm_engine/shader.rb', line 292

def use(&block)
  return unless compiled?
  raise "Another shader is already in use! #{Shader.active_shader.name.inspect}" if Shader.active_shader
  Shader.active_shader=self

  glUseProgram(@program)

  if block
    block.call(self)
    stop
  end
end

#variable(variable) ⇒ Integer

Returns the location of a uniform variable

Parameters:

  • variable (String)

Returns:

  • (Integer) —

    location of uniform



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# File 'lib/cyberarm_engine/shader.rb', line 282

def variable(variable)
  loc = glGetUniformLocation(@program, variable)
  if (loc == -1)
    puts "Shader Error: Program \"#{@name}\" has no such uniform named \"#{variable}\"", "  Is it used in the shader? GLSL may have optimized it out.", "  Is it miss spelled?" unless @variable_missing[variable]
    @variable_missing[variable] = true
  end
  return loc
end