Add deserts to map generator

diff --git a/src/mapgen.cpp b/src/mapgen.cpp
index d3ba6a973e2d3e4315c46ed4a19d00caf5e4f0ec..1d1d663c097306e39ca046295db0e397af3056e3 100644 (file)
--- a/src/mapgen.cpp
+++ b/src/mapgen.cpp
@@ -102,10 +102,13 @@ static s16 find_stone_level(VoxelManipulator &vmanip, v2s16 p2d,
        u32 i = vmanip.m_area.index(v3s16(p2d.X, y_nodes_max, p2d.Y));
        s16 y;
        content_t c_stone = ndef->getId("mapgen_stone");
+       content_t c_desert_stone = ndef->getId("mapgen_desert_stone");
        for(y=y_nodes_max; y>=y_nodes_min; y--)
        {
                MapNode &n = vmanip.m_data[i];
-               if(n.getContent() == c_stone)
+               content_t c = n.getContent();
+               if(c != CONTENT_IGNORE && (
+                               c == c_stone || c == c_desert_stone))
                        break;
 
                vmanip.m_area.add_y(em, i, -1);
@@ -1282,6 +1285,23 @@ bool get_have_beach(u64 seed, v2s16 p2d)
        return (sandnoise > 0.15);
 }
 
+enum BiomeType
+{
+       BT_NORMAL,
+       BT_DESERT
+};
+
+BiomeType get_biome(u64 seed, v2s16 p2d)
+{
+       // Just do something very simple as for now
+       double d = noise2d_perlin(
+                       0.6+(float)p2d.X/250, 0.2+(float)p2d.Y/250,
+                       seed+9130, 3, 0.50);
+       if(d > 0.2)
+               return BT_DESERT;
+       return BT_NORMAL;
+};
+
 u32 get_blockseed(u64 seed, v3s16 p)
 {
        s32 x=p.X, y=p.Y, z=p.Z;
@@ -1359,6 +1379,12 @@ void make_block(BlockMakeData *data)
 #define CONTENT_VARIABLE(ndef, name)\
        content_t c_##name = ndef->getId("mapgen_" #name);\
        MapNode n_##name(c_##name);
+// Default to something else if was CONTENT_IGNORE
+#define CONTENT_VARIABLE_FALLBACK(name, dname)\
+       if(c_##name == CONTENT_IGNORE){\
+               c_##name = c_##dname;\
+               n_##name = n_##dname;\
+       }
 
        CONTENT_VARIABLE(ndef, stone);
        CONTENT_VARIABLE(ndef, air);
@@ -1375,6 +1401,10 @@ void make_block(BlockMakeData *data)
        CONTENT_VARIABLE(ndef, stone_with_coal);
        CONTENT_VARIABLE(ndef, stone_with_iron);
        CONTENT_VARIABLE(ndef, mese);
+       CONTENT_VARIABLE(ndef, desert_sand);
+       CONTENT_VARIABLE_FALLBACK(desert_sand, sand);
+       CONTENT_VARIABLE(ndef, desert_stone);
+       CONTENT_VARIABLE_FALLBACK(desert_stone, stone);
 
        // Maximum height of the stone surface and obstacles.
        // This is used to guide the cave generation
@@ -1422,6 +1452,7 @@ void make_block(BlockMakeData *data)
                if(surface_y > stone_surface_max_y)
                        stone_surface_max_y = surface_y;
 
+               BiomeType bt = get_biome(data->seed, p2d);
                /*
                        Fill ground with stone
                */
@@ -1431,15 +1462,18 @@ void make_block(BlockMakeData *data)
                        u32 i = vmanip.m_area.index(v3s16(p2d.X, node_min.Y, p2d.Y));
                        for(s16 y=node_min.Y; y<=node_max.Y; y++)
                        {
-                               if(y <= surface_y){
-                                       if(vmanip.m_data[i].getContent() == CONTENT_IGNORE)
-                                               vmanip.m_data[i] = MapNode(c_stone);
-                               } else if(y <= WATER_LEVEL){
-                                       vmanip.m_data[i] = MapNode(c_water_source);
-                               } else {
-                                       vmanip.m_data[i] = MapNode(c_air);
+                               if(vmanip.m_data[i].getContent() == CONTENT_IGNORE){
+                                       if(y <= surface_y){
+                                               if(y > WATER_LEVEL && bt == BT_DESERT)
+                                                       vmanip.m_data[i] = n_desert_stone;
+                                               else
+                                                       vmanip.m_data[i] = n_stone;
+                                       } else if(y <= WATER_LEVEL){
+                                               vmanip.m_data[i] = MapNode(c_water_source);
+                                       } else {
+                                               vmanip.m_data[i] = MapNode(c_air);
+                                       }
                                }
-
                                vmanip.m_area.add_y(em, i, 1);
                        }
                }
@@ -1481,6 +1515,10 @@ void make_block(BlockMakeData *data)
        PseudoRandom ps(blockseed+21343);
        if(ps.range(1, 4) == 1)
                bruises_count = ps.range(0, ps.range(0, 2));
+       if(get_biome(data->seed, v2s16(node_min.X, node_min.Y)) == BT_DESERT){
+               caves_count /= 3;
+               bruises_count /= 3;
+       }
        for(u32 jj=0; jj<caves_count+bruises_count; jj++)
        {
                bool large_cave = (jj >= caves_count);
@@ -1753,6 +1791,9 @@ void make_block(BlockMakeData *data)
                v2s16 p2d = v2s16(x,z);
                
                MapNode addnode(c_dirt);
+               BiomeType bt = get_biome(data->seed, p2d);
+               if(bt == BT_DESERT)
+                       addnode = MapNode(c_desert_sand);
 
                // Randomize mud amount
                s16 mud_add_amount = get_mud_add_amount(data->seed, p2d) / 2.0 + 0.5;
@@ -1766,10 +1807,16 @@ void make_block(BlockMakeData *data)
                if(mud_add_amount <= 0){
                        mud_add_amount = 1 - mud_add_amount;
                        addnode = MapNode(c_gravel);
-               } else if(get_have_beach(data->seed, p2d) &&
+               } else if(bt == BT_NORMAL && get_have_beach(data->seed, p2d) &&
                                surface_y + mud_add_amount <= WATER_LEVEL+2){
                        addnode = MapNode(c_sand);
                }
+               
+               if(bt == BT_DESERT){
+                       if(surface_y > 20){
+                               mud_add_amount = MYMAX(0, mud_add_amount - (surface_y - 20)/5);
+                       }
+               }
 
                /*
                        If topmost node is grass, change it to mud.
@@ -1812,6 +1859,7 @@ void make_block(BlockMakeData *data)
        /*
                Add blobs of dirt and gravel underground
        */
+       if(get_biome(data->seed, v2s16(node_min.X, node_min.Y)) == BT_NORMAL)
        {
        PseudoRandom pr(blockseed+983);
        for(int i=0; i<volume_nodes/10/10/10; i++)