// Generates a simple map for a given image. The image will be positioned at the top-left hand corner of the map.
// tiles_ram_offset is the VRAM address of the first tile. All tiles must be contiguous, in reading order (left to right, top to bottom)
// null_tile_offset is used to fill cells that are outside the image.
// out must be at least 'compute_map_size' bytes long.
void gen_simple_map(char *out, sv tiles_ram_offset, sv null_tile_offset, unsigned int width, unsigned int height)
{
int hcells = compute_cells(width);
if(hcells < 64) hcells = 64;
int vcells = compute_cells(height);
int img_hcells = (width + 7) / 8;
int img_vcells = (height + 7) / 8;
tiles_ram_offset /= 32; // Compute ram offset in cells.
null_tile_offset /= 32;
int x, y;
for(y = 0; y < img_vcells; ++y) {
for(x = 0; x < img_hcells; ++x) {
int cellindex = (x + y * hcells) * 2;
int cellid = x + y * img_hcells + tiles_ram_offset;
out[cellindex] = cellid >> 8;
out[cellindex + 1] = cellid & 0xFF;
}
for(; x < hcells; ++x) {
int cellindex = (x + y * hcells) * 2;
out[cellindex] = null_tile_offset >> 8;
out[cellindex + 1] = null_tile_offset & 0xFF;
}
}
for(; y < vcells; ++y) {
for(x = 0; x < hcells; ++x) {
int cellindex = (x + y * hcells) * 2;
out[cellindex] = null_tile_offset >> 8;
out[cellindex + 1] = null_tile_offset & 0xFF;
}
}
}
sv compute_map_size(unsigned int width, unsigned int height)
{
int hcells = compute_cells(width);
if(hcells < 64) hcells = 64;
int vcells = compute_cells(height);
return hcells * vcells * 2;
}
explicit traits(size_t capacity, double error_rate)
: cells(compute_cells(capacity, error_rate)),
hashes(compute_hashes(capacity, cells)) {}