FSASM support in DynKit 

• Introduction
• Macros for defining dynamic library structure
• Special SDL instructions
• Special dynamic scenery instructions
• Variables
• DynKit feature constants
• Generating ID strings

The DYNKIT.DEF file included in DynKit allows developing dynamic libraries with FSASM. It also allows accessing new dynamic object shapes from section 15 code.

In order to use definitions from DYNKIT.DEF, put the line

.include "dynkit.def"

into your FSASM source file after the inclusion of FSAHEAD.DEF. You can copy DYNKIT.DEF either into the DEF subdirectory of the main FSASM directory, or into the current directory.

DYNKIT.DEF was developed for FSASM 6.0.0. Newer versions of FSASM will most likely include these definitions into default precompiled headers and thus not need DYNKIT.DEF.

This document assumes knowledge of dynamic library structure.

There is an example dynamic object shape and a simple dynamic scenery made with FSASM: saucer10.fsa and saucer15.fsa.

DynLibHeader id0,id1,id2,id3,id4,id5,id6,id7

Defines the dynamic library BGL header. Should be used instead of .BGLHeader. DynLibHeader should normally be followed by the

.section 10

directive. The following macros should be used inside section 10.

DynLibTableEntry Label:, id0,id1,id2,id3,id4,id5,id6,id7, id8,id9,id10,id11,id12,id13,id14,id15

Defines an entry in the dynamic library table. The label should point to the BeginDynShape at the beginning of the shape.

DynLibTableEnd

Must conclude the dynamic library table.

BeginDynShape

Begins a dynamic object shape definition. A DynLibTableEntry record with the shape ID should point to BeginDynShape. The SDL code for drawing the shape must be between BeginDynShape and EndDynShape.

EndDynShape

Ends a dynamic object shape definition.

This section describes SDL instructions often used by the code that displays dynamic object shapes but not in static sceneries.

RefPtIndirect JumpLabel:,Variable,Arg1=0,Arg2=0,Arg3=0

Sets a new reference point using latitude, longitude and altitude values stored at the memory location beginning at the given variable address. The meaning of Arg1, Arg2 and Arg3 arguments is unknown, default objects use zeroes. This instruction probably does some sort of a visibility test and performs a jump to JumpLabel: when it fails. Dynamic objects should use SetScale/SetScaleX2 for visibility tests.

ShadowRefPtIndirect Variable

Sets a reference point for the shadow of the object. The memory location beginning at the given variable address should contain latitude, longitude and altitude values of a point that is projected on the ground according to the sun position and used as the reference point.

SetScale ...
SetScaleX2 ...

Set the scale factor using a reference point defined earlier. Used for dynamic objects because indirect reference point instructions do not set the scale factor themselves. These instructions are described in the FSASM manual.

RotCallIndirect JumpLabel:,Variable

Calls a drawing routine in a rotated coordinate system using pitch, bank and heading values stored at the memory location beginning at the given variable address.

ShadowRotCallIndirect JumpLabel:,Variable

Rotates the coordinate system using pitch, bank and heading values stored at the memory location beginning at the given variable address, then projects it onto the reference point level according to the sun position in order to produce a realistic shadow. Calls the routine at JumpLabel: in a special mode that produces shadows instead of full-colored primitives. Used to display object shadows.

SurfaceColorIndirect Variable

Loads the surface color from a variable. Used to access colors set in the dynamic scenery with the DynColor instruction.

LineColorIndirect Variable

Loads the line color from a variable.

ShadedColorIndirect Variable

Loads the color for shaded polygons from a variable.

SetLocalVar Variable,Value

Sets a variable local to the dynamic object. Equivalent to SetVar.

SetGlobalVar Variable,Value

Sets a global variable. Normally used to set vCrashFlag in crash detection code. Equivalent to SetVar7E.

This section describes section 15 instructions added in DYNKIT.DEF..

PatternDefEx Label:,VisFlag, id0,id1,id2,id3,id4,id5,id6,id7, id8,id9,id10,id11,id12,id13,id14,id15

This instruction is similar to PatternDef, but references a dynamic object by a 16-byte ID string, thus allowing accesses to dynamic libraries.

DynPositionEx GearHeignt, N, E, A

This instruction is similar to DynPosition, but requires specifying the gear height explicitly. It should be used for custom dynamic objects, where FSASM has no information about the gear height.

DynColor VarNumber, value

This instruction sets one color variable. The value for VarNumber should be between 0 and 4, which would correspond to vDynColor0..vDynColor4 in section 10 code.

This section lists FSASM names for variables local to dynamic objects.

These constants define bits of vDynFeatures that control individual features. They match bit values used by DynKit Hangar in converted FSFS aircraft. Note that unlike other features, the landing gear is controlled by the vDynGear variable instead of vDynFeatures.

See the DynKit Hangar documentation for details on features.

DynKit Hangar generates ID strings based on the system time and the user registration information. This reduces the risk of ID string conflicts to nearly zero. You can use DynKit Hangar to generate ID strings used in your FSASM code:

• Start DynKit Hangar.
• Import some FSFS airplane. A pseudo-unique ID string will be generated.
• Copy and paste this ID string into your FSASM source code.
• Exit DynKit Hangar without saving the dynamic library.
• Now you have a pseudo-unique ID string in your FSASM source code.

Repeat these steps for additional ID strings you need.