DojoG3D Help Session

1
Dojo/G3D Help Session

• CS196-2
• Sunday 1/29

2
What is Dojo?

• Game engine
• Graphics G3D
• http//g3d-cpp.sourceforge.net/html/
• Physics ODE
• http//www.ode.org/

3
Getting Started

• Work in Windows, MS Visual Studio 2005
• Use MSLab, or work at home (recommended)
• Get Visual Studio 2005 Professional CD from CIS
  Help Desk
• Or download Visual C 2005 Express Edition at
  http//msdn.microsoft.com/vstudio/express/visualc/
  download/
• Copy files from Y/course/cs196-2/asgn/0/dojo/
• Copy Dojo to a local directory (on the C/ drive)
  when working, otherwise compiling will take
  forever. Note in the MSLab, the desktop is NOT
  a local directory.
• Open dojo.sln with Visual Studio.

4
Visual Studio

• Set up path to Dojos library files.
• Select Tools-gtOptions-gtProjects and
  Solutions-gtVC Directories, and in the top right
  corner of the window, select Library files
• Add the path Y/course/cs196-2/libraries/win32-vc
  8-lib to the list.
• If youre working at home, youll need to copy
  the contents of that directory to your PC, and
  set the appropriate path.

5
Visual Studio (cont.)

• In the Solution Explorer on the left hand side of
  the Visual Studio window, right click on the line
  Solution dojo (3 projects).
• In the dialog that comes up, select Single
  startup project and select scratch from the
  drop-down list.
• Use the Solution Explorer to select the files you
  want to edit.
• Can add new files to a project by right clicking
  on the project name and selecting Add-gtNew Item.
• Compile using Build-gtBuild Solution (F7)
• Run using Debug-gtStart Debugging (F5)
• If youve made any changes since last compiling,
  this option will compile for you as well.

6
scratch/main.cpp

• include "dojo/dojo.h
• include "ui/ui.h"
• include "dojo/physicsunits.h"
• include "App.h"
• int main(int argc, char argv)
• GAppSettings settings
• dojoapp new App(settings)
• dojoapp-gtrun()
• delete dojoapp
• dojoapp NULL
• return 0

G3D class use it to set a number of settings for
your application
?
App is your game application (see next slide).
dojoapp is a global pointer to the application.
Call run() to start your game.
?
7
scratch/App.h

• Subclass of Dojos DApp
• DAppmain()
• Called by DApprun()
• Override this to perform any initializations you
  need
• Specifically, need to instantiate a DApplet and
  once youre ready to begin the game, call its
  run() method.

8
scratch/Demo.h

• Subclass of Dojos DApplet
• A DApp can contain multiple DApplets
• Only 1 DApplet can be running at any time
• Create a separate DApplet for each portion of
  your game (e.g. one for the actual game and one
  for the initial menu screen).
• DAppletrun() begins execution of the game loop.

9
scratch/Demo.h (cont.)

• The DApplet game loop
• onInit()
• Called once, before the game loop begins.
• Perform any necessary initializations here.
• onGraphics()
• Render the current frame and perform any other
  drawing operations.
• onNetwork()
• Perform network message polling.

10
scratch/Demo.h (cont.)

• onUserInput()
• Process any keyboard/mouse/gamepad events.
• onSimulation()
• Advance the state of your game objects from the
  previous frame (e.g. using a physics simulator).
• onCleanup()
• Called only once, at the end of a run() call.
• Perform any necessary cleanup operations here.

11
dojoEntity

• The base class for all graphical/physical objects
  in Dojo.
• create()
• Static method used to create new Entities.
• Use instead of constructor.
• Returns a reference-counted pointer dont
  delete.
• See Ball, Helicopter, Crate classes for examples.

12
dojoWorld

• Handles rendering/physics.
• Insert Entities into World
• EntityRef ball Ballcreate("Basketball")
• Worldworld()-gtinsert(ball, CoordinateFrame())
  
• CoordinateFrame is a G3D class used to specify an
  objects position and orientation in 3-space.
• Worldworld()
• Returns the global World instance. The first
  time you call this method in your program a new
  World is created.
• Have to initialize it with a subsequent call to
• Worldworld()-gtinit()

13
dojoWorld (cont.)

• Rendering
• The World renders all the Entities that you
  insert into it
• void DemoonGraphics(RenderDevice rd)
• Worldworld()-gtactiveCamera
  app-gtdebugCamera
• rd-gtsetProjectionAndCameraMatrix(Worldworld()-
  gtactiveCamera)
• Worldworld()-gtonGraphics(rd)
• DAppletonGraphics(rd)

14
dojoWorld (cont.)

• Physics
• The World also handles physics on all inserted
  Entities for you
• void DemoonSimulation(RealTime rdt, SimTime
  sdt, SimTime idt)
• DAppletonSimulation(rdt, sdt, idt)