Make plantlike drawtype more fun

Adds several new ways that the plantlike drawtype mesh can be changed.

This requires paramtype2 = "meshoptions" to be set in the node
definition. The drawtype for these nodes should be "plantlike".

These modifications are all done using param2. This field is now
a complex bitfield that allows some or more of the combinations to
be chosen, and the mesh draw code will choose the options based as
neeeded for each plantlike node.

bit layout:
bits 0, 1 and 2 (values 0x1 through 0x7) are for choosing the plant
mesh shape:
  0 - ordinary plantlike plant ("x" shaped)
  1 - ordinary plant, but rotated 45 degrees ("+" shaped)
  2 - a plant with 3 faces ("*" shaped)
  3 - a plant with 4 faces ("#" shaped)
  4 - a plant with 4 faces ("#" shaped, leaning outwards)
  5 through 7 are unused and reserved for future mesh shapes.

bit 3 (0x8) causes the plant to be randomly offset in the x,z
plane. The plant should fall within the 1x1x1 nodebox if regularly
sized.

bit 4 (0x10) causes the plant mesh to grow by sqrt(2), and will cause
the plant mesh to fill out 1x1x1, and appear slightly larger. Texture
makers will want to make their plant texture 23x16 pixels to have the
best visual fit in 1x1x1 size.

bit 5 (0x20) causes each face of the plant to have a slight negative
Y offset in position, descending up to 0.125 downwards into the node
below. Because this is per face, this causes the plant model to be
less symmetric.

bit 6 (0x40) through bit 7 (0x80) are unused and reserved for
future use.

!(https://youtu.be/qWuI664krsI)

1 files changed, 141 insertions, 11 deletions

diff --git a/src/content_mapblock.cpp b/src/content_mapblock.cpp
index 6a83bd8f3..b86b97822 100644
--- a/src/content_mapblock.cpp
+++ b/src/content_mapblock.cpp
@@ -28,6 +28,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include <IMeshManipulator.h>
 #include "gamedef.h"
 #include "log.h"
+#include "noise.h"
 
 
 // Create a cuboid.
@@ -1104,6 +1105,8 @@ void mapblock_mesh_generate_special(MeshMakeData *data,
 		break;}
 		case NDT_PLANTLIKE:
 		{
+			PseudoRandom rng(x<<8 | z | y<<16);
+
 			TileSpec tile = getNodeTileN(n, p, 0, data);
 			tile.material_flags |= MATERIAL_FLAG_CRACK_OVERLAY;
 
@@ -1111,9 +1114,18 @@ void mapblock_mesh_generate_special(MeshMakeData *data,
 			video::SColor c = MapBlock_LightColor(255, l, f.light_source);
 
 			float s = BS / 2 * f.visual_scale;
+			// add sqrt(2) visual scale
+			if ((f.param_type_2 == CPT2_MESHOPTIONS) && ((n.param2 & 0x10) != 0))
+				s *= 1.41421;
+
+			float random_offset_X = .0;
+			float random_offset_Z = .0;
+			if ((f.param_type_2 == CPT2_MESHOPTIONS) && ((n.param2 & 0x8) != 0)) {
+				random_offset_X = BS * ((rng.next() % 16 / 16.0) * 0.29 - 0.145);
+				random_offset_Z = BS * ((rng.next() % 16 / 16.0) * 0.29 - 0.145);
+			}
 
-			for (int j = 0; j < 2; j++)
-			{
+			for (int j = 0; j < 4; j++) {
 				video::S3DVertex vertices[4] =
 				{
 					video::S3DVertex(-s,-BS/2, 0, 0,0,0, c, 0,1),
@@ -1121,28 +1133,146 @@ void mapblock_mesh_generate_special(MeshMakeData *data,
 					video::S3DVertex( s,-BS/2 + s*2,0, 0,0,0, c, 1,0),
 					video::S3DVertex(-s,-BS/2 + s*2,0, 0,0,0, c, 0,0),
 				};
+
 				float rotate_degree = 0;
+				u8 p2mesh = 0;
 				if (f.param_type_2 == CPT2_DEGROTATE)
 					rotate_degree = n.param2 * 2;
-
-				if (j == 0) {
-					for(u16 i = 0; i < 4; i++)
-						vertices[i].Pos.rotateXZBy(46 + rotate_degree);
-				} else if (j == 1) {
-					for(u16 i = 0; i < 4; i++)
-						vertices[i].Pos.rotateXZBy(-44 + rotate_degree);
+				else if (f.param_type_2 != CPT2_MESHOPTIONS) {
+					if (j == 0) {
+						for (u16 i = 0; i < 4; i++)
+							vertices[i].Pos.rotateXZBy(46 + rotate_degree);
+					} else if (j == 1) {
+						for (u16 i = 0; i < 4; i++)
+							vertices[i].Pos.rotateXZBy(-44 + rotate_degree);
+					}
+				} else {
+					p2mesh = n.param2 & 0x7;
+					switch (p2mesh) {
+					case 0:
+						// x
+						if (j == 0) {
+							for (u16 i = 0; i < 4; i++)
+								vertices[i].Pos.rotateXZBy(46);
+						} else if (j == 1) {
+							for (u16 i = 0; i < 4; i++)
+								vertices[i].Pos.rotateXZBy(-44);
+						}
+						break;
+					case 1:
+						// +
+						if (j == 0) {
+							for (u16 i = 0; i < 4; i++)
+								vertices[i].Pos.rotateXZBy(91);
+						} else if (j == 1) {
+							for (u16 i = 0; i < 4; i++)
+								vertices[i].Pos.rotateXZBy(1);
+						}
+						break;
+					case 2:
+						// *
+						if (j == 0) {
+							for (u16 i = 0; i < 4; i++)
+								vertices[i].Pos.rotateXZBy(121);
+						} else if (j == 1) {
+							for (u16 i = 0; i < 4; i++)
+								vertices[i].Pos.rotateXZBy(241);
+						} else { // (j == 2)
+							for (u16 i = 0; i < 4; i++)
+								vertices[i].Pos.rotateXZBy(1);
+						}
+						break;
+					case 3:
+						// #
+						switch (j) {
+						case 0:
+							for (u16 i = 0; i < 4; i++) {
+								vertices[i].Pos.rotateXZBy(1);
+								vertices[i].Pos.Z += BS / 4;
+							}
+							break;
+						case 1:
+							for (u16 i = 0; i < 4; i++) {
+								vertices[i].Pos.rotateXZBy(91);
+								vertices[i].Pos.X += BS / 4;
+							}
+							break;
+						case 2:
+							for (u16 i = 0; i < 4; i++) {
+								vertices[i].Pos.rotateXZBy(181);
+								vertices[i].Pos.Z -= BS / 4;
+							}
+							break;
+						case 3:
+							for (u16 i = 0; i < 4; i++) {
+								vertices[i].Pos.rotateXZBy(271);
+								vertices[i].Pos.X -= BS / 4;
+							}
+							break;
+						}
+						break;
+					case 4:
+						// outward leaning #-like
+						switch (j) {
+						case 0:
+							for (u16 i = 2; i < 4; i++)
+								vertices[i].Pos.Z -= BS / 2;
+							for (u16 i = 0; i < 4; i++)
+								vertices[i].Pos.rotateXZBy(1);
+							break;
+						case 1:
+							for (u16 i = 2; i < 4; i++)
+								vertices[i].Pos.Z -= BS / 2;
+							for (u16 i = 0; i < 4; i++)
+								vertices[i].Pos.rotateXZBy(91);
+							break;
+						case 2:
+							for (u16 i = 2; i < 4; i++)
+								vertices[i].Pos.Z -= BS / 2;
+							for (u16 i = 0; i < 4; i++)
+								vertices[i].Pos.rotateXZBy(181);
+							break;
+						case 3:
+							for (u16 i = 2; i < 4; i++)
+								vertices[i].Pos.Z -= BS / 2;
+							for (u16 i = 0; i < 4; i++)
+								vertices[i].Pos.rotateXZBy(271);
+							break;
+						}
+						break;
+					}
 				}
 
-				for (int i = 0; i < 4; i++)
-				{
+				for (int i = 0; i < 4; i++) {
 					vertices[i].Pos *= f.visual_scale;
 					vertices[i].Pos.Y += BS/2 * (f.visual_scale - 1);
 					vertices[i].Pos += intToFloat(p, BS);
+					// move to a random spot to avoid moire
+					if ((f.param_type_2 == CPT2_MESHOPTIONS) && ((n.param2 & 0x8) != 0)) {
+						vertices[i].Pos.X += random_offset_X;
+						vertices[i].Pos.Z += random_offset_Z;
+					}
+					// randomly move each face up/down
+					if ((f.param_type_2 == CPT2_MESHOPTIONS) && ((n.param2 & 0x20) != 0)) {
+						PseudoRandom yrng(j | x<<16 | z<<8 | y<<24 );
+						vertices[i].Pos.Y -= BS * ((yrng.next() % 16 / 16.0) * 0.125);
+					}
 				}
 
 				u16 indices[] = {0, 1, 2, 2, 3, 0};
 				// Add to mesh collector
 				collector.append(tile, vertices, 4, indices, 6);
+
+				// stop adding faces for meshes with less than 4 faces
+				if (f.param_type_2 == CPT2_MESHOPTIONS) {
+					if (((p2mesh == 0) || (p2mesh == 1)) && (j == 1))
+						break;
+					else if ((p2mesh == 2) && (j == 2))
+						break;
+				} else if (j == 1) {
+					break;
+				}
+
 			}
 		break;}
 		case NDT_FIRELIKE: