Class: RubyGL::Shader

Inherits:
Object
  • Object
show all
Defined in:
lib/rubygl/shader.rb

Instance Method Summary collapse

Constructor Details

#initialize(vert_src, frag_src) ⇒ Shader

Returns a new instance of Shader.



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# File 'lib/rubygl/shader.rb', line 6

def initialize(vert_src, frag_src)
    @v_shader_id = Native.glCreateShader(Native::GL_VERTEX_SHADER)
    @f_shader_id = Native.glCreateShader(Native::GL_FRAGMENT_SHADER)
    @attrib_locs, @uniform_locs = {}, {}
    
    # Pointer Used To Point To The String Of Our Source Code
    shader_src_ptr = FFI::MemoryPointer.new(:pointer)
    shader_src_len = FFI::MemoryPointer.new(:int)
    
    v_shader_ptr = FFI::MemoryPointer.from_string(vert_src)
    f_shader_ptr = FFI::MemoryPointer.from_string(frag_src)
    
    shader_src_ptr.write_pointer(v_shader_ptr.address)
    shader_src_len.write_int(vert_src.size)
    Native.glShaderSource(@v_shader_id, 1, shader_src_ptr, shader_src_len)
    
    shader_src_ptr.write_pointer(f_shader_ptr.address)
    shader_src_len.write_int(frag_src.size)
    Native.glShaderSource(@f_shader_id, 1, shader_src_ptr, shader_src_len)
    
    Native.glCompileShader(@v_shader_id)
    Native.glCompileShader(@f_shader_id)
    
    # Throw Exception With Compile Error If Compilation Failed
    Shader.compile_status(@v_shader_id)
    Shader.compile_status(@f_shader_id)
    
    @program_id = Native.glCreateProgram()
    
    Native.glAttachShader(@program_id, @v_shader_id)
    Native.glAttachShader(@program_id, @f_shader_id)
    
    Native.glLinkProgram(@program_id)
    
    Shader.link_status(@program_id)
end

Instance Method Details

#attrib_location(var_name) ⇒ Object 



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# File 'lib/rubygl/shader.rb', line 63

def attrib_location(var_name)
    Native.glGetAttribLocation(@program_id, var_name)
end

#send_uniform(method_sym, var_name, data = nil, *args) ⇒ Object

Splat Operator Aggregates Incoming Parameters And Expands Outgoing Parameters If method_sym Does Not Accept A Pointer To The Data, Pass nil For data And Pass In The Normal Parameters Required For The Specific Method.



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# File 'lib/rubygl/shader.rb', line 50

def send_uniform(method_sym, var_name, data = nil, *args)
    loc = @uniform_locs[var_name] ||= uniform_location(var_name)
    
    if data != nil then
        data_ptr = FFI::MemoryPointer.new(:float, data.size)
        data_ptr.write_array_of_float(data)
        
        RubyGL::Native.send(method_sym, loc, *args, data_ptr)
    else
        RubyGL::Native.send(method_sym, loc, *args)
    end
end

#use_program ⇒ Object 



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

def use_program()
    Native.glUseProgram(@program_id)
end