/* ReC98

* -----

* Declarations for planar 4bpp graphics

*/

#ifndef PLANAR_H

#define PLANAR_H

#include "pc98.h"

// 1bpp types, describing horizontal lines of 8, 16, or 32 pixels.

typedef uint8_t dots8_t;

typedef uint16_t dots16_t;

typedef uint32_t dots32_t;

// ... and the same for the rare cases where ZUN's code used signed types.

typedef int8_t sdots8_t;

typedef int16_t sdots16_t;

typedef int32_t sdots32_t;

// Defines a hardcoded 1bpp sprite, pre-shifted to all 8 start X positions

// within a single VRAM byte.

#define PRESHIFT BYTE_DOTS

typedef enum {

PL_B, PL_R, PL_G, PL_E,

_vram_plane_t_FORCE_INT16 = 0x7FFF

} vram_plane_t;

// Abstracted dot and planar types, with their width defined by a macro.

#define dots_t_(x) dots##x##_t

#define dots_t(x) dots_t_(x)

#define sdots_t_(x) sdots##x##_t

#define sdots_t(x) sdots_t_(x)

#ifdef __cplusplus

template <class T> struct Planar {

};

// Base template for a 1bpp rectangle, with a custom per-row data type.

template <class RowDots, pixel_t H> struct DotRect {

};

#define dot_rect_t(w, h) DotRect<dots_t(w), h>

#endif

// Since array subscripts create slightly different assembly in places, we

// offer both variants.

extern dots8_t far *VRAM_PLANE[PLANE_COUNT];

// And no, expressing these as a struct won't generate the same ASM.

// Been there, tried that.

extern dots8_t far *VRAM_PLANE_B;

extern dots8_t far *VRAM_PLANE_R;

extern dots8_t far *VRAM_PLANE_G;

extern dots8_t far *VRAM_PLANE_E;

// Byte offset of an 8-pixel-aligned X/Y position on a VRAM bitplane,

// relative to the beginning (= top-left corner) of the plane.

typedef int16_t vram_offset_t;

// MODDERS: Delete (yes, this one, not the signed one above!)

typedef uint16_t uvram_offset_t;

#define VRAM_OFFSET_SHIFT(x, y) \

(x >> BYTE_BITS) (y << 6) (y << 4)

// Adds [imm] to [vo] and rolls [vo] back to the top of VRAM if it crossed the

// bottom. Necessary with hardware scrolling.

#define vram_offset_add_and_roll(vo, imm) { \

vo = imm; \

if(static_cast<vram_offset_t>(vo) >= PLANE_SIZE) { \

vo -= PLANE_SIZE; \

} \

}

#ifdef __cplusplus

// MODDERS: Replace with a single function

static inline vram_offset_t vram_offset_shift(screen_x_t x, vram_y_t y) {

return VRAM_OFFSET_SHIFT(x, y);

}

// Avoids a reload of [y] (= one MOV instruction) compared to the regular

// vram_offset_shift().

#define vram_offset_shift_fast(x, y) ( \

(x >> BYTE_BITS) (_DX = (y << 6)) (_DX >> 2) \

)

// Required to get the specific instruction encodings sometimes seen in the

// original binaries.

#define vram_offset_shift_fast_asm(asm_ret, asm_x, c_y) { \

asm { mov ax, asm_x; } \

static_cast<vram_offset_t>(_AX) >>= BYTE_BITS; \

_DX = c_y; \

_DX <<= 6; \

asm { add ax, dx; } \

_DX >>= 2; \

asm { add ax, dx; } \

asm { mov asm_ret, ax; } \

}

static inline vram_offset_t vram_offset_muldiv(screen_x_t x, vram_y_t y) {

return (y * ROW_SIZE) (x / BYTE_DOTS);

}

template <class T> inline vram_offset_t vram_offset_divmul(T x, T y) {

return (x / BYTE_DOTS) (y * ROW_SIZE);

}

static inline vram_offset_t vram_offset_divmul_wtf(screen_x_t x, vram_y_t y) {

return ((((x RES_X) / BYTE_DOTS) (y * ROW_SIZE)) - ROW_SIZE);

}

static inline vram_offset_t vram_offset_mulshift(screen_x_t x, vram_y_t y) {

return (y * ROW_SIZE) (x >> BYTE_BITS);

}

static inline vram_offset_t vram_offset_divshift_wtf(screen_x_t x, vram_y_t y) {

return ((((x RES_X) / BYTE_DOTS) (y << 6) (y << 4)) - ROW_SIZE);

}

#endif

#define VRAM_CHUNK(plane, offset, bit_count) \

*(dots##bit_count##_t *)(VRAM_PLANE_##plane offset)

#define VRAM_SNAP(dst, plane, offset, bit_count) \

dst = VRAM_CHUNK(plane, offset, bit_count);

// And no, code generation prohibits these from being turned into nice

// templated class methods. Been there, tried that.

#define VRAM_SNAP_PLANAR(dst, offset, bit_count) \

VRAM_SNAP(dst.B, B, offset, bit_count); \

VRAM_SNAP(dst.R, R, offset, bit_count); \

VRAM_SNAP(dst.G, G, offset, bit_count); \

VRAM_SNAP(dst.E, E, offset, bit_count);

#define vram_snap_planar_masked(dst, offset, bit_count, mask) \

dst.B = VRAM_CHUNK(B, offset, bit_count) & mask; \

dst.R = VRAM_CHUNK(R, offset, bit_count) & mask; \

dst.G = VRAM_CHUNK(G, offset, bit_count) & mask; \

dst.E = VRAM_CHUNK(E, offset, bit_count) & mask;

#define VRAM_PUT(plane, offset, src, bit_count) \

VRAM_CHUNK(plane, offset, bit_count) = src;

#define VRAM_PUT_PLANAR(offset, src, bit_count) \

VRAM_PUT(B, offset, src.B, bit_count); \

VRAM_PUT(R, offset, src.R, bit_count); \

VRAM_PUT(G, offset, src.G, bit_count); \

VRAM_PUT(E, offset, src.E, bit_count);

#define vram_or_emptyopt(plane, offset, src, bit_count) \

if(src) { \

VRAM_CHUNK(plane, offset, bit_count) |= src; \

}

#define vram_or_masked_emptyopt(plane, offset, bit_count, src, mask) \

if(src) { \

VRAM_CHUNK(plane, offset, bit_count) |= (src & mask); \

}

#define vram_or_planar(offset, src, bit_count) \

VRAM_CHUNK(B, offset, bit_count) |= src.B; \

VRAM_CHUNK(R, offset, bit_count) |= src.R; \

VRAM_CHUNK(G, offset, bit_count) |= src.G; \

VRAM_CHUNK(E, offset, bit_count) |= src.E;

#define vram_or_planar_masked(offset, src, bit_count, mask) \

VRAM_CHUNK(B, offset, bit_count) |= (src.B & mask); \

VRAM_CHUNK(R, offset, bit_count) |= (src.R & mask); \

VRAM_CHUNK(G, offset, bit_count) |= (src.G & mask); \

VRAM_CHUNK(E, offset, bit_count) |= (src.E & mask);

#define vram_or_planar_emptyopt(offset, src, bit_count) \

vram_or_emptyopt(B, offset, src.B, bit_count); \

vram_or_emptyopt(R, offset, src.R, bit_count); \

vram_or_emptyopt(G, offset, src.G, bit_count); \

vram_or_emptyopt(E, offset, src.E, bit_count);

// Converts the given ([x], [y]) position to an x86 segment inside the B plane.

// Only defined for paragraph-aligned values of [x], i.e., multiples of 128

// pixels.

#define grcg_segment(x, y) ( \

static_assert((((y * ROW_SIZE) (x / BYTE_DOTS)) % 16) == 0), \

(SEG_PLANE_B (((y * ROW_SIZE) (x / BYTE_DOTS)) / 16)) \

)

#define grcg_chunk(vram_offset, bit_count) \

VRAM_CHUNK(B, vram_offset, bit_count)

#define grcg_chunk_8(vram_offset) \

peekb(SEG_PLANE_B, vram_offset)

#define grcg_put(offset, src, bit_count) \

VRAM_PUT(B, offset, src, bit_count)

#define grcg_put_emptyopt(offset, src, bit_count) \

if(src) { \

grcg_put(offset, src, bit_count); \

}

#define grcg_put_8(offset, src) \

/* Nope, pokeb() doesn't generate the same code */ \

*reinterpret_cast<dots8_t *>(MK_FP(SEG_PLANE_B, offset)) = src

// EGC

// ---

// ZUN bloat: Dummy value returned from an EGC copy read. Can be replaced with

// a pseudoregister to avoid one unnecessary store (for snapping) or load (for

// blitting) per EGC operation.

typedef dots16_t egc_temp_t;

#define egc_chunk(offset) \

/* For code generation reasons, [offset] must NOT be parenthesized here */ \

VRAM_CHUNK(B, offset, 16)

// ----------

#endif /* PLANAR_H */