Added a large portion of I-MIC-FPS's opengl rendering and model loading systems

lib/cyberarm_engine/opengl/renderer/g_buffer.rb

@@ -0,0 +1,162 @@
+module CyberarmEngine
+  class GBuffer
+    attr_reader :screen_vbo, :vertices, :uvs
+    def initialize(width:, height:)
+    @width, @height = width, height
+
+      @framebuffer = nil
+      @buffers = [:position, :diffuse, :normal, :texcoord]
+      @textures = {}
+      @screen_vbo = nil
+      @ready = false
+
+      @vertices = [
+        -1.0, -1.0, 0,
+        1.0,  -1.0, 0,
+        -1.0,  1.0, 0,
+
+        -1.0,  1.0, 0,
+        1.0,  -1.0, 0,
+        1.0,   1.0, 0,
+    ].freeze
+
+      @uvs = [
+        0, 0,
+        1, 0,
+        0, 1,
+
+        0, 1,
+        1, 0,
+        1, 1
+      ].freeze
+
+      create_framebuffer
+      create_screen_vbo
+    end
+
+    def create_framebuffer
+      buffer = ' ' * 4
+      glGenFramebuffers(1, buffer)
+      @framebuffer = buffer.unpack('L2').first
+
+      glBindFramebuffer(GL_DRAW_FRAMEBUFFER, @framebuffer)
+
+      create_textures
+
+      status = glCheckFramebufferStatus(GL_FRAMEBUFFER)
+
+      if status != GL_FRAMEBUFFER_COMPLETE
+        message = ""
+
+        case status
+        when GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT
+          message = "GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT"
+        when GL_FRAMEBUFFER_INCOMPLETE_MISSING_ATTACHMENT
+          message = "GL_FRAMEBUFFER_INCOMPLETE_MISSING_ATTACHMENT"
+        when GL_FRAMEBUFFER_INCOMPLETE_DRAW_BUFFER
+          message = "GL_FRAMEBUFFER_INCOMPLETE_DRAW_BUFFER"
+        when GL_FRAMEBUFFER_INCOMPLETE_READ_BUFFER
+          message = "GL_FRAMEBUFFER_INCOMPLETE_READ_BUFFER"
+        when GL_FRAMEBUFFER_UNSUPPORTED
+          message = "GL_FRAMEBUFFER_UNSUPPORTED"
+        else
+          message = "Unknown error!"
+        end
+        puts "Incomplete framebuffer: #{status}\nError: #{message}"
+      else
+        @ready = true
+      end
+
+      glBindFramebuffer(GL_DRAW_FRAMEBUFFER, 0)
+    end
+
+    def create_textures
+      @buffers.size.times do |i|
+        buffer = ' ' * 4
+        glGenTextures(1, buffer)
+        texture_id = buffer.unpack('L2').first
+        @textures[@buffers[i]] = texture_id
+
+        glBindTexture(GL_TEXTURE_2D, texture_id)
+        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA16F, @width, @height, 0, GL_RGBA, GL_FLOAT, nil)
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR)
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR)
+        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0 + i, GL_TEXTURE_2D, texture_id, 0)
+      end
+
+      buffer = ' ' * 4
+      glGenTextures(1, buffer)
+      texture_id = buffer.unpack('L2').first
+      @textures[:depth] = texture_id
+
+      glBindTexture(GL_TEXTURE_2D, texture_id)
+      glTexImage2D(GL_TEXTURE_2D, 0, GL_DEPTH_COMPONENT32F, @width, @height, 0, GL_DEPTH_COMPONENT, GL_FLOAT, nil)
+      glFramebufferTexture2D(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_TEXTURE_2D, texture_id, 0)
+
+      draw_buffers = [ GL_COLOR_ATTACHMENT0, GL_COLOR_ATTACHMENT1, GL_COLOR_ATTACHMENT2, GL_COLOR_ATTACHMENT3 ]
+      glDrawBuffers(draw_buffers.size, draw_buffers.pack("I*"))
+    end
+
+    def create_screen_vbo
+      buffer = ' ' * 4
+      glGenVertexArrays(1, buffer)
+      @screen_vbo = buffer.unpack('L2').first
+
+      buffer = " " * 4
+      glGenBuffers(1, buffer)
+      @positions_buffer_id = buffer.unpack('L2').first
+
+      buffer = " " * 4
+      glGenBuffers(1, buffer)
+      @uvs_buffer_id = buffer.unpack('L2').first
+
+      glBindVertexArray(@screen_vbo)
+      glBindBuffer(GL_ARRAY_BUFFER, @positions_buffer_id)
+      glBufferData(GL_ARRAY_BUFFER, @vertices.size * Fiddle::SIZEOF_FLOAT, @vertices.pack("f*"), GL_STATIC_DRAW);
+      glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, nil)
+
+      glBindBuffer(GL_ARRAY_BUFFER, @uvs_buffer_id)
+      glBufferData(GL_ARRAY_BUFFER, @uvs.size * Fiddle::SIZEOF_FLOAT, @uvs.pack("f*"), GL_STATIC_DRAW);
+      glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 0, nil)
+
+      glEnableVertexAttribArray(0)
+      glEnableVertexAttribArray(1)
+
+      glBindVertexArray(0)
+    end
+
+    def bind_for_writing
+      glBindFramebuffer(GL_DRAW_FRAMEBUFFER, @framebuffer)
+    end
+
+    def bind_for_reading
+      glBindFramebuffer(GL_READ_FRAMEBUFFER, @framebuffer)
+    end
+
+    def set_read_buffer(buffer)
+      glReadBuffer(GL_COLOR_ATTACHMENT0 + @textures.keys.index(buffer))
+    end
+
+    def set_read_buffer_depth
+      glReadBuffer(GL_DEPTH_ATTACHMENT)
+    end
+
+    def unbind_framebuffer
+      glBindFramebuffer(GL_FRAMEBUFFER, 0)
+    end
+
+    def texture(type)
+      @textures[type]
+    end
+
+    def clean_up
+      glDeleteFramebuffers(1, [@framebuffer].pack("L"))
+
+      glDeleteTextures(@textures.values.size, @textures.values.pack("L*"))
+
+      glDeleteBuffers(2, [@positions_buffer_id, @uvs_buffer_id].pack("L*"))
+      glDeleteVertexArrays(1, [@screen_vbo].pack("L"))
+      gl_error?
+    end
+  end
+end