place blocks

internal/world/block.go

@@ -19,7 +19,7 @@ const (
 // BlockAppearance describes basic appearance of a kind of block.
 type BlockAppearance struct {
 	Name        string // A short name, like "stone" or "dirt", used for texture lookups
-	Transparent bool   // Is block transparent?
+	Transparent bool   // Is block transparent, i.e., does not block nearby blocks in rendering?
 	NotSolid    bool   // Is block not solid, i.e., has no hitbox at all? (this makes the zero value reasonable)
 	Light       int    // The light level it emits, 0 is none
 
@@ -72,6 +72,9 @@ type BlockBehaviour interface {
 	//
 	// Return true if this block also changed state, false otherwise.
 	BlockUpdate(position itype.Vec3i, aux int, data itype.Dataset, world *World) bool
+
+	// Break is called when the block is broken by natural means.
+	Break(position itype.Vec3i, aux int, data itype.Dataset, world *World)
 }
 
 type blockBehaviourStatic struct {
@@ -87,6 +90,7 @@ func (b blockBehaviourStatic) Appearance(position itype.Vec3i, aux int, data ity
 func (blockBehaviourStatic) BlockUpdate(position itype.Vec3i, aux int, data itype.Dataset, world *World) bool {
 	return false
 }
+func (blockBehaviourStatic) Break(position itype.Vec3i, aux int, data itype.Dataset, world *World) {}
 
 // BlockBehaviourStatic returns a Static BlockBehaviour that has the given BlockAppearance.
 func BlockBehaviourStatic(app BlockAppearance) BlockBehaviour {
@@ -172,6 +176,9 @@ type Block struct {
 // Appearance is a shortcut for Behaviour.Appearance().
 // It returns the Appearance of the block with the given parameters.
 func (b Block) Appearance(position itype.Vec3i) BlockAppearance {
+	if b.Behaviour == nil {
+		return BlockAppearance{}
+	}
 	app := b.Behaviour.Appearance(position, b.Aux, b.Dataset, b.World)
 	if !app.NotSolid && len(app.Hitbox) == 0 {
 		app.Hitbox = []itype.Boxd{{