add abstract base class to be used for TileMesh's that work with Model objects

src/com/blarg/gdx/tilemap3d/tilemesh/BaseModelTileMesh.java

@@ -0,0 +1,127 @@
+package com.blarg.gdx.tilemap3d.tilemesh;
+
+import com.badlogic.gdx.graphics.Color;
+import com.badlogic.gdx.graphics.VertexAttributes;
+import com.badlogic.gdx.graphics.g3d.Model;
+import com.badlogic.gdx.graphics.g3d.model.MeshPart;
+import com.badlogic.gdx.graphics.g3d.model.Node;
+import com.badlogic.gdx.graphics.g3d.model.NodePart;
+import com.badlogic.gdx.math.Matrix4;
+import com.badlogic.gdx.math.Vector2;
+import com.badlogic.gdx.math.Vector3;
+import com.badlogic.gdx.math.collision.BoundingBox;
+import com.badlogic.gdx.utils.Array;
+import com.blarg.gdx.graphics.Vertices;
+import com.blarg.gdx.graphics.atlas.TextureAtlas;
+import com.blarg.gdx.math.MathHelpers;
+
+import java.nio.FloatBuffer;
+import java.nio.ShortBuffer;
+
+public abstract class BaseModelTileMesh extends TileMesh {
+	private final Vector3 tmpPosition = new Vector3();
+	private final Vector3 tmpNormal = new Vector3();
+	private final BoundingBox tmpBounds = new BoundingBox();
+
+	public BaseModelTileMesh(byte opaqueSides, boolean alpha, float translucency, byte lightValue, Color color) {
+		super(opaqueSides, alpha, translucency, lightValue, color);
+	}
+
+
+	protected void collectModelNodeVertices(Node node, Vertices destVertices, MaterialTileMapping textures, Color color, Vector3 scaleFactor, Vector3 positionOffset) {
+		final Matrix4 transform = node.globalTransform;
+
+		for (int i = 0; i < node.parts.size; ++i) {
+			NodePart nodePart = node.parts.get(i);
+			MaterialTileMapping.TileTexture texture = textures.get(nodePart.material.id);
+			MeshPart meshPart = nodePart.meshPart;
+			ShortBuffer indices = meshPart.mesh.getIndicesBuffer();
+			FloatBuffer vertices = meshPart.mesh.getVerticesBuffer();
+			final int strideInFloats = meshPart.mesh.getVertexSize() / (Float.SIZE / 8);
+
+			if (destVertices.remainingSpace() < meshPart.numVertices)
+				throw new RuntimeException("Not enough space to collect this MeshPart's vertices.");
+
+			for (int j = 0; j < meshPart.numVertices; ++j) {
+				int index = indices.get(meshPart.indexOffset + j);
+				int offset = index * strideInFloats;
+
+				tmpPosition.set(vertices.get(offset), vertices.get(offset + 1), vertices.get(offset + 2))
+				           .add(positionOffset)
+				           .scl(scaleFactor)
+				           .mul(transform);
+				destVertices.setPos(tmpPosition);
+				offset += 3;
+
+				if (meshPart.mesh.getVertexAttribute(VertexAttributes.Usage.Color) != null) {
+					// TODO: blend mesh color and source model color somehow?
+					destVertices.setCol(vertices.get(offset), vertices.get(offset + 1), vertices.get(offset + 2), vertices.get(offset + 3));
+					offset += 4;
+				} else
+					destVertices.setCol(color);
+
+				// TODO: better to throw exception (or check beforehand) if this is missing? setting zero's doesn't feel like the best solution
+				if (meshPart.mesh.getVertexAttribute(VertexAttributes.Usage.Normal) != null) {
+					tmpNormal.set(vertices.get(offset), vertices.get(offset + 1), vertices.get(offset + 2))
+					         .rot(transform);
+					destVertices.setNor(tmpNormal);
+					offset += 3;
+				} else
+					destVertices.setNor(Vector3.Zero);
+
+				// TODO: better to throw exception (or check beforehand) if this is missing? setting zero's doesn't feel like the best solution
+				if (meshPart.mesh.getVertexAttribute(VertexAttributes.Usage.TextureCoordinates) != null) {
+					destVertices.setUV(
+							TextureAtlas.scaleTexCoordU(vertices.get(offset), texture.materialMinU, texture.materialMaxU, texture.region),
+							TextureAtlas.scaleTexCoordV(vertices.get(offset + 1), texture.materialMinV, texture.materialMaxV, texture.region)
+					);
+					offset += 3;
+				} else
+					destVertices.setUV(Vector2.Zero);
+
+				destVertices.moveNext();
+			}
+		}
+
+		for (int i = 0; i < node.children.size; ++i)
+			collectModelNodeVertices(node.children.get(i), destVertices, textures, color, scaleFactor, positionOffset);
+	}
+
+	protected void collectModelNodeVertexPositions(Node node, Array<Vector3> destVertices, Vector3 scaleFactor, Vector3 positionOffset) {
+		final Matrix4 transform = node.globalTransform;
+
+		for (int i = 0; i < node.parts.size; ++i) {
+			NodePart nodePart = node.parts.get(i);
+			MeshPart meshPart = nodePart.meshPart;
+			ShortBuffer indices = meshPart.mesh.getIndicesBuffer();
+			FloatBuffer vertices = meshPart.mesh.getVerticesBuffer();
+			final int strideInFloats = meshPart.mesh.getVertexSize() / (Float.SIZE / 8);
+
+			for (int j = 0; j < meshPart.numVertices; ++j) {
+				int index = indices.get(meshPart.indexOffset + j);
+				int offset = index * strideInFloats;
+
+				tmpPosition.set(vertices.get(offset), vertices.get(offset + 1), vertices.get(offset + 2))
+				           .add(positionOffset)
+				           .scl(scaleFactor)
+				           .mul(transform);
+				destVertices.add(new Vector3(tmpPosition));
+			}
+		}
+
+		for (int i = 0; i < node.children.size; ++i)
+			collectModelNodeVertexPositions(node.children.get(i), destVertices, scaleFactor, positionOffset);
+	}
+
+	protected void getScaleFactorForModel(Model model, Vector3 scaleToSize, Vector3 out) {
+		model.getBoundingBox(tmpBounds);
+		MathHelpers.getScaleFactor(tmpBounds.getDimensions(), scaleToSize, out);
+	}
+
+	protected int countModelVertices(Model model) {
+		int numVertices = 0;
+		for (int i = 0; i < model.meshParts.size; ++i)
+			numVertices += model.meshParts.get(i).numVertices;
+		return numVertices;
+	}
+}