migrant a SDL3

CLAUDE.md

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+# CLAUDE.md
+
+This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.
+
+## Project Overview
+
+This is an Asteroids-style game originally written in Turbo Pascal 7 for DOS, now being converted to modern C++ with SDL2. The game features a spaceship that must avoid and destroy enemies ("cosinus mesisinus" mounted in UFOs/ORNIs). The codebase contains both the original Pascal implementation and the in-progress C++ port.
+
+**Language**: The code and comments are in Catalan/Valencian.
+
+## Build Commands
+
+**macOS**:
+```bash
+make macos
+./bin/asteroids_macos
+```
+
+**Linux**:
+```bash
+make linux
+./bin/asteroids_linux
+```
+
+Both commands compile from `source/*.cpp` with `-std=c++11 -Wall -O2` and link against SDL2.
+
+## Architecture
+
+### Code Structure
+
+- `source/ASTEROID.PAS` - Original Turbo Pascal 7 implementation (DOS)
+- `source/asteroids.cpp` - C++ port using SDL2 (in progress)
+
+### Core Data Structures
+
+The game uses polar coordinates (`ipunt`) for geometric objects:
+- `ipunt` - Polar coordinate point (radius `r`, angle `angle`)
+- `punt` - Cartesian coordinate point (x, y)
+- `triangle` - The player's ship (3 polar points + center + angle + velocity)
+- `poligon` - Generic polygon for enemies and bullets (vector of polar points + center + angle + velocity + rotation)
+
+### Key Game Constants
+
+Defined in `asteroids.cpp`:
+- Screen bounds: `MARGE_DALT` (20), `MARGE_BAIX` (460), `MARGE_ESQ` (20), `MARGE_DRET` (620)
+- `MAX_ORNIS` (15) - Maximum enemies
+- `MAX_BALES` (3) - Maximum bullets
+- `VELOCITAT` (2), `VELOCITAT_MAX` (6) - Speed constraints
+
+### Rendering System
+
+The original Pascal code used VGA Mode 13h (320x200, 256 colors) with custom bit-packed framebuffer:
+- `pvirt` - Virtual screen buffer (38400 bytes)
+- `posa(x,y,color)` - Set pixel in virtual buffer (bit-packed)
+- `llig(x,y)` - Read pixel from virtual buffer
+- `volca()` - Flip virtual buffer to VGA memory
+- Line drawing using Bresenham algorithm
+
+The C++ port uses SDL2 for rendering.
+
+### Game Mechanics
+
+- **Movement**: Ship uses polar velocity - angle determines direction, velocity determines speed
+- **Collision**: Line drawing returns collision state; `rota_tri()` returns 1 on pixel collision
+- **Death sequence**: Ship shrinks (`nau.p*.r` decreases), explodes into debris (`chatarra_cosmica`), then respawns after 250 frames
+- **Enemies**: `orni[]` array of polygons with autonomous movement, random angle adjustments
+- **Bullets**: Only one bullet active at a time (`bales[1].esta` flag)
+
+### Pascal-to-C++ Conversion Notes
+
+The C++ file contains hybrid Pascal/C++ syntax that needs completion:
+- Lines 63-450 are uncommented Pascal code
+- Pascal procedures/functions need conversion to C++ equivalents
+- Assembly blocks (`waitretrace`, VGA mode setting) need SDL2 replacements
+- Turbo Pascal keyboard handling (`teclapuls`, `instalarkb`) needs SDL event system
+- Memory management (`getmem`, pointer segments) needs modern C++ approach
+
+### Game Controls (from README)
+
+- Up Arrow: Accelerate
+- Down Arrow: Brake
+- Right Arrow: Rotate clockwise
+- Left Arrow: Rotate counterclockwise
+- Space: Fire
+- Esc: Exit
+
+## Development Notes
+
+- The conversion is incomplete - much Pascal code remains in comments
+- Focus on SDL2 for cross-platform graphics/input instead of DOS VGA/keyboard
+- Original used bit-packed monochrome framebuffer; consider SDL surfaces or textures
+- Preserve the polar coordinate geometry system - it's core to the game's physics