Metaformática

Miscelaneous programs, simulations, algorithms and tests. Mainly with Free Pascal using cCHXSDL3Engine.

About the repository

This repository has unsorted programs with miscellaneous small little projects: Fractals, Minigames, Simulations, Data Structures visualization, and other experiments.

Folder structure

The basic directory structure of Metaformática is:

• CHANGELOG.md: Full change log.
• LastChanges.md: Last changes commited to the repository.
• NewProject.sh: Script to create structure for a new program.
• README.md: This text.
• 0Base/: Template structure for programs (to be copied with NewProject.sh).
  • README.md: Information about the program.
  • build.sh and Build.bat: Created by NewProject.sh.
  • bin/: Final program directory.
    • {Executable}: Actual executable program (and dll).
    • {OtherFolderOrFiles}: Whatever executable needs to run.
  • lib/: Where compiler will put compilation files.
  • src/: Source directory.
    • {MainProgram}.pas Main program(s) for compiling.
    • fp.cfg: FPC config file for easy compiling.
    • Units/: Directory with non common units used by the program.
  • res/, man/, doc/: Compilation recurses, User manual, Documentation, &c; if exists.
• 0Common/: Submodules and common units.
  • Units/: Common units between programs but not in CHXPas or other submodule.
  • CHXPas/: CHXPas repository as git submodule, where cCHXSDL3Engine actually is.
  • SDL3/: SDL3-for-Pascal submodule, used by cCHXSDL3Engine.
• {Category}/{ProgramDir}/: Actual programs directory, each in its own folder.

Maybe, someday, all of above is under Pascal directory because programs in other languages are added... (but surely I will try to port to Pascal).

Compilation

Every project have a Build.{sh|bat} for easy compilation, but they only creates output dirs, changes to src folder and execute:

fpc @fpMeta.cfg {MainFile}.pas

fpMeta.cfg sets directories for searching units and include files. FPC parameters can be added to build.sh too, and -dRELEASE parameter creates an optimized and striped executable.

Executable file will be created at bin directory, and it must run from there.

On Windows, fpc compiler program is suposed to be in PATH enviroment variable and executable's folder must have SDL3.dll (and other .dll if needed) and be sure that they are for the compiled and system architecture (32/64bits).

If Lazarus is used for compilation, maybe it's needed to add units folders manually to the project configuration.

About cCHXSDL3Engine

cCHXSDL3Engine is a class very similar to GameEngine pattern. Two main differences are very little anyways:

• Main Loop is divided in three methods: Compute, Draw and HandleEvent. Nothing stops to use only one for all things, but have some differences:
  • Compute is intended for algorithm computation. With ExitProg variable can finish program execution by itself. Time spend inside it is monitorized by cCHXSDLFPSManager.
  • Draw is for drawing of course. It's not called if the Window is minimized.
  • HandleEvent is called once per Event ocurred between frames. Some of then are automatically handled by cCHXSDL3Engine or its components.
• Order of the loop is Compute, Draw and HandleEvent while usually GameEngine pattern is to handle events first; and then compute and draw. In real time there is not difference at all.
• Actually there are 2 other methods:
  • Setup is called once before entering the main loop for setting initial values, object creation, etc.
  • Finish is called after exiting main loop for memory freeing or other finalization stuff.

Other classes and units are developed to help:

• cCHXSDLWindow (Window property inside of the engine) encapsulates SDL_Window and handles window events.
• cCHXSDLFrameManager (FPSMng property) keeps framerate constant with interpolation and stores some information related: FrameCounter, LastFrameTime (Total frame time) and LastCompTime (Last computation time).
• cCHXSDLRenderer (Render property) encapsulates SDL_Renderer and its primitive functions, and proporcionate more primitives to draw than vanilla SDL3 without SDL_gfx library.
• cCHXSDLTypeHelpers is a unit with helpers for SDL types, operator overloads and some other useful types.

The engine uses SDL3-for-FreePascal project headers.