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Dominic Masters
2025-10-10 09:16:08 -05:00
parent c4c43b23ad
commit 349e6e7c94
16 changed files with 164 additions and 220 deletions
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1
src/rpg/world/CMakeLists.txt
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@@ -6,5 +6,4 @@
# Sources
target_sources(${DUSK_TARGET_NAME}
PRIVATE
worldunit.c
)

62
src/rpg/world/worldunit.c
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@@ -1,62 +0,0 @@
/**
* Copyright (c) 2025 Dominic Masters
*
* This software is released under the MIT License.
* https://opensource.org/licenses/MIT
*/
#include "worldunit.h"
#include "assert/assert.h"
void worldChunkPosAdd(worldchunkpos_t *pos, const worldsubtile_t amt) {
assertNotNull(pos, "Position pointer cannot be NULL");
/*
int32_t sum = (int32_t)pos->subtile + (int32_t)amt;
int32_t shifted = sum + 128; // may be negative or large
int32_t carry = div_floor(shifted, 256); // tiles to add (can be neg)
int32_t rem = mod_floor(shifted, 256); // 0..255
int32_t new_sub = rem - 128; // back to [-128,127]
pos->subtile = (int8_t)new_sub;
pos->tile = (uint8_t)((int32_t)pos->tile + carry); // wrap mod 256
*/
int32_t shiftedTotal = (int32_t)pos->subtile + (int32_t)amt + 128;
int32_t tileCarry = shiftedTotal >> 8; // divide by 256
int32_t wrappedSubtile = shiftedTotal - (tileCarry << 8);
pos->subtile = (int8_t)(wrappedSubtile - 128);
pos->tile = (uint8_t)(pos->tile + (uint8_t)tileCarry);
}
void worldPosAddSubtile(worldpos_t *pos, const worldsubtile_t amt) {
assertNotNull(pos, "Position pointer cannot be NULL");
// Same as worldChunkPosAdd but with chunk handling.
int32_t shiftedTotal = (int32_t)pos->subtile + (int32_t)amt + 128;
int32_t tileCarry = shiftedTotal >> 8; // divide by 256
int32_t wrappedSubtile = shiftedTotal - (tileCarry << 8);
pos->subtile = (int8_t)(wrappedSubtile - 128);
int32_t newTile = (int32_t)pos->tile + (int32_t)tileCarry;
int32_t chunkCarry = newTile / WORLD_CHUNK_SIZE;
pos->tile = (uint8_t)(newTile % WORLD_CHUNK_SIZE);
pos->chunk = (uint8_t)(pos->chunk + (uint8_t)chunkCarry);
}
float_t worldChunkPosToF32(const worldchunkpos_t pos, const uint8_t tileSize) {
const float_t scaleFactor = (float_t)tileSize * (1.0f / 256.0f);
return (
(float_t)pos.tile * (float_t)tileSize + ((float_t)pos.subtile + 128.0f) *
scaleFactor
);
}
float_t worldPosToF32(const worldpos_t pos, const uint8_t tileSize) {
const float_t scaleFactor = (float_t)tileSize * (1.0f / 256.0f);
const float_t chunkFactor = WORLD_CHUNK_SIZE * (float_t)tileSize;
return (
(float_t)pos.chunk * chunkFactor +
(float_t)pos.tile * (float_t)tileSize +
((float_t)pos.subtile + 128.0f) * scaleFactor
);
}

100
src/rpg/world/worldunit.h
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@@ -1,100 +0,0 @@
/**
* Copyright (c) 2025 Dominic Masters
*
* This software is released under the MIT License.
* https://opensource.org/licenses/MIT
*/
#pragma once
#include "dusk.h"
#define WORLD_DIMENSIONS 3
#define WORLD_SUBTITLE_MIN -128
#define WORLD_SUBTITLE_MAX 127
#define WORLD_CHUNK_SIZE 256 // Tiles per axis per chunk.
/**
* Position in SUBTILE space in a world, each unit represents a single subtile.
* This is divided by the size of the tile, e.g. if a tile is 16x16 then there
* are 128 / tile size = units per pixel of a tile. This means there are always
* between WORLD_SUBTITLE_MIN and WORLD_SUBTITLE_MAX subtiles in a tile.
*
* The extra benefit of this is that different tile sizes don't require any game
* logic updates!
*/
typedef int8_t worldsubtile_t;
/**
* Position in TILE space in a world, each unit represents a single tile. This
* is within CHUNK space. This is not different depending on chunk size, if the
* chunks are 32 tiles wide then the max tile value is 31.
*/
typedef uint8_t worldtile_t;
/**
* Represents a position in a world in SUBTILE and TILE space. This is basically
* just a convenience struct so you don't have to pass two variables around.
*
* For example, an entity may be at tile (2, 3) and subtile (8, 12).
* meaning that the entity is at pixel (2 * TILE_SIZE + 8, 3 * TILE_SIZE + 12)
* in world space.
*
* This is still within CHUNK space.
*/
typedef struct worldchunkpos_s {
worldsubtile_t subtile;
worldtile_t tile;
} worldchunkpos_t;
/**
* Position in CHUNK space in a world, each unit represents a single chunk.
*/
typedef uint8_t worldchunk_t;
/**
* Represents a position in a world in SUBTILE, TILE and CHUNK space. This is in
* WORLD space, so this is the full position of an entity in the world.
*/
typedef struct worldpos_s {
worldsubtile_t subtile;
worldtile_t tile;
worldchunk_t chunk;
} worldpos_t;
/**
* Adds a number of subtiles to a world chunk position, rolling over into tiles
* and chunks as necessary.
*
* @param pos Pointer to the world chunk position to modify.
* @param amt The amount of subtiles to add (can be negative).
*/
void worldChunkPosAdd(worldchunkpos_t *pos, const worldsubtile_t amt);
/**
* Adds a number of subtiles to a world position, rolling over into tiles and
* chunks as necessary.
*
* @param pos Pointer to the world position to modify.
* @param amt The amount of subtiles to add (can be negative).
*/
void worldPosAddSubtile(worldpos_t *pos, const worldsubtile_t amt);
/**
* Converts a world chunk position to a floating point number, given the tile
* size in pixels.
*
* @param pos Pointer to the world chunk position to convert.
* @param tileSize The size of a tile in pixels.
* @return The position as a floating point number.
*/
float_t worldChunkPosToF32(const worldchunkpos_t pos, const uint8_t tileSize);
/**
* Converts a world position to a floating point number, given the tile size
* in pixels.
*
* @param pos Pointer to the world position to convert.
* @param tileSize The size of a tile in pixels.
* @return The position as a floating point number.
*/
float_t worldPosToF32(const worldpos_t pos, const uint8_t tileSize);