Flight model: ApplyFlightModel (Part 6 of 7)

       Name: ApplyFlightModel (Part 6 of 7)                          [Show more]
       Type: Subroutine
   Category: Flight model
    Summary: Adjust the plane's velocity and turn rate, rotate the plane
             according to the forces on the aircraft, process landing
  Deep dive: The flight model
    Context: See this subroutine in context in the source code
 References: No direct references to this subroutine in this source file


 This part does the following:

   * Rotate (xLinear, yLinear, zLinear) from the plane's frame of reference to
     the outside world's frame of reference using matrix 2, then subtract 16
     from yLinearHi and store the result in (dxVelocity, dyVelocity,
     dzVelocity):

       [ dxVelocity ]             [ xLinear ]   [   0  ]
       [ dyVelocity ] = matrix2 x [ yLinear ] - [ 4096 ]
       [ dzVelocity ]             [ zLinear ]   [   0  ]

   * Call the AdjustVelocity routine to adjust the plane's velocity as follows:

       [ xVelocity ]   [ xVelocity ]   [ dxVelocity ]
       [ yVelocity ] = [ yVelocity ] + [ dyVelocity ] * 2
       [ zVelocity ]   [ zVelocity ]   [ dzVelocity ]

   * Call the AdjustTurn routine to adjust the plane's turn rate as follows:

       [ xTurn ]   [ xTurn ]   [ dxTurn ]
       [ yTurn ] = [ yTurn ] + [ dyTurn ]
       [ zTurn ]   [ zTurn ]   [ dzTurn ]

   * Rotate (xTurn, yTurn, zTurn) using matrix 3, which rotates by the current
     roll angle, and store the result in (dxRotation, dyRotation, dzRotation):

       [ dxRotation ]             [ xTurn ]
       [ dyRotation ] = matrix3 x [ yTurn ]
       [ dzRotation ]             [ zTurn ]

   * Call the AdjustRotation routine to move the plane as follows:

       [ xPlane ]   [ xPlane ]   [ xVelocity ]
       [ yPlane ] = [ yPlane ] + [ yVelocity ]
       [ zPlane ]   [ zPlane ]   [ zVelocity ]

     and adjust the plane's rotation as follows:

       [ xRotation ]   [ xRotation ]   [ dxRotation ]
       [ yRotation ] = [ yRotation ] + [ dyRotation ]
       [ zRotation ]   [ zRotation ]   [ dzRotation ]

     The plane is flipped around if this makes it point backwards.

   * Make the engine sound.

   * Call the ProcessLanding routine to check to see if we are landing, and if
     we are, process the landing and the effect on the plane.

   * Call the ShowUpsideDownBar routine to show or hide the bar in the
     artificial horizon that shows whether the plane is upside down.


.fmod17

 LDA #9                 \ Set the matrix number so the call to SetPointCoords
 STA matrixNumber       \ uses matrix 2 in the calculation, so it rotates the
                        \ point from the plane's frame of reference to the
                        \ outside world's frame of reference

 LDA #252               \ Set GG to the ID of the xLinear vector (which is
 STA GG                 \ stored in point 252), to pass to the call to
                        \ SetPointCoords

 JSR SetPointCoords     \ Calculate the coordinates of the xLinear vector in
                        \ (xLinear, yLinear, zLinear)

 LDA yLinearHi          \ Set yLinearHi = yLinearHi - 16
 SEC
 SBC #16
 STA yLinearHi

 LDX #LO(dxVelocityLo)  \ Set X so the call to CopyPointToWork copies the
                        \ coordinates to (dxVelocity, dyVelocity, dzVelocity)

 LDY #252               \ Set Y so the call to CopyPointToWork copies the
                        \ coordinates from the xLinear vector (in point 252)

 JSR CopyPointToWork    \ Copy (xLinear, yLinear, zLinear) to
                        \ (dxVelocity, dyVelocity, dzVelocity)

 JSR AdjustVelocity     \ Adjust the plane's velocity as follows:
                        \
                        \   [ xVelocity ]   [ xVelocity ]   [ dxVelocity ]
                        \   [ yVelocity ] = [ yVelocity ] + [ dyVelocity ] * 2
                        \   [ zVelocity ]   [ zVelocity ]   [ dzVelocity ]

 JSR AdjustTurn         \ Adjust the plane's turn rate as follows:
                        \
                        \   [ xTurn ]   [ xTurn ]   [ dxTurn ]
                        \   [ yTurn ] = [ yTurn ] + [ dyTurn ]
                        \   [ zTurn ]   [ zTurn ]   [ dzTurn ]

 LDX #LO(xTurnHi)       \ Set X so the call to CopyWorkToPoint copies the
                        \ coordinates from (xTurnHi, yTurnHi, zTurnHi)

                        \ We now rotate (xTurn, yTurn, zTurn), using matrix 3,
                        \ into (dxRotation, dyRotation, dzRotation)

 LDY #254               \ Set Y so the call to CopyWorkToPoint copies the
                        \ coordinates to point 254

 STY GG                 \ Set GG to point ID 254, to pass to the call to
                        \ SetPointCoords

 JSR CopyWorkToPoint    \ Copy the coordinates from (xTurn, yTurn, zTurn)
                        \ to point 254

 LDA #18                \ Set the matrix number so the call to SetPointCoords
 STA matrixNumber       \ uses matrix 3 in the calculation, so it rotates the
                        \ point by the plane's current roll angle

 JSR SetPointCoords     \ Calculate the coordinates for point 254

 LDX #LO(dxRotationLo)  \ Set X so the call to CopyPointToWork copies the
                        \ coordinates to (dxRotation, dyRotation, dzRotation)

 LDY #254               \ Set Y so the call to CopyPointToWork copies the
                        \ coordinates from point 254

 JSR CopyPointToWork    \ Copy the coordinates from point 254 to
                        \ (dxRotation, dyRotation, dzRotation)

 JSR AdjustRotation     \ Move the plane according to its velocity as follows:
                        \
                        \       [ xPlane ]   [ xPlane ]   [ xVelocity ]
                        \       [ yPlane ] = [ yPlane ] + [ yVelocity ]
                        \       [ zPlane ]   [ zPlane ]   [ zVelocity ]
                        \
                        \ and adjust the plane's rotation as follows:
                        \
                        \       [ xRotation ]   [ xRotation ]   [ dxRotation ]
                        \       [ yRotation ] = [ yRotation ] + [ dyRotation ]
                        \       [ zRotation ]   [ zRotation ]   [ dzRotation ]
                        \
                        \ The plane is flipped around if this makes it point
                        \ backwards

 LDA #7                 \ Make the engine sound
 JSR ToggleEngineSound

 JSR ProcessLanding     \ Check to see if we are landing, and if we are, process
                        \ the landing and the effect on the plane

 JSR ShowUpsideDownBar  \ Show or hide the bar in the artificial horizon that
                        \ shows whether the plane is upside down