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

lib/cyberarm_engine/opengl/orthographic_camera.rb

@@ -0,0 +1,42 @@
+module CyberarmEngine
+  class OrthographicCamera
+    attr_accessor :position, :orientation, :zoom, :left, :right, :bottom, :top,
+                  :min_view_distance, :max_view_distance
+    def initialize(
+                    position:, orientation: Vector.new(0, 0, 0),
+                    zoom: 1, left: 0, right:, bottom: 0, top:,
+                    min_view_distance: 0.1, max_view_distance: 200.0
+                  )
+      @position = position
+      @orientation = orientation
+
+      @zoom = zoom
+
+      @left, @right, @bottom, @top = left, right, bottom, top
+
+      @min_view_distance = min_view_distance
+      @max_view_distance = max_view_distance
+    end
+
+    # Immediate mode renderering fallback
+    def draw
+      glMatrixMode(GL_PROJECTION)
+      glLoadIdentity
+      glOrtho(@left, @right, @bottom, @top, @min_view_distance, @max_view_distance)
+      glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST)
+      glRotatef(@orientation.x, 1, 0, 0)
+      glRotatef(@orientation.y, 0, 1, 0)
+      glTranslatef(-@position.x, -@position.y, -@position.z)
+      glMatrixMode(GL_MODELVIEW)
+      glLoadIdentity
+    end
+
+    def projection_matrix
+      Transform.orthographic(@left, @right, @bottom, @top, @min_view_distance, @max_view_distance)
+    end
+
+    def view_matrix
+      Transform.translate_3d(@position * -1) * Transform.rotate_3d(@orientation)
+    end
+  end
+end