raycaster.h

#pragma once

#include <stdint.h>

/* specify the precalcuated tables */
#define TABLES_320

#define SCREEN_WIDTH (uint16_t) 320
#define SCREEN_HEIGHT (uint16_t) 256
#define FB_WIDTH (SCREEN_WIDTH * SCREEN_SCALE)
#define FB_HEIGHT (SCREEN_HEIGHT * SCREEN_SCALE)
#define SCREEN_SCALE 2
#define INV_FACTOR (float) (SCREEN_WIDTH * 95.0f / 320.0f)
#define LOOKUP_TBL
#define LOOKUP8(tbl, offset) tbl[offset]
#define LOOKUP16(tbl, offset) tbl[offset]

#define MAP_X (uint8_t) 32
#define MAP_XS (uint8_t) 5
#define MAP_Y (uint8_t) 32
#define INV_FACTOR_INT ((uint16_t) (SCREEN_WIDTH * 75))
#define MIN_DIST (int) ((150 * ((float) SCREEN_WIDTH / (float) SCREEN_HEIGHT)))
#define HORIZON_HEIGHT (SCREEN_HEIGHT >> 1)
#define INVERT(x) (uint8_t)((x ^ 255) + 1)
#define UMULT(x, y) (uint16_t)(((uint32_t) (x) * (uint32_t) (y)) >> 8)
#define ABS(x) (x < 0 ? -x : x)
#define MIN(x, y) ((x) < (y) ? (x) : (y))

typedef struct RayCaster {
    void *derived;

    void (*Destruct)(struct RayCaster *rayCaster);

    void (*Start)(struct RayCaster *rayCaster,
                  uint16_t playerX,
                  uint16_t playerY,
                  int16_t playerA);
    void (*Trace)(struct RayCaster *rayCaster,
                  uint16_t screenX,
                  uint8_t *screenY,
                  uint8_t *textureNo,
                  uint8_t *textureX,
                  uint16_t *textureY,
                  uint16_t *textureStep);
} RayCaster;

RayCaster *RayCasterConstruct(void);

void RayCasterDestruct(RayCaster *rayCaster);