Contraption triangles

src/main/java/com/jozufozu/flywheel/backend/gl/GlNumericType.java

@@ -1,5 +1,6 @@
 package com.jozufozu.flywheel.backend.gl;
 
+import java.nio.ByteBuffer;
 import java.util.Arrays;
 import java.util.Locale;
 import java.util.Map;
@@ -27,18 +28,18 @@ public enum GlNumericType {
 	private static final Map<String, GlNumericType> NAME_LOOKUP = Arrays.stream(VALUES)
 			.collect(Collectors.toMap(GlNumericType::getDisplayName, type -> type));
 
-	private final int size;
+	private final int byteWidth;
 	private final String displayName;
 	private final int glEnum;
 
 	GlNumericType(int bytes, String name, int glEnum) {
-		this.size = bytes;
+		this.byteWidth = bytes;
 		this.displayName = name;
 		this.glEnum = glEnum;
 	}
 
-	public int getSize() {
+	public int getByteWidth() {
-		return this.size;
+		return this.byteWidth;
 	}
 
 	public String getDisplayName() {
@@ -49,6 +50,16 @@ public enum GlNumericType {
 		return this.glEnum;
 	}
 
+	public void castAndBuffer(ByteBuffer buf, int val) {
+		if (this == UBYTE || this == BYTE) {
+			buf.put((byte) val);
+		} else if (this == USHORT || this == SHORT) {
+			buf.putShort((short) val);
+		} else if (this == UINT || this == INT) {
+			buf.putInt(val);
+		}
+	}
+
 	@Nullable
 	public static GlNumericType byName(String name) {
 		return name == null ? null : NAME_LOOKUP.get(name.toLowerCase(Locale.ROOT));

src/main/java/com/jozufozu/flywheel/backend/gl/attrib/MatrixAttributes.java

@@ -20,14 +20,14 @@ public enum MatrixAttributes implements IAttribSpec {
 	@Override
 	public void vertexAttribPointer(int stride, int index, int pointer) {
 		for (int i = 0; i < rows; i++) {
-			long attribPointer = pointer + (long) i * cols * GlNumericType.FLOAT.getSize();
+			long attribPointer = pointer + (long) i * cols * GlNumericType.FLOAT.getByteWidth();
 			GL20.glVertexAttribPointer(index + i, cols, GlNumericType.FLOAT.getGlEnum(), false, stride, attribPointer);
 		}
 	}
 
 	@Override
 	public int getSize() {
-		return GlNumericType.FLOAT.getSize() * rows * cols;
+		return GlNumericType.FLOAT.getByteWidth() * rows * cols;
 	}
 
 	@Override

src/main/java/com/jozufozu/flywheel/backend/gl/attrib/VertexAttribSpec.java

@@ -19,7 +19,7 @@ public class VertexAttribSpec implements IAttribSpec {
 	public VertexAttribSpec(GlNumericType type, int count, boolean normalized) {
 		this.type = type;
 		this.count = count;
-		this.size = type.getSize() * count;
+		this.size = type.getByteWidth() * count;
 		this.attributeCount = (this.size + 15) / 16; // ceiling division. GLSL vertex attributes can only be 16 bytes wide
 		this.normalized = normalized;
 	}

src/main/java/com/jozufozu/flywheel/core/IndexedModel.java

@@ -25,7 +25,7 @@ public class IndexedModel extends BufferedModel {
 		this.eboIndexType = indexType;
 		this.elementCount = elementCount;
 
-		int indicesSize = elementCount * indexType.getSize();
+		int indicesSize = elementCount * indexType.getByteWidth();
 
 		ebo.bind();
 
@@ -38,13 +38,13 @@ public class IndexedModel extends BufferedModel {
 	}
 
 	public void draw() {
-		vbo.bind();
 		ebo.bind();
+		vbo.bind();
 
 		AttribUtil.enableArrays(getAttributeCount());
 		format.vertexAttribPointers(0);
 
-		GL20.glDrawElements(primitiveMode.glEnum, vertexCount, eboIndexType.getGlEnum(), 0);
+		GL20.glDrawElements(primitiveMode.glEnum, elementCount, eboIndexType.getGlEnum(), 0);
 
 		AttribUtil.disableArrays(getAttributeCount());
 

src/main/java/com/simibubi/create/content/contraptions/components/structureMovement/render/RenderedContraption.java

@@ -10,12 +10,13 @@ import java.util.Map;
 import javax.annotation.Nullable;
 
 import com.jozufozu.flywheel.backend.Backend;
+import com.jozufozu.flywheel.backend.gl.GlNumericType;
 import com.jozufozu.flywheel.backend.gl.GlPrimitive;
 import com.jozufozu.flywheel.backend.gl.attrib.CommonAttributes;
 import com.jozufozu.flywheel.backend.gl.attrib.VertexFormat;
 import com.jozufozu.flywheel.backend.instancing.IInstanceRendered;
-import com.jozufozu.flywheel.core.BufferedArrayModel;
 import com.jozufozu.flywheel.core.BufferedModel;
+import com.jozufozu.flywheel.core.IndexedModel;
 import com.jozufozu.flywheel.light.GridAlignedBB;
 import com.jozufozu.flywheel.util.BufferBuilderReader;
 import com.mojang.blaze3d.matrix.MatrixStack;
@@ -163,40 +164,74 @@ public class RenderedContraption extends ContraptionWorldHolder {
 
 		VertexFormat format = FORMAT;
 
-		ByteBuffer to = ByteBuffer.allocate(format.getStride() * vertexCount);
+		ByteBuffer vertices = ByteBuffer.allocate(format.getStride() * vertexCount);
-		to.order(ByteOrder.nativeOrder());
+		vertices.order(ByteOrder.nativeOrder());
 
 		for (int i = 0; i < vertexCount; i++) {
-			to.putFloat(reader.getX(i));
+			vertices.putFloat(reader.getX(i));
-			to.putFloat(reader.getY(i));
+			vertices.putFloat(reader.getY(i));
-			to.putFloat(reader.getZ(i));
+			vertices.putFloat(reader.getZ(i));
 
-			to.put(reader.getNX(i));
+			vertices.put(reader.getNX(i));
-			to.put(reader.getNY(i));
+			vertices.put(reader.getNY(i));
-			to.put(reader.getNZ(i));
+			vertices.put(reader.getNZ(i));
 
-			to.putFloat(reader.getU(i));
+			vertices.putFloat(reader.getU(i));
-			to.putFloat(reader.getV(i));
+			vertices.putFloat(reader.getV(i));
 
-			to.put(reader.getR(i));
+			vertices.put(reader.getR(i));
-			to.put(reader.getG(i));
+			vertices.put(reader.getG(i));
-			to.put(reader.getB(i));
+			vertices.put(reader.getB(i));
-			to.put(reader.getA(i));
+			vertices.put(reader.getA(i));
 
 			int light = reader.getLight(i);
 
 			byte block = (byte) (LightTexture.getBlockLightCoordinates(light) << 4);
 			byte sky = (byte) (LightTexture.getSkyLightCoordinates(light) << 4);
 
-			to.put(block);
+			vertices.put(block);
-			to.put(sky);
+			vertices.put(sky);
 		}
 
-		to.rewind();
+		vertices.rewind();
 
-		if (Backend.compat.vertexArrayObjectsSupported())
+////		if (Backend.compat.vertexArrayObjectsSupported())
-			return new BufferedArrayModel(GlPrimitive.QUADS, format, to, vertexCount);
+////			return new BufferedArrayModel(GlPrimitive.QUADS, format, vertices, vertexCount);
-		else
+////		else
-			return new BufferedModel(GlPrimitive.QUADS, format, to, vertexCount);
+//			return new BufferedModel(GlPrimitive.QUADS, format, vertices, vertexCount);
+
+		int quadCount = vertexCount / 4;
+		int triangleCount = vertexCount / 2;
+		int indexCount = triangleCount * 3;
+
+		GlNumericType type;
+
+		int bitWidth = MathHelper.log2(indexCount);
+		if (bitWidth <= 8) {
+			type = GlNumericType.UBYTE;
+		} else if (bitWidth <= 16) {
+			type = GlNumericType.USHORT;
+		} else {
+			type = GlNumericType.UINT;
+		}
+
+		ByteBuffer indices = ByteBuffer.allocate(indexCount * type.getByteWidth());
+		indices.order(ByteOrder.nativeOrder());
+
+		for (int i = 0; i < quadCount; i++) {
+			int qStart = 4 * i;
+			// triangle 1
+			type.castAndBuffer(indices, qStart);
+			type.castAndBuffer(indices, qStart + 1);
+			type.castAndBuffer(indices, qStart + 2);
+			// triangle 2
+			type.castAndBuffer(indices, qStart);
+			type.castAndBuffer(indices, qStart + 2);
+			type.castAndBuffer(indices, qStart + 3);
+		}
+
+		indices.flip();
+
+		return new IndexedModel(GlPrimitive.TRIANGLES, format, vertices, vertexCount, indices, indexCount, type);
 	}
 }