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#include "map.h"
#include "maths.h"
#include <stdlib.h>
int map_size(int w, int h) {
return
sizeof(Map) +
w * h * sizeof(Map_Tile) +
w * h * sizeof(Map_Light_Tile);
}
Map_Tile* map_tiles(Map* m) {
return (Map_Tile*)&m[1];
}
const Map_Tile* map_tilesc(const Map* m) {
return (Map_Tile*)&m[1];
}
Map_Light_Tile* map_light_tiles(Map* m) {
return (Map_Light_Tile*)&map_tiles(m)[m->w * m->h];
}
const Map_Light_Tile* map_light_tilesc(const Map* m) {
return (Map_Light_Tile*)&map_tilesc(m)[m->w * m->h];
}
typedef struct {
Line a, b;
} Ray;
void init_ray(Ray* r, const int* f, const int* t) {
int fa[2], ta[2];
int fb[2], tb[2];
fa[0] = f[0];
fa[1] = f[1];
ta[0] = t[0];
ta[1] = t[1];
fb[0] = f[0];
fb[1] = f[2];
tb[0] = t[0];
tb[1] = t[2];
init_line(&r->a, fa, ta);
init_line(&r->b, fb, tb);
}
void step_ray(Ray* r) {
step_line(&r->a);
while (r->a.x != r->b.x)
step_line(&r->b);
}
void get_ray(const Ray* r, int* d) {
d[0] = r->a.x;
d[1] = r->a.y;
d[2] = r->b.y;
}
int trace_ray(
Map* m,
const int* f,
const int* t
) {
Ray r;
int pos[3], w[3];
init_ray(&r, f, t);
while (1) {
int mp[2], coord;
get_ray(&r, pos);
mp[0] = pos[0] >> fbits;
mp[1] = pos[1] >> fbits;
if (mp[0] < 0) goto end;
if (mp[1] < 0) goto end;
if (mp[0] >= m->w) goto end;
if (mp[1] >= m->h) goto end;
if (pos[2] < 0) { /* hit the floor */
goto end;
}
if (pos[2] >= f1) { /* hit the ceiling */
goto end;
}
coord = mp[0] + mp[1] * m->w;
if (map_tilesc(m)[coord]) {
goto end;
}
step_ray(&r);
}
end:
return vec_dist(w, pos, t, 3) < 2;
}
void init_tile(Map* m, int tx, int ty, Map_Light_Tile* t) {
int i, x, y;
Map_Fragment full = {
{ 0xff, 0xff, 0xff, 0xff },
{ 0xff, 0xff, 0xff, 0xff }, {
{ 0xff, 0xff, 0xff, 0xff },
{ 0xff, 0xff, 0xff, 0xff },
{ 0xff, 0xff, 0xff, 0xff },
{ 0xff, 0xff, 0xff, 0xff },
}};
(void)m;
(void)tx;
(void)ty;
for (i = y = 0; y < map_light_tile_size; y++) {
for (x = 0; x < map_light_tile_size; x++, i++) {
t->fragments[i] = full;
}
}
}
Colour bake_pixel(
Map* m,
Colour src,
const int* fr,
const Map_Light* light,
int tx,
int ty,
int x,
int y,
int side
) {
int to[3];
switch (side) {
case 0: /* ceiling */
to[0] = (tx + x * 32);
to[1] = (ty + y * 32);
to[2] = f1;
break;
case 1: /* floor */
to[0] = (tx + x * 32);
to[1] = (ty + y * 32);
to[2] = 0;
break;
case 2:
to[0] = ty + f1;
to[1] = tx + f1 - x * 32;
to[2] = f1 - (y * 32);
break;
case 3:
to[0] = ty + x * 32;
to[1] = tx + f1;
to[2] = f1 - (y * 32);
break;
case 4:
to[0] = tx + f1;
to[1] = ty + f1 - x * 32;
to[2] = f1 - (y * 32);
break;
case 5:
to[0] = tx + x * 32;
to[1] = ty + f1;
to[2] = f1 - (y * 32);
break;
default: return make_white();
}
if (trace_ray(m, fr, to)) {
int w[3];
int atten = vec_dist(w, fr, to, 3);
atten = mini(
(f1 << fbits) / maxi(1, (atten * atten) >> fbits),
f1
) - 1;
atten = (atten * light->brightness) >> fbits;
return col_add(src, col_scl(
light->c,
(unsigned char)(atten / 2)
));
return make_white();
}
return src;
}
void bake_tile(
Map* m,
int tx,
int ty,
Map_Light_Tile* t,
const Map_Light* light
) {
int i, x, y, fr[3];
tx <<= fbits;
ty <<= fbits;
fr[0] = light->x;
fr[1] = light->y;
fr[2] = light->z;
for (i = y = 0; y < map_light_tile_size; y++) {
for (x = 0; x < map_light_tile_size; x++, i++) {
Map_Fragment* f = &t->fragments[i];
#define bp(t, s) \
f->t = bake_pixel(m, f->t, fr, light, tx, ty, x, y, s);
bp(u, 0);
bp(d, 1);
bp(side[0], 2);
bp(side[1], 3);
bp(side[2], 4);
bp(side[3], 5);
}
}
}
void bake_light(Map* m, const Map_Light* light) {
int x, y, i;
Map_Light_Tile* lt = map_light_tiles(m);
for (i = y = 0; y < m->h; y++) {
for (x = 0; x < m->w; x++, i++) {
bake_tile(m, x, y, <[i], light);
}
}
}
void bake_map(Map* m) {
Map_Light l = { f1 * 2 + 100, f1 * 2, f1/4, f1, { 0xff, 0xff, 0xff, 0xff } };
bake_light(m, &l);
}
const Map_Fragment* sample_map_light(
const Map* m,
int tx,
int ty,
int u,
int v
) {
int coord;
const Map_Light_Tile* t =
&map_light_tilesc(m)[tx + ty * m->w];
int x = (u * map_light_tile_size) >> fbits;
int y = (v * map_light_tile_size) >> fbits;
x &= map_light_tile_size - 1;
y &= map_light_tile_size - 1;
coord = x + y * map_light_tile_size;
return &t->fragments[coord];
}
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