3D Sprite

 

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Rotates a sprite in 3D Requires Dave"s 3D engine The newest version and full example files are always available at http://www.dubbus.com/devnull

-- Dave's Lingo 3D Engine v7.1 FULL - Last Modified 12/14/99 -- Dave Cole - dcole@sigma6.com -- Special thanks to Terry Schussler of Trevi Media (http://www.trevimedia.com) for optimizations! -- -- Dave's 3D Engine is Shareware.  If you use this source for commercial gain, you -- must send a $20 shareware registration fee to: -- -- Dave Cole -- 575 Leroy -- Ferndale, MI 48220 -- -- -- -- Copyright (c) 1998 David Cole -- All rights reserved. -- Redistribution and use in source and binary forms are permitted -- provided that the above copyright notice and this paragraph are -- duplicated in all such forms and that any documentation, -- advertising materials, and other materials related to such -- distribution and use acknowledge that the software was developed -- by David Cole, as well as that the user, if using this software -- for financial gain, has paid the $20 shareware registration fee. -- THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR -- IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED -- WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE. -- -- You may freely redistribute this 3D engine so long as the credits and accompanying -- credits README file remain with the engine at all times.  If you modify it, please -- annotate notes about your modification and notify me about your changes -- I would -- like to learn what others can do with this thing! -- -- The intention of this code is to allow the representation, transformation, and 2D -- projection and display of 3-dimensional graphics from within a director film.  The -- interface has been styled loosely after OpenGL for ease of use. -- -- If this source exists in its original distribution, a manual is available in cast -- member 3. -- -- This graphics engine uses a right-handed coordinate system with a view that defaults -- to looking down the negative z axis from the origin. -- -- This is the FULL release of Dave's Lingo 3D Engine.  That means that although care -- has been taken to optimize the routines for speed, the primary intention of this code is -- to offer a flexibile, accurate, fully-functional 3D graphics system. -- -- All points use homogenous coordinates.  4x4 Matrices are represented as nested lists: -- (i.e. [[],[],[],[]]).  1x4 Matrices are represented as a single 4-element list (i.e. -- [0.0, 0.0, 0.0, 1.0]).   -- -- *Note: If this engine is removed from its original distribution movie, the lingo below -- in green can be deleted, all green lingo below is demo-movie specific and not necessary -- for the 3D Engine to function properly. -------------------------------------------------------------------------------------------------------- -- Globals  -------------------------------------------------------------------------------------------- -------------------------------------------------------------------------------------------------------- global mModelView         -- A 4x4 matrix that represents the current ModelView matrix. global mProjection        -- A 4x4 matrix that represents the current Projection matrix. global mModelViewStack    -- A stack of saved ModelView matrices global mProjectionStack   -- A stack of saved Projection matrices global mv                 -- 1: Current Matrix Operations performed on ModelView matrix, 0: Current Matrix Ops Performed on Projection Matrix global point              -- A point datatype for misc. use (in homogenous coordinates) global xCoefficient       -- used in viewport transformations global yCoefficient       -- used in viewport transformations global halffov            -- used to scale sprites accurately global sortSprites        -- 1: Sprites with a nearer Z value will take a higher # sprite channel (slower) --                        -- 0: Sprites will stay in their channels (less accurate looking but faster) global cullBackfaces      -- 1: Cull backfacing quads, 0: don't global cullBackfaces_cw   -- 1: Clockwise defined vertices determine the front face of a quad, 0: Counterclockwise --                        -- .. This property only is checked if cullBackfaces = 1 global activateClipping   -- 1: Quads/Sprites are clipped when outside the frustum, 0: no clipping is done global lookupList global DWatcher global DWatcher_newChange global use3DWatcher global lightingList       -- a list of lights (format: [uniqueID:[x, y, z, r, g, b]]) global debug              -- Set to 1 to dump tons of debugging information. global xSlider, ySlider, zSlider, xScale, yScale, zScale, Frustum, rox, roy, roz, roton  -- custom demo program specific on prepareMovie   clearGlobals      set mModelView = [[1000, 0, 0, 0], [0, 1000, 0, 0], [0, 0, 1000, 0], [0, 0, 0, 1000]]   set mProjection = [[1000, 0, 0, 0], [0, 1000, 0, 0], [0, 0, 1000, 0], [0, 0, 0, 1000]]      set activateClipping = 0   set use3DWatcher = 0   set cullBackfaces = 1   set cullBackfaces_cw = 1   set DWatcher_newChange = 1   set mModelViewStack = []   set mProjectionStack = []   set point = [0, 0, 0, 1.0]   set lookupList = [:]   sort lookupList   set mv = 1   set sortSprites = 1   set halffov = 1      set debug = 0                 -- Set to 1 to print tons of debugging info   ---- custom for-the-demo-only, you can delete this stuff   set Frustum = 0.8   set xSlider = 0.0   set ySlider = 0.0   set zSlider = -40.0      set xScale = 1.0   set yScale = 1.0   set zScale = 1.0      set rox = 0.0   set roy = 0.0   set roz = 0.0   set roton = 1   ---- end custom for-the-demo-only    end on stopMovie   set the actorlist = [] end ---------------------------------------------------------------------------------------------------------- --  HIGH-LEVEL ROUTINES  --------------------------------------------------------------------------------- ---------------------------------------------------------------------------------------------------------- -- xFormPoint takes a 4-element list which defines a point as [x, y, z, w] (homogeneous coordinates) and -- transforms it into a screen position point in the form of a 3-element list [h, v, z] which represents -- where on the screen the point should appear after being transformed by the ModelView matrix, the -- projection matrix, the perspective division, and the viewport transformation.  These are known as the -- window coordinates.  The z element is returned so that the programmer can illicit depth information -- about this point.  For more info on this process, research a 3D graphics tutorial near you. -- 0 is returned if the point is not to be drawn. (i.e. it is outside of the clipping planes.) on xFormPoint p   --  if debug then put "xFormPoint--------------"   --  if debug then put "ModelView: "&RETURN&mModelView   --  if debug then put "Projection:"&RETURN&mProjection   --  if debug then put "p = "&p   set z = getAProp(lookupList, p)   if z = 0 then     set m = Matrix1x4Mult(p, mModelView)                    -- Do ModelView xformation     if debug then put "XFormMV:"&RETURN&m     if (m <> 0) then set m = Matrix1x4Mult(m, mProjection)  -- Do Projection xformation     else       beep       put "ERROR!:  Point couldn't be converted: "&p       return 0     end if     if debug then put "XFormP:"&RETURN&m     set m = PerspectiveDivide(m)                            -- Do Perspective division & clipping     if debug then put "XFormPD:"&RETURN&m     if (m <> 0) then set m = ViewPortXForm(m)               -- Do viewport transformation     if debug then put "XFormV:"&RETURN&m          addProp(lookUplist, p, m)     return m   else     return z   end if    end -- Nudge can be used by a 3DSprite or 3DQuad, or your own custom code, to retrieve the transformed -- coordinates of a geometry based on the current ModelView matrix without performing any of the -- projection transformation, perspective division, clipping, or viewport transformations. -- Useful in multi-step transformations. on Nudge p   return(Matrix1x4Mult(p, mModelView)) end -- pFrustum creates a perspective projection matrix with the viewing frustum volume -- described by the arguments and multiplies it to the current projection matrix.  It is recommended -- you call mLoadIdentity before calling this, since its effects are cumulative.  (left, bottom, -near) and -- (right, top, -near) specify the (x, y, z) coordinates of the lower-left and upper-right corners of the -- near clipping plane; near and far give the distances from the viewpoint to the near and far clipping planes. -- near & far should be positive. on pFrustum left, right, bottom, top, near, far   lookupList = [:]   set nn = 2.0*near   set rl = right - left   set tb = top - bottom   set fn = far - near   set mProjection = [[integer(1000*nn/rl), 0, integer(1000*(right+left)/rl), 0], [0, integer(1000*nn/tb), integer(1000*(top+bottom)/tb), 0], [0, 0, integer(1000*-(far+near)/fn), integer(1000*-(far*nn)/fn)], [0, 0, -1000, 0]]   set halffov = (1.5708 / abs(atan(float(top) / float(near))))   return 1   end -- pOrtho creates an orthagonal projection matrix with the parallel viewing volume described by the given -- arguments and multiplies it to the current projection matrix.  It is recommended you call mLoadIdentity before -- calling this, since its effects are cumulative.  (left, bottom, -near) and (right, top, -near) are mapped to -- the lower-left and upper-right corners of the viewport window in the near clipping plane.  (left, bottom, -far) -- and (right, top, -far) are mapped to the lower-left and upper-right corners of the far clipping plane which -- are also mapped to the same corners of the viewport window.  Both near and far can be positive or negative. on pOrtho left, right, bottom, top, near, far   lookUpList = [:]   set rl = right - left   set tb = top - bottom   set fn = far - near   set mProjection = [[integer(2000/rl), 0, 0, integer(1000*(right+left)/rl)], [0, integer(2000/tb), 0, integer(1000*(top+bottom)/tb)], [0, 0, integer(-200/fn), integer(1000*(far+near)/fn)], [0, 0, 0, 1000]]   set halffov = -1   return 1 end -- pViewPort defines the viewport for the view onto the 3D world.  It defines a pixel rectangle in the -- window where the final image is mapped.  x and y specify the upper lefthand corner of the viewport, -- width and height are the size of the viewport rectangle in pixels.  An example use of this would -- be calling pViewPort(0, 0, windowWidth, windowHeight). on pViewPort x, y, width, height   set xCoefficient = (width/2) + x   set yCoefficient = (height/2) + y   return 1 end ---------------------------------------------------------------------------------------------------------- --  MATRIX OPERATIONS  ----------------------------------------------------------------------------------- ---------------------------------------------------------------------------------------------------------- -- mSelectMatrix takes either "Projection" or "ModelView" as arguments, and designates the current matrix -- to have any of the transformations or matrix operations done to it. on mSelectMatrix arg   if (arg) = "Projection" then set mv = 0   else set mv = 1   return 1 end -- Push current matrix onto stack, current matrix is a copy of what is on top of the stack until you change it. on mPush   if (mv) then     addAt(mModelViewStack, 1, mModelView)   else     addAt(mProjectionStack, 1, mProjection)   end if   return 1 end -- Pop a matrix off the stack, current matrix is now what was on top of the stack on mPop   lookUpList = [:]   if (mv) then     if count(mModelViewStack) then       set mModelView = getAt(mModelViewStack, 1)       deleteAt(mModelViewStack, 1)     end if   else     if count(mProjectionStack) then       set mProjection = getAt(mProjectionStack, 1)       deleteAt(mProjectionStack, 1)     end if   end if   return 1 end -- Load the identity matrix into the current matrix on mLoadIdentity   lookupList = [:]   if (mv) then     set mModelView = [[1000, 0, 0, 0], [0, 1000, 0, 0], [0, 0, 1000, 0], [0, 0, 0, 1000]]   else     set mProjection = [[1000, 0, 0, 0], [0, 1000, 0, 0], [0, 0, 1000, 0], [0, 0, 0, 1000]]   end if   return 1 end --------------------------------------------------------------------------------------------------- --   MODELVIEW TRANSFORMATIONS   ------------------------------------------------------------------ --------------------------------------------------------------------------------------------------- -- MODELING TRANSFORMATIONS: -- Translate the current matrix by x, y, z -- Viewing transformations should always preceed modeling transformation in your code. on xTranslate x, y, z   lookUpList = [:]   set m1 = [[1000, 0, 0, integer(1000*x)], [0, 1000, 0, integer(1000*y)], [0, 0, 1000, integer(1000*z)], [0, 0, 0, 1000]]   set mModelView = Matrix4x4Mult(m1, mModelView)   if mModelView <> 0 then return 1   else return 0 end -- Rotate the current matrix on the X axis by angle (in radians) -- Viewing transformations should always preceed modeling transformation in your code. on xRotateX a   lookUpList = [:]   set m3 = [[1000, 0, 0, 0], [0, integer(1000*cos(a)), integer(1000*-sin(a)), 0], [0, integer(1000*sin(a)), integer(1000*cos(a)), 0], [0, 0, 0, 1000]]   set mModelView = Matrix4x4Mult(m3, mModelView)   if mModelView <> 0 then return 1   else return 0 end -- Rotate the current matrix on the Y axis by angle (in radians) -- Viewing transformations should always preceed modeling transformation in your code. on xRotateY a   lookUpList = [:]   set m4 = [[integer(1000*cos(a)), 0, integer(1000*sin(a)), 0], [0, 1000, 0, 0], [integer(1000*-sin(a)), 0, integer(1000*cos(a)), 0], [0, 0, 0, 1000]]   set mModelView = Matrix4x4Mult(m4, mModelView)   if mModelView <> 0 then return 1   else return 0 end -- Rotate the current matrix on the Z axis by angle (in radians) -- Viewing transformations should always preceed modeling transformation in your code. on xRotateZ a   lookUpList = [:]   set m5 = [[integer(1000*cos(a)), integer(1000*-sin(a)), 0, 0], [integer(1000*sin(a)), integer(1000*cos(a)), 0, 0], [0, 0, 1000, 0], [0, 0, 0, 1000]]   set mModelView = Matrix4x4Mult(m5, mModelView)   if mModelView <> 0 then return 1   else return 0 end -- Scale the current matrix by x, y, z (>1.0 grows, <1.0 shrinks) -- Viewing transformations should always preceed modeling transformation in your code. on xScale x, y, z   lookUpList = [:]   set m2 = [[integer(1000*x), 0, 0, 0], [0, integer(1000*y), 0, 0], [0, 0, integer(1000*z), 0], [0, 0, 0, 1000]]   set mModelView = Matrix4x4Mult(m2, mModelView)   if mModelView <> 0 then return 1   else return 0 end -- VIEWING TRANSFORMATIONS: Camera placement routines: -- pilotView uses the analogy of a plane to position the camera, with the runway at the origin and the -- plane at coordinates (plane_x, plane_y, plane_z), with a roll, pitch, and heading (in all in degrees) -- Viewing transformations should always preceed modeling transformation in your code. on pilotView plane_x, plane_y, plane_z, roll, pitch, heading   lookUpList = [:]   set roll = (roll/360.0) * (2.0*PI)   set pitch = (pitch/360.0) * (2.0*PI)   set heading = (heading/360.0) * (2.0*PI)      if (xRotateZ(roll) AND xRotateY(pitch) AND xRotateX(heading) AND xTranslate(-plane_x, -plane_y, -plane_z)) then     return 1   else     return 0   end if end -- polarView uses the analogy of a camera orbiting around an object that's centered at the origin, constantly -- pointing at the origin.  Distance defines the radius of the orbit, azimuth describes the angle of rotation -- of the camera around the object on the x-y plane, measured from the positive y-axis.  Elevation measures -- the angle of rotation of the camera in the y-z plane, measured from the positive z-axis.  Twist represents -- the rotation of the viewing volume around its line of sight. -- Viewing transformations should always preceed modeling transformation in your code. on polarView distance, twist, elevation, azimuth   lookUpList = [:]   if (xTranslate(0, 0, -distance) AND xRotateZ(-twist) AND xRotateX(-elevation) AND xRotateZ(azimuth)) then     return 1   else     return 0   end if end ----------------------------------------------------------------------------------------------------- -- Utility Routines --------------------------------------------------------------------------------- ----------------------------------------------------------------------------------------------------- on spawnDWatcher   set DWatcher = new (script "3DWatcher") end on killDWatcher   repeat while deleteOne(the actorlist, DWatcher)   end repeat end -- isBackfacing determines if, from the given list of transformed vertices and certain environmental variables, -- a quad's front or back is facing the camera, and returns a 1 if it is backfacing, 0 otherwise. on isBackfacing vPList   a = 0   repeat with i = 0 to 3     set z = ((i + 1) mod 4)     set m = i+1     set n = z+1     a = a + ((vPList[m][1] * vPList[n][2]) - (vPList[n][1] * vPList[m][2]))   end repeat   set a = a/2.0   if cullBackfaces_cw then     if a > 0 then return 0     else return 1   else     if a > 0 then return 1     else return 0   end if end -- zSort sets the locZ properties of the on zSort listB      put count(listB) into listBCount   repeat with i = 1 to listBCount     set vP = listB[i].myVPos               if vP <> 0 then       sprite(listb[i].mySprite).locZ = 1000-(vP[3] * 1000)         end if         end repeat      return 0    end -- Juggle is an old sprite sorting routine for D6.5 and below.  If you are using D7, use the zSort handler above. -- It works just like Juggle but doesn't move any sprites around, it instead uses the locZ property and takes one -- less argument. on Juggle listB, lowSprite   global passCtr   global countlist   set listA = [:]   sort listA      put count(listB) into listBCount   repeat with i = 1 to listBCount     set vP = the myVPos of getAt(listB, i)          if vP <> 0 then              addProp(listA, getAt(vP, 3), getAt(listB, i))            else       addProp(listA, 0.0, getAt(listB, i))            end if         end repeat   set countlist = count(lista)   --sort listA   --put listA   set j = 0      put (lowSprite + listBCount - 1) into highSprite   repeat with i = highSprite down to lowSprite     set j = j + 1     set z= getAt(listA, j)     --    fixScriptInstanceList(z, i)          setSprite(z, i)          set the member of sprite i = the myMember of z       set the rect of sprite i = the myRect of z     set the blend of sprite i = the myBlend of z     set the ink of sprite i = the myInk of z                    -- backColor, foreColor, editable, moveableSprite, constraint, trails   end repeat      return 0    end ------------------------------------------------------------------------------------------ -- OTHER UTILITY & MATH FUNCTIONS YOU PROBABLY DON'T NEED TO DIRECTLY ACCESS ------------- ------------------------------------------------------------------------------------------ -- PerspectiveDivide converts a homogeneous coordinate into a normalized device coordinate. -- point is a 4 element list.  Returns a 3-element list on success, 0 if the point is not to be drawn. on PerspectiveDivide thePoint      if count(thePoint) = 4 then     set w = getAt(thePoint, 4)     if w <> 0 then       set x = getAt(thePoint, 1)       set y = getAt(thePoint, 2)       set z = getAt(thePoint, 3)              if activateClipping = TRUE then         case TRUE of           (z < -w), (z > w), (y < -w), (y > w), (x < -w), (x > w)   : return 0   -- clipping         end case       end if              return [x/w, y/w, abs(z/w)]     else       return 0     end if   else     return 0   end if     end -- ViewportXForm takes a normalized device coordinate point and transforms it into a -- window coordinate.  The argument is a 3-element list.  A 3-element list, [h, v, z] is -- returned on success.  0 if the point is not to be drawn on ViewportXForm thePoint   if count(thePoint) = 3 then     return [(getAt(thePoint, 1) + 1.0) * xCoefficient, (getAt(thePoint, 2) + 1.0) * yCoefficient, getAt(thePoint, 3)]   else     return 0   end if end --Useful math functions -- 4x4 Matrices are defined as nested lists:  [[],[],[],[]] -- 1x4 Matrices are defined as a 4 element list: [,,,] on test   a = [3,3,3,3]         starttimer   repeat with i = 1 to 500000     set z = getAt(a, 3)   end repeat   put the timer      starttimer   repeat with i = 1 to 500000     z = a[3]   end repeat   put the timer    end --Matrix4x4Mult takes two 4x4 matrices, multiples them and returns the 4x4 result. -- (Thanks to Jakob Hede Madsen for the optimization!) on Matrix4x4Mult a, b      a1 = a[1]   if a1.count - b.count then     put "Error: Could not multiply matrices, a.cols != b.rows != 4."     return 0   end if   ----   a2 = a[2]   a3 = a[3]   a4 = a[4]   --   b1 = b[1]   b2 = b[2]   b3 = b[3]   b4 = b[4]   --------   a11 = a1[1]   a12 = a1[2]   a13 = a1[3]   a14 = a1[4]   --   a21 = a2[1]   a22 = a2[2]   a23 = a2[3]   a24 = a2[4]   --   a31 = a3[1]   a32 = a3[2]   a33 = a3[3]   a34 = a3[4]   --   a41 = a4[1]   a42 = a4[2]   a43 = a4[3]   a44 = a4[4]   ----   b11 = b1[1]   b12 = b1[2]   b13 = b1[3]   b14 = b1[4]   --   b21 = b2[1]   b22 = b2[2]   b23 = b2[3]   b24 = b2[4]   --   b31 = b3[1]   b32 = b3[2]   b33 = b3[3]   b34 = b3[4]   --   b41 = b4[1]   b42 = b4[2]   b43 = b4[3]   b44 = b4[4]   ----   return [¬ [((a11*b11)+(a12*b21)+(a13*b31)+(a14*b41))/1000,¬ ((a11*b12)+(a12*b22)+(a13*b32)+(a14*b42))/1000,¬ ((a11*b13)+(a12*b23)+(a13*b33)+(a14*b43))/1000,¬ ((a11*b14)+(a12*b24)+(a13*b34)+(a14*b44))/1000],¬ [((a21*b11)+(a22*b21)+(a23*b31)+(a24*b41))/1000,¬ ((a21*b12)+(a22*b22)+(a23*b32)+(a24*b42))/1000,¬ ((a21*b13)+(a22*b23)+(a23*b33)+(a24*b43))/1000,¬ ((a21*b14)+(a22*b24)+(a23*b34)+(a24*b44))/1000],¬ [((a31*b11)+(a32*b21)+(a33*b31)+(a34*b41))/1000,¬ ((a31*b12)+(a32*b22)+(a33*b32)+(a34*b42))/1000,¬ ((a31*b13)+(a32*b23)+(a33*b33)+(a34*b43))/1000,¬ ((a31*b14)+(a32*b24)+(a33*b34)+(a34*b44))/1000],¬ [((a41*b11)+(a42*b21)+(a43*b31)+(a44*b41))/1000,¬ ((a41*b12)+(a42*b22)+(a43*b32)+(a44*b42))/1000,¬ ((a41*b13)+(a42*b23)+(a43*b33)+(a44*b43))/1000,¬ ((a41*b14)+(a42*b24)+(a43*b34)+(a44*b44))/1000]]    end -- -- Matrix4x4Mult takes two 4x4 matrices, multiples them and returns the 4x4 result. --on Matrix4x4Mult a, b --   --  if count(a[1]) = count(b) then --    put a[1][1] into a11 --    put a[2][1] into a21 --    put a[3][1] into a31 --    put a[4][1] into a41 --    put a[1][2] into a12 --    put a[2][2] into a22 --    put a[3][2] into a32 --    put a[4][2] into a42 --    put a[1][3] into a13 --    put a[2][3] into a23 --    put a[3][3] into a33 --    put a[4][3] into a43 --    put a[1][4] into a14 --    put a[2][4] into a24 --    put a[3][4] into a34 --    put a[4][4] into a44 --    put b[1][1] into b11 --    put b[2][1] into b21 --    put b[3][1] into b31 --    put b[4][1] into b41 --    put b[1][2] into b12 --    put b[2][2] into b22 --    put b[3][2] into b32 --    put b[4][2] into b42 --    put b[1][3] into b13 --    put b[2][3] into b23 --    put b[3][3] into b33 --    put b[4][3] into b43 --    put b[1][4] into b14 --    put b[2][4] into b24 --    put b[3][4] into b34 --    put b[4][4] into b44 --    return [¬ --[((a11*b11)+(a12*b21)+(a13*b31)+(a14*b41))/1000,¬ -- ((a11*b12)+(a12*b22)+(a13*b32)+(a14*b42))/1000,¬ -- ((a11*b13)+(a12*b23)+(a13*b33)+(a14*b43))/1000,¬ -- ((a11*b14)+(a12*b24)+(a13*b34)+(a14*b44))/1000],¬ --[((a21*b11)+(a22*b21)+(a23*b31)+(a24*b41))/1000,¬ -- ((a21*b12)+(a22*b22)+(a23*b32)+(a24*b42))/1000,¬ -- ((a21*b13)+(a22*b23)+(a23*b33)+(a24*b43))/1000,¬ -- ((a21*b14)+(a22*b24)+(a23*b34)+(a24*b44))/1000],¬ --[((a31*b11)+(a32*b21)+(a33*b31)+(a34*b41))/1000,¬ -- ((a31*b12)+(a32*b22)+(a33*b32)+(a34*b42))/1000,¬ -- ((a31*b13)+(a32*b23)+(a33*b33)+(a34*b43))/1000,¬ -- ((a31*b14)+(a32*b24)+(a33*b34)+(a34*b44))/1000],¬ --[((a41*b11)+(a42*b21)+(a43*b31)+(a44*b41))/1000,¬ -- ((a41*b12)+(a42*b22)+(a43*b32)+(a44*b42))/1000,¬ -- ((a41*b13)+(a42*b23)+(a43*b33)+(a44*b43))/1000,¬ -- ((a41*b14)+(a42*b24)+(a43*b34)+(a44*b44))/1000]] --  else --    put "Error: Could not multiply matrices, a.cols != b.rows != 4." --    return 0 --  end if --end -- Matrix1x4Mult takes a 1x4 matrix as its first argument and a 4x4 matrix as its second argument -- and multiplies them, returning the resulting 1x4 matrix. on Matrix1x4Mult c, b   if count(b[1]) = count(c) then     a1 = integer(c[1]*1000)     a2 = integer(c[2]*1000)     a3 = integer(c[3]*1000)     a4 = integer(c[4]*1000)          return [¬ ((b[1][1]*a1)+(b[1][2]*a2)+(b[1][3]*a3)+(b[1][4]*a4))/100000.0,¬ ((b[2][1]*a1)+(b[2][2]*a2)+(b[2][3]*a3)+(b[2][4]*a4))/100000.0,¬ ((b[3][1]*a1)+(b[3][2]*a2)+(b[3][3]*a3)+(b[3][4]*a4))/100000.0,¬ ((b[4][1]*a1)+(b[4][2]*a2)+(b[4][3]*a3)+(b[4][4]*a4))/100000.0]   else     put "Error: Could not multiple matrices, a.cols != b.rows."     return 0   end if end -- location = x, y, z, intensity = r, g, b -- creates a light and returns its unique ID in the lightingList on createLight location, intensity   set x = count(lightinglist)      lightingList.addProp(x+1, [location[1], location[2], location[3], intensity[1], intensity[2], intensity[3]])      return x end -- deletes a light on deleteLight uniqueID   lightingList.deleteProp(uniqueID) end on deleteAllLights   lightinglist = [:] end on calculateIntensity polygon, lightingList   --, viewPoint   set x = count(lightingList)   repeat with i = 1 to x                  end repeat   if x = 0 then return 0 end on vGetViewingVector viewPoint, normalTail   return( [0, 0, 1] ) end -- vGetH takes the lighting vector and the viewing vector and returns the unit vector halfway between these two. -- This is cheaper than using the exact reflection vector. on vGetH l, v   return vScalarMult(vAdd(l, v)*0.5) end   -- vGetReflectionVector takes the normal vector of a surface, n, and the incident lighting vector l, -- and returns the reflected vector. on vGetReflectionVector n, l   return( vSubtract(vScalarMult(n, 2 * vDotProduct(n, l)), l) ) end -- vGetLightingVector takes the coordinates of a light (4 element list) and a vertex (4 element list) and -- returns a the lighting vector associated with them. on vGetLightingVector light, normalTail   return([light[1] - normalTail[1], light[2] - normalTail[2], light[3] - normalTail[3]]) end -- vNormal takes three vertices (4 element lists) of a polygon (v2 being "between" v1 and v3) and returns -- the normal vector to that polygon. on vNormal v1, v2, v3   -- convert vertices to two vectors   nv1 = [v3[1] - v2[1], v3[2] - v2[2], v3[3] - v2[3]]   nv2 = [v1[1] - v2[1], v1[2] - v2[2], v1[3] - v2[3]]   -- calculate normal   return(vCrossProduct(nv1, nv2)) end -- vCrossProduct takes two vectors (3 element lists each) and returns their cross product (a 3 element list) on vCrossProduct v, w   return([v[2]*w[3] - v[3]*w[2], v[3]*w[1] - v[1]*w[3], v[1]*w[2] - v[2]*w[1]]) end -- vDotProduct takes two vectors (3 element lists each) and returns their dot product on vDotProduct v, w   return(v[1]*w[1] + v[2]*w[2] + v[3]*w[3]) end -- vScalarMult multiplies vector v by a scalar on vScalarMult v, scalar   return([v[1] * scalar, v[2] * scalar, v[3] * scalar]) end -- vNormalize takes a vector and returns the normalize unit vector of that vector on vNormalize v   z = vMagnitude(v)   return([v[1]/float(z[1]), v[2]/float(z[2]), v[3]/float(z[3])]) end -- vMagnitude takes a vector and returns its magnitude on vMagnitude v   return(sqrt((v[1]*v[1] + v[2]*v[2] + v[3]*v[3]))) end -- vAdd adds one vector to another on vAdd v, w   return([v[1] + w[1], v[2] + w[2], v[3] + w[3]]) end -- vSubtract subtracts one vector from another on vSubtract v, w   return([v[1] - w[1], v[2] - w[2], v[3] - w[3]]) end -- scaleRect takes a rect and scales the size of the rect based on the scalar coefficient -- returns the new Rect() on scaleRect oldrect, scalar   --  set oldh = (the bottom of oldrect) - (the top of oldrect)   --  set oldw = (the right of oldrect) - (the left of oldrect)      set oldh = the height of oldrect   set oldw = the width of oldrect      set midw = (oldw/2)+the left of oldrect   set midh = (oldh/2)+the top of oldrect      set halfh = (scalar * oldh)/2   set halfw = (scalar * oldw)/2      return(Rect(midw - halfw, midh - halfh, midw + halfw, midh + halfh)) end -- positionRect positions a rect centered at a point lH, lV on positionRect oldrect, lH, lV      set oldh2 = (the height of oldrect)/2   set oldw2 = (the width of oldrect)/2      return(Rect(lH - oldw2, lV - oldh2, lH + oldw2, lV + oldh2)) end ------------------------------------------------------------------------------ -- The functions below aren't used directly in Dave's 3D Engine, but are    -- -- provided for backwards compatibility with previous versions.             -- ------------------------------------------------------------------------------ -- acos() - arccosine function (Thanks Hopper-Ex!) -- takes values between -1 and 1, returns values between 0 and PI on acos x   if abs(x) > 1 then     return 0   else if x = 0 then     return 0   else     return(atan(sqrt(1.0 - x*x)/float(x)))   end if end -- asin() - arcsine function (Thanks Again Hopper-Ex!) -- takes values between -1 and 1, returns values between -PI/2.0 and PI/2.0 on asin x   if abs(x) > 1 then     return void   else if x = 1 then     return(PI/2.0)   else if x = -1 then     return(-PI/2.0)   else     return atan(float(x)/sqrt(1.0 - x*x))   end if end asin on floatDiv floatA, floatB   return integer(floatA - 0.5) / integer(floatB - 0.5) end