Improve texture atlas generation

diff --git a/src/tile.cpp b/src/tile.cpp
index 73c286fb3e3488cccc66ba22aae5aa9e758112bf..9497c4ca9ac2e8b6a3c1d4c009bad35c02a0906b 100644 (file)
--- a/src/tile.cpp
+++ b/src/tile.cpp
@@ -830,7 +830,10 @@ void TextureSource::buildMainAtlas(class IGameDef *gamedef)
        JMutexAutoLock lock(m_atlaspointer_cache_mutex);
 
        // Create an image of the right size
-       core::dimension2d<u32> atlas_dim(1024,1024);
+       core::dimension2d<u32> max_dim = driver->getMaxTextureSize();
+       core::dimension2d<u32> atlas_dim(2048,2048);
+       atlas_dim.Width  = MYMIN(atlas_dim.Width,  max_dim.Width);
+       atlas_dim.Height = MYMIN(atlas_dim.Height, max_dim.Height);
        video::IImage *atlas_img =
                        driver->createImage(video::ECF_A8R8G8B8, atlas_dim);
        //assert(atlas_img);
@@ -871,16 +874,17 @@ void TextureSource::buildMainAtlas(class IGameDef *gamedef)
        infostream<<std::endl;
 
        // Padding to disallow texture bleeding
+       // (16 needed if mipmapping is used; otherwise less will work too)
        s32 padding = 16;
-
-       s32 column_width = 256;
        s32 column_padding = 16;
+       s32 column_width = 256; // Space for 16 pieces of 16x16 textures
 
        /*
                First pass: generate almost everything
        */
        core::position2d<s32> pos_in_atlas(0,0);
        
+       pos_in_atlas.X = column_padding;
        pos_in_atlas.Y = padding;
 
        for(core::map<std::string, bool>::Iterator
@@ -901,8 +905,8 @@ void TextureSource::buildMainAtlas(class IGameDef *gamedef)
 
                core::dimension2d<u32> dim = img2->getDimension();
 
-               // Don't add to atlas if image is large
-               core::dimension2d<u32> max_size_in_atlas(32,32);
+               // Don't add to atlas if image is too large
+               core::dimension2d<u32> max_size_in_atlas(64,64);
                if(dim.Width > max_size_in_atlas.Width
                || dim.Height > max_size_in_atlas.Height)
                {
@@ -914,14 +918,14 @@ void TextureSource::buildMainAtlas(class IGameDef *gamedef)
                // Wrap columns and stop making atlas if atlas is full
                if(pos_in_atlas.Y + dim.Height > atlas_dim.Height)
                {
-                       if(pos_in_atlas.X > (s32)atlas_dim.Width - 256 - padding){
+                       if(pos_in_atlas.X > (s32)atlas_dim.Width - column_width - column_padding){
                                errorstream<<"TextureSource::buildMainAtlas(): "
                                                <<"Atlas is full, not adding more textures."
                                                <<std::endl;
                                break;
                        }
                        pos_in_atlas.Y = padding;
-                       pos_in_atlas.X += column_width + column_padding;
+                       pos_in_atlas.X += column_width + column_padding*2;
                }
                
                /*infostream<<"TextureSource::buildMainAtlas(): Adding \""<<name
@@ -967,6 +971,29 @@ void TextureSource::buildMainAtlas(class IGameDef *gamedef)
                        atlas_img->setPixel(x,dst_y,c);
                }
 
+               for(u32 side=0; side<2; side++) // left and right
+               for(s32 x0=0; x0<column_padding; x0++)
+               for(s32 y0=-padding; y0<(s32)dim.Height+padding; y0++)
+               {
+                       s32 dst_x;
+                       s32 src_x;
+                       if(side==0)
+                       {
+                               dst_x = x0 + pos_in_atlas.X + dim.Width*xwise_tiling;
+                               src_x = pos_in_atlas.X + dim.Width*xwise_tiling - 1;
+                       }
+                       else
+                       {
+                               dst_x = -x0 + pos_in_atlas.X-1;
+                               src_x = pos_in_atlas.X;
+                       }
+                       s32 y = y0 + pos_in_atlas.Y;
+                       s32 src_y = MYMAX(pos_in_atlas.Y, MYMIN(pos_in_atlas.Y + dim.Height - 1, y));
+                       s32 dst_y = y;
+                       video::SColor c = atlas_img->getPixel(src_x, src_y);
+                       atlas_img->setPixel(dst_x,dst_y,c);
+               }
+
                img2->drop();
 
                /*