OBJ model enhancements and builder

src/main/java/ru/bclib/client/models/OBJModelBuilder.java

@@ -0,0 +1,95 @@
+package ru.bclib.client.models;
+
+import com.google.common.collect.Lists;
+import net.fabricmc.api.EnvType;
+import net.fabricmc.api.Environment;
+import net.minecraft.resources.ResourceLocation;
+
+import java.util.List;
+
+@Environment(EnvType.CLIENT)
+public class OBJModelBuilder {
+	private static final OBJModelBuilder INSTANCE = new OBJModelBuilder();
+	private final List<ResourceLocation> textures = Lists.newArrayList();
+	private ResourceLocation modelLocation;
+	private ResourceLocation particles;
+	private boolean useCulling;
+	private boolean useShading;
+	
+	private OBJModelBuilder() {}
+	
+	/**
+	 * Start a new bodel building process, clears data of previous builder.
+	 * @return {@link OBJModelBuilder} instance.
+	 */
+	public static OBJModelBuilder start(ResourceLocation modelLocation) {
+		INSTANCE.modelLocation = modelLocation;
+		INSTANCE.useCulling = true;
+		INSTANCE.useShading = true;
+		INSTANCE.particles = null;
+		INSTANCE.textures.clear();
+		return INSTANCE;
+	}
+	
+	/**
+	 * Add texture to the model. All textures have indexes with same order as in source OBJ model.
+	 * @param texture {@link ResourceLocation} texture ID.
+	 * @return this {@link OBJModelBuilder}.
+	 */
+	public OBJModelBuilder addTexture(ResourceLocation texture) {
+		textures.add(texture);
+		return this;
+	}
+	
+	/**
+	 * Culling used to remove block faces if they are on block faces or outside of the block to reduce faces count in rendering.
+	 * Opaque blocks shoud have this as true to reduce geometry issues, block like plants should have this as false.
+	 * Default value is {@code true}.
+	 * @param useCulling {@link Boolean}.
+	 * @return this {@link OBJModelBuilder}.
+	 */
+	public OBJModelBuilder useCulling(boolean useCulling) {
+		this.useCulling = useCulling;
+		return this;
+	}
+	
+	/**
+	 * Shading tints block faces in shades of gray to immitate volume in MC rendering.
+	 * Blocks like plants don't have shading, most full opaque blocks - have.
+	 * Default value is {@code true}.
+	 * @param useShading {@link Boolean}.
+	 * @return this {@link OBJModelBuilder}.
+	 */
+	public OBJModelBuilder useShading(boolean useShading) {
+		this.useShading = useShading;
+		return this;
+	}
+	
+	/**
+	 * Set particle texture for this model.
+	 * Not required, if texture is not selected the first texture will be used instead of it.
+	 * @param texture {@link ResourceLocation} texture ID.
+	 * @return this {@link OBJModelBuilder}.
+	 */
+	public OBJModelBuilder setParticlesTexture(ResourceLocation texture) {
+		this.particles = texture;
+		return this;
+	}
+	
+	/**
+	 * Builds model from all required data.
+	 * @return {@link OBJBlockModel}.
+	 */
+	public OBJBlockModel build() {
+		byte particleIndex = 0;
+		if (particles != null) {
+			particleIndex = (byte) textures.indexOf(particles);
+			if (particleIndex < 0) {
+				particleIndex = (byte) textures.size();
+				textures.add(particles);
+			}
+		}
+		ResourceLocation[] sprites = textures.toArray(new ResourceLocation[textures.size()]);
+		return new OBJBlockModel(modelLocation, useCulling, useShading, particleIndex, sprites);
+	}
+}