Framed glasslike: Don't use cuboids to draw glass faces (#7828)

Previously, each glass face used drawAutoLightedCuboid() to draw a
flat cuboid. This also disallowed backface culling, making the
backface culling inconsistent with 'glasslike'.

Use code from 'glasslike' to draw glass faces using drawQuad().

Remove long-unknown top/bottom textures feature:
Makes the code simpler and cleaner.
Never documented, long-unknown and not of much use.

diff --git a/src/content_mapblock.cpp b/src/content_mapblock.cpp
index 6572e52f2a31525a2a34b7b93c090dcd9d454a38..4a0df617142c5c36d02cf541ce5eb5d19a2aa0dd 100644 (file)
--- a/src/content_mapblock.cpp
+++ b/src/content_mapblock.cpp
@@ -697,20 +697,12 @@ void MapblockMeshGenerator::drawGlasslikeFramedNode()
        for (int face = 0; face < 6; face++)
                getTile(g_6dirs[face], &tiles[face]);
 
+       if (!data->m_smooth_lighting)
+               color = encode_light(light, f->light_source);
+
        TileSpec glass_tiles[6];
-       if (tiles[1].layers[0].texture &&
-                       tiles[2].layers[0].texture &&
-                       tiles[3].layers[0].texture) {
-               glass_tiles[0] = tiles[4];
-               glass_tiles[1] = tiles[2];
-               glass_tiles[2] = tiles[4];
-               glass_tiles[3] = tiles[4];
-               glass_tiles[4] = tiles[3];
-               glass_tiles[5] = tiles[4];
-       } else {
-               for (auto &glass_tile : glass_tiles)
-                       glass_tile = tiles[4];
-       }
+       for (auto &glass_tile : glass_tiles)
+               glass_tile = tiles[4];
 
        u8 param2 = n.getParam2();
        bool H_merge = !(param2 & 128);
@@ -735,14 +727,6 @@ void MapblockMeshGenerator::drawGlasslikeFramedNode()
                aabb3f(-a, -a, -a,  a, -b, -b), // z-
                aabb3f(-a,  b, -a,  a,  a, -b), // z-
        };
-       static const aabb3f glass_faces[6] = {
-               aabb3f(-g, -g,  g,  g,  g,  g), // z+
-               aabb3f(-g,  g, -g,  g,  g,  g), // y+
-               aabb3f( g, -g, -g,  g,  g,  g), // x+
-               aabb3f(-g, -g, -g,  g,  g, -g), // z-
-               aabb3f(-g, -g, -g,  g, -g,  g), // y-
-               aabb3f(-g, -g, -g, -g,  g,  g), // x-
-       };
 
        // tables of neighbour (connect if same type and merge allowed),
        // checked with g_26dirs
@@ -800,8 +784,34 @@ void MapblockMeshGenerator::drawGlasslikeFramedNode()
        for (int face = 0; face < 6; face++) {
                if (nb[face])
                        continue;
+
                tile = glass_tiles[face];
-               drawAutoLightedCuboid(glass_faces[face]);
+               // Face at Z-
+               v3f vertices[4] = {
+                       v3f(-a,  a, -g),
+                       v3f( a,  a, -g),
+                       v3f( a, -a, -g),
+                       v3f(-a, -a, -g),
+               };
+
+               for (v3f &vertex : vertices) {
+                       switch (face) {
+                               case D6D_ZP:
+                                       vertex.rotateXZBy(180); break;
+                               case D6D_YP:
+                                       vertex.rotateYZBy( 90); break;
+                               case D6D_XP:
+                                       vertex.rotateXZBy( 90); break;
+                               case D6D_ZN:
+                                       vertex.rotateXZBy(  0); break;
+                               case D6D_YN:
+                                       vertex.rotateYZBy(-90); break;
+                               case D6D_XN:
+                                       vertex.rotateXZBy(-90); break;
+                       }
+               }
+               v3s16 dir = g_6dirs[face];
+               drawQuad(vertices, dir);
        }
 
        // Optionally render internal liquid level defined by param2