Files
asteroids/text.c
2025-10-15 14:21:31 +01:00

118 lines
2.2 KiB
C

#include "text.h"
#include "renderer.h"
#include <assert.h>
#define NELEMS(arr) (sizeof(arr) / sizeof(arr[0]))
#define MAX_LINES 2
#define TEXT_HEIGHT 8
#define TEXT_SCALE 0.025
#define LETTER_WIDTH 3
#define SPACE_WIDTH 1
typedef struct {
unsigned line_count;
unsigned line_lens[MAX_LINES];
vec2_t lines[MAX_LINES][MAX_VERTS];
} glyph_t;
static const mat3_t text_transform = {
{ TEXT_SCALE, 0, 0 },
{ 0, TEXT_SCALE, 0 },
{ 0, 0, 1 },
};
static const glyph_t font[] = {
['A'] = {
.line_count = 2,
.line_lens = { 3, 2 },
.lines = {
{ { -1, -4 }, { 0, 4 }, { 1, -4 } },
{ { -0.75, -2 }, { 0.75, -2 } },
},
},
['E'] = {
.line_count = 2,
.line_lens = { 4, 2 },
.lines = {
{ { 1, 4 }, { -1, 4 }, { -1, -4 }, { 1, -4 } },
{ { -1, -2 }, { 0, -2 } },
},
},
['G'] = {
.line_count = 1,
.line_lens = { 5 },
.lines = {
{ { 1, 4 }, { -1, 4 }, { -1, -4 }, { 1, -4 }, { 1, -2 } },
},
},
['M'] = {
.line_count = 1,
.line_lens = { 5 },
.lines = {
{ { -1, -4 }, { -1, 4 }, { 0, -4 }, { 1, 4 }, { 1, -4 } },
},
},
['O'] = {
.line_count = 1,
.line_lens = { 5 },
.lines = {
{ { -1, 4 }, { -1, -4 }, { 1, -4 }, { 1, 4 }, { -1, 4 } },
},
},
['R'] = {
.line_count = 1,
.line_lens = { 6 },
.lines = {
{
{ -1, -4 }, { -1, 4 }, { 1, 4 },
{ 1, -2 }, { -1, -2 }, { 1, -4 },
},
},
},
['V'] = {
.line_count = 1,
.line_lens = { 3 },
.lines = {
{ { -1, 4 }, { 0, -4 }, { 1, 4 } },
},
},
};
void text_draw(const char *s)
{
int width = 0;
for (const char *p = s; *p != '\0'; ++p)
width += *p == ' ' ? SPACE_WIDTH : LETTER_WIDTH;
--width;
const vec2_t bg_size = {
.x = TEXT_SCALE * (width + 2),
.y = TEXT_SCALE * (TEXT_HEIGHT + 2),
};
renderer_clear_rect((vec2_t) { 0, 0 }, bg_size);
int x = -width / 2 + 1;
for (const char *p = s; *p != '\0'; ++p) {
if (*p == ' ') {
x += SPACE_WIDTH;
} else {
const unsigned c = (unsigned)*p;
assert(c < NELEMS(font) && font[c].line_count != 0);
const glyph_t *g = font + c;
const vec2_t t = { .x = x };
const mat3_t m
= mat3_mul_mat3(text_transform, mat3_translation(t));
for (unsigned i = 0; i < g->line_count; ++i)
renderer_draw(g->lines[i], g->line_lens[i], m, false);
x += LETTER_WIDTH;
}
}
}