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#ifndef TEXT_H
#define TEXT_H
#include "posprintf.h"
typedef void (*TxtDrawc)(char c, size_t x, size_t y, u8 clr);
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;
u8 buffer[30 * 20];
u8 spacing;
u8 color;
TxtDrawc drawc;
} TextEngine;
static TextEngine text_engine = {0};
// Initializes the text engine.
static inline
void
txt_init(TxtDrawc drawc) {
// Initialize remaining variables.
text_engine.spacing = 8;
text_engine.color = 1;
text_engine.drawc = drawc;
}
// Writes a message to the tile text background.
static inline
void
txt_puts(char *msg) {
while (*msg) {
char c = *msg++;
if (c == '\0') {
continue;
}
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.buffer[x + 30 * y] = 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;
}
}
}
// Clears the current line on the tile text mode.
static inline
void
txt_clear_line(void) {
dma_fill(text_engine.buffer, 0, sizeof(text_engine.buffer), 3);
text_engine.cursor_x = 0;
text_engine.cursor_y = 0;
}
// Clears the screen on the tile text mode.
static inline
void
txt_clear(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;
}
// Moves the tile mode cursor to the specified position.
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;
}
static inline
void
txt_color(u8 clr) {
text_engine.color = clr;
}
static inline
void
txt_spacing(u8 spacing) {
text_engine.spacing = spacing;
}
// Renders the contents of the scrollback buffer to the screen.
void
txt_render(void) {
for (size_t y = 0; y < 20; y++) {
for (size_t x = 0; x < 30; x++) {
size_t pos = x + y * 30;
if (text_engine.buffer[pos] == 0) {
continue;
}
text_engine.drawc(
text_engine.buffer[pos],
x * text_engine.spacing,
y * text_engine.spacing,
text_engine.color);
}
}
}
// Draws a message where the first character's top-left corner begins at the
// given x and y position. The character spacing can be adjusted, but beware of
// color merging issues.
static inline
void
txt_draws(char *msg, size_t x, size_t y, u8 clr) {
size_t i = 0;
while (*msg) {
char c = *msg++;
text_engine.drawc(c, x + i++ * text_engine.spacing, y, clr);
}
}
// Print text to the screen with formatting.
#define txt_printf(msg, ...) \
{ \
char buf[256] = {0}; \
posprintf(buf, msg, ##__VA_ARGS__); \
txt_puts(buf); \
}
// Draws text to the screen with formatting starting on the x and y position and
// with custom character spacing.
#define txt_drawf(msg, x, y, c, ...) \
{ \
char buf[256] = {0}; \
posprintf(buf, msg, ##__VA_ARGS__); \
txt_draws(buf, x, y, c); \
}
#endif // TEXT_H
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