minetest/src/client/minimap.cpp
Pierre-Yves Rollo 81c66d6efb Minimap as HUD element with API control
Features:
 * Define Minimap available modes (surface/radar, scale) from Lua, using player:set_minimap_modes()
 * New HUD elements for displaying minimap with custom size and placing
 * New minimap mode for displaying a texture instead of the map
2020-10-04 15:24:34 +02:00

744 lines
20 KiB
C++

/*
Minetest
Copyright (C) 2010-2015 celeron55, Perttu Ahola <celeron55@gmail.com>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License along
with this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include "minimap.h"
#include <cmath>
#include "client.h"
#include "clientmap.h"
#include "settings.h"
#include "shader.h"
#include "mapblock.h"
#include "client/renderingengine.h"
#include "gettext.h"
////
//// MinimapUpdateThread
////
MinimapUpdateThread::~MinimapUpdateThread()
{
for (auto &it : m_blocks_cache) {
delete it.second;
}
for (auto &q : m_update_queue) {
delete q.data;
}
}
bool MinimapUpdateThread::pushBlockUpdate(v3s16 pos, MinimapMapblock *data)
{
MutexAutoLock lock(m_queue_mutex);
// Find if block is already in queue.
// If it is, update the data and quit.
for (QueuedMinimapUpdate &q : m_update_queue) {
if (q.pos == pos) {
delete q.data;
q.data = data;
return false;
}
}
// Add the block
QueuedMinimapUpdate q;
q.pos = pos;
q.data = data;
m_update_queue.push_back(q);
return true;
}
bool MinimapUpdateThread::popBlockUpdate(QueuedMinimapUpdate *update)
{
MutexAutoLock lock(m_queue_mutex);
if (m_update_queue.empty())
return false;
*update = m_update_queue.front();
m_update_queue.pop_front();
return true;
}
void MinimapUpdateThread::enqueueBlock(v3s16 pos, MinimapMapblock *data)
{
pushBlockUpdate(pos, data);
deferUpdate();
}
void MinimapUpdateThread::doUpdate()
{
QueuedMinimapUpdate update;
while (popBlockUpdate(&update)) {
if (update.data) {
// Swap two values in the map using single lookup
std::pair<std::map<v3s16, MinimapMapblock*>::iterator, bool>
result = m_blocks_cache.insert(std::make_pair(update.pos, update.data));
if (!result.second) {
delete result.first->second;
result.first->second = update.data;
}
} else {
std::map<v3s16, MinimapMapblock *>::iterator it;
it = m_blocks_cache.find(update.pos);
if (it != m_blocks_cache.end()) {
delete it->second;
m_blocks_cache.erase(it);
}
}
}
if (data->map_invalidated && (
data->mode.type == MINIMAP_TYPE_RADAR ||
data->mode.type == MINIMAP_TYPE_SURFACE)) {
getMap(data->pos, data->mode.map_size, data->mode.scan_height);
data->map_invalidated = false;
}
}
void MinimapUpdateThread::getMap(v3s16 pos, s16 size, s16 height)
{
v3s16 pos_min(pos.X - size / 2, pos.Y - height / 2, pos.Z - size / 2);
v3s16 pos_max(pos_min.X + size - 1, pos.Y + height / 2, pos_min.Z + size - 1);
v3s16 blockpos_min = getNodeBlockPos(pos_min);
v3s16 blockpos_max = getNodeBlockPos(pos_max);
// clear the map
for (int z = 0; z < size; z++)
for (int x = 0; x < size; x++) {
MinimapPixel &mmpixel = data->minimap_scan[x + z * size];
mmpixel.air_count = 0;
mmpixel.height = 0;
mmpixel.n = MapNode(CONTENT_AIR);
}
// draw the map
v3s16 blockpos;
for (blockpos.Z = blockpos_min.Z; blockpos.Z <= blockpos_max.Z; ++blockpos.Z)
for (blockpos.Y = blockpos_min.Y; blockpos.Y <= blockpos_max.Y; ++blockpos.Y)
for (blockpos.X = blockpos_min.X; blockpos.X <= blockpos_max.X; ++blockpos.X) {
std::map<v3s16, MinimapMapblock *>::const_iterator pblock =
m_blocks_cache.find(blockpos);
if (pblock == m_blocks_cache.end())
continue;
const MinimapMapblock &block = *pblock->second;
v3s16 block_node_min(blockpos * MAP_BLOCKSIZE);
v3s16 block_node_max(block_node_min + MAP_BLOCKSIZE - 1);
// clip
v3s16 range_min = componentwise_max(block_node_min, pos_min);
v3s16 range_max = componentwise_min(block_node_max, pos_max);
v3s16 pos;
pos.Y = range_min.Y;
for (pos.Z = range_min.Z; pos.Z <= range_max.Z; ++pos.Z)
for (pos.X = range_min.X; pos.X <= range_max.X; ++pos.X) {
v3s16 inblock_pos = pos - block_node_min;
const MinimapPixel &in_pixel =
block.data[inblock_pos.Z * MAP_BLOCKSIZE + inblock_pos.X];
v3s16 inmap_pos = pos - pos_min;
MinimapPixel &out_pixel =
data->minimap_scan[inmap_pos.X + inmap_pos.Z * size];
out_pixel.air_count += in_pixel.air_count;
if (in_pixel.n.param0 != CONTENT_AIR) {
out_pixel.n = in_pixel.n;
out_pixel.height = inmap_pos.Y + in_pixel.height;
}
}
}
}
////
//// Mapper
////
Minimap::Minimap(Client *client)
{
this->client = client;
this->driver = RenderingEngine::get_video_driver();
this->m_tsrc = client->getTextureSource();
this->m_shdrsrc = client->getShaderSource();
this->m_ndef = client->getNodeDefManager();
m_angle = 0.f;
m_current_mode_index = 0;
// Initialize static settings
m_enable_shaders = g_settings->getBool("enable_shaders");
m_surface_mode_scan_height =
g_settings->getBool("minimap_double_scan_height") ? 256 : 128;
// Initialize minimap modes
addMode(MINIMAP_TYPE_OFF);
addMode(MINIMAP_TYPE_SURFACE, 256);
addMode(MINIMAP_TYPE_SURFACE, 128);
addMode(MINIMAP_TYPE_SURFACE, 64);
addMode(MINIMAP_TYPE_RADAR, 512);
addMode(MINIMAP_TYPE_RADAR, 256);
addMode(MINIMAP_TYPE_RADAR, 128);
// Initialize minimap data
data = new MinimapData;
data->map_invalidated = true;
data->minimap_shape_round = g_settings->getBool("minimap_shape_round");
// Get round minimap textures
data->minimap_mask_round = driver->createImage(
m_tsrc->getTexture("minimap_mask_round.png"),
core::position2d<s32>(0, 0),
core::dimension2d<u32>(MINIMAP_MAX_SX, MINIMAP_MAX_SY));
data->minimap_overlay_round = m_tsrc->getTexture("minimap_overlay_round.png");
// Get square minimap textures
data->minimap_mask_square = driver->createImage(
m_tsrc->getTexture("minimap_mask_square.png"),
core::position2d<s32>(0, 0),
core::dimension2d<u32>(MINIMAP_MAX_SX, MINIMAP_MAX_SY));
data->minimap_overlay_square = m_tsrc->getTexture("minimap_overlay_square.png");
// Create player marker texture
data->player_marker = m_tsrc->getTexture("player_marker.png");
// Create object marker texture
data->object_marker_red = m_tsrc->getTexture("object_marker_red.png");
setModeIndex(0);
// Create mesh buffer for minimap
m_meshbuffer = getMinimapMeshBuffer();
// Initialize and start thread
m_minimap_update_thread = new MinimapUpdateThread();
m_minimap_update_thread->data = data;
m_minimap_update_thread->start();
}
Minimap::~Minimap()
{
m_minimap_update_thread->stop();
m_minimap_update_thread->wait();
m_meshbuffer->drop();
data->minimap_mask_round->drop();
data->minimap_mask_square->drop();
driver->removeTexture(data->texture);
driver->removeTexture(data->heightmap_texture);
driver->removeTexture(data->minimap_overlay_round);
driver->removeTexture(data->minimap_overlay_square);
driver->removeTexture(data->object_marker_red);
delete data;
delete m_minimap_update_thread;
}
void Minimap::addBlock(v3s16 pos, MinimapMapblock *data)
{
m_minimap_update_thread->enqueueBlock(pos, data);
}
void Minimap::toggleMinimapShape()
{
MutexAutoLock lock(m_mutex);
data->minimap_shape_round = !data->minimap_shape_round;
g_settings->setBool("minimap_shape_round", data->minimap_shape_round);
m_minimap_update_thread->deferUpdate();
}
void Minimap::setMinimapShape(MinimapShape shape)
{
MutexAutoLock lock(m_mutex);
if (shape == MINIMAP_SHAPE_SQUARE)
data->minimap_shape_round = false;
else if (shape == MINIMAP_SHAPE_ROUND)
data->minimap_shape_round = true;
g_settings->setBool("minimap_shape_round", data->minimap_shape_round);
m_minimap_update_thread->deferUpdate();
}
MinimapShape Minimap::getMinimapShape()
{
if (data->minimap_shape_round) {
return MINIMAP_SHAPE_ROUND;
}
return MINIMAP_SHAPE_SQUARE;
}
void Minimap::setModeIndex(size_t index)
{
MutexAutoLock lock(m_mutex);
if (index < m_modes.size()) {
data->mode = m_modes[index];
m_current_mode_index = index;
} else {
data->mode = MinimapModeDef{MINIMAP_TYPE_OFF, N_("Minimap hidden"), 0, 0, ""};
m_current_mode_index = 0;
}
data->map_invalidated = true;
if (m_minimap_update_thread)
m_minimap_update_thread->deferUpdate();
}
void Minimap::addMode(MinimapModeDef mode)
{
// Check validity
if (mode.type == MINIMAP_TYPE_TEXTURE) {
if (mode.texture.empty())
return;
if (mode.scale < 1)
mode.scale = 1;
}
int zoom = -1;
// Build a default standard label
if (mode.label == "") {
switch (mode.type) {
case MINIMAP_TYPE_OFF:
mode.label = N_("Minimap hidden");
break;
case MINIMAP_TYPE_SURFACE:
mode.label = N_("Minimap in surface mode, Zoom x%d");
if (mode.map_size > 0)
zoom = 256 / mode.map_size;
break;
case MINIMAP_TYPE_RADAR:
mode.label = N_("Minimap in radar mode, Zoom x%d");
if (mode.map_size > 0)
zoom = 512 / mode.map_size;
break;
case MINIMAP_TYPE_TEXTURE:
mode.label = N_("Minimap in texture mode");
break;
default:
break;
}
}
if (zoom >= 0) {
char label_buf[1024];
porting::mt_snprintf(label_buf, sizeof(label_buf),
mode.label.c_str(), zoom);
mode.label = label_buf;
}
m_modes.push_back(mode);
}
void Minimap::addMode(MinimapType type, u16 size, std::string label,
std::string texture, u16 scale)
{
MinimapModeDef mode;
mode.type = type;
mode.label = label;
mode.map_size = size;
mode.texture = texture;
mode.scale = scale;
switch (type) {
case MINIMAP_TYPE_SURFACE:
mode.scan_height = m_surface_mode_scan_height;
break;
case MINIMAP_TYPE_RADAR:
mode.scan_height = 32;
break;
default:
mode.scan_height = 0;
}
addMode(mode);
}
void Minimap::nextMode()
{
if (m_modes.empty())
return;
m_current_mode_index++;
if (m_current_mode_index >= m_modes.size())
m_current_mode_index = 0;
setModeIndex(m_current_mode_index);
}
void Minimap::setPos(v3s16 pos)
{
bool do_update = false;
{
MutexAutoLock lock(m_mutex);
if (pos != data->old_pos) {
data->old_pos = data->pos;
data->pos = pos;
do_update = true;
}
}
if (do_update)
m_minimap_update_thread->deferUpdate();
}
void Minimap::setAngle(f32 angle)
{
m_angle = angle;
}
void Minimap::blitMinimapPixelsToImageRadar(video::IImage *map_image)
{
video::SColor c(240, 0, 0, 0);
for (s16 x = 0; x < data->mode.map_size; x++)
for (s16 z = 0; z < data->mode.map_size; z++) {
MinimapPixel *mmpixel = &data->minimap_scan[x + z * data->mode.map_size];
if (mmpixel->air_count > 0)
c.setGreen(core::clamp(core::round32(32 + mmpixel->air_count * 8), 0, 255));
else
c.setGreen(0);
map_image->setPixel(x, data->mode.map_size - z - 1, c);
}
}
void Minimap::blitMinimapPixelsToImageSurface(
video::IImage *map_image, video::IImage *heightmap_image)
{
// This variable creation/destruction has a 1% cost on rendering minimap
video::SColor tilecolor;
for (s16 x = 0; x < data->mode.map_size; x++)
for (s16 z = 0; z < data->mode.map_size; z++) {
MinimapPixel *mmpixel = &data->minimap_scan[x + z * data->mode.map_size];
const ContentFeatures &f = m_ndef->get(mmpixel->n);
const TileDef *tile = &f.tiledef[0];
// Color of the 0th tile (mostly this is the topmost)
if(tile->has_color)
tilecolor = tile->color;
else
mmpixel->n.getColor(f, &tilecolor);
tilecolor.setRed(tilecolor.getRed() * f.minimap_color.getRed() / 255);
tilecolor.setGreen(tilecolor.getGreen() * f.minimap_color.getGreen() / 255);
tilecolor.setBlue(tilecolor.getBlue() * f.minimap_color.getBlue() / 255);
tilecolor.setAlpha(240);
map_image->setPixel(x, data->mode.map_size - z - 1, tilecolor);
u32 h = mmpixel->height;
heightmap_image->setPixel(x,data->mode.map_size - z - 1,
video::SColor(255, h, h, h));
}
}
video::ITexture *Minimap::getMinimapTexture()
{
// update minimap textures when new scan is ready
if (data->map_invalidated && data->mode.type != MINIMAP_TYPE_TEXTURE)
return data->texture;
// create minimap and heightmap images in memory
core::dimension2d<u32> dim(data->mode.map_size, data->mode.map_size);
video::IImage *map_image = driver->createImage(video::ECF_A8R8G8B8, dim);
video::IImage *heightmap_image = driver->createImage(video::ECF_A8R8G8B8, dim);
video::IImage *minimap_image = driver->createImage(video::ECF_A8R8G8B8,
core::dimension2d<u32>(MINIMAP_MAX_SX, MINIMAP_MAX_SY));
// Blit MinimapPixels to images
switch(data->mode.type) {
case MINIMAP_TYPE_OFF:
break;
case MINIMAP_TYPE_SURFACE:
blitMinimapPixelsToImageSurface(map_image, heightmap_image);
break;
case MINIMAP_TYPE_RADAR:
blitMinimapPixelsToImageRadar(map_image);
break;
case MINIMAP_TYPE_TEXTURE:
// Want to use texture source, to : 1 find texture, 2 cache it
video::ITexture* texture = m_tsrc->getTexture(data->mode.texture);
video::IImage* image = driver->createImageFromData(
texture->getColorFormat(), texture->getSize(), texture->lock(), true, false);
texture->unlock();
auto dim = image->getDimension();
map_image->fill(video::SColor(255, 0, 0, 0));
image->copyTo(map_image,
irr::core::vector2d<int> {
((data->mode.map_size - (static_cast<int>(dim.Width))) >> 1)
- data->pos.X / data->mode.scale,
((data->mode.map_size - (static_cast<int>(dim.Height))) >> 1)
+ data->pos.Z / data->mode.scale
});
image->drop();
}
map_image->copyToScaling(minimap_image);
map_image->drop();
video::IImage *minimap_mask = data->minimap_shape_round ?
data->minimap_mask_round : data->minimap_mask_square;
if (minimap_mask) {
for (s16 y = 0; y < MINIMAP_MAX_SY; y++)
for (s16 x = 0; x < MINIMAP_MAX_SX; x++) {
const video::SColor &mask_col = minimap_mask->getPixel(x, y);
if (!mask_col.getAlpha())
minimap_image->setPixel(x, y, video::SColor(0,0,0,0));
}
}
if (data->texture)
driver->removeTexture(data->texture);
if (data->heightmap_texture)
driver->removeTexture(data->heightmap_texture);
data->texture = driver->addTexture("minimap__", minimap_image);
data->heightmap_texture =
driver->addTexture("minimap_heightmap__", heightmap_image);
minimap_image->drop();
heightmap_image->drop();
data->map_invalidated = true;
return data->texture;
}
v3f Minimap::getYawVec()
{
if (data->minimap_shape_round) {
return v3f(
std::cos(m_angle * core::DEGTORAD),
std::sin(m_angle * core::DEGTORAD),
1.0);
}
return v3f(1.0, 0.0, 1.0);
}
scene::SMeshBuffer *Minimap::getMinimapMeshBuffer()
{
scene::SMeshBuffer *buf = new scene::SMeshBuffer();
buf->Vertices.set_used(4);
buf->Indices.set_used(6);
static const video::SColor c(255, 255, 255, 255);
buf->Vertices[0] = video::S3DVertex(-1, -1, 0, 0, 0, 1, c, 0, 1);
buf->Vertices[1] = video::S3DVertex(-1, 1, 0, 0, 0, 1, c, 0, 0);
buf->Vertices[2] = video::S3DVertex( 1, 1, 0, 0, 0, 1, c, 1, 0);
buf->Vertices[3] = video::S3DVertex( 1, -1, 0, 0, 0, 1, c, 1, 1);
buf->Indices[0] = 0;
buf->Indices[1] = 1;
buf->Indices[2] = 2;
buf->Indices[3] = 2;
buf->Indices[4] = 3;
buf->Indices[5] = 0;
return buf;
}
void Minimap::drawMinimap()
{
// Non hud managed minimap drawing (legacy minimap)
v2u32 screensize = RenderingEngine::get_instance()->getWindowSize();
const u32 size = 0.25 * screensize.Y;
drawMinimap(core::rect<s32>(
screensize.X - size - 10, 10,
screensize.X - 10, size + 10));
}
void Minimap::drawMinimap(core::rect<s32> rect) {
video::ITexture *minimap_texture = getMinimapTexture();
if (!minimap_texture)
return;
if (data->mode.type == MINIMAP_TYPE_OFF)
return;
updateActiveMarkers();
core::rect<s32> oldViewPort = driver->getViewPort();
core::matrix4 oldProjMat = driver->getTransform(video::ETS_PROJECTION);
core::matrix4 oldViewMat = driver->getTransform(video::ETS_VIEW);
driver->setViewPort(rect);
driver->setTransform(video::ETS_PROJECTION, core::matrix4());
driver->setTransform(video::ETS_VIEW, core::matrix4());
core::matrix4 matrix;
matrix.makeIdentity();
video::SMaterial &material = m_meshbuffer->getMaterial();
material.setFlag(video::EMF_TRILINEAR_FILTER, true);
material.Lighting = false;
material.TextureLayer[0].Texture = minimap_texture;
material.TextureLayer[1].Texture = data->heightmap_texture;
if (m_enable_shaders && data->mode.type == MINIMAP_TYPE_SURFACE) {
u16 sid = m_shdrsrc->getShader("minimap_shader", 1, 1);
material.MaterialType = m_shdrsrc->getShaderInfo(sid).material;
} else {
material.MaterialType = video::EMT_TRANSPARENT_ALPHA_CHANNEL;
}
if (data->minimap_shape_round)
matrix.setRotationDegrees(core::vector3df(0, 0, 360 - m_angle));
// Draw minimap
driver->setTransform(video::ETS_WORLD, matrix);
driver->setMaterial(material);
driver->drawMeshBuffer(m_meshbuffer);
// Draw overlay
video::ITexture *minimap_overlay = data->minimap_shape_round ?
data->minimap_overlay_round : data->minimap_overlay_square;
material.TextureLayer[0].Texture = minimap_overlay;
material.MaterialType = video::EMT_TRANSPARENT_ALPHA_CHANNEL;
driver->setMaterial(material);
driver->drawMeshBuffer(m_meshbuffer);
// Draw player marker on minimap
if (data->minimap_shape_round) {
matrix.setRotationDegrees(core::vector3df(0, 0, 0));
} else {
matrix.setRotationDegrees(core::vector3df(0, 0, m_angle));
}
material.TextureLayer[0].Texture = data->player_marker;
driver->setTransform(video::ETS_WORLD, matrix);
driver->setMaterial(material);
driver->drawMeshBuffer(m_meshbuffer);
// Reset transformations
driver->setTransform(video::ETS_VIEW, oldViewMat);
driver->setTransform(video::ETS_PROJECTION, oldProjMat);
driver->setViewPort(oldViewPort);
// Draw player markers
v2s32 s_pos(rect.UpperLeftCorner.X, rect.UpperLeftCorner.Y);
core::dimension2di imgsize(data->object_marker_red->getOriginalSize());
core::rect<s32> img_rect(0, 0, imgsize.Width, imgsize.Height);
static const video::SColor col(255, 255, 255, 255);
static const video::SColor c[4] = {col, col, col, col};
f32 sin_angle = std::sin(m_angle * core::DEGTORAD);
f32 cos_angle = std::cos(m_angle * core::DEGTORAD);
s32 marker_size2 = 0.025 * (float)rect.getWidth();;
for (std::list<v2f>::const_iterator
i = m_active_markers.begin();
i != m_active_markers.end(); ++i) {
v2f posf = *i;
if (data->minimap_shape_round) {
f32 t1 = posf.X * cos_angle - posf.Y * sin_angle;
f32 t2 = posf.X * sin_angle + posf.Y * cos_angle;
posf.X = t1;
posf.Y = t2;
}
posf.X = (posf.X + 0.5) * (float)rect.getWidth();
posf.Y = (posf.Y + 0.5) * (float)rect.getHeight();
core::rect<s32> dest_rect(
s_pos.X + posf.X - marker_size2,
s_pos.Y + posf.Y - marker_size2,
s_pos.X + posf.X + marker_size2,
s_pos.Y + posf.Y + marker_size2);
driver->draw2DImage(data->object_marker_red, dest_rect,
img_rect, &dest_rect, &c[0], true);
}
}
void Minimap::updateActiveMarkers()
{
video::IImage *minimap_mask = data->minimap_shape_round ?
data->minimap_mask_round : data->minimap_mask_square;
const std::list<Nametag *> &nametags = client->getCamera()->getNametags();
m_active_markers.clear();
for (Nametag *nametag : nametags) {
v3s16 pos = floatToInt(nametag->parent_node->getAbsolutePosition() +
intToFloat(client->getCamera()->getOffset(), BS), BS);
pos -= data->pos - v3s16(data->mode.map_size / 2,
data->mode.scan_height / 2,
data->mode.map_size / 2);
if (pos.X < 0 || pos.X > data->mode.map_size ||
pos.Y < 0 || pos.Y > data->mode.scan_height ||
pos.Z < 0 || pos.Z > data->mode.map_size) {
continue;
}
pos.X = ((float)pos.X / data->mode.map_size) * MINIMAP_MAX_SX;
pos.Z = ((float)pos.Z / data->mode.map_size) * MINIMAP_MAX_SY;
const video::SColor &mask_col = minimap_mask->getPixel(pos.X, pos.Z);
if (!mask_col.getAlpha()) {
continue;
}
m_active_markers.emplace_back(((float)pos.X / (float)MINIMAP_MAX_SX) - 0.5,
(1.0 - (float)pos.Z / (float)MINIMAP_MAX_SY) - 0.5);
}
}
////
//// MinimapMapblock
////
void MinimapMapblock::getMinimapNodes(VoxelManipulator *vmanip, const v3s16 &pos)
{
for (s16 x = 0; x < MAP_BLOCKSIZE; x++)
for (s16 z = 0; z < MAP_BLOCKSIZE; z++) {
s16 air_count = 0;
bool surface_found = false;
MinimapPixel *mmpixel = &data[z * MAP_BLOCKSIZE + x];
for (s16 y = MAP_BLOCKSIZE -1; y >= 0; y--) {
v3s16 p(x, y, z);
MapNode n = vmanip->getNodeNoEx(pos + p);
if (!surface_found && n.getContent() != CONTENT_AIR) {
mmpixel->height = y;
mmpixel->n = n;
surface_found = true;
} else if (n.getContent() == CONTENT_AIR) {
air_count++;
}
}
if (!surface_found)
mmpixel->n = MapNode(CONTENT_AIR);
mmpixel->air_count = air_count;
}
}