CODE = &00008000 \ The build address for the game codeLANDER GAME SOURCE Lander was written by David Braben and is copyright D.J.Braben 1987 The code on this site has been reconstructed from a disassembly of the game on the Arthur and RISC OS 2 application discs The commentary is copyright Mark Moxon, and any misunderstandings or mistakes in the documentation are entirely my fault The terminology and notations used in this commentary are explained at https://lander.bbcelite.com/terminology The deep dive articles referred to in this commentary can be found at https://lander.bbcelite.com/deep_dives
This source file produces the following binary file: * GameCode.binTILE_SIZE = &01000000 \ The length of one side of a square \ landscape tile in 3D coordinates \ \ [Show more]Configuration variables\ \ This variable is used by the following: \ \ * DrawLandscapeAndBuffers (Part 2 of 4) \ * DrawLandscapeAndBuffers (Part 3 of 4) \ * DrawObjects (Part 1 of 3) \ * DrawParticleToBuffer \ * DrawTriangleToBuffer \ * MoveAndDrawParticles (Part 3 of 4) \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned aboveTILES_X = 13 \ The number of tile corners in a landscape \ row from left to right (i.e. 12 tiles) \ \ [Show more]\ \ This variable is used by the following: \ \ * DrawObjects (Part 1 of 3) \ * landscapeConfig \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned aboveTILES_Z = 11 \ The number of tile corners in a landscape \ row from front to back (i.e. 10 tiles) \ \ [Show more]\ \ This variable is used by the following: \ \ * AddTerminatorsToBuffers \ * DrawLandscapeAndBuffers (Part 3 of 4) \ * DrawLandscapeAndBuffers (Part 4 of 4) \ * DrawObjects (Part 1 of 3) \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned aboveMAX_PARTICLES = 484 \ The maximum number of particles at any one \ time \ \ [Show more]\ \ This variable is used by the following: \ \ * StoreParticleData \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned aboveLAUNCHPAD_OBJECT = 9 \ The type of object along the right edge of \ the launchpad (i.e. the three rockets) \ \ [Show more]\ \ This variable is used by the following: \ \ * PlaceObjectsOnMap \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned aboveLAUNCHPAD_ALTITUDE = &03500000 \ The altitude of the launchpad \ \ [Show more]\ \ This variable is used by the following: \ \ * GetLandscapeAltitude \ * GetLandscapeTileColour \ * PlaceObjectsOnMap \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned aboveSEA_LEVEL = &05500000 \ The altitude of sea level \ \ [Show more]\ \ This variable is used by the following: \ \ * BounceParticle \ * DrawObjects (Part 2 of 3) \ * GetLandscapeAltitude \ * GetLandscapeTileColour \ * PlaceObjectsOnMap \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned aboveLANDING_SPEED = &00200000 \ The maximum safe landing speed \ \ [Show more]\ \ This variable is used by the following: \ \ * LandOnLaunchpad \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned aboveSMOKE_RISING_SPEED = &00080000 \ The speed at which smoke particles rise up \ from a destroyed object \ \ [Show more]\ \ This variable is used by the following: \ \ * AddSmokeParticleToBuffer \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned aboveUNDERCARRIAGE_Y = &00640000 \ The height of the ship's undercarriage \ (0.390625 tiles), which is the distance \ from the centre of the ship to the bottom \ of the ship \ \ [Show more]\ \ This variable is used by the following: \ \ * MoveAndDrawPlayer (Part 3 of 5) \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned aboveBUFFER_SIZE = 4308 \ The size of each of the graphics buffers \ in bytesSTORE = 256 * INT(TILES_X / 32) \ We need 256 bytes of cornerStore for every \ 32 tiles across the landscape, so STORE \ contains the number of extra bytes of data \ we need for each extra set of 32 tiles on \ top of the default 256 byte buffers (so \ STORE is zero for the default landscape) LAUNCHPAD_Y = LAUNCHPAD_ALTITUDE - UNDERCARRIAGE_Y \ The y-coordinate of the \ ship as it sits on the \ launchpad, and on top of \ its undercarriage \ \ [Show more]Calculated constants\ \ This variable is used by the following: \ \ * LandOnLaunchpad \ * PlacePlayerOnLaunchpad \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned aboveLAUNCHPAD_SIZE = TILE_SIZE * 8 \ Size of the launchpad (8 tile sizes) \ \ [Show more]\ \ This variable is used by the following: \ \ * GetLandscapeAltitude \ * LandOnLaunchpad \ * PlacePlayerOnLaunchpad \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned aboveHIGHEST_ALTITUDE = TILE_SIZE * 52 \ Highest altitude for the engines to work \ (52 tile sizes, but as a positive number; \ the altitude is actually -TILE_SIZE * 52) \ \ [Show more]\ \ This variable is used by the following: \ \ * MoveAndDrawPlayer (Part 2 of 5) \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned aboveSPLASH_HEIGHT = TILE_SIZE / 16 \ The height above the sea at which splash \ particles are added when a particle \ splashes into the sea (1/16 of a tile) \ \ [Show more]\ \ This variable is used by the following: \ \ * SplashParticleIntoSea \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned aboveCRASH_CLOUD_Y = TILE_SIZE * 5 / 16 \ The vertical distance above the \ player's ship where we add the \ explosion cloud when they crash \ (5/16-th of a tile) \ \ [Show more]\ \ This variable is used by the following: \ \ * LoseLife \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned aboveSMOKE_HEIGHT = TILE_SIZE * 3 / 4 \ The height at which smoke particles are \ added above the bottom of a destroyed \ object (3/4 of a tile) \ \ [Show more]\ \ This variable is used by the following: \ \ * DrawObjects (Part 3 of 3) \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned aboveSAFE_HEIGHT = TILE_SIZE * 3 / 2 \ The minimum safe height for avoiding \ objects on the ground (1.5 tile sizes) \ \ [Show more]\ \ This variable is used by the following: \ \ * MoveAndDrawPlayer (Part 3 of 5) \ * ProcessObjectDestruction \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned aboveCAMERA_PLAYER_Z = (TILES_Z - 6) * TILE_SIZE \ The distance along the z-axis \ between the player and the \ camera position (which is at \ the back of the landscape, in \ the middle) \ \ [Show more]\ \ This variable is used by the following: \ \ * MoveAndDrawPlayer (Part 3 of 5) \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned aboveLAND_MID_HEIGHT = TILE_SIZE * 5 \ The altitude of the mid-point of the \ generated landscape, to which the height \ of +/- 5 tiles is added by the Fourier \ synthesis in GetLandscapeAltitude \ \ [Show more]\ \ This variable is used by the following: \ \ * GetLandscapeAltitude \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned abovePLAYER_FRONT_Z = (TILES_Z - 5) * TILE_SIZE \ The distance along the z-axis \ between the tile in front of the \ player and the camera, which is \ where we spawn explosions and \ falling rocks (set to six tiles \ forwards from the camera) \ \ [Show more]\ \ This variable is used by the following: \ \ * AddShipExplosionToBuffer \ * AddSparkCloudToBuffer \ * DropRocksFromTheSky \ * SpawnRock \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned aboveROCK_HEIGHT = TILE_SIZE * 32 \ The height from which we drop rocks from \ the sky (32 tile sizes) \ \ [Show more]\ \ This variable is used by the following: \ \ * DropRocksFromTheSky \ * SpawnRock \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned aboveLANDSCAPE_X_WIDTH = TILE_SIZE * (TILES_X - 2) \ The width of the visible \ landscape in x-coordinates, \ counting whole tiles only, \ and ignoring the centre tile LANDSCAPE_Z_DEPTH = TILE_SIZE * (TILES_Z - 1) \ The depth of the visible \ landscape in z-coordinates, \ counting whole tiles only \ \ [Show more]\ \ This variable is used by the following: \ \ * DrawTriangleShadowToBuffer \ * DrawTriangleToBuffer \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned aboveLANDSCAPE_X = LANDSCAPE_X_WIDTH / 2 \ The x-coordinate of the landscape \ offset, which is set to the whole \ number of tiles that fit into the half \ the width of the landscape, so we end \ up looking at the middle point of the \ landscape \ \ [Show more]\ \ This variable is used by the following: \ \ * DrawLandscapeAndBuffers (Part 2 of 4) \ * DrawObjects (Part 1 of 3) \ * landscapeOffset \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned aboveLANDSCAPE_Y = 0 \ The y-coordinate of the landscape offset, \ which is zero so the landscape remains at \ the same height \ \ [Show more]\ \ This variable is used by the following: \ \ * landscapeOffset \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned aboveLANDSCAPE_Z = LANDSCAPE_Z_DEPTH + (10 * TILE_SIZE) \ The z-coordinate of the \ landscape offset, which is \ set to push the landscape \ away from the viewer by \ ten tile sizes \ \ [Show more]\ \ This variable is used by the following: \ \ * DrawObjects (Part 2 of 3) \ * DrawParticleShadowToBuffer \ * DrawParticleToBuffer \ * DrawTriangleShadowToBuffer \ * DrawTriangleToBuffer \ * GetLandscapeBelowVertex \ * landscapeOffset \ * MoveAndDrawParticles (Part 2 of 4) \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned aboveHALF_TILES_X = INT(TILES_X / 2) \ Half the number of tiles from left to \ right in the landscape LANDSCAPE_X_HALF = TILE_SIZE * HALF_TILES_X \ The width of half the number \ of tiles from left to right in \ the landscape in x-coordinates \ \ [Show more]\ \ This variable is used by the following: \ \ * MoveAndDrawParticles (Part 2 of 4) \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned aboveLANDSCAPE_Z_BEYOND = LANDSCAPE_Z_DEPTH + TILE_SIZE \ The depth of the visible \ landscape in z-coordinates \ plus one more tile \ \ [Show more]\ \ This variable is used by the following: \ \ * DrawTriangleShadowToBuffer \ * DrawTriangleToBuffer \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned aboveLANDSCAPE_Z_FRONT = LANDSCAPE_Z - LANDSCAPE_Z_DEPTH \ The z-coordinate of \ the front of the \ visible landscape \ \ [Show more]\ \ This variable is used by the following: \ \ * MoveAndDrawParticles (Part 2 of 4) \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned aboveLANDSCAPE_Z_MID = LANDSCAPE_Z - CAMERA_PLAYER_Z \ The z-coordinate of the \ mid-point of the landscape \ depth (i.e. the player) \ \ [Show more]\ \ This variable is used by the following: \ \ * MoveAndDrawParticles (Part 3 of 4) \ * MoveAndDrawPlayer (Part 3 of 5) \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned aboveOS_WriteC = &00 \ The operating system call to write a \ character to all the output streams \ \ [Show more]Operating system SWI numbers\ \ This variable is used by the following: \ \ * EndGame \ * Entry \ * GameOver \ * PrintCurrentScore \ * PrintHexDigit \ * PrintHexNumber \ * PrintScoreInBothBanks \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned aboveOS_WriteS = &01 \ The operating system call to write a \ string to all the output streams \ \ [Show more]\ \ This variable is used by the following: \ \ * AbortWithMemoryError \ * Entry \ * GameOver \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned aboveOS_ReadC = &04 \ The operating system call to read a key \ press \ \ [Show more]\ \ This variable is used by the following: \ \ * GameOver \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned aboveOS_Byte = &06 \ General-purpose operating system calls \ \ [Show more]\ \ This variable is used by the following: \ \ * EndGame \ * Entry \ * GameOver \ * MainLoop \ * PrintScoreInBothBanks \ * SwitchScreenBank \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned aboveOS_Word = &07 \ General-purpose operating system calls \ \ [Show more]\ \ This variable is used by the following: \ \ * ResetMousePosition \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned aboveOS_Mouse = &1C \ The operating system call to read the \ mouse status \ \ [Show more]\ \ This variable is used by the following: \ \ * MoveAndDrawPlayer (Part 1 of 5) \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned aboveOS_BinaryToDecimal = &28 \ The operating system call to convert a \ number into a string \ \ [Show more]\ \ This variable is used by the following: \ \ * PrintCurrentScore \ * PrintScoreInBothBanks \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned abovestack = &000121FC \ The stack is after the end of the main \ game code and descends from this address \ down to &00012000 (to give a stack size of \ 512 32-bit entries) \ \ [Show more]Workspace variables\ \ This variable is used by the following: \ \ * stackAddr \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned aboveworkspace = stack + 4 \ The variable workspace starts just after \ the top of the stack \ \ [Show more]\ \ This variable is used by the following: \ \ * workspaceAddr \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned above\ R11 typically contains the address of the \ workspace, so each of the variables in the \ workspace can be referred to as: \ \ [R11, #offset] \ \ where #offset is one of the following \ variables xObject = &00 \ The x-coordinate of the object currently \ being drawn \ \ [Show more]\ \ This variable is used by the following: \ \ * DrawObject (Part 1 of 5) \ * DrawObject (Part 2 of 5) \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned aboveyObject = &04 \ The y-coordinate of the object currently \ being drawn zObject = &08 \ The z-coordinate of the object currently \ being drawn \ \ [Show more]\ \ This variable is used by the following: \ \ * DrawTriangleShadowToBuffer \ * DrawTriangleToBuffer \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned above\ Offsets &0C to &2C appear to be unused rotationMatrix = &30 \ The rotation matrix of the object \ currently being drawn (i.e. the matrix \ formed from the object's three orientation \ vectors) \ \ [Show more]\ \ This variable is used by the following: \ \ * DrawObject (Part 1 of 5) \ * DrawObjects (Part 2 of 3) \ * MoveAndDrawParticles (Part 3 of 4) \ * MoveAndDrawPlayer (Part 3 of 5) \ * MultiplyVectorByMatrix \ * TransposeRotationMatrix \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned abovexNoseV = &30 \ The x-coordinate of the nose vector \ \ [Show more]\ \ This variable is used by the following: \ \ * CalculateRotationMatrix \ * MoveAndDrawPlayer (Part 5 of 5) \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned abovexRoofV = &34 \ The x-coordinate of the roof vector \ \ [Show more]\ \ This variable is used by the following: \ \ * CalculateRotationMatrix \ * MoveAndDrawPlayer (Part 2 of 5) \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned abovexSideV = &38 \ The x-coordinate of the side vector \ \ [Show more]\ \ This variable is used by the following: \ \ * CalculateRotationMatrix \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned aboveyNoseV = &3C \ The y-coordinate of the nose vector \ \ [Show more]\ \ This variable is used by the following: \ \ * CalculateRotationMatrix \ * MoveAndDrawPlayer (Part 5 of 5) \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned aboveyRoofV = &40 \ The y-coordinate of the roof vector \ \ [Show more]\ \ This variable is used by the following: \ \ * CalculateRotationMatrix \ * MoveAndDrawPlayer (Part 2 of 5) \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned aboveySideV = &44 \ The y-coordinate of the side vector \ \ [Show more]\ \ This variable is used by the following: \ \ * CalculateRotationMatrix \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned abovezNoseV = &48 \ The z-coordinate of the nose vector \ \ [Show more]\ \ This variable is used by the following: \ \ * CalculateRotationMatrix \ * MoveAndDrawPlayer (Part 5 of 5) \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned abovezRoofV = &4C \ The z-coordinate of the roof vector \ \ [Show more]\ \ This variable is used by the following: \ \ * CalculateRotationMatrix \ * MoveAndDrawPlayer (Part 2 of 5) \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned abovezSideV = &50 \ The z-coordinate of the side vector \ \ [Show more]\ \ This variable is used by the following: \ \ * CalculateRotationMatrix \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned abovexVertex = &54 \ The x-coordinate of the vertex being \ processed, relative to the object's origin \ \ [Show more]\ \ This variable is used by the following: \ \ * DrawObject (Part 2 of 5) \ * DrawObject (Part 3 of 5) \ * DrawObject (Part 5 of 5) \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned aboveyVertex = &58 \ The y-coordinate of the vertex being \ processed, relative to the object's origin \ \ [Show more]\ \ This variable is used by the following: \ \ * DrawObject (Part 3 of 5) \ * DrawObject (Part 5 of 5) \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned abovezVertex = &5C \ The z-coordinate of the vertex being \ processed, relative to the object's origin \ Offset &60 appears to be unused xVertexRotated = &64 \ The x-coordinate of the vertex after being \ rotated by the object's rotation matrix \ \ [Show more]\ \ This variable is used by the following: \ \ * AddVectors \ * AddVectorToVertices \ * DrawObject (Part 2 of 5) \ * MultiplyVectorByConstant \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned aboveyVertexRotated = &68 \ The y-coordinate of the vertex after being \ rotated by the object's rotation matrix zVertexRotated = &6C \ The z-coordinate of the vertex after being \ rotated by the object's rotation matrix \ Offset &70 appears to be unused xCoord = &74 \ The x-coordinate of the vertex being \ processed, in the game's 3D coordinate \ system \ \ [Show more]\ \ This variable is used by the following: \ \ * AddVectors \ * AddVectorToVertices \ * DrawObject (Part 2 of 5) \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned aboveyCoord = &78 \ The y-coordinate of the vertex being \ processed, in the game's 3D coordinate \ system \ \ [Show more]\ \ This variable is used by the following: \ \ * DrawObject (Part 2 of 5) \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned abovezCoord = &7C \ The z-coordinate of the vertex being \ processed, in the game's 3D coordinate \ system \ Offset &80 appears to be unused xObjectScaled = &84 \ The x-coordinate of the vertex being \ processed, scaled as high as possible \ \ [Show more]\ \ This variable is used by the following: \ \ * DrawObject (Part 1 of 5) \ * DrawObject (Part 3 of 5) \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned aboveyObjectScaled = &88 \ The y-coordinate of the vertex being \ processed, scaled as high as possible zObjectScaled = &8C \ The z-coordinate of the vertex being \ processed, scaled as high as possible \ Offset &90 appears to be unused xPlayer = &94 \ The x-coordinate of the player's ship \ \ [Show more]\ \ This variable is used by the following: \ \ * LandOnLaunchpad \ * LoseLife \ * MoveAndDrawPlayer (Part 2 of 5) \ * MoveAndDrawPlayer (Part 4 of 5) \ * MoveAndDrawPlayer (Part 5 of 5) \ * PlacePlayerOnLaunchpad \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned aboveyPlayer = &98 \ The y-coordinate of the player's ship \ \ [Show more]\ \ This variable is used by the following: \ \ * LandOnLaunchpad \ * MoveAndDrawParticles (Part 3 of 4) \ * MoveAndDrawPlayer (Part 3 of 5) \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned abovezPlayer = &9C \ The z-coordinate of the player's ship xVelocity = &A0 \ The player's velocity in the x-axis \ \ [Show more]\ \ This variable is used by the following: \ \ * LandOnLaunchpad \ * MoveAndDrawPlayer (Part 4 of 5) \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned aboveyVelocity = &A4 \ The player's velocity in the y-axis \ \ [Show more]\ \ This variable is used by the following: \ \ * LandOnLaunchpad \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned abovezVelocity = &A8 \ The player's velocity in the z-axis \ \ [Show more]\ \ This variable is used by the following: \ \ * LandOnLaunchpad \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned abovexExhaust = &AC \ The x-coordinate of the ship's exhaust \ vector, which points along the exhaust \ plume yExhaust = &B0 \ The y-coordinate of the ship's exhaust \ vector, which points along the exhaust \ plume zExhaust = &B4 \ The z-coordinate of the ship's exhaust \ vector, which points along the exhaust \ plume \ Offsets &B8 to &C0 appear to be unused previousColumn = &C4 \ The corner coordinates of the previous \ column while working along a row from left \ to right \ \ [Show more]\ \ This variable is used by the following: \ \ * DrawLandscapeAndBuffers (Part 2 of 4) \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned abovetileCornerRow = &E4 \ The number of the landscape tile corner \ row that is currently being processed \ \ [Show more]\ \ This variable is used by the following: \ \ * DrawLandscapeAndBuffers (Part 1 of 4) \ * DrawLandscapeAndBuffers (Part 2 of 4) \ * DrawLandscapeAndBuffers (Part 3 of 4) \ * GetLandscapeTileColour \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned above\ Offset &E8 appears to be unused unusedConfig = &F0 \ Storage for the first configuration value \ in the landscapeConfig table, which is \ stored but not used \ \ [Show more]\ \ This variable is used by the following: \ \ * DrawLandscapeAndBuffers (Part 2 of 4) \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned aboveobjectType = &F4 \ The type of the object currently being \ drawn \ \ [Show more]\ \ This variable is used by the following: \ \ * DrawObjects (Part 2 of 3) \ * ProcessObjectDestruction \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned abovetileRowOddEven = &F8 \ A counter that flips every time we process \ a tile corner row when drawing the \ landscape, so we can trigger actions \ accordingly \ \ [Show more]\ \ This variable is used by the following: \ \ * DrawLandscapeAndBuffers (Part 1 of 4) \ * DrawLandscapeAndBuffers (Part 3 of 4) \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned above\ Offset &FC appears to be unused altitude = &100 \ The altitude of the landscape at the \ most recently calculated coordinate \ \ [Show more]\ \ This variable is used by the following: \ \ * GetLandscapeAltitude \ * GetLandscapeTileColour \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned aboveprevAltitude = &104 \ The altitude of the landscape at the \ previously calculated coordinate \ \ [Show more]\ \ This variable is used by the following: \ \ * GetLandscapeAltitude \ * GetLandscapeTileColour \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned aboveparticleEnd = &108 \ The address of the end of the particle \ data in the particle data buffer \ \ [Show more]\ \ This variable is used by the following: \ \ * DeleteParticleData \ * InitialiseParticleData \ * StoreParticleData \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned aboveparticleCount = &10C \ The number of particles currently \ on-screen \ \ [Show more]\ \ This variable is used by the following: \ \ * DeleteParticleData \ * InitialiseParticleData \ * StoreParticleData \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned aboveobjectData = &110 \ The address of the blueprint for the \ object currently being drawn \ \ [Show more]\ \ This variable is used by the following: \ \ * DrawObject (Part 2 of 5) \ * DrawObject (Part 3 of 5) \ * DrawObjects (Part 2 of 3) \ * MoveAndDrawParticles (Part 3 of 4) \ * MoveAndDrawPlayer (Part 3 of 5) \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned aboveobjectFlags = &114 \ The flags of the object currently being \ drawn \ \ [Show more]\ \ This variable is used by the following: \ \ * DrawObject (Part 2 of 5) \ * DrawObject (Part 3 of 5) \ * DrawObject (Part 4 of 5) \ * MultiplyVectorByMatrix \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned abovemainLoopCount = &118 \ The main loop counter \ \ [Show more]\ \ This variable is used by the following: \ \ * DrawObjects (Part 3 of 3) \ * LoseLife \ * MainLoop \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned abovecrashLoopCount = &11C \ The loop counter for the crash animation \ \ [Show more]\ \ This variable is used by the following: \ \ * LoseLife \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned abovecrashedFlag = &120 \ If this is non-zero then the object being \ processed has crashed into the ground \ \ [Show more]\ \ This variable is used by the following: \ \ * DrawObject (Part 1 of 5) \ * DrawObject (Part 2 of 5) \ * MoveAndDrawPlayer (Part 3 of 5) \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned abovecurrentScore = &124 \ Our current score, which is displayed at \ the left end of the score bar \ \ It is initialised to initialScore at the \ start of each new game \ \ It goes down by one each time we fire a \ bullet, and goes up by 20 for each object \ we destroy \ \ [Show more]\ \ This variable is used by the following: \ \ * DropRocksFromTheSky \ * Entry \ * MoveAndDrawPlayer (Part 5 of 5) \ * PrintCurrentScore \ * ProcessObjectDestruction \ * StartNewGame \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned abovefuelLevel = &128 \ The player's fuel level \ \ [Show more]\ \ This variable is used by the following: \ \ * DrawFuelLevel \ * LandOnLaunchpad \ * MoveAndDrawPlayer (Part 1 of 5) \ * StartNewGame \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned abovegravity = &12C \ The current setting of gravity (which \ changes on higher levels) \ \ [Show more]\ \ This variable is used by the following: \ \ * MoveAndDrawParticles (Part 1 of 4) \ * MoveAndDrawPlayer (Part 2 of 5) \ * PrintCurrentScore \ * StartNewGame \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned aboveplayingGame = &130 \ A flag to determine whether the game is \ being player, or whether this is the crash \ animation: \ \ * 0 = this is the crash animation \ \ * -1 = game is being played \ \ [Show more]\ \ This variable is used by the following: \ \ * LoseLife \ * MoveAndDrawParticles (Part 3 of 4) \ * PlacePlayerOnLaunchpad \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned aboveremainingLives = &134 \ The number of remaining lives, which is \ displayed towards the right end of the \ score bar, just before the high score \ \ It is initialised to 3 at the start of \ each new game \ \ [Show more]\ \ This variable is used by the following: \ \ * LoseLife \ * PlacePlayerOnLaunchpad \ * StartNewGame \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned abovehighScore = &138 \ The high score, which is displayed at the \ right end of the score bar \ \ It is initialised to initialHighScore when \ the game is loaded \ \ [Show more]\ \ This variable is used by the following: \ \ * Entry \ * StartNewGame \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned abovexCamera = &13C \ The 3D x-coordinate of the camera position \ (though note that the camera position is \ actually at the back of the on-screen \ landscape, not the front) \ \ [Show more]\ \ This variable is used by the following: \ \ * AddShipExplosionToBuffer \ * AddSparkCloudToBuffer \ * DrawLandscapeAndBuffers (Part 1 of 4) \ * DrawObjects (Part 1 of 3) \ * DrawObjects (Part 2 of 3) \ * DropRocksFromTheSky \ * GetLandscapeBelowVertex \ * MoveAndDrawParticles (Part 2 of 4) \ * MoveAndDrawPlayer (Part 3 of 5) \ * PlacePlayerOnLaunchpad \ * SpawnRock \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned aboveyCamera = &140 \ The 3D y-coordinate of the camera position \ (though note that the camera position is \ actually at the back of the on-screen \ landscape, not the front) \ \ [Show more]\ \ This variable is used by the following: \ \ * DrawLandscapeAndBuffers (Part 2 of 4) \ * DrawObjects (Part 2 of 3) \ * DrawObjects (Part 3 of 3) \ * GetLandscapeBelowVertex \ * MoveAndDrawParticles (Part 2 of 4) \ * MoveAndDrawParticles (Part 3 of 4) \ * MoveAndDrawParticles (Part 4 of 4) \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned abovezCamera = &144 \ The 3D z-coordinate of the camera position \ (though note that the camera position is \ actually at the back of the on-screen \ landscape, not the front, so the camera's \ z-coordinate is larger than it would be \ for a more traditional camera position; \ it is more like the camera's focal point \ than position, in a sense) \ \ [Show more]\ \ This variable is used by the following: \ \ * AddShipExplosionToBuffer \ * AddSparkCloudToBuffer \ * DrawLandscapeAndBuffers (Part 1 of 4) \ * DrawObjects (Part 1 of 3) \ * DrawObjects (Part 2 of 3) \ * DropRocksFromTheSky \ * GetLandscapeBelowVertex \ * MoveAndDrawParticles (Part 2 of 4) \ * PlacePlayerOnLaunchpad \ * SpawnRock \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned abovexCameraTile = &148 \ The 3D x-coordinate of the camera, clipped \ to the nearest tile \ \ [Show more]\ \ This variable is used by the following: \ \ * DrawLandscapeAndBuffers (Part 1 of 4) \ * DrawLandscapeAndBuffers (Part 2 of 4) \ * DrawObjects (Part 1 of 3) \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned aboveyCameraTile = &14C \ The 3D y-coordinate of the camera, clipped \ to the nearest tile zCameraTile = &150 \ The 3D z-coordinate of the camera, clipped \ to the nearest tile \ \ [Show more]\ \ This variable is used by the following: \ \ * DrawLandscapeAndBuffers (Part 1 of 4) \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned aboveshipDirection = &154 \ The direction in which the player's ship \ faces, which is angle b in the rotation \ matrix, and which is determined by the \ angle of the mouse from the centre point \ \ [Show more]\ \ This variable is used by the following: \ \ * MoveAndDrawPlayer (Part 1 of 5) \ * PlacePlayerOnLaunchpad \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned aboveshipPitch = &158 \ The pitch of the player's ship, which is \ angle a in the rotation matrix, and which \ is determined by the distance of the mouse \ from the centre point \ \ [Show more]\ \ This variable is used by the following: \ \ * MoveAndDrawPlayer (Part 1 of 5) \ * PlacePlayerOnLaunchpad \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned abovefuelBurnRate = &15C \ The current fuel burn rate (bit 0 is \ ignored) \ \ [Show more]\ \ This variable is used by the following: \ \ * DrawFuelLevel \ * MoveAndDrawPlayer (Part 1 of 5) \ * MoveAndDrawPlayer (Part 2 of 5) \ * MoveAndDrawPlayer (Part 4 of 5) \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned abovexLandscapeRow = &160 \ The x-coordinate of the far-left corner \ of the landscape row that we are drawing, \ where rows run from left to right across \ the screen (this is a relative coordinate) \ \ [Show more]\ \ This variable is used by the following: \ \ * AddVectors \ * DrawLandscapeAndBuffers (Part 1 of 4) \ * DrawLandscapeAndBuffers (Part 2 of 4) \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned aboveyLandscapeRow = &164 \ The y-coordinate of the far-left corner \ of the landscape row that we are drawing, \ where rows run from left to right across \ the screen (this is a relative coordinate) zLandscapeRow = &168 \ The z-coordinate of the far-left corner \ of the landscape row that we are drawing, \ where rows run from left to right across \ the screen (this is a relative coordinate) \ \ [Show more]\ \ This variable is used by the following: \ \ * DrawLandscapeAndBuffers (Part 3 of 4) \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned above\ Offset &16C appears to be unused xLandscapeCol = &170 \ The x-coordinate of the far-left corner \ of the column (i.e. tile) that we are \ drawing in the current landscape row, \ where columns run in and out of the screen \ (this is a relative coordinate) \ \ [Show more]\ \ This variable is used by the following: \ \ * AddVectors \ * DrawLandscapeAndBuffers (Part 2 of 4) \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned aboveyLandscapeCol = &174 \ The y-coordinate of the far-left corner \ of the column (i.e. tile) that we are \ drawing in the current landscape row, \ where columns run in and out of the screen \ (this is a relative coordinate) \ \ [Show more]\ \ This variable is used by the following: \ \ * DrawLandscapeAndBuffers (Part 2 of 4) \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned abovezLandscapeCol = &178 \ The z-coordinate of the far-left corner \ of the column (i.e. tile) that we are \ drawing in the current landscape row, \ where columns run in and out of the screen \ (this is a relative coordinate) \ Offsets &17C to &1FC appear to be unused stringBuffer = &200 \ A string buffer that's used when printing \ the scores \ \ [Show more]\ \ This variable is used by the following: \ \ * PrintCurrentScore \ * PrintScoreInBothBanks \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned abovecornerStore1 = &400 \ Storage for coordinates of tile corners as \ we work our way through the landscape \ \ [Show more]\ \ This variable is used by the following: \ \ * DrawLandscapeAndBuffers (Part 1 of 4) \ * DrawLandscapeAndBuffers (Part 3 of 4) \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned abovecornerStore2 = &500 + STORE \ Storage for coordinates of tile corners as \ we work our way through the landscape \ \ [Show more]\ \ This variable is used by the following: \ \ * DrawLandscapeAndBuffers (Part 3 of 4) \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned abovevertexProjected = &600 + STORE * 2 \ Storage for projected vertices \ \ [Show more]\ \ This variable is used by the following: \ \ * DrawObject (Part 2 of 5) \ * DrawObject (Part 4 of 5) \ * DrawObject (Part 5 of 5) \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned aboveparticleData = &700 + STORE * 2 \ The particle data buffer, which stores \ eight data bytes for each on-screen \ particle \ \ [Show more]\ \ This variable is used by the following: \ \ * InitialiseParticleData \ * MoveAndDrawParticles (Part 1 of 4) \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned aboveobjectMap = &4400 + STORE * 2 \ The object map determines which objects \ appear on the landscape, where objects are \ trees, buildings, rockets and so on (size \ of object map is 256 * 256 bytes = &10000) \ \ [Show more]\ \ This variable is used by the following: \ \ * DrawObjects (Part 1 of 3) \ * MoveAndDrawPlayer (Part 3 of 5) \ * PlaceObjectsOnMap \ * ProcessObjectDestruction \ \ This list only includes code that refers \ to the variable by name; there may be \ other references to this memory location \ that don't use this label, and these will \ not be mentioned abovebuffers = &14400 + STORE * 2 \ The graphics buffers, one for each tile \ corner row (so there are TILE_Z of them)