static void
put_text (void *tileidx, int row, int startcol, unsigned char *text,
unsigned int textlen, int offset, int len)
{
unsigned char *c = tileidx;
int i;
for (i = 0; i < len; i++)
{
int offset2 = offset + i * 4;
int idx = tex_index (startcol + i, row, TILES_W, 8);
c[idx] = (offset2 >= 0 && offset2 < textlen)
? ascii_to_char[text[offset2]] : 0;
}
DCFlushRange (c, GX_GetTexBufferSize (TILES_W, TILES_H, TILES_FMT, GX_FALSE,
0));
}
// Returns final color
uint8_t raytrace(vec3 pos, vec3 dir, hit* info) {
// Finish early if there's no direction
if (dir.x == 0.0f && dir.y == 0.0f && dir.z == 0.0f) {
goto nohit;
}
vec3 start = pos;
int x = (int) pos.x;
int y = (int) pos.y;
int z = (int) pos.z;
int x_dir = dir.x >= 0.0f ? 1 : -1;
int y_dir = dir.y >= 0.0f ? 1 : -1;
int z_dir = dir.z >= 0.0f ? 1 : -1;
float dx_off = x_dir > 0 ? 1.0f : 0.0f;
float dy_off = y_dir > 0 ? 1.0f : 0.0f;
float dz_off = z_dir > 0 ? 1.0f : 0.0f;
int x_face = x_dir > 0 ? FACE_LEFT : FACE_RIGHT;
int y_face = y_dir > 0 ? FACE_BOTTOM : FACE_TOP;
int z_face = z_dir > 0 ? FACE_BACK : FACE_FRONT;
int face = FACE_TOP;
// Assumption is made that the camera is never outside the world
while (IN_WORLD(x, y, z)) {
// Determine if block is solid
if (get_block(x, y, z) != BLOCK_AIR) {
float dx = start.x - pos.x;
float dy = start.y - pos.y;
float dz = start.z - pos.z;
float dist = dx*dx + dy*dy + dz*dz;
vec3 relPos = pos;
relPos.x -= x;
relPos.y -= y;
relPos.z -= z;
// If hit info is requested, no color computation is done
if (info != NULL) {
int nx, ny, nz;
face_normal(face, &nx, &ny, &nz);
info->hit = true;
info->x = x;
info->y = y;
info->z = z;
info->nx = nx;
info->ny = ny;
info->nz = nz;
info->dist = dist;
return 0;
}
int tex = tex_index(relPos, face);
return ray_color(x, y, z, pos, tex, face);
}
// Remaining distance inside this block given ray direction
float dx = x - pos.x + dx_off;
float dy = y - pos.y + dy_off;
float dz = z - pos.z + dz_off;
// Calculate distance for each dimension
float t1 = dx / dir.x;
float t2 = dy / dir.y;
float t3 = dz / dir.z;
// Find closest hit
if (t1 <= t2 && t1 <= t3) {
pos.x += dx;
pos.y += t1 * dir.y;
pos.z += t1 * dir.z;
x += x_dir;
face = x_face;
}
if (t2 <= t1 && t2 <= t3) {
pos.x += t2 * dir.x;
pos.y += dy;
pos.z += t2 * dir.z;
y += y_dir;
face = y_face;
}
if (t3 <= t1 && t3 <= t2) {
pos.x += t3 * dir.x;
pos.y += t3 * dir.y;
pos.z += dz;
z += z_dir;
face = z_face;
}
}
nohit:
if (info != NULL) {
info->hit = false;
}
// Sky color
return skyColor;
}
