Things to fix

Code

• Change AllocateGraphic(...) so that it also requires camera as an argument and deal with the camera automatically.
• Change inline constexpr constants to extern const, and move them from header to TU

Scene

• Add scene::StageSelect

scene::Game

• Fix entities at times not aligning properly by 1 pixel to the tilemap
• Add Back to stage select on pause menu

Transition

• Fix spike transition crash when zone transition is already taking place

Mechanics

• Reset button press & symbol pickup/drop on midair when hit by spikes
• Add moving platform
• Add touch-fading platform

Player

• Fix holding B takes too long to merge/split the symbol(s).
• Fix player collision (which is only 1 bn::fixed_rect right now, need to make more rects)
• Fix 2 tiles (mostly 2 corner tiles) collision not done properly, resulting in clipping into a wall
• Fix player not turn around to heading direction when falling

Level design

• #3
• Add more tutorial-like levels to showcase how the mechanics work

W1_S2_Z3

• Fix player can't know if you can do this when they merge the inverted ^ symbol.
  https://youtu.be/BzbC8qBSv4g?t=134

C:/butano/homebrew/sym_merged/src/game_system_PhysicsMovement.cpp: In function 'bn::optional<sym::game::system::{anonymous}::PushbackDirection> sym::game::system::{anonymous}::PlatformCollisionResolution_(sym::game::entity::IPhysicsEntity&, const sym::helper::tilemap::TileInfo&)':
C:/butano/homebrew/sym_merged/src/game_system_PhysicsMovement.cpp:97:90: error: 'const class bn::fixed_rect' has no member named 'top_right'
   97 |     const TileInfo::Flags topRightTileFlag = mapTileInfo.GetTileFlagsByPosition(collider.top_right());
      |
                    ^~~~~~~~~
C:/butano/homebrew/sym_merged/src/game_system_PhysicsMovement.cpp:98:92: error: 'const class bn::fixed_rect' has no member named 'bottom_left'; did you mean 'top_left'?
   98 |     const TileInfo::Flags bottomLeftTileFlag = mapTileInfo.GetTileFlagsByPosition(collider.bottom_left());
      |
                      ^~~~~~~~~~~
      |
                      top_left
C:/butano/homebrew/sym_merged/src/game_system_PhysicsMovement.cpp: In member 
function 'void sym::game::system::PhysicsMovement::SymbolCollision_(sym::game::entity::Symbol&)':
C:/butano/homebrew/sym_merged/src/game_system_PhysicsMovement.cpp:569:32: error: 'struct sym::scene::GameState' has no member named 'fadeIn'
  569 |                     if (state_.fadeIn.GetState() != effect::Transition::State::ONGOING)
      |                                ^~~~~~
make[1]: *** [/opt/devkitpro/devkitARM/base_rules:80: game_system_PhysicsMovement.o] Error 1
make: *** [/c/butano/butano/butano.mak:156: build] Error 2

For some reason I get this error.

a = World number
b = Stage number
c = Zone number
n = image number (single image can contain multiple zones)

Implement stage-codegen.py

• Generate game_stage_Wa_Sb.cpp
  • Learn to parse *.tmx file, which is basically *.xml file
  • Restructure bg_wa_sb_n.tmx file(s), so that the zone boundaries can be identified with the zone number.
    • Change Tiled layers so that each zone takes each Tiled layers
    • Find the first non-zero cell from the front and back on each zone, to find top-left and bottom-right cell
    • (Optional) Fix the helper::tilemap::IndexRect ctor, so that it can take top-left and bottom-right cell
    • (Optional) Add object template to Tiled object layer
  • Parse bg_wa_sb_n.tmx file(s) and generate game_stage_Wa_Sb.cpp
    • When there is no certain entity available on zone c, generate constexpr bn::span<ZoneInfo::{EntityInfo}> Zc_{entityInfo}s_ instead of constexpr ZoneInfo::{EntityInfo} Zc_{entityInfo}s_[]
• Overwrite game_stage_getter.h to currently existing stages

Optional things

• Rebuild a stage only when it is edited
  • Compare the modified time of generated zone header and the *.tmx file(s) of the zone
    • os.path.getmtime() considered helpful
• Verify if the stage is valid
  • Check if there is at least one entrance on Z0_entranceInfos_ (index 0 of it is where the stage starts)
  • Check if it has only one black hole (stage clear)
  • Check if every Zc_exitInfos_ is connected to a valid zone number and a valid entrance index of that zone
  • Check if every size of the zone is same or bigger than (30, 20) cells
  • Check if unsupported items present (or simply ignore that one?)
  • Warn unused entrance (exception: Z0_Ent0, where the stage starts)
• Optimize codegen by generating each game_stage_Wa_Sb.cpp asynchronously.

It looks like this repo got quite a lot of stars, thanks everyone!
But I need to mention that it is quite messy and very far from optimal, so beware of the messy code.

• This uses affine_bg to get unique cell id, but now there's better way to do this with Butano. Check the dynamic_regular_bg example and this demo I made
• I didn't know how to structure my code the time I was working on this one. Like, it's full of if~else checks, updating game variables from everywhere etc. If I decide to make this a full game someday, I have to rewrite it from scratch at this point.

Originally posted by @copyrat90 in #4