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#ifndef TEXT_H
#define TEXT_H
#include "bd-font.c"
#include "shorthand.h"
#include "posprintf.h"
typedef struct TextEngine {
// Cursor for tiled text mode The X and Y positions correspond to the tile
// X and Y starting from the top left of the screen. For a 240x160 screen,
// we have 30x20 tiles available.
size_t cursor_x;
size_t cursor_y;
// Memory location of font tile data and tilemap. Likely located on the
// VRAM.
u32 *font_data;
u16 *font_tilemap;
// The font map for tiled text. Writing the character stored in this
// position on the tilemap will show a character on the screen.
u16 font_map[256];
} TextEngine;
static TextEngine text_engine = {0};
static inline
void
txt_init(u32 *font_data, u16 *font_tilemap, u16 font_offset) {
// Load font data into VRAM.
unpack_tiles(&bd_font, font_data, 256);
// Initialize the font map translation table. That way we can write
// a character on the text background layer with:
// FONT_TILEMAP[tile_x + 32 * tile_y] = font_map['A'];
for (size_t i = 0; i < 256; ++i) {
text_engine.font_map[i] = font_offset + i;
}
// Initialize remaining variables.
text_engine.font_data = font_data;
text_engine.font_tilemap = font_tilemap;
}
static inline
void
txt_putc(char c) {
if (c == '\0') {
return;
}
if (c == '\n') {
text_engine.cursor_x = 0;
text_engine.cursor_y++;
} else {
int x = text_engine.cursor_x;
int y = text_engine.cursor_y;
text_engine.font_tilemap[x + 32 * y] = text_engine.font_map[(u16)c];
text_engine.cursor_x += 1;
if (text_engine.cursor_x >= 30) {
text_engine.cursor_x = 0;
text_engine.cursor_y++;
}
}
if (text_engine.cursor_y >= 20) {
text_engine.cursor_y = 0;
}
}
static inline
void
txt_puts(char *msg) {
while (*msg) {
txt_putc(*msg++);
}
}
static inline
void
txt_clear_line(void) {
for (size_t i = 0; i < 30; ++i) {
int x = text_engine.cursor_x;
int y = text_engine.cursor_y;
text_engine.font_tilemap[x + 32 * y] = text_engine.font_map[0];
}
text_engine.cursor_x = 0;
}
static inline
void
txt_clear_screen(void) {
for (size_t j = 0; j < 20; ++j) {
text_engine.cursor_y = j;
txt_clear_line();
}
text_engine.cursor_x = 0;
text_engine.cursor_y = 0;
}
static inline
void
txt_position(size_t tile_x, size_t tile_y) {
text_engine.cursor_x = tile_x;
text_engine.cursor_y = tile_y;
}
// Print text to the screen with formatting.
#define txt_printf(msg, ...) \
{ \
char buf[256] = {0}; \
posprintf(buf, msg, ##__VA_ARGS__); \
txt_puts(buf); \
}
#endif // TEXT_H
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