Initial files

src/mapnode.h

@@ -0,0 +1,280 @@
+/*
+(c) 2010 Perttu Ahola <celeron55@gmail.com>
+*/
+
+#ifndef MAPNODE_HEADER
+#define MAPNODE_HEADER
+
+#include <iostream>
+#include "common_irrlicht.h"
+#include "light.h"
+#include "utility.h"
+#include "exceptions.h"
+#include "serialization.h"
+
+// Size of node in rendering units
+#define BS 10
+
+#define MATERIALS_COUNT 256
+
+// This is completely ignored. It doesn't create faces with anything.
+#define MATERIAL_IGNORE 255
+// This is the common material through which the player can walk
+// and which is transparent to light
+#define MATERIAL_AIR 254
+
+/*
+	Materials-todo:
+
+	GRAVEL
+	  - Dynamics of gravel: if there is a drop of more than two
+	    blocks on any side, it will drop in there. Is this doable?
+*/
+
+enum Material
+{
+	MATERIAL_STONE=0,
+
+	MATERIAL_GRASS,
+
+	/*
+		For water, the param is water pressure. 0...127.
+		TODO: No, at least the lowest nibble is used for lighting.
+		
+		- Water will be a bit like light, but with different flow
+		  behavior.
+		- Water blocks will fall down if there is empty space below.
+		- If there is water below, the pressure of the block below is
+		  the pressure of the current block + 1, or higher.
+		- If there is any pressure in a horizontally neighboring
+		  block, a water block will try to move away from it.
+		- If there is >=2 of pressure in a block below, water will
+		  try to move upwards.
+		- NOTE: To keep large operations fast, we have to keep a
+		        cache of the water-air-surfaces, just like with light
+	*/
+	MATERIAL_WATER,
+
+	MATERIAL_LIGHT,
+
+	MATERIAL_TREE,
+	MATERIAL_LEAVES,
+
+	MATERIAL_GRASS_FOOTSTEPS,
+	
+	MATERIAL_MESE,
+	
+	// This is set to the number of the actual values in this enum
+	USEFUL_MATERIAL_COUNT
+};
+
+/*
+	If true, the material allows light propagation and brightness is stored
+	in param.
+*/
+inline bool light_propagates_material(u8 m)
+{
+	return (m == MATERIAL_AIR || m == MATERIAL_LIGHT || m == MATERIAL_WATER);
+}
+
+/*
+	If true, the material allows lossless sunlight propagation.
+*/
+inline bool sunlight_propagates_material(u8 m)
+{
+	return (m == MATERIAL_AIR);
+}
+
+/*
+	On a node-node surface, the material of the node with higher solidness
+	is used for drawing.
+	0: Invisible
+	1: Transparent
+	2: Opaque
+*/
+inline u8 material_solidness(u8 m)
+{
+	if(m == MATERIAL_AIR)
+		return 0;
+	if(m == MATERIAL_WATER)
+		return 1;
+	return 2;
+}
+
+/*
+	Nodes make a face if materials differ and solidness differs.
+	Return value:
+		0: No face
+		1: Face uses m1's material
+		2: Face uses m2's material
+*/
+inline u8 face_materials(u8 m1, u8 m2)
+{
+	if(m1 == MATERIAL_IGNORE || m2 == MATERIAL_IGNORE)
+		return 0;
+	
+	bool materials_differ = (m1 != m2);
+	bool solidness_differs = (material_solidness(m1) != material_solidness(m2));
+	bool makes_face = materials_differ && solidness_differs;
+
+	if(makes_face == false)
+		return 0;
+
+	if(material_solidness(m1) > material_solidness(m2))
+		return 1;
+	else
+		return 2;
+}
+
+struct MapNode
+{
+	//TODO: block type to differ from material
+	//      (e.g. grass edges or something)
+	// block type
+	u8 d;
+
+	// Removed because light is now stored in param for air
+	// f32 light;
+
+	/*
+		Misc parameter. Initialized to 0.
+		- For light_propagates() blocks, this is light intensity,
+		  stored logarithmically from 0 to LIGHT_MAX.
+		  Sunlight is LIGHT_SUN, which is LIGHT_MAX+1.
+	*/
+	s8 param;
+
+	MapNode(const MapNode & n)
+	{
+		*this = n;
+	}
+	
+	MapNode(u8 data=MATERIAL_AIR, u8 a_param=0)
+	{
+		d = data;
+		param = a_param;
+	}
+
+	bool light_propagates()
+	{
+		return light_propagates_material(d);
+	}
+	
+	bool sunlight_propagates()
+	{
+		return sunlight_propagates_material(d);
+	}
+	
+	u8 solidness()
+	{
+		return material_solidness(d);
+	}
+
+	u8 light_source()
+	{
+		/*
+			Note that a block that isn't light_propagates() can be a light source.
+		*/
+		if(d == MATERIAL_LIGHT)
+			return LIGHT_MAX;
+		
+		return 0;
+	}
+
+	u8 getLight()
+	{
+		// Select the brightest of [light_source, transparent_light]
+		u8 light = 0;
+		if(light_propagates())
+			light = param & 0x0f;
+		if(light_source() > light)
+			light = light_source();
+		return light;
+	}
+
+	void setLight(u8 a_light)
+	{
+		// If not transparent, can't set light
+		if(light_propagates() == false)
+			return;
+		param = a_light;
+	}
+
+	static u32 serializedLength(u8 version)
+	{
+		if(!ser_ver_supported(version))
+			throw VersionMismatchException("ERROR: MapNode format not supported");
+			
+		if(version == 0)
+			return 1;
+		else
+			return 2;
+	}
+	void serialize(u8 *dest, u8 version)
+	{
+		if(!ser_ver_supported(version))
+			throw VersionMismatchException("ERROR: MapNode format not supported");
+			
+		if(version == 0)
+		{
+			dest[0] = d;
+		}
+		else
+		{
+			dest[0] = d;
+			dest[1] = param;
+		}
+	}
+	void deSerialize(u8 *source, u8 version)
+	{
+		if(!ser_ver_supported(version))
+			throw VersionMismatchException("ERROR: MapNode format not supported");
+			
+		if(version == 0)
+		{
+			d = source[0];
+		}
+		else if(version == 1)
+		{
+			d = source[0];
+			// This version doesn't support saved lighting
+			if(light_propagates() || light_source() > 0)
+				param = 0;
+			else
+				param = source[1];
+		}
+		else
+		{
+			d = source[0];
+			param = source[1];
+		}
+	}
+};
+
+/*
+	Returns integer position of the node in given
+	floating point position.
+*/
+inline v3s16 floatToInt(v3f p)
+{
+	v3s16 p2(
+		(p.X + (p.X>0 ? BS/2 : -BS/2))/BS,
+		(p.Y + (p.Y>0 ? BS/2 : -BS/2))/BS,
+		(p.Z + (p.Z>0 ? BS/2 : -BS/2))/BS);
+	return p2;
+}
+
+inline v3f intToFloat(v3s16 p)
+{
+	v3f p2(
+		p.X * BS,
+		p.Y * BS,
+		p.Z * BS
+	);
+	return p2;
+}
+
+
+
+#endif
+